Record #326 , #317 and #306 's rebased heads (same content as landed in #530 and #529 )

Merge #312 : test(canvas): grow the slow zoom-preview scene until it crosses the threshold (@tylerjenningsw)
Community batch 4: 11 reviewed PRs (#530 )
2026-11-14 06:44:43 +00:00 · 2026-10-16 01:17:17 +07:00 · 2026-10-16 01:17:16 +07:00 · 2026-10-16 01:11:44 +07:00 · 2026-10-16 01:11:29 +07:00 · 2026-10-15 20:24:05 +03:00
179 changed files with 19117 additions and 831 deletions
@@ -29,6 +29,7 @@ concurrency:

 jobs:
  test:
+    timeout-minutes: 35
    name: test (ubuntu-latest)
    runs-on: ubuntu-latest
    steps:
@@ -69,6 +70,7 @@ jobs:
        run: cargo run --locked -q -p xtask -- assets

  wasm:
+    timeout-minutes: 30
    name: wasm32 check
    runs-on: ubuntu-latest
    steps:
@@ -5,12 +5,14 @@
 # uploaded and no secrets are used.
 name: FreeBSD

-# The VM build takes one to several hours, so it runs nightly on main rather than on every push
-# or dependency change: a drifted dependency still shows up within a day. PRs that change the
-# FreeBSD packaging itself still run it.
+# The VM build is slow, so it runs nightly on main and on pushes to `release`, not on every push
+# or dependency change: a drifted dependency still shows up within a day, and always before a
+# release ships. PRs that change the FreeBSD packaging itself still run it.
 on:
  schedule:
    - cron: "17 2 * * *"
+  push:
+    branches: [release]
  pull_request:
    paths:
      - .github/workflows/freebsd.yml
@@ -41,8 +43,9 @@ jobs:
          mem: 12288
          # Nothing to bring back; copying the target dir out of the VM fails on large builds.
          copyback: false
+          # dejavu: the text tests need one real font, as the Ubuntu runner has.
          prepare: |
-            pkg install -y bash git curl pkgconf cmake python3 libxkbcommon wayland libX11 libXcursor libXrandr libXi libxcb mesa-libs vulkan-loader gtk3 fontconfig freetype2
+            pkg install -y bash git curl pkgconf cmake python3 libxkbcommon wayland libX11 libXcursor libXrandr libXi libxcb mesa-libs vulkan-loader gtk3 fontconfig freetype2 dejavu
            curl -fsSL https://sh.rustup.rs | sh -s -- -y --profile minimal
          run: |
            set -e
@@ -19,6 +19,7 @@ concurrency:

 jobs:
  lint:
+    timeout-minutes: 15
    runs-on: ubuntu-latest
    env:
      ACTIONLINT_VERSION: 1.7.12
@@ -41,6 +41,7 @@ env:

 jobs:
  version:
+    timeout-minutes: 10
    name: version
    runs-on: ubuntu-latest
    # No `environment: release`: this job reads no secrets, so a branch dry run can run it.
@@ -69,6 +70,7 @@ jobs:
          echo "### FigCraft v$v (\`${GITHUB_SHA::9}\`)" >>"$GITHUB_STEP_SUMMARY"

  macos:
+    timeout-minutes: 90
    name: macOS universal
    needs: version
    runs-on: macos-15-xlarge  # M2 Pro larger runner; use only in release.yml (actions_macos_xl budget caps spend)
@@ -127,6 +129,7 @@ jobs:
          if [ -n "${MACOS_KEYCHAIN:-}" ]; then security delete-keychain "$MACOS_KEYCHAIN" || true; fi

  windows:
+    timeout-minutes: 90
    name: Windows ${{ matrix.arch }}
    needs: version
    runs-on: windows-latest
@@ -187,6 +190,7 @@ jobs:
          if-no-files-found: error

  linux:
+    timeout-minutes: 90
    name: Linux ${{ matrix.arch }}
    needs: version
    # The oldest GitHub-hosted image, so the binaries only need glibc >= 2.35 (Ubuntu 22.04+,
@@ -252,6 +256,7 @@ jobs:
          if-no-files-found: error

  server:
+    timeout-minutes: 90
    name: Server Linux ${{ matrix.arch }}
    needs: version
    # The headless collaboration server (docs/server.md): figcraft-server-<v>-linux-<arch>.tar.gz
@@ -295,6 +300,7 @@ jobs:
          if-no-files-found: error

  flatpak:
+    timeout-minutes: 90
    name: Flatpak ${{ matrix.arch }}
    needs: [version, linux]
    # Repackages the Linux job's tarball (the same binaries as the AppImage/deb/rpm); no Rust
@@ -388,6 +394,7 @@ jobs:
          if-no-files-found: error

  web:
+    timeout-minutes: 90
    name: Web (wasm)
    needs: version
    runs-on: ubuntu-latest
@@ -433,6 +440,7 @@ jobs:
          if-no-files-found: error

  linux-riscv64:
+    timeout-minutes: 90
    name: Linux riscv64
    needs: version
    # Cross-compiled on x86_64 (no hosted RISC-V runners) against the runner's own Ubuntu release
@@ -502,6 +510,7 @@ jobs:
          if-no-files-found: error

  release:
+    timeout-minutes: 10
    name: Draft GitHub Release
    needs: [version, macos, windows, linux, linux-riscv64, flatpak, freebsd, web, server]
    runs-on: ubuntu-latest
@@ -4,15 +4,17 @@
 # out for now: PdfCraft saw an intermittent access violation in egui UI tests there.)
 name: Windows ARM64

-# Nightly on main (dependency and runner-image drift shows up within a day), and on PRs that
-# change the Windows packaging itself.
+# Nightly on main and on pushes to `release` (dependency and runner-image drift shows up within a
+# day, and always before a release ships), and on PRs that change the Windows packaging itself.
 on:
+  schedule:
+    - cron: "41 4 * * *"
+  push:
+    branches: [release]
  pull_request:
    paths:
      - .github/workflows/windows-arm64.yml
      - packaging/windows/**
-  schedule:
-    - cron: "41 4 * * *"
  workflow_dispatch:

 concurrency:
@@ -1407,7 +1407,7 @@ checksum = "b97b65636e5b9ef369943878ac74335ba1c55c1cb6adbf1e2c293c624248d693"

 [[package]]
 name = "figcraft"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "arboard",
 "eframe",
@@ -1418,6 +1418,7 @@ dependencies = [
 "figcraft-format",
 "figcraft-text",
 "figcraft-ui-egui",
+ "fmv-macos-events",
 "image",
 "log",
 "rfd",
@@ -1430,7 +1431,7 @@ dependencies = [

 [[package]]
 name = "figcraft-cli"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-doc",
 "figcraft-engine",
@@ -1444,7 +1445,7 @@ dependencies = [

 [[package]]
 name = "figcraft-collab"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "figcraft-color",
@@ -1459,7 +1460,7 @@ dependencies = [

 [[package]]
 name = "figcraft-collab-net"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "figcraft-collab",
@@ -1482,7 +1483,7 @@ dependencies = [

 [[package]]
 name = "figcraft-color"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "kurbo",
 "serde",
@@ -1491,7 +1492,7 @@ dependencies = [

 [[package]]
 name = "figcraft-doc"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-color",
 "figcraft-geom",
@@ -1503,7 +1504,7 @@ dependencies = [

 [[package]]
 name = "figcraft-engine"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "figcraft-collab",
@@ -1530,7 +1531,7 @@ dependencies = [

 [[package]]
 name = "figcraft-format"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-doc",
 "figcraft-pathops",
@@ -1545,7 +1546,7 @@ dependencies = [

 [[package]]
 name = "figcraft-geom"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "kurbo",
 "serde",
@@ -1553,7 +1554,7 @@ dependencies = [

 [[package]]
 name = "figcraft-layout"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-doc",
 "figcraft-geom",
@@ -1561,7 +1562,7 @@ dependencies = [

 [[package]]
 name = "figcraft-mcp"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "figcraft-collab-net",
@@ -1577,7 +1578,7 @@ dependencies = [

 [[package]]
 name = "figcraft-pathops"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-doc",
 "figcraft-geom",
@@ -1586,7 +1587,7 @@ dependencies = [

 [[package]]
 name = "figcraft-pdf"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-color",
 "figcraft-doc",
@@ -1603,7 +1604,7 @@ dependencies = [

 [[package]]
 name = "figcraft-plugin"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-color",
 "serde",
@@ -1616,7 +1617,7 @@ dependencies = [

 [[package]]
 name = "figcraft-render"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "crc32fast",
 "figcraft-color",
@@ -1634,7 +1635,7 @@ dependencies = [

 [[package]]
 name = "figcraft-server"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "crc32fast",
 "ctrlc",
@@ -1658,7 +1659,7 @@ dependencies = [

 [[package]]
 name = "figcraft-svg"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "figcraft-color",
@@ -1674,12 +1675,13 @@ dependencies = [

 [[package]]
 name = "figcraft-text"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-doc",
 "figcraft-geom",
 "harfrust 0.13.3",
 "log",
+ "png",
 "skrifa 0.47.0",
 "unicode-bidi",
 "unicode-segmentation",
@@ -1687,7 +1689,7 @@ dependencies = [

 [[package]]
 name = "figcraft-ui-egui"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "base64 0.22.1",
 "egui",
@@ -1695,6 +1697,7 @@ dependencies = [
 "figcraft-color",
 "figcraft-doc",
 "figcraft-engine",
+ "figcraft-format",
 "figcraft-geom",
 "figcraft-layout",
 "figcraft-pathops",
@@ -1706,17 +1709,19 @@ dependencies = [
 "serde_json",
 "toml",
 "wat",
+ "web-time",
 ]

 [[package]]
 name = "figcraft-web"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "eframe",
 "egui",
 "figcraft-collab-net",
 "figcraft-engine",
 "figcraft-ui-egui",
+ "js-sys",
 "log",
 "wasm-bindgen",
 "wasm-bindgen-futures",
@@ -1749,6 +1754,17 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "fmv-macos-events"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90642cf66dde7f205dc8b42dfe57b47d0f3a29f571b832742883ef512e23fe55"
+dependencies = [
+ "objc2 0.6.5",
+ "objc2-app-kit 0.3.2",
+ "objc2-foundation 0.3.2",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -5806,7 +5822,7 @@ checksum = "9440ea3e5aeabb0ac63af70daf835274065238cdd0cec83418f417eae38bacee"

 [[package]]
 name = "xtask"
-version = "0.5.1"
+version = "0.6.0"
 dependencies = [
 "figcraft-engine",
 "serde_json",
@@ -6,7 +6,7 @@ exclude = ["plugins"]
 # default-members = ["crates/*", "apps/figcraft", "apps/figcraft-cli", "xtask"]

 [workspace.package]
-version = "0.5.1"
+version = "0.6.0"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 rust-version = "1.95"
@@ -227,7 +227,7 @@ The desktop app also offers a loopback-only control channel (`figcraft --control
 - **Its own renderer:** tiny-skia on every core for the canvas and exports, with layer blending, effects and masks; booleans from linesweeper, geometry from kurbo, text from skrifa and HarfRust.
 - **Runs in the browser:** the whole engine and UI compile to WebAssembly.
 - **Accessible:** screen readers get names, roles, values and states for the tools, layer rows, fields, dropdowns, tabs and menus (AccessKit on desktop), F6 moves the keyboard between the toolbar, layers, canvas and properties (Tab within them, Escape back to the canvas), the system's reduce-motion setting is honoured, and panel text meets WCAG AA contrast in both themes.
- **Languages:** English and Spanish (a draft waiting for a native speaker's review), picked in Preferences or taken from the system or browser and switched live; adding a language is one catalog file ([`docs/translating.md`](docs/translating.md)).
+- **Languages:** English, Russian and Turkish (reviewed by native speakers), and Spanish, French, German, Brazilian Portuguese, Japanese, Korean, Simplified Chinese, Czech and Indonesian drafts, picked in Preferences or taken from the system or browser and switched live; adding a language is one catalog file ([`docs/translating.md`](docs/translating.md)).
 - **Plugins:** sandboxed WebAssembly plugins (a metered, pure-Rust interpreter with a memory cap and no file or network access, in the browser too) that act through the same commands, each run one undo step, within the permissions their manifest asks for. A Rust SDK and two example plugins are in [`plugins/`](plugins); see [`docs/plugins.md`](docs/plugins.md).
 - **Live sessions (preview):** share the open file from the app (Share ▸ Start sharing: online through a server, or on your local network), give the others the short join code it shows (or the invite link), and edit it together: everyone's changes sync live, with cursors, selections, avatars and follow, and undo takes back only your own changes. Others join from the desktop app (invite links open it) or from the browser build. See [`docs/collab-protocol.md`](docs/collab-protocol.md).
 - **A server of your own (preview):** `figcraft-server` keeps a team's files, publishes them from the app (File ▸ Publish to server…, or Share ▸ Online with your server in Preferences) and hands out share links and join codes that let people edit or only view; files survive restarts and apps reconnect where they were. No accounts yet: links are the access. Releases ship it for Linux, and the desktop app joins over `wss://`; [hosting it on a rented Linux server](docs/server.md#deploy-on-a-linux-server) takes a systemd unit and Caddy or nginx (or Docker). See [`docs/server.md`](docs/server.md).
@@ -2,7 +2,7 @@

 **Stage: alpha** · next: beta, ~26 points and ~162–292 h away (one Opus 5.5 agent; ~33–67 h wall-clock with 5 agents)

-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-14 · **Change:** minor (community fixes: lost images reported on loading (#207), SVG import budgets (#190), Leptos code (#223), full screen (#227), server snapshots readable again (#188), owner-only preferences (#200), ruzstd 0.9.1 (#182), layer cycle repair (#205), batch rollback, Direct3D 12 on Windows, plugin metering (#192); vector edit mode regions: hover hatch, selection and drag; SVG/PDF exports refuse over-depth documents (#208); bounded MCP/control framing, connections and queues (#201); plugin log limits (#191); live-session revert guard (#198); attached MCP no longer replays after a lost reply (#194); repeat command recursion fix; the Layout panel's constrain-proportions link scales the other side, #220; core editor leftovers: component playground, auto gap handles, variables inside styles, inner shadows and background blur on groups, command-made text readable on dark pages, a one-step frame/group convert, delays on mouse triggers and manual overlay offsets, wrapped-line alignment; `.fig` export: instance sizes, variables with modes, shared styles, variable-width strokes; starter templates, a Templates tab and Getting started tips on the home screen; your online files; everyday editing partials: number fields, outline options, Hide when publishing, cursors, panel widths, dark pages; sharing with a join code; text box sizes measured against documents re-saved by other software; live sessions per document; .fig export checked by opening written files in other software; a public figcraft-server: open hosting, owner tokens, per-address limits, idle expiry, moderation, install.sh; experimental .fig export; keyboard shortcut parity suite and bindings; Simplified Chinese draft catalog; Latin American Spanish overlay; prototyping tail: gamepad triggers, widgets in prototypes, mode lookups; plugin directory on figcraft-server; Japanese and Korean draft catalogs and CJK UI fonts; plugin widgets and the plugin panel tail; French, German and Brazilian Portuguese draft catalogs; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and edit tail; dev resources links; extended collections tail; branch version history and finer list merges; headline percentages recomputed from the area table: feature breadth ~84%, core ~94%, mainstream ~50%; text lists, hanging punctuation and decoration styles; comments and version history behaviour suite and fixes; canvas navigation, guides and grids behaviour suite and fixes; export and inspect behaviour suite and fixes; .fig import: editable vector networks and more layer kinds; shapes and vector behaviour suite and fixes; paint and effects behaviour suite and fixes; frames, groups, sections and masks behaviour suite and fixes; styles and variables behaviour suite and fixes; prototyping behaviour suite and fixes; components behaviour suite and fixes; embedded image colour profiles; layers panel keyboard: F2 rename, Shift+F10 context menu, keyboard box selection, 10k-layer QA; per-side stroke weight variables; text behaviour suite: CJK line breaking, metrics, vertical trim; selection and transform behaviour suite and fixes; `.fig` import, best effort; Windows QA pass with eight fixes; auto layout behaviour suite and fixes; Display P3: gamut warning and soft-proof (true P3 blocked upstream); several windows; localization layer with a draft Spanish catalog; hosting figcraft-server: wss in the desktop app, server releases, deployment guide; plugin panels and settings; canvas fixes: boolean hit testing on the result, group drags, frame outlines and slices; code connect; stretch and scatter brushes, pen pressure; text on a path and pattern fills; team libraries on the server and swap library; branches: create, update from main, review and merge; animated GIF fills and TIFF images; Open recent, outlines for the selection and mask outlines: menu breadth 100%; extended collections, variables import/export, gradient stop and variant bindings; feature breadth ~80%; ready ~49%) · **Target:** Figma Design (desktop app 126.10.7)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-14 · **Change:** minor (system theme on first run; recent files as cards with thumbnails on the home screen; community fixes: lost images reported on loading (#207), SVG import budgets (#190), Leptos code (#223), full screen (#227), server snapshots readable again (#188), owner-only preferences (#200), ruzstd 0.9.1 (#182), layer cycle repair (#205), batch rollback, Direct3D 12 on Windows, plugin metering (#192); vector edit mode regions: hover hatch, selection and drag; SVG/PDF exports refuse over-depth documents (#208); bounded MCP/control framing, connections and queues (#201); plugin log limits (#191); live-session revert guard (#198); attached MCP no longer replays after a lost reply (#194); repeat command recursion fix; the Layout panel's constrain-proportions link scales the other side, #220; core editor leftovers: component playground, auto gap handles, variables inside styles, inner shadows and background blur on groups, command-made text readable on dark pages, a one-step frame/group convert, delays on mouse triggers and manual overlay offsets, wrapped-line alignment; `.fig` export: instance sizes, variables with modes, shared styles, variable-width strokes; starter templates, a Templates tab and Getting started tips on the home screen; your online files; everyday editing partials: number fields, outline options, Hide when publishing, cursors, panel widths, dark pages; sharing with a join code; text box sizes measured against documents re-saved by other software; live sessions per document; .fig export checked by opening written files in other software; a public figcraft-server: open hosting, owner tokens, per-address limits, idle expiry, moderation, install.sh; experimental .fig export; keyboard shortcut parity suite and bindings; Simplified Chinese draft catalog; Latin American Spanish overlay; prototyping tail: gamepad triggers, widgets in prototypes, mode lookups; plugin directory on figcraft-server; Japanese and Korean draft catalogs and CJK UI fonts; plugin widgets and the plugin panel tail; French, German and Brazilian Portuguese draft catalogs; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and edit tail; dev resources links; extended collections tail; branch version history and finer list merges; headline percentages recomputed from the area table: feature breadth ~84%, core ~94%, mainstream ~50%; text lists, hanging punctuation and decoration styles; comments and version history behaviour suite and fixes; canvas navigation, guides and grids behaviour suite and fixes; export and inspect behaviour suite and fixes; .fig import: editable vector networks and more layer kinds; shapes and vector behaviour suite and fixes; paint and effects behaviour suite and fixes; frames, groups, sections and masks behaviour suite and fixes; styles and variables behaviour suite and fixes; prototyping behaviour suite and fixes; components behaviour suite and fixes; embedded image colour profiles; layers panel keyboard: F2 rename, Shift+F10 context menu, keyboard box selection, 10k-layer QA; per-side stroke weight variables; text behaviour suite: CJK line breaking, metrics, vertical trim; selection and transform behaviour suite and fixes; `.fig` import, best effort; Windows QA pass with eight fixes; auto layout behaviour suite and fixes; Display P3: gamut warning and soft-proof (true P3 blocked upstream); several windows; localization layer with a draft Spanish catalog; hosting figcraft-server: wss in the desktop app, server releases, deployment guide; plugin panels and settings; canvas fixes: boolean hit testing on the result, group drags, frame outlines and slices; code connect; stretch and scatter brushes, pen pressure; text on a path and pattern fills; team libraries on the server and swap library; branches: create, update from main, review and merge; animated GIF fills and TIFF images; Open recent, outlines for the selection and mask outlines: menu breadth 100%; extended collections, variables import/export, gradient stop and variant bindings; feature breadth ~80%; ready ~49%) · **Target:** Figma Design (desktop app 126.10.7)

 FigCraft is a clean-room, open-source, pure-Rust reimplementation of the Figma design workflow,
 native on macOS, Windows, Linux and FreeBSD and in the browser, fully drivable by agents through
@@ -131,6 +131,8 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).

 ## Progress log

+- **2026-10-14** · Corner handles win over the corner-radius handles (M1, #292): a press on the inner half of a corner handle's square picked the radius handle 10 px in, so the drag neither resized nor (dragging outward) rounded anything. Inside the drawn square the corner now resizes both sides (in ratio with Shift or the link); further in the radius handle still answers. Regression test in the transform behaviour suite. Numbers unchanged.
+- **2026-10-14** · Home screen recent files as cards (M7): each card shows the picture its file carries on its first page's colour, the file's icon, name and "Edited ... ago"; sort by name, creation or last change either way; a table view; a click selects, a double-click or Enter opens, arrow keys move; Open, Show in folder and Remove from recents on right-click. Numbers unchanged.
 - **2026-10-13** · Vector edit mode regions (M4): with the Move tool, the filled area under the pointer is hatched with "/" lines in the selection colour, clipped by the area's own fill rule so holes stay clear; the hatch goes near points (3.5 px) and segments (2 px), and its spacing follows octave folding (8 px at every power-of-two zoom), fixed to the shape. A click selects the area with its points (they move with it but keep the unselected look), Shift adds or removes one, a press on a selected area drags the whole selection as one undo step, and a click on an empty spot clears the areas and stays in edit mode. `vector.edit.select {regions}` and `vector.edit.state` (`regions`, `regionVertices`, `regionHover`); `vector_regions_tests` and `regions_tests`. Numbers unchanged.
 - **2026-10-14** · SVG/PDF export depth (M0.9, #208): visible descendants deeper than 256 levels below an exported root are refused before bounds or drawing, including masks and raster fallbacks. SVG has a checked API; the engine and CLI report the limit and suggest selecting an inner layer. Existing destination files survive refusal. Boundary, inner-root, hidden-subtree, multi-root/page and command/CLI regressions cover the change. Numbers unchanged.
 - **2026-10-13** · MCP/control transport hardening (#201): 32 MiB incoming frames are bounded while reading; oversized frames return an error and close without draining. The opt-in loopback control listener caps active workers at 8, applies 60 s socket read/write inactivity timeouts and caps both request queues at 8, discarding timed-out requests including those deferred to hidden windows. Reader, queue, idle-client and blocked-writer regressions cover the limits. Numbers unchanged.
@@ -311,6 +313,8 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).

 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-14 | minor | System theme on first run (M7): preferences without a theme default to System; the first frame reads the OS appearance directly, including when returning from a manual theme. Saved Light/Dark choices stay explicit; unavailable OS appearance falls back to Light. Numbers unchanged. |
+| 2026-10-14 | minor | Home screen recent files as cards (M7): each card shows the picture its file carries on its first page's colour, the file's icon, name and "Edited ... ago"; sort by name, creation or last change either way; a table view; a click selects, a double-click or Enter opens, arrow keys move; Open, Show in folder and Remove from recents on right-click. Numbers unchanged. |
 | 2026-10-14 | minor | Lost images reported on loading (#207): a `.figcraft` file whose image member is damaged, too large or missing no longer loads in silence; each lost image (up to 20, then a count) is listed in `repairs` on `file.open` with its hash and the reason, and the app shows it as a toast. Saving still writes the file without the lost images. Numbers unchanged |
 | 2026-10-14 | minor | SVG import budgets (#190): gzipped SVG is unpacked by FigCraft within 64 MiB before parsing (it was unpacked without a limit), so the nesting check sees the real document; SVG documents embedded in `<image>` data URIs share one 32 MiB budget and at most 4 levels, and one past a budget is left out. Linked files stay unread. Numbers unchanged |
 | 2026-10-14 | minor | Leptos code (#223): `inspect.code`, `inspect.componentCode` and `codeConnect.set` take `language: leptos`: a `#[component]` with `#[prop]` defaults, variant enums and `view!` markup, instances as calls, Code Connect `use` lines; the Dev Mode language list and rem units include it. Numbers unchanged |
@@ -78,6 +78,27 @@ fn run_export_info_convert() {
    std::fs::remove_dir_all(&d).ok();
 }

+#[test]
+fn run_takes_the_documented_gradient_shorthand() {
+    // #252: only MCP used to accept it; `run` said "`fills` must be paints or colours".
+    let d = tmp("gradient");
+    let script = d.join("s.json");
+    std::fs::write(
+        &script,
+        r##"[{"command":"shape.rectangle","params":{"x":0,"y":0,"width":200,"height":100}},
+            {"command":"node.set","params":{"ids":[2],"fills":[{"type":"linearGradient","stops":["#ff0000","#0000ff"],"from":[0,0.5],"to":[1,0.5]}]}}]"##,
+    )
+    .unwrap();
+    let file = d.join("g.figcraft");
+    let out = bin().arg("run").arg(&script).arg("--out").arg(&file).output().unwrap();
+    assert!(out.status.success(), "{}{}", String::from_utf8_lossy(&out.stdout), String::from_utf8_lossy(&out.stderr));
+    let json = d.join("g.json");
+    assert!(bin().arg("convert").arg(&file).arg(&json).status().unwrap().success());
+    let doc = std::fs::read_to_string(&json).unwrap();
+    assert!(doc.contains("\"kind\":\"linear\"") || doc.contains("\"kind\": \"linear\""), "{doc}");
+    std::fs::remove_dir_all(&d).ok();
+}
+
 #[test]
 fn mcp_over_stdio() {
    let mut child = bin().arg("mcp").stdin(Stdio::piped()).stdout(Stdio::piped()).stderr(Stdio::null()).spawn().unwrap();
@@ -800,3 +800,41 @@ fn the_server_forgets_addresses_whose_connections_are_gone() {
    assert!(server.blocks_remembered() <= 2, "{} blocks remembered", server.blocks_remembered());
    server.stop();
 }
+
+#[test]
+fn a_library_publish_that_fails_keeps_serving_the_old_version() {
+    let dir = TempDir::new("libfail");
+    let mut store = Store::open(dir.path(), config(dir.path()).store()).unwrap();
+    let (file, ..) = store.publish("Library", &snapshot("Library")).unwrap();
+    // Version 1, then a changed library as version 2.
+    let mut s = Session::new();
+    let f = s.execute("frame.create", &json!({"x": 0, "y": 0, "width": 50, "height": 20, "name": "Button"})).unwrap()["id"].as_u64().unwrap();
+    let c = s.execute("component.create", &json!({"ids": [f]})).unwrap()["id"].as_u64().unwrap();
+    s.execute("library.publish", &json!({})).unwrap();
+    let v1 = figcraft_engine::library_server::archive(&s.doc().unwrap().published.clone().unwrap()).unwrap();
+    s.execute("node.set", &json!({"id": c, "props": {"fill": "#00ff00"}})).unwrap();
+    s.execute("library.publish", &json!({})).unwrap();
+    let v2 = figcraft_engine::library_server::archive(&s.doc().unwrap().published.clone().unwrap()).unwrap();
+    assert_eq!(store.publish_library(&file.id, &v1).unwrap(), 1);
+    let files = dir.path().join(crate::store::FILES).join(&file.id);
+    // The description can't be written: a directory sits where its temporary file goes.
+    let tmp = crate::disk::temp_of(&files.join(crate::disk::META));
+    std::fs::create_dir(&tmp).unwrap();
+    assert!(store.publish_library(&file.id, &v2).is_err());
+    let fetch = |s: &mut Store| s.library(ip("198.51.100.1"), &file.id, Access::View, LibraryReq::Fetch { have: None, usage: None });
+    let served = |reply: LibraryReply| match reply {
+        LibraryReply::Library { version, archive } => (version, archive),
+        other => panic!("{other:?}"),
+    };
+    assert_eq!(served(fetch(&mut store)), (1, v1.clone()), "version 1, with its own bytes");
+    // A crash right after the archive was written leaves it on disk, the description unchanged.
+    std::fs::write(files.join(crate::store::library_name(2)), &v2).unwrap();
+    drop(store);
+    std::fs::remove_dir(&tmp).unwrap();
+    let mut store = Store::open(dir.path(), config(dir.path()).store()).unwrap();
+    assert_eq!(served(fetch(&mut store)), (1, v1), "still version 1 after a restart");
+    // Publishing again works, and serves the new version.
+    assert_eq!(store.publish_library(&file.id, &v2).unwrap(), 2);
+    assert_eq!(served(fetch(&mut store)), (2, v2));
+    assert!(!files.join(crate::store::library_name(1)).exists(), "the old version is deleted");
+}
@@ -10,7 +10,8 @@
 //!                                and a join code's hash and wrapped token (see `codes`)
 //! <data>/files/<id>/snapshot.bin the session state at the last compaction
 //! <data>/files/<id>/log.bin      what changed since (see `disk`)
-//! <data>/files/<id>/library.bin  its team library, when one was published (a `.figcraft` archive)
+//! <data>/files/<id>/library-<version>.bin  its team library, when one was published (a `.figcraft`
+//!                                archive; `library.bin` from servers before versioned names)
 //! <data>/files/<id>/usage.json   how other files use that library, as their apps report it
 //! <data>/plugins/                the plugin directory (see `directory`)
 //! <data>/blocked.json            addresses the operator blocked
@@ -179,7 +180,7 @@ impl Meta {
    }
 }

-/// What a file's team library is (`library.bin` holds it).
+/// What a file's team library is ([`library_file`] holds it).
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 struct LibraryMeta {
    id: String,
@@ -265,6 +266,9 @@ pub struct Store {
    next_sweep: u64,
    /// Compactions so far (tests count them).
    compactions: u64,
+    /// Open files closed by a compaction cut short (their snapshot replaced, their log not):
+    /// reported at the next flush, so nothing appended after it is confirmed.
+    cut_short: Vec<String>,
    /// The free space last seen on the data directory's disk, and when.
    free: Option<(Instant, Option<u64>)>,
    _lock: File,
@@ -360,6 +364,7 @@ impl Store {
            gone_codes: VecDeque::new(),
            next_sweep: 0,
            compactions: 0,
+            cut_short: Vec::new(),
            free: None,
            _lock: lock,
        };
@@ -919,11 +924,12 @@ impl Store {
    /// A file's team library for `ip`, unless its version is `have`; within what one address and
    /// everyone may download (the size is known before anything is read).
    fn fetch_library(&mut self, ip: IpAddr, file: &str, have: Option<u64>) -> Result<LibraryReply, String> {
-        let (path, max) = (self.dir(file).join(LIBRARY), self.cfg.max_file_bytes);
+        let (dir, max) = (self.dir(file), self.cfg.max_file_bytes);
        let Some(lib) = self.entry(file)?.meta.library.clone() else { return Ok(LibraryReply::Empty) };
        if have == Some(lib.version) {
            return Ok(LibraryReply::Unchanged { version: lib.version });
        }
+        let path = library_file(&dir, lib.version);
        let size = fs::metadata(&path).map_or(0, |m| m.len());
        let now = Instant::now();
        if !self.abuse.allow(ip, Action::Download(usize::try_from(size).unwrap_or(usize::MAX)), now) || !self.served.take_n(now, size as f64) {
@@ -965,14 +971,24 @@ impl Store {
                return Err(format!("version {} is on the server already: publish again to follow it", old.version));
            }
        }
-        // The archive first: a description never names a version whose library isn't there (a
-        // failed description write leaves the older number, which the next publish follows).
-        disk::write_atomic(&dir.join(LIBRARY), archive).map_err(|e| format!("couldn't keep the library: {e}"))?;
+        // Each version has a file of its own, written before the description names it: a failed
+        // description write or a crash in between leaves the previous version served whole, never
+        // the new bytes under the old number.
+        let path = dir.join(library_name(m.version));
+        disk::write_atomic(&path, archive).map_err(|e| format!("couldn't keep the library: {e}"))?;
        let before = entry.meta.library.replace(LibraryMeta { id: m.id.clone(), name: m.name.clone(), version: m.version });
        if let Err(e) = write_json(&dir.join(META), &entry.meta) {
+            // Never served (the description doesn't name it); the next publish of it replaces it.
+            if let Err(r) = fs::remove_file(&path) {
+                log::warn!("file {file}: an unpublished library version couldn't be deleted: {r}");
+            }
            entry.meta.library = before;
            return Err(format!("couldn't keep the library: {e}"));
        }
+        // The previous version isn't served any more.
+        if let Some(Err(e)) = before.map(|old| fs::remove_file(library_file(&dir, old.version))) {
+            log::warn!("file {file}: the previous library version couldn't be deleted: {e}");
+        }
        log::info!("file {file}: published library version {} ({} bytes)", m.version, archive.len());
        Ok(m.version)
    }
@@ -1124,7 +1140,7 @@ impl Store {
                Log { generation, file: f, pending: Vec::new(), entries: kept, bytes, dirty: kept > 0 }
            }
            // A new snapshot and log of the next generation, so appends start clean.
-            _ => self.rewrite(file, generation + 1, &server)?,
+            _ => self.rewrite(file, generation + 1, &server).map_err(|e| e.why)?,
        };
        self.entry(file)?.log = Some(log);
        Ok(server)
@@ -1137,21 +1153,24 @@ impl Store {
    }

    /// Write `server`'s state as snapshot `generation` and start an empty log of it.
-    fn rewrite(&mut self, file: &str, generation: u64, server: &Server) -> Result<Log, String> {
+    fn rewrite(&mut self, file: &str, generation: u64, server: &Server) -> Result<Log, RewriteError> {
        let dir = self.dir(file);
-        let state = server.state().map_err(|e| e.to_string())?;
-        let bytes = disk::encode_snapshot(generation, &state)?;
+        let kept = |why: String| RewriteError { why, snapshot_replaced: false };
+        let state = server.state().map_err(|e| kept(e.to_string()))?;
+        let bytes = disk::encode_snapshot(generation, &state).map_err(kept)?;
        // Never replace a readable snapshot with one that can't be opened again: the old snapshot
        // and log still hold everything.
        if bytes.len() as u64 > self.snapshot_cap() {
-            return Err(format!("the snapshot would be {} MiB, more than can be opened again", bytes.len() >> 20));
+            return Err(kept(format!("the snapshot would be {} MiB, more than can be opened again", bytes.len() >> 20)));
        }
        if bytes.len() as u64 > self.cfg.max_file_bytes {
            log::warn!("file {file} is {} MiB, over the {} MiB cap (kept anyway)", bytes.len() >> 20, self.cfg.max_file_bytes >> 20);
        }
-        disk::write_atomic(&dir.join(SNAPSHOT), &bytes).map_err(|e| format!("couldn't write the snapshot: {e}"))?;
-        disk::write_atomic(&dir.join(LOG), &disk::log_header(generation)).map_err(|e| format!("couldn't start the log: {e}"))?;
-        let f = OpenOptions::new().append(true).open(dir.join(LOG)).map_err(|e| format!("couldn't open the log: {e}"))?;
+        disk::write_atomic(&dir.join(SNAPSHOT), &bytes).map_err(|e| kept(format!("couldn't write the snapshot: {e}")))?;
+        // From here the old log no longer goes with the snapshot on disk.
+        let replaced = |why: String| RewriteError { why, snapshot_replaced: true };
+        disk::write_atomic(&dir.join(LOG), &disk::log_header(generation)).map_err(|e| replaced(format!("couldn't start the log: {e}")))?;
+        let f = OpenOptions::new().append(true).open(dir.join(LOG)).map_err(|e| replaced(format!("couldn't open the log: {e}")))?;
        if let Ok(e) = self.entry(file) {
            e.bytes = (bytes.len() + LOG_HEADER) as u64;
            e.meta.seq = server.seq();
@@ -1204,8 +1223,19 @@ impl Store {
                }
                log::debug!("compacted file {file}");
            }
+            // The new snapshot holds everything, but a restart would drop whatever is appended to
+            // the old log now (its generation no longer matches): the file closes, the hub hears
+            // it at the next flush, and it opens again from the new snapshot.
+            Err(RewriteError { why, snapshot_replaced: true }) => {
+                self.note(format!("file {file}: compaction was cut short ({why}); it was closed"));
+                log::error!("file {file}: compaction was cut short: {why}");
+                if let Some(e) = self.files.get_mut(file) {
+                    e.log = None;
+                }
+                self.cut_short.push(file.to_string());
+            }
            // The old snapshot and log still hold everything: carry on appending.
-            Err(e) => log::error!("file {file}: compaction failed: {e}"),
+            Err(RewriteError { why, .. }) => log::error!("file {file}: compaction failed: {why}"),
        }
    }

@@ -1213,7 +1243,7 @@ impl Store {
    /// Those are closed here (their pending records dropped: nobody was told of them) and open
    /// again from what is on disk.
    fn flush_all(&mut self) -> Vec<String> {
-        let mut failed = Vec::new();
+        let mut failed = std::mem::take(&mut self.cut_short);
        for (id, e) in &mut self.files {
            if let Some(log) = e.log.as_mut() {
                match flush_log(id, log) {
@@ -1229,6 +1259,13 @@ impl Store {
    }
 }

+/// Why a snapshot and log couldn't be rewritten, and whether the snapshot on disk was replaced
+/// before it failed (then the old log no longer goes with it).
+struct RewriteError {
+    why: String,
+    snapshot_replaced: bool,
+}
+
 /// Write and sync a log's pending records: the bytes written, or `Err` when that failed (the log
 /// can't be trusted to hold them).
 fn flush_log(id: &str, log: &mut Log) -> Result<u64, ()> {
@@ -1249,6 +1286,18 @@ fn flush_log(id: &str, log: &mut Log) -> Result<u64, ()> {
    }
 }

+/// The name of the file holding version `version` of a file's team library.
+pub fn library_name(version: u64) -> String {
+    format!("library-{version}.bin")
+}
+
+/// Where version `version` of the team library in `dir` is: its own file, or `library.bin` for a
+/// version published before each version had one.
+fn library_file(dir: &Path, version: u64) -> PathBuf {
+    let path = dir.join(library_name(version));
+    if path.exists() { path } else { dir.join(LIBRARY) }
+}
+
 fn write_json<T: Serialize + ?Sized>(path: &Path, value: &T) -> Result<(), String> {
    let text = serde_json::to_vec_pretty(value).map_err(|e| e.to_string())?;
    disk::write_atomic(path, &text).map_err(|e| e.to_string())
@@ -1316,6 +1365,8 @@ impl Backend for Store {
        if dirty {
            self.compact(file, server);
        }
+        // It closes anyway, everything in its snapshot: a compaction cut short needs no report.
+        self.cut_short.retain(|f| f != file);
        if let Some(e) = self.files.get_mut(file) {
            e.log = None;
        }
@@ -1438,6 +1489,8 @@ impl Backend for Store {
            Admin::Blocked => AdminReply::Blocked(self.blocked()).into(),
            Admin::Code { file, token } => self.set_code(&file, &token).map_or_else(failed, |code| AdminReply::Code { code }.into()),
            Admin::Owned { files } => self.owned(&files).into(),
+            // The hub removes people itself (it knows who is connected); it never asks the store.
+            Admin::RemovePeer { .. } => failed("removing someone from a file is done by the server's hub".into()),
            Admin::Remove { file } => {
                if !self.files.contains_key(&file) {
                    return failed("this file isn't on the server (it may have been removed)".into());
@@ -269,3 +269,47 @@ fn random_bytes_never_panic_the_readers() {
        let _ = disk::read_log(&bytes);
    }
 }
+
+/// The first page's name in `server`'s document.
+fn page_name(server: &Server) -> String {
+    let d = server.replica().document();
+    d.node(d.first_page().unwrap()).unwrap().name.clone()
+}
+
+#[test]
+fn edits_confirmed_after_a_compaction_cut_short_survive_a_restart() {
+    let dir = TempDir::new("cutshort");
+    let c = StoreConfig { compact_after: 3, ..cfg(dir.path()) };
+    let folder = dir.path().join(FILES);
+    let mut store = Store::open(dir.path(), c.clone()).unwrap();
+    let (id, _, _) = publish(&mut store, "Busy");
+    let mut server = store.open(&id).unwrap();
+    let mut a = join(&mut server, Access::Edit);
+    store.changed(&id, &mut server);
+    // The next compaction writes its snapshot, then can't start its log.
+    let blocker = disk::temp_of(&folder.join(&id).join(LOG));
+    fs::create_dir(&blocker).unwrap();
+    // What the hub would confirm: every change whose flush didn't report the file.
+    let mut confirmed = String::new();
+    let mut failed = false;
+    let names = ["P0", "P1", "P2", "After 1", "After 2"];
+    for name in names {
+        rename(&mut server, &mut a, name);
+        store.changed(&id, &mut server);
+        if store.flush().contains(&id) {
+            failed = true;
+            break;
+        }
+        confirmed = name.to_string();
+    }
+    assert!(failed, "the hub hears the file can't be kept; confirmed {confirmed:?}");
+    // A crash, then the disk recovers.
+    drop(store);
+    fs::remove_dir(&blocker).unwrap();
+    let mut store = Store::open(dir.path(), c).unwrap();
+    let restored = store.open(&id).unwrap();
+    // Every confirmed change is there (the snapshot may also hold the one that was cut short).
+    let at = |n: &str| names.iter().position(|x| *x == n);
+    let name = page_name(&restored);
+    assert!(at(&name) >= at(&confirmed), "restored {name:?}, confirmed {confirmed:?}");
+}
@@ -24,5 +24,6 @@ log = { workspace = true }
 # `wgpu` pulls egui-wgpu's defaults: WebGPU plus the WebGL2 fallback.
 eframe = { workspace = true, features = ["default_fonts", "wgpu", "accesskit"] }
 wasm-bindgen = "0.2"
+js-sys = "0.3"
 wasm-bindgen-futures = "0.4"
-web-sys = { version = "0.3", features = ["Window", "Document", "Element", "HtmlCanvasElement", "Location", "MediaQueryList", "Navigator", "Gamepad", "GamepadButton", "GamepadMappingType"] }
+web-sys = { version = "0.3", features = ["Window", "Document", "Element", "HtmlCanvasElement", "HtmlElement", "HtmlAnchorElement", "Node", "Blob", "BlobPropertyBag", "Url", "Location", "MediaQueryList", "Navigator", "Gamepad", "GamepadButton", "GamepadMappingType"] }
@@ -40,7 +40,7 @@ pub fn start() {
                    // on the socket wakes the page for a frame.
                    let ctx = cc.egui_ctx.clone();
                    session.live.install(Box::new(figcraft_collab_net::NetLink::new(std::sync::Arc::new(move || ctx.request_repaint()))));
-                    let fig = FigApp::new(session, Box::new(WebServices { reduce_motion }));
+                    let fig = FigApp::new(session, Box::new(WebServices { reduce_motion, ctx: cc.egui_ctx.clone() }));
                    Ok(Box::new(WebShell { fig }))
                }),
            )
@@ -69,14 +69,35 @@ impl eframe::App for WebShell {
    }
 }

-/// Browser services. File dialogs return nothing for now (the trait's defaults); the clipboard
-/// goes through egui's own web clipboard handling.
+/// Browser services. Open dialogs return nothing for now (the trait's defaults); files are saved
+/// as downloads. Copies go to the system clipboard through egui's output; pastes arrive as paste
+/// events with their text (a page can't read the clipboard when it likes).
 struct WebServices {
    /// `prefers-reduced-motion: reduce` (it follows the setting while the page is open).
    reduce_motion: Option<web_sys::MediaQueryList>,
+    ctx: egui::Context,
 }

 impl Services for WebServices {
+    fn downloads(&self) -> bool {
+        true
+    }
+    /// A Blob behind a temporary `<a download>` link, clicked and removed.
+    fn download(&mut self, name: &str, bytes: &[u8]) -> bool {
+        match download(name, bytes) {
+            Ok(()) => true,
+            Err(e) => {
+                log::error!("couldn't download {name}: {e:?}");
+                false
+            }
+        }
+    }
+    fn clipboard_set_text(&mut self, s: &str) {
+        figcraft_ui_egui::egui_copy_text(&self.ctx, s);
+    }
+    fn clipboard_set_png(&mut self, w: u32, h: u32, rgba: &[u8]) {
+        figcraft_ui_egui::egui_copy_png(&self.ctx, w, h, rgba);
+    }
    fn open_url(&mut self, url: &str) {
        let Some(window) = web_sys::window() else { return };
        if let Err(e) = window.open_with_url_and_target(url, "_blank") {
@@ -108,3 +129,32 @@ impl Services for WebServices {
        held
    }
 }
+
+fn download(name: &str, bytes: &[u8]) -> Result<(), wasm_bindgen::JsValue> {
+    let window = web_sys::window().ok_or("no window")?;
+    let document = window.document().ok_or("no document")?;
+    let body = document.body().ok_or("no body")?;
+    let parts = js_sys::Array::of1(&js_sys::Uint8Array::from(bytes));
+    let blob = web_sys::Blob::new_with_u8_array_sequence_and_options(&parts, &{
+        let o = web_sys::BlobPropertyBag::new();
+        o.set_type("application/octet-stream");
+        o
+    })?;
+    let url = web_sys::Url::create_object_url_with_blob(&blob)?;
+    let a: web_sys::HtmlAnchorElement = document.create_element("a")?.dyn_into()?;
+    a.set_href(&url);
+    a.set_download(name);
+    body.append_child(&a)?;
+    a.click();
+    a.remove();
+    // Revoked later, not at once: some browsers cancel a download whose URL goes before it starts.
+    let revoke = wasm_bindgen::closure::Closure::once_into_js(move || {
+        let _ = web_sys::Url::revoke_object_url(&url);
+    });
+    // Without the timer the URL just stays until the page closes.
+    let _ = window.set_timeout_with_callback_and_timeout_and_arguments_0(revoke.unchecked_ref(), REVOKE_DOWNLOAD_MS);
+    Ok(())
+}
+
+/// How long a download's object URL is kept (milliseconds).
+const REVOKE_DOWNLOAD_MS: i32 = 40_000;
@@ -31,6 +31,13 @@ env_logger = { version = "0.11", default-features = false, features = ["auto-col
 [target.'cfg(windows)'.dependencies]
 windows = { version = "0.62", default-features = false, features = ["UI_ViewManagement", "System_UserProfile", "Foundation_Collections", "Gaming_Input"] }

+# Finder double-clicks, Open With, Dock drops and `open -a FigCraft file.figcraft` arrive as a
+# kAEOpenDocuments Apple event, which winit 0.30 doesn't handle. This crate (also used by GridCraft,
+# EffectCraft and PhotoCraft) registers the handler behind a safe API (Objective-C interop needs
+# unsafe, which the workspace forbids). Pinned exactly: review the diff before bumping.
+[target.'cfg(target_os = "macos")'.dependencies]
+fmv-macos-events = "=0.1.0"
+
 [dev-dependencies]
 wat = { workspace = true }

@@ -0,0 +1,57 @@
+//! macOS open-documents and quit Apple events (#289).
+//!
+//! Finder double-clicks, Open With, drops on the Dock icon and `open -a FigCraft file.figcraft`
+//! don't pass paths on the command line: LaunchServices sends the running (or just-launched) app a
+//! `kAEOpenDocuments` ('odoc') Apple event. winit 0.30 doesn't handle it and owns the
+//! `NSApplicationDelegate`, so AppKit answered "FigCraft cannot open files in the FigCraft Document
+//! format". Handling it ourselves needs Objective-C class declarations, i.e. `unsafe`, which this
+//! workspace forbids. The `fmv-macos-events` crate (also used by GridCraft, EffectCraft and
+//! PhotoCraft) wraps exactly that, an `NSAppleEventManager` handler registered before Finder's
+//! launch event that leaves winit's delegate alone, behind a safe main-thread API.
+
+use std::path::PathBuf;
+
+use figcraft_ui_egui::FigApp;
+use fmv_macos_events::{Event, Inbox, Registration};
+use serde_json::json;
+
+/// Keeps the Apple-event handlers registered; hold it until the event loop returns.
+pub struct AppleEvents {
+    _registration: Registration,
+    inbox: Inbox,
+}
+
+impl AppleEvents {
+    /// Register the handlers. Call on the main thread before the event loop starts, so the event
+    /// that launched the app (a Finder double-click) is caught too.
+    pub fn install() -> Self {
+        let (registration, inbox) = Registration::install();
+        Self { _registration: registration, inbox }
+    }
+
+    /// The queue the app drains every frame ([`poll`]); events arriving later wake `ctx`.
+    pub fn connect(&self, ctx: &egui::Context) -> Inbox {
+        let ctx = ctx.clone();
+        self.inbox.set_wake(move || ctx.request_repaint());
+        self.inbox.clone()
+    }
+}
+
+/// Open the documents and act on the quit requests that arrived since the last frame.
+pub fn poll(inbox: &Inbox, fig: &mut FigApp, ctx: &egui::Context) {
+    for e in inbox.drain() {
+        match e {
+            Event::Open(paths) => open_documents(fig, paths),
+            Event::Quit => ctx.send_viewport_cmd(egui::ViewportCommand::Close),
+        }
+    }
+}
+
+/// Open `paths` as File › Open does; a file that fails shows its error and the others still open.
+pub fn open_documents(fig: &mut FigApp, paths: Vec<PathBuf>) {
+    for p in paths {
+        if fig.run("file.open", json!({"path": p.to_string_lossy()})).is_some() {
+            fig.ui.home = false;
+        }
+    }
+}
@@ -0,0 +1,30 @@
+//! Documents macOS hands over in an open-documents Apple event (a Finder double-click, Open With,
+//! a drop on the Dock icon) open as File › Open opens them (#289).
+
+use std::path::PathBuf;
+
+use figcraft_engine::Session;
+use figcraft_ui_egui::{FigApp, NoServices};
+use serde_json::json;
+
+use crate::apple_events::open_documents;
+
+#[test]
+fn documents_from_finder_open_and_leave_the_home_screen() {
+    let dir = std::env::temp_dir().join(format!("figcraft-apple-events-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&dir);
+    std::fs::create_dir_all(&dir).unwrap();
+    let file = dir.join("BLA-001.figcraft");
+    let mut s = Session::new();
+    s.execute("file.saveAs", &json!({"path": file.to_string_lossy()})).unwrap();
+
+    let mut app = FigApp::new(Session::empty(), Box::new(NoServices));
+    app.ui.home = true;
+    // A file that can't be read is reported and doesn't keep the others from opening.
+    open_documents(&mut app, vec![dir.join("Missing.figcraft"), file.clone()]);
+    let paths: Vec<_> = app.session.docs.iter().map(|d| d.path.clone().map(PathBuf::from)).collect();
+    assert_eq!(paths, [Some(file)]);
+    assert!(!app.ui.home, "the opened document shows");
+    assert!(app.ui.last_error.as_deref().is_some_and(|e| e.contains("Missing.figcraft")), "{:?}", app.ui.last_error);
+    let _ = std::fs::remove_dir_all(&dir);
+}
@@ -107,7 +107,7 @@ fn serve(mut out: TcpStream, queue: Queue, ctx: CtxSlot, timeout: Duration) -> s
                    },
                    Err(_) => {
                        cancelled.store(true, std::sync::atomic::Ordering::Relaxed);
-                        json!({"id": id, "ok": false, "error": "timed out waiting for the UI (is the window visible?)"})
+                        json!({"id": id, "ok": false, "error": "timed out waiting for the UI: screenshots and input need the FigCraft window on screen (is it minimised or covered?)"})
                    }
                }
            }
@@ -9,13 +9,18 @@
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 #![cfg_attr(all(target_os = "windows", not(debug_assertions)), windows_subsystem = "windows")]

+#[cfg(target_os = "macos")]
+mod apple_events;
 mod args;
 mod control_server;
 mod gamepad;
 mod graphics;
 mod recovery;
 mod services;
+mod startup;

+#[cfg(all(test, target_os = "macos"))]
+mod apple_events_tests;
 #[cfg(test)]
 mod args_tests;
 #[cfg(test)]
@@ -26,6 +31,8 @@ mod recovery_online_tests;
 mod recovery_tests;
 #[cfg(test)]
 mod services_tests;
+#[cfg(test)]
+mod startup_tests;

 use std::sync::{Arc, Mutex};

@@ -43,6 +50,9 @@ struct App {
    title: String,
    /// Shared with the services, which write the copies after a panic.
    recovery: recovery::Shared,
+    /// Documents and quit requests from Finder, the Dock and Open With.
+    #[cfg(target_os = "macos")]
+    apple_events: fmv_macos_events::Inbox,
 }

 impl eframe::App for App {
@@ -55,6 +65,9 @@ impl eframe::App for App {
        }
        let title = with_app(|fig| {
            control_server::drain_queue(&self.queue, &mut fig.control_queue);
+            figcraft_ui_egui::control::drain_hidden(fig, ctx);
+            #[cfg(target_os = "macos")]
+            apple_events::poll(&self.apple_events, fig, ctx);
            // Closing the window asks about unsaved changes (and keeps the app running while other
            // windows are open).
            figcraft_ui_egui::windows::on_close_request(fig, ctx);
@@ -81,9 +94,9 @@ impl eframe::App for App {
        }
    }

-    fn ui(&mut self, ui: &mut egui::Ui, _frame: &mut eframe::Frame) {
+    fn ui(&mut self, ui: &mut egui::Ui, frame: &mut eframe::Frame) {
        let ctx = ui.ctx().clone();
-        with_app(|fig| figcraft_ui_egui::windows::guard(fig, &ctx, |fig| fig.ui(ui)));
+        services::parented(frame, || with_app(|fig| figcraft_ui_egui::windows::guard(fig, &ctx, |fig| fig.ui(ui))));
    }

    fn on_exit(&mut self) {
@@ -157,6 +170,9 @@ fn main() -> eframe::Result {
    if session.docs.is_empty() && !first_run {
        let _ = session.execute("file.new", &json!({}));
    }
+    // The interface language from the first frame on, and for the message when the window can't
+    // open (no frame then).
+    figcraft_ui_egui::i18n::set(&session.prefs.language, figcraft_ui_egui::Services::system_language(&svc).as_deref());
    let mut fig = FigApp::new(session, Box::new(svc));
    fig.ui.home = false;
    fig.note_recovered(recovered.copies);
@@ -168,8 +184,11 @@ fn main() -> eframe::Result {
        control_server::start(p, queue.clone(), ctx_slot.clone());
    }
    let icon = services::window_icon();
+    // The app id is the Wayland app_id and the X11 window class on Linux: the desktop entry's name
+    // and StartupWMClass (FreeBSD's package matches the binary's name instead).
    let mut viewport = egui::ViewportBuilder::default()
        .with_title("FigCraft")
+        .with_app_id("ai.storyteller.figcraft")
        .with_inner_size([1440.0, 900.0])
        .with_min_inner_size([800.0, 500.0])
        .with_drag_and_drop(true);
@@ -188,5 +207,29 @@ fn main() -> eframe::Result {
    let mut options = eframe::NativeOptions { viewport, renderer: eframe::Renderer::Wgpu, ..Default::default() };
    graphics::configure(&mut options.wgpu_options);
    figcraft_ui_egui::windows::install(fig);
-    eframe::run_native("FigCraft", options, Box::new(move |_cc| Ok(Box::new(App { queue, ctx_slot, title: String::new(), recovery }))))
+    // Registered before the event loop starts, so it catches the Finder event that launched the app
+    // as well as later ones. Lives until the event loop returns; the app creator only borrows it.
+    #[cfg(target_os = "macos")]
+    let apple_events = apple_events::AppleEvents::install();
+    #[cfg(target_os = "macos")]
+    let apple_events = &apple_events;
+    let result = eframe::run_native(
+        "FigCraft",
+        options,
+        Box::new(move |_cc| {
+            Ok(Box::new(App {
+                queue,
+                ctx_slot,
+                title: String::new(),
+                recovery,
+                #[cfg(target_os = "macos")]
+                apple_events: apple_events.connect(&_cc.egui_ctx),
+            }))
+        }),
+    );
+    // Say why instead of quitting silently: release builds on Windows have no console.
+    if let Err(e) = &result {
+        startup::failed(e, port.is_some());
+    }
+    result
 }
@@ -4,7 +4,10 @@
 //! in the config folder, in the background, at most every [`INTERVAL`] seconds, and the copy goes
 //! once the document is saved or closed. The app holds a lock on its folder. At startup, the folders
 //! whose lock is free belong to runs that ended without closing: their copies open again as
-//! unsaved documents (`file.recover`) and the folder goes. Closing the app normally removes its own.
+//! unsaved documents (`file.recover`). Each such copy **stays until this run has its own copy of
+//! the document** (or it is saved or closed): until then it is the only copy on disk, and a run
+//! that can't keep copies of its own leaves it for the next start. Then it goes, and its folder
+//! with its last copy. Closing the app normally removes its own.
 //!
 //! A document that is one of your online files has a note beside its copy (`<uid>.online`, written
 //! after the copy it describes): the server, the file's id, and who the app was in the file with
@@ -22,7 +25,8 @@ use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, MutexGuard};
 use std::thread::JoinHandle;

-use figcraft_engine::Session;
+use figcraft_engine::{DocState, Session};
+use figcraft_format::{Branch, Version};
 use serde_json::json;

 /// Seconds between copies of a document that keeps changing.
@@ -41,20 +45,61 @@ pub struct Recovery {
    dir: PathBuf,
    /// Held while the app runs: a free lock means the run that wrote the folder is gone.
    _lock: File,
-    /// The revision each document was last copied at, and the write in flight.
-    written: HashMap<u64, (u64, Option<JoinHandle<()>>)>,
+    /// What was copied of each document, and the write in flight.
+    written: HashMap<u64, Copy>,
    /// When (UI clock) the next copies are due.
    next: f64,
    /// Copies of online files from earlier runs, kept until their outcome is known.
    waiting: Vec<Waiting>,
 }

-/// A copy of one of your online files whose file is being joined again as session `session`.
+/// The state of the copy of one document: only a write that succeeded counts as a copy.
+#[derive(Default)]
+struct Copy {
+    /// The [`stamp`] whose copy was written.
+    done: Option<Vec<u64>>,
+    /// The write in flight: the stamp it copies, and whether it succeeded once it ends.
+    flight: Option<(Vec<u64>, JoinHandle<bool>)>,
+}
+
+impl Copy {
+    /// Take in the result of the write in flight once it ended; a failed one leaves its revision uncopied.
+    fn reap(&mut self) {
+        if self.flight.as_ref().is_some_and(|f| f.1.is_finished()) {
+            self.join();
+        }
+    }
+
+    /// Wait for the write in flight and take in its result.
+    fn join(&mut self) {
+        if let Some((stamp, h)) = self.flight.take()
+            && h.join().unwrap_or(false)
+        {
+            self.done = Some(stamp);
+        }
+    }
+
+    /// Whether `stamp` has neither been copied nor is being copied.
+    fn pending(&self, stamp: &[u64]) -> bool {
+        self.done.as_deref() != Some(stamp) && self.flight.as_ref().is_none_or(|f| f.0 != stamp)
+    }
+}
+
+/// A copy from an earlier run, kept until what it became is safe.
 pub struct Waiting {
-    session: u64,
+    until: Until,
    copy: PathBuf,
-    /// The lock of the folder it is in: no other start takes the copy meanwhile.
-    _lock: Arc<File>,
+    /// The lock of the folder it is in: no other start takes the copy meanwhile (none for a copy
+    /// left directly in the root by older versions).
+    _lock: Option<Arc<File>>,
+}
+
+/// What a kept copy waits for.
+enum Until {
+    /// One of your online files, joined again as this session: its outcome.
+    Session(u64),
+    /// Opened as document `uid`: this run's own copy of it (or its save or close).
+    Copied(u64),
 }

 /// What [`recover_all`] brought back.
@@ -62,21 +107,26 @@ pub struct Waiting {
 pub struct Recovered {
    /// Documents opened from their copies.
    pub copies: usize,
-    /// Copies of online files waiting for their file ([`Recovery::adopt`]).
+    /// The copies kept until what they became is safe ([`Recovery::adopt`]).
    pub waiting: Vec<Waiting>,
 }

 impl Recovery {
    /// Take this run's folder under `root` (`None` when it can't be created or locked: no copies).
+    /// A crashed run with the same process id may still hold its folder (its copies kept): then
+    /// another name is taken.
    pub fn start(root: &Path) -> Option<Self> {
-        let dir = root.join(std::process::id().to_string());
-        std::fs::create_dir_all(&dir).ok()?;
-        let lock = File::create(dir.join(LOCK)).ok()?;
-        lock.try_lock().ok()?;
-        Some(Self { dir, _lock: lock, written: HashMap::new(), next: 0.0, waiting: Vec::new() })
+        let pid = std::process::id();
+        (0..10).find_map(|n| {
+            let dir = root.join(if n == 0 { pid.to_string() } else { format!("{pid}-{n}") });
+            std::fs::create_dir_all(&dir).ok()?;
+            let lock = File::options().write(true).create(true).truncate(false).open(dir.join(LOCK)).ok()?;
+            lock.try_lock().ok()?;
+            Some(Self { dir, _lock: lock, written: HashMap::new(), next: 0.0, waiting: Vec::new() })
+        })
    }

-    /// Keep earlier runs' copies of online files until their outcome is known.
+    /// Keep earlier runs' copies until what they became is safe.
    pub fn adopt(&mut self, waiting: Vec<Waiting>) {
        self.waiting.extend(waiting);
    }
@@ -85,38 +135,47 @@ impl Recovery {
    /// were saved or closed. Returns how long until it needs to run again (`None`: nothing pending,
    /// an idle window can sleep).
    pub fn tick(&mut self, s: &Session, now: f64) -> Option<f64> {
+        self.written.values_mut().for_each(Copy::reap);
        self.settle(s);
-        // A join on its way settles within its timeouts: look again soon.
-        let settling = (!self.waiting.is_empty()).then_some(0.5);
-        let pending = s.docs.iter().any(|d| needs_copy(d) && self.written.get(&d.uid).is_none_or(|w| w.0 != d.revision));
+        // A join on its way settles within its timeouts: look again soon. A copy waiting for this
+        // run's own is looked at again with the next copies.
+        let joining = self.waiting.iter().any(|w| matches!(w.until, Until::Session(_)));
+        let settling = if joining { Some(0.5) } else { (!self.waiting.is_empty()).then_some(INTERVAL) };
        if now < self.next {
-            return pending.then_some(self.next - now).or(settling);
+            return self.pending(s).then_some(self.next - now).or(settling);
        }
        self.write(s, false);
        self.next = now + INTERVAL;
-        settling
+        // A copy that failed is tried again at the next turn, without another edit.
+        settling.or(self.pending(s).then_some(INTERVAL))
    }

-    /// Remove earlier runs' copies whose outcome is known, once what they became is copied here.
-    fn settle(&mut self, s: &Session) {
-        if self.waiting.iter().all(|w| s.live.recovering(w.session)) {
-            return;
+    /// Whether a document with unsaved changes has a revision that is neither copied nor being copied.
+    fn pending(&self, s: &Session) -> bool {
+        s.docs.iter().any(|d| needs_copy(s, d) && self.written.get(&d.uid).is_none_or(|w| w.pending(&stamp(s, d))))
+    }
+
+    /// Remove earlier runs' copies once what they became is safe: copied here (the write
+    /// succeeded), saved or closed. An online file's copy goes once its outcome is known and every
+    /// document is safe, since which of them it became isn't known.
+    pub fn settle(&mut self, s: &Session) {
+        let joined = |w: &Waiting| matches!(w.until, Until::Session(id) if !s.live.recovering(id));
+        if self.waiting.iter().any(joined) {
+            self.write(s, true);
        }
-        self.write(s, true);
-        let (done, waiting): (Vec<Waiting>, Vec<Waiting>) =
-            std::mem::take(&mut self.waiting).into_iter().partition(|w| !s.live.recovering(w.session));
+        let all_safe = s.docs.iter().all(|d| self.safe(s, d));
+        let (done, waiting): (Vec<Waiting>, Vec<Waiting>) = std::mem::take(&mut self.waiting).into_iter().partition(|w| match w.until {
+            Until::Session(_) => joined(w) && all_safe,
+            Until::Copied(uid) => s.docs.iter().find(|d| d.uid == uid).is_none_or(|d| self.safe(s, d)),
+        });
        self.waiting = waiting;
-        for w in done {
-            let _ = std::fs::remove_file(&w.copy);
-            let _ = std::fs::remove_file(w.copy.with_extension(ONLINE));
-            // The folder goes with its last copy (while another waits there its lock is held).
-            let dir = w.copy.parent().map(Path::to_path_buf).filter(|_| Arc::strong_count(&w._lock) == 1);
-            drop(w);
-            if let Some(dir) = dir {
-                let _ = std::fs::remove_file(dir.join(LOCK));
-                let _ = std::fs::remove_dir(dir);
-            }
-        }
+        done.into_iter().for_each(remove_kept);
+    }
+
+    /// Whether document `d`'s work is on disk: saved (or nothing to keep), or copied here (a write
+    /// that succeeded) with no write in flight.
+    fn safe(&self, s: &Session, d: &DocState) -> bool {
+        !needs_copy(s, d) || self.written.get(&d.uid).is_some_and(|w| w.done.is_some() && w.flight.is_none())
    }

    /// Copy every document with unsaved changes; `wait`: before returning (after a panic).
@@ -124,47 +183,60 @@ impl Recovery {
        for d in &s.docs {
            let path = self.dir.join(format!("{}.figcraft", d.uid));
            let note = path.with_extension(ONLINE);
-            if !needs_copy(d) {
-                if self.written.remove(&d.uid).is_some() {
+            if !needs_copy(s, d) {
+                if let Some(mut w) = self.written.remove(&d.uid) {
+                    // A write still running would bring the copy back after it was removed.
+                    w.join();
                    let _ = std::fs::remove_file(&path);
                    let _ = std::fs::remove_file(&note);
                }
                continue;
            }
-            let entry = self.written.entry(d.uid).or_insert((0, None));
-            let busy = entry.1.as_ref().is_some_and(|h| !h.is_finished());
-            if entry.0 == d.revision || busy {
+            let entry = self.written.entry(d.uid).or_default();
+            // An emergency save must copy the newest revision: let the write in flight finish first.
+            if wait {
+                entry.join();
+            } else {
+                entry.reap();
+            }
+            // A write still in flight (for any revision) is waited for; a failed one is tried again.
+            let stamp = stamp(s, d);
+            if entry.done.as_ref() == Some(&stamp) || entry.flight.is_some() {
                continue;
            }
            let doc = d.doc.clone();
+            let (versions, branches) = (d.versions.clone(), figcraft_engine::branches::current(s, d.uid));
            // Which online file it is and what of the server's this very copy has (a line each:
            // the server, the file's id, then the session, client id and last change), while it
            // is one. Written after the copy, never before: a note must not promise more of the
            // server's changes than its copy holds.
            let online = s.online_of(d.uid).map(|(server, file, at)| format!("{server}\n{file}\n{} {} {}", at.session, at.client_id, at.seq));
            let job = move || {
-                if !write_atomic(&path, &doc) {
-                    return;
+                if !write_atomic(&path, &doc, &versions, &branches) {
+                    return false;
                }
                let _ = match online {
                    Some(text) => std::fs::write(&note, text),
                    None => std::fs::remove_file(&note),
                };
+                true
            };
+            // The stamp counts as copied only once its write succeeded.
            if wait {
-                job();
-                entry.1 = None;
+                if job() {
+                    entry.done = Some(stamp);
+                }
            } else {
-                entry.1 = std::thread::Builder::new().name("recovery".into()).spawn(job).ok();
+                entry.flight = std::thread::Builder::new().name("recovery".into()).spawn(job).ok().map(|h| (stamp, h));
            }
-            entry.0 = d.revision;
        }
        // Closed documents.
        let open: Vec<u64> = s.docs.iter().map(|d| d.uid).collect();
        let dir = &self.dir;
-        self.written.retain(|uid, _| {
+        self.written.retain(|uid, w| {
            let keep = open.contains(uid);
            if !keep {
+                w.join();
                let _ = std::fs::remove_file(dir.join(format!("{uid}.figcraft")));
                let _ = std::fs::remove_file(dir.join(format!("{uid}.{ONLINE}")));
            }
@@ -172,12 +244,20 @@ impl Recovery {
        });
    }

+    /// Test hook: pretend a write of `uid` at `revision` is in flight in `writer`.
+    #[cfg(test)]
+    pub fn hold(&mut self, uid: u64, revision: u64, writer: JoinHandle<bool>) {
+        self.written.insert(uid, Copy { done: None, flight: Some((vec![revision], writer)) });
+    }
+
    /// A normal quit: the documents were saved or their changes discarded on purpose. (Earlier
    /// runs' copies still waiting for their outcome stay for the next start.)
    pub fn finish(self) {
-        let Self { dir, _lock, written, .. } = self;
+        let Self { dir, _lock, written, waiting, .. } = self;
+        // The documents earlier runs' copies became were saved or discarded too.
+        waiting.into_iter().filter(|w| matches!(w.until, Until::Copied(_))).for_each(remove_kept);
        // Windows removes a folder only once nothing in it is open: copies being written first.
-        for h in written.into_values().filter_map(|w| w.1) {
+        for (_, h) in written.into_values().filter_map(|w| w.flight) {
            let _ = h.join();
        }
        drop(_lock);
@@ -185,6 +265,20 @@ impl Recovery {
    }
 }

+/// Remove a kept copy and its note, and its folder with its last copy (while another is kept
+/// there, its lock is held).
+fn remove_kept(w: Waiting) {
+    let _ = std::fs::remove_file(&w.copy);
+    let _ = std::fs::remove_file(w.copy.with_extension(ONLINE));
+    let last = w._lock.as_ref().is_some_and(|l| Arc::strong_count(l) == 1);
+    let dir = w.copy.parent().map(Path::to_path_buf).filter(|_| last);
+    drop(w);
+    if let Some(dir) = dir {
+        let _ = std::fs::remove_file(dir.join(LOCK));
+        let _ = std::fs::remove_dir(dir);
+    }
+}
+
 /// The extension of the note beside the copy of a document that is one of your online files.
 const ONLINE: &str = "online";

@@ -201,15 +295,27 @@ fn rejoin_online(file: &Path, s: &mut Session) -> Option<u64> {
    s.execute("collab.recoverFile", &params).ok()?.get("session")?.as_u64()
 }

-/// A document whose changes would be lost (a branch tab's edits are in its main file).
-fn needs_copy(d: &figcraft_engine::DocState) -> bool {
-    d.is_dirty() && d.branch_of.is_none()
+/// A file whose changes would be lost: in its document, its history or one of its branch tabs
+/// (a branch tab's edits are saved with its main file, so the tab has no copy of its own).
+fn needs_copy(s: &Session, d: &DocState) -> bool {
+    d.branch_of.is_none() && (d.is_dirty() || branch_tabs(s, d.uid).any(DocState::is_dirty))
 }

-/// Write `doc` to `path` through a temporary file; false when it couldn't be written (the copy
-/// before it is still there).
-fn write_atomic(path: &Path, doc: &figcraft_engine::doc::Document) -> bool {
-    let Ok(bytes) = figcraft_format::save_bytes(doc, None) else { return false };
+/// The tabs showing branches of the file in tab `uid`.
+fn branch_tabs(s: &Session, uid: u64) -> impl Iterator<Item = &DocState> {
+    s.docs.iter().filter(move |t| t.branch_of.as_ref().is_some_and(|(main, _)| *main == uid))
+}
+
+/// The revisions a copy of `d` is of: its own and its branch tabs' (a branch tab's edits change
+/// only its own revision). A new copy is due when they change.
+fn stamp(s: &Session, d: &DocState) -> Vec<u64> {
+    std::iter::once(d.revision).chain(branch_tabs(s, d.uid).map(|t| t.revision)).collect()
+}
+
+/// Write `doc` with its version history and branches to `path` through a temporary file; false
+/// when it couldn't be written (the copy before it is still there).
+fn write_atomic(path: &Path, doc: &figcraft_engine::doc::Document, versions: &[Version], branches: &[Branch]) -> bool {
+    let Ok(bytes) = figcraft_format::save_bytes_with_history(doc, None, versions, branches) else { return false };
    let tmp = path.with_extension("tmp");
    std::fs::write(&tmp, bytes).is_ok() && std::fs::rename(&tmp, path).is_ok()
 }
@@ -222,9 +328,9 @@ pub fn recover(root: &Path, s: &mut Session) -> usize {
 }

 /// Open the copies left by runs that ended without closing (folders under `root` whose lock is
-/// free, and copies directly in `root` from older versions) as unsaved documents, then remove them.
-/// A copy that can't be read stays where it is. A copy of one of your online files is kept
-/// instead while its file is joined again ([`Recovered::waiting`]).
+/// free, and copies directly in `root` from older versions) as unsaved documents. Each is kept
+/// until this run has its own copy of the document ([`Recovered::waiting`]); a copy of one of your
+/// online files, while its file is joined again. A copy that can't be read stays where it is.
 pub fn recover_all(root: &Path, s: &mut Session) -> Recovered {
    let mut out = Recovered::default();
    let Ok(entries) = std::fs::read_dir(root) else { return out };
@@ -234,10 +340,15 @@ pub fn recover_all(root: &Path, s: &mut Session) -> Recovered {
        }
        // One of your online files comes back from its server, its copy kept until then.
        if let Some((session, lock)) = lock.and_then(|l| Some((rejoin_online(file, s)?, l))) {
-            out.waiting.push(Waiting { session, copy: file.to_path_buf(), _lock: lock.clone() });
-        } else if s.execute("file.recover", &json!({"path": file.to_string_lossy()})).is_ok() {
+            out.waiting.push(Waiting { until: Until::Session(session), copy: file.to_path_buf(), _lock: Some(lock.clone()) });
+            return;
+        }
+        let before: Vec<u64> = s.docs.iter().map(|d| d.uid).collect();
+        if s.execute("file.recover", &json!({"path": file.to_string_lossy()})).is_ok() {
            out.copies += 1;
-            let _ = std::fs::remove_file(file);
+            if let Some(uid) = s.docs.iter().map(|d| d.uid).find(|u| !before.contains(u)) {
+                out.waiting.push(Waiting { until: Until::Copied(uid), copy: file.to_path_buf(), _lock: lock.cloned() });
+            }
        }
    };
    for e in entries.flatten() {
@@ -265,7 +376,7 @@ pub fn recover_all(root: &Path, s: &mut Session) -> Recovered {
        for f in files.iter().filter(|f| f.extension().is_some_and(|e| e == ONLINE) && !f.with_extension("figcraft").exists()) {
            let _ = std::fs::remove_file(f);
        }
-        // Empty now unless a copy couldn't be read, or waits for its file (kept, its lock held).
+        // Empty now unless a copy couldn't be read, or is kept (its lock held).
        if Arc::strong_count(&lock) == 1 {
            drop(lock);
            let _ = std::fs::remove_file(path.join(LOCK));
@@ -223,6 +223,30 @@ fn a_copy_ahead_of_the_server_has_its_edits_applied_and_sent() {
    let _ = std::fs::remove_dir_all(&root);
 }

+#[test]
+fn an_online_copy_stays_while_what_it_became_cant_be_copied() {
+    let root = root("ahead-blocked");
+    let (mut s, script, mut server, _) = shared();
+    s.execute("shape.ellipse", &json!({"x": 30, "y": 0, "width": 10, "height": 10})).unwrap();
+    script.lock().unwrap().sent.clear();
+    let left = crash(&s, &root);
+    let (mut next, script, mut r, _) = restart(&s, &root);
+    arrive(&mut next, &script, &mut server);
+    assert!(next.docs[1].is_dirty(), "the copy's edit is on top, not saved anywhere yet");
+    // Something is in the way of this run's copy: writing it fails.
+    let mine = root.join(std::process::id().to_string()).join(format!("{}.figcraft", next.docs[1].uid));
+    std::fs::create_dir_all(&mine).unwrap();
+    r.tick(&next, 1.0);
+    assert_eq!((copies(&left, "figcraft"), copies(&left, "online")), (1, 1), "kept: the work is nowhere else on disk");
+    // Once it can be written, the old copy goes.
+    std::fs::remove_dir(&mine).unwrap();
+    next.execute("shape.rectangle", &json!({"x": 50, "y": 0, "width": 4, "height": 4})).unwrap();
+    r.tick(&next, 2.0);
+    assert!(!left.exists());
+    drop(r);
+    let _ = std::fs::remove_dir_all(&root);
+}
+
 #[test]
 fn a_copy_the_server_already_has_is_discarded() {
    let root = root("equal");
@@ -332,7 +356,7 @@ fn without_its_record_the_copy_opens_as_any_other() {
    assert_eq!(recover(&root, &mut next), 1);
    assert!(script.lock().unwrap().joined.is_empty());
    assert!(next.docs.first().is_some_and(|d| d.is_dirty() && d.path.is_none()));
-    assert!(std::fs::read_dir(&root).unwrap().next().is_none(), "the folder is gone");
+    assert!(std::fs::read_dir(&root).unwrap().next().is_some(), "the copy stays until a run has its own");
    let _ = std::fs::remove_dir_all(&root);
 }

@@ -4,7 +4,7 @@
 use figcraft_engine::Session;
 use serde_json::json;

-use crate::recovery::{Recovery, recover};
+use crate::recovery::{Recovery, recover, recover_all};

 fn root(name: &str) -> std::path::PathBuf {
    let r = std::env::temp_dir().join(format!("figcraft-recovery-{name}-{}", std::process::id()));
@@ -34,7 +34,7 @@ fn a_crashed_runs_unsaved_documents_come_back() {
    let ds = next.docs.first().unwrap();
    assert!(ds.is_dirty() && ds.path.is_none());
    assert_eq!(next.doc().unwrap().node(next.doc().unwrap().pages[0]).map(|p| p.children.len()), Some(1));
-    assert!(std::fs::read_dir(&root).unwrap().next().is_none(), "the folder is gone");
+    assert!(std::fs::read_dir(&root).unwrap().next().is_some(), "the copy stays until a run has its own");
    let _ = std::fs::remove_dir_all(&root);
 }

@@ -62,3 +62,289 @@ fn copies_follow_saves_and_a_normal_quit_leaves_nothing() {
    assert!(!dir.exists(), "a normal quit removes the copies");
    let _ = std::fs::remove_dir_all(&root);
 }
+
+/// A run that ended without closing, leaving a copy of `s`'s unsaved document: its folder (as
+/// another process's).
+fn crashed(s: &Session, root: &std::path::Path) -> std::path::PathBuf {
+    let mut r = Recovery::start(root).unwrap();
+    r.write(s, true);
+    drop(r);
+    let left = root.join("crashed");
+    std::fs::rename(root.join(std::process::id().to_string()), &left).unwrap();
+    left
+}
+
+fn copies_in(d: &std::path::Path) -> usize {
+    std::fs::read_dir(d).map_or(0, |d| d.flatten().filter(|f| f.path().extension().is_some_and(|e| e == "figcraft")).count())
+}
+
+/// The next start: the copies come back, and this run's recovery keeps them until it covers them.
+fn restart(root: &std::path::Path) -> (Session, Recovery) {
+    let mut next = Session::empty();
+    let recovered = recover_all(root, &mut next);
+    assert_eq!(recovered.copies, 1);
+    let mut r = Recovery::start(root).unwrap();
+    r.adopt(recovered.waiting);
+    (next, r)
+}
+
+#[test]
+fn a_recovered_copy_stays_until_this_run_has_its_own_copy() {
+    let root = root("handoff");
+    let left = crashed(&edited(), &root);
+    let (next, mut r) = restart(&root);
+    assert_eq!(copies_in(&left), 1, "the only copy on disk until this run writes one");
+    r.write(&next, true);
+    r.tick(&next, 100.0);
+    assert!(!left.exists(), "covered by this run's copy, the old one goes");
+    assert_eq!(copies_in(&root.join(std::process::id().to_string())), 1);
+    r.finish();
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn a_recovered_copy_stays_while_its_replacement_cant_be_written() {
+    let root = root("blocked");
+    let left = crashed(&edited(), &root);
+    let (next, mut r) = restart(&root);
+    // Something is in the way of this run's copy: writing it fails.
+    let mine = root.join(std::process::id().to_string()).join(format!("{}.figcraft", next.docs[0].uid));
+    std::fs::create_dir_all(&mine).unwrap();
+    r.write(&next, true);
+    r.tick(&next, 100.0);
+    assert_eq!(copies_in(&left), 1, "kept: the work is nowhere else on disk");
+    // Once it can be written, the old copy goes.
+    std::fs::remove_dir(&mine).unwrap();
+    let mut next = next;
+    next.execute("shape.rectangle", &json!({"x": 1, "y": 1, "width": 2, "height": 2})).unwrap();
+    r.write(&next, true);
+    r.tick(&next, 200.0);
+    assert!(!left.exists());
+    r.finish();
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn without_a_recovery_of_its_own_the_copy_stays_for_the_next_start() {
+    let root = root("nocopies");
+    crashed(&edited(), &root);
+    let mut next = Session::empty();
+    let recovered = recover_all(&root, &mut next);
+    assert_eq!(recovered.copies, 1);
+    // This run couldn't take a folder of its own: it ends (or crashes) with nothing copied.
+    drop(recovered);
+    let mut after = Session::empty();
+    assert_eq!(recover(&root, &mut after), 1, "the work comes back again");
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn a_recovered_copy_goes_once_its_document_is_saved_or_closed() {
+    for close in [false, true] {
+        let root = root(if close { "closed" } else { "saved" });
+        let left = crashed(&edited(), &root);
+        let (mut next, mut r) = restart(&root);
+        if close {
+            next.docs.clear();
+        } else {
+            next.ds_mut().unwrap().mark_saved();
+        }
+        r.tick(&next, 0.0);
+        assert!(!left.exists(), "close {close}");
+        r.finish();
+        let _ = std::fs::remove_dir_all(&root);
+    }
+}
+
+#[test]
+fn a_normal_quit_removes_the_recovered_copies_it_took_over() {
+    let root = root("quitafter");
+    let left = crashed(&edited(), &root);
+    let (_, r) = restart(&root);
+    // Quitting asked to save or discard every document.
+    r.finish();
+    assert!(!left.exists());
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn a_run_whose_folder_name_is_still_held_takes_another() {
+    let root = root("pidreuse");
+    // A crashed run with this process's id whose folder the start still holds (its copy waits).
+    let held = root.join(std::process::id().to_string());
+    std::fs::create_dir_all(&held).unwrap();
+    let lock = std::fs::File::create(held.join("lock")).unwrap();
+    lock.try_lock().unwrap();
+    let mut r = Recovery::start(&root).expect("a folder of its own");
+    let s = edited();
+    r.write(&s, true);
+    assert_eq!(copies_in(&held), 0);
+    let dirs = std::fs::read_dir(&root).unwrap().flatten().filter(|e| e.path() != held).count();
+    assert_eq!(dirs, 1);
+    r.finish();
+    drop(lock);
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+/// The rectangles in `doc`.
+fn rectangles(doc: &figcraft_engine::doc::Document) -> usize {
+    doc.nodes().filter(|n| matches!(n.kind, figcraft_engine::doc::NodeKind::Rectangle)).count()
+}
+
+/// The documents a crashed run's copies under `root` open as.
+fn crash_and_recover(r: Recovery, root: &std::path::Path) -> Session {
+    drop(r);
+    let mut next = Session::empty();
+    assert_eq!(recover(root, &mut next), 1);
+    next
+}
+
+#[test]
+fn copies_keep_the_version_history_and_branches() {
+    // #185: a copy has what a save would write, the latest edits on a branch tab included.
+    let root = root("history");
+    let mut s = edited();
+    s.execute("file.saveVersion", &json!({"name": "v1"})).unwrap();
+    s.execute("branch.create", &json!({"name": "Explore"})).unwrap();
+    s.execute("shape.rectangle", &json!({"x": 20, "y": 0, "width": 10, "height": 10})).unwrap();
+    let mut r = Recovery::start(&root).unwrap();
+    r.write(&s, true);
+    let next = crash_and_recover(r, &root);
+    let ds = next.docs.first().unwrap();
+    assert_eq!(ds.versions.iter().map(|v| v.name.as_str()).collect::<Vec<_>>(), ["v1"]);
+    assert_eq!(ds.branches.iter().map(|b| (b.name.as_str(), rectangles(&b.head))).collect::<Vec<_>>(), [("Explore", 2)]);
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+/// The one copy under `root` (the run's folder), read back.
+fn copy(root: &std::path::Path) -> figcraft_format::Loaded {
+    let dir = std::fs::read_dir(root).unwrap().flatten().next().unwrap().path();
+    let file = std::fs::read_dir(dir).unwrap().flatten().map(|f| f.path()).find(|f| f.extension().is_some_and(|e| e == "figcraft")).unwrap();
+    figcraft_format::load_bytes_with_versions(&std::fs::read(file).unwrap()).unwrap()
+}
+
+#[test]
+fn a_change_only_on_a_branch_tab_or_to_the_history_is_copied() {
+    let root = root("history-only");
+    let mut s = edited();
+    s.execute("file.saveVersion", &json!({"name": "v1"})).unwrap();
+    s.execute("branch.create", &json!({"name": "Explore"})).unwrap();
+    for d in &mut s.docs {
+        d.mark_saved();
+    }
+    let mut r = Recovery::start(&root).unwrap();
+    // An edit on the branch tab only: the main file has no changes of its own yet.
+    s.execute("shape.rectangle", &json!({"x": 20, "y": 0, "width": 10, "height": 10})).unwrap();
+    r.write(&s, true);
+    assert_eq!(copy(&root).branches.iter().map(|b| rectangles(&b.head)).collect::<Vec<_>>(), [2]);
+    s.execute("shape.rectangle", &json!({"x": 40, "y": 0, "width": 10, "height": 10})).unwrap();
+    r.write(&s, true);
+    assert_eq!(copy(&root).branches.iter().map(|b| rectangles(&b.head)).collect::<Vec<_>>(), [3]);
+    // A version renamed on the main file leaves its document as it was.
+    s.execute("doc.switch", &json!({"index": 0})).unwrap();
+    r.write(&s, true);
+    let id = s.docs[0].versions[0].id.clone();
+    s.execute("version.rename", &json!({"id": id, "name": "v1 (renamed)"})).unwrap();
+    r.write(&s, true);
+    assert_eq!(copy(&root).versions.iter().map(|v| v.name.as_str()).collect::<Vec<_>>(), ["v1 (renamed)"]);
+    r.finish();
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+fn slow_write(path: std::path::PathBuf) -> std::thread::JoinHandle<bool> {
+    std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(150));
+        std::fs::write(path, b"stale").is_ok()
+    })
+}
+
+#[test]
+fn saving_or_closing_waits_for_a_slow_write_so_the_copy_does_not_come_back() {
+    let root = root("slow-cleanup");
+    let mut s = edited();
+    let mut r = Recovery::start(&root).unwrap();
+    let dir = std::fs::read_dir(&root).unwrap().flatten().next().unwrap().path();
+    let uid = s.docs[0].uid;
+    let copy = dir.join(format!("{uid}.figcraft"));
+    r.hold(uid, 1, slow_write(copy.clone()));
+    s.ds_mut().unwrap().mark_saved();
+    r.write(&s, false);
+    std::thread::sleep(std::time::Duration::from_millis(400));
+    assert!(!copy.exists(), "a saved document's copy stays removed");
+    // Closed: the same.
+    let s = edited();
+    let uid = s.docs[0].uid;
+    let copy = dir.join(format!("{uid}.figcraft"));
+    r.hold(uid, 1, slow_write(copy.clone()));
+    r.write(&Session::empty(), false);
+    std::thread::sleep(std::time::Duration::from_millis(400));
+    assert!(!copy.exists(), "a closed document's copy stays removed");
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn an_emergency_save_waits_for_the_write_in_flight_and_copies_the_newest_revision() {
+    let root = root("slow-emergency");
+    let s = edited();
+    let mut r = Recovery::start(&root).unwrap();
+    let dir = std::fs::read_dir(&root).unwrap().flatten().next().unwrap().path();
+    let uid = s.docs[0].uid;
+    let copy = dir.join(format!("{uid}.figcraft"));
+    r.hold(uid, 0, slow_write(copy.clone()));
+    r.write(&s, true);
+    assert!(std::fs::read(&copy).is_ok_and(|b| b != b"stale"), "the newest revision replaced the slow write");
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+/// The files named `*.figcraft` in the run folder under `root`.
+fn copy_count(root: &std::path::Path) -> usize {
+    let Some(dir) = std::fs::read_dir(root).unwrap().flatten().next().map(|e| e.path()) else { return 0 };
+    std::fs::read_dir(dir).unwrap().flatten().filter(|f| f.path().extension().is_some_and(|e| e == "figcraft")).count()
+}
+
+/// A folder at the path of `s`'s first document's copy in the run folder under `root`.
+fn blocked_copy(root: &std::path::Path, s: &Session) -> std::path::PathBuf {
+    let dir = std::fs::read_dir(root).unwrap().flatten().next().unwrap().path();
+    let blocker = dir.join(format!("{}.figcraft", s.docs[0].uid));
+    std::fs::create_dir(&blocker).unwrap();
+    blocker
+}
+
+#[test]
+fn a_copy_that_failed_is_tried_again_without_another_edit() {
+    let root = root("retry");
+    let s = edited();
+    let mut r = Recovery::start(&root).unwrap();
+    // A folder where the copy goes makes its write fail on every platform (renaming the run folder
+    // away fails on Windows, where the run's lock file keeps it open).
+    let blocker = blocked_copy(&root, &s);
+    r.write(&s, true);
+    std::fs::remove_dir(&blocker).unwrap();
+    // Nothing was edited since: the same revision still has to be copied.
+    r.write(&s, true);
+    assert_eq!(copy_count(&root), 1, "the failed revision was copied again");
+    r.finish();
+    let _ = std::fs::remove_dir_all(&root);
+}
+
+#[test]
+fn a_background_copy_that_failed_is_tried_again_without_another_edit() {
+    let root = root("retry-bg");
+    let s = edited();
+    let mut r = Recovery::start(&root).unwrap();
+    let blocker = blocked_copy(&root, &s);
+    r.write(&s, false);
+    // Let the failing write end before the way is clear again.
+    std::thread::sleep(std::time::Duration::from_millis(300));
+    std::fs::remove_dir(&blocker).unwrap();
+    for _ in 0..50 {
+        r.write(&s, false);
+        if copy_count(&root) == 1 {
+            break;
+        }
+        std::thread::sleep(std::time::Duration::from_millis(100));
+    }
+    assert_eq!(copy_count(&root), 1, "the failed revision was copied again");
+    r.finish();
+    let _ = std::fs::remove_dir_all(&root);
+}
@@ -1,11 +1,12 @@
 //! Desktop services: native file dialogs, clipboard, URLs, persisted preferences.

+use std::cell::RefCell;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};

 use figcraft_engine::{Prefs, Session};
-use figcraft_ui_egui::{FigApp, Services};
+use figcraft_ui_egui::{DialogFuture, FigApp, Services};
 use serde_json::{Value, json};

 pub struct Desktop {
@@ -59,12 +60,16 @@ impl Desktop {

 /// The system's preferred interface languages, most preferred first, comma-separated
 /// ("nl-NL,de-DE,en-US"): Windows' language list, macOS's AppleLanguages, `LANGUAGE` and the
-/// locale variables elsewhere. The UI shows the first one it has a catalog for.
+/// locale variables elsewhere. The UI shows the first language in the list that has a catalog.
+/// Windows keeps only its first preferred language (and English when it has no catalog): that
+/// list is also the input-language list, so a language added for a keyboard (Deutsch on a Polish
+/// system) must not decide the interface language.
 fn system_language() -> Option<String> {
    #[cfg(target_os = "windows")]
    {
        windows::System::UserProfile::GlobalizationPreferences::Languages()
-            .map(|l| l.into_iter().map(|s| s.to_string()).collect::<Vec<_>>().join(","))
+            .and_then(|l| l.GetAt(0))
+            .map(|s| s.to_string())
            .inspect_err(|e| log::info!("language: can't read the system languages: {e}"))
            .ok()
    }
@@ -131,6 +136,34 @@ fn command_says(program: &str, args: &[&str], want: &str) -> bool {
        .is_some_and(|o| String::from_utf8_lossy(&o.stdout).trim() == want)
 }

+/// Show `path` in the file manager: selected in Finder and Explorer, its folder elsewhere.
+fn reveal(path: &Path) -> std::io::Result<()> {
+    #[cfg(target_os = "macos")]
+    let mut command = {
+        let mut c = std::process::Command::new("open");
+        c.arg("-R").arg(path);
+        c
+    };
+    #[cfg(windows)]
+    let mut command = {
+        let mut arg = std::ffi::OsString::from("/select,");
+        arg.push(path);
+        let mut c = std::process::Command::new("explorer");
+        c.arg(arg);
+        c
+    };
+    #[cfg(not(any(target_os = "macos", windows)))]
+    let mut command = {
+        let mut c = std::process::Command::new("xdg-open");
+        c.arg(path.parent().unwrap_or(path));
+        c
+    };
+    // The file manager keeps running; reap it off this thread so it leaves no zombie.
+    let mut child = command.spawn()?;
+    let _ = std::thread::Builder::new().name("figcraft-reveal".into()).spawn(move || child.wait());
+    Ok(())
+}
+
 /// The preferences' file in the config folder.
 const STATE: &str = "state.json";

@@ -166,15 +199,39 @@ fn write_private(path: &Path, bytes: &[u8]) -> std::io::Result<()> {
    f.write_all(bytes)
 }

+thread_local! {
+    /// While the main window draws: a dialog parented to it, so a dialog opened from it stays in
+    /// front of it (a sheet on macOS). eframe gives other windows no handle: theirs have no parent.
+    static PARENT: RefCell<Option<rfd::AsyncFileDialog>> = const { RefCell::new(None) };
+}
+
+/// Run the main window's frame `f` with the dialogs it opens parented to `frame`'s window.
+pub fn parented<R>(frame: &eframe::Frame, f: impl FnOnce() -> R) -> R {
+    PARENT.with(|p| p.replace(Some(rfd::AsyncFileDialog::new().set_parent(frame))));
+    let r = f();
+    PARENT.with(|p| p.replace(None));
+    r
+}
+
+/// A dialog with `title`, parented to the main window while it draws.
+fn dialog(title: &str) -> rfd::AsyncFileDialog {
+    PARENT.with(|p| p.borrow().clone()).unwrap_or_default().set_title(title)
+}
+
+/// The dialog opens now; its future gives the path picked.
+fn picked(pick: impl Future<Output = Option<rfd::FileHandle>> + 'static) -> DialogFuture {
+    Box::pin(async move { pick.await.map(|f| f.path().to_path_buf()) })
+}
+
 impl Services for Desktop {
-    fn pick_open(&mut self, title: &str, exts: &[&str]) -> Option<PathBuf> {
-        rfd::FileDialog::new().set_title(title).add_filter("Supported files", exts).pick_file()
+    fn pick_open(&mut self, title: &str, exts: &[&str]) -> DialogFuture {
+        picked(dialog(title).add_filter("Supported files", exts).pick_file())
    }
-    fn pick_save(&mut self, title: &str, name: &str, exts: &[&str]) -> Option<PathBuf> {
-        rfd::FileDialog::new().set_title(title).set_file_name(name).add_filter("File", exts).save_file()
+    fn pick_save(&mut self, title: &str, name: &str, exts: &[&str]) -> DialogFuture {
+        picked(dialog(title).set_file_name(name).add_filter("File", exts).save_file())
    }
-    fn pick_folder(&mut self, title: &str) -> Option<PathBuf> {
-        rfd::FileDialog::new().set_title(title).pick_folder()
+    fn pick_folder(&mut self, title: &str) -> DialogFuture {
+        picked(dialog(title).pick_folder())
    }
    fn clipboard_set_text(&mut self, s: &str) {
        if let Some(c) = self.clipboard.as_mut() {
@@ -201,6 +258,11 @@ impl Services for Desktop {
    fn open_url(&mut self, url: &str) {
        let _ = webbrowser::open(url);
    }
+    fn reveal_path(&mut self, path: &Path) {
+        if let Err(e) = reveal(path) {
+            log::warn!("show in folder: {}: {e}", path.display());
+        }
+    }
    fn save_prefs(&mut self, prefs: &Prefs) {
        if let Some(dir) = &self.dir {
            write_prefs(dir, prefs);
@@ -209,6 +271,8 @@ impl Services for Desktop {
    fn emergency_save(&mut self, session: &Session) {
        if let Some(r) = crate::recovery::lock(&self.recovery).as_mut() {
            r.write(session, true);
+            // Earlier runs' copies now covered go, so the next start doesn't open them twice.
+            r.settle(session);
        }
    }
    fn reduce_motion(&self) -> bool {
@@ -0,0 +1,27 @@
+//! When the window can't open.
+//!
+//! Release builds on Windows have no console, so an error from `eframe::run_native` (no usable
+//! graphics adapter, a surface or device the driver refuses) went to a standard error nobody sees
+//! and the app quit without a word (#261). Now it is logged and shown in a message box.
+
+/// Log the failure and, unless `quiet` (started for an agent with `--control`: a modal box would
+/// keep the caller waiting, and it reads standard error), show it in a message box.
+pub fn failed(error: &eframe::Error, quiet: bool) {
+    // In the interface language: the text and its catalog entries are the UI crate's.
+    let text = figcraft_ui_egui::dialogs::window_failed(&error.to_string(), std::env::var_os("WGPU_BACKEND").is_some());
+    // Standard error even when RUST_LOG turned errors off.
+    if log::log_enabled!(log::Level::Error) {
+        log::error!("{text}");
+    } else {
+        eprintln!("figcraft: {text}");
+    }
+    if quiet {
+        return;
+    }
+    let _ = rfd::MessageDialog::new()
+        .set_level(rfd::MessageLevel::Error)
+        .set_title("FigCraft")
+        .set_description(text)
+        .set_buttons(rfd::MessageButtons::Ok)
+        .show();
+}
@@ -0,0 +1,35 @@
+//! The message shown when the window can't open: it carries the error, a next step and where to
+//! report it, instead of the app quitting silently (#261).
+
+use figcraft_ui_egui::dialogs::window_failed as message;
+
+const ERROR: &str = "WGPU error: Failed to create surface for any enabled backend: {}";
+
+#[test]
+fn the_message_carries_the_error_and_where_to_report_it() {
+    let text = message(ERROR, false);
+    assert!(text.contains(ERROR), "the error itself: {text}");
+    assert!(text.contains("https://github.com/storytold/figcraft/issues"), "where to report it: {text}");
+}
+
+#[test]
+fn without_wgpu_backend_it_suggests_the_driver_and_another_graphics_api() {
+    let text = message(ERROR, false);
+    assert!(text.contains("graphics driver"), "{text}");
+    assert!(text.contains("WGPU_BACKEND"), "another graphics API to try: {text}");
+    assert!(!text.contains("unsetting"), "{text}");
+}
+
+#[cfg(windows)]
+#[test]
+fn on_windows_it_shows_how_to_start_with_opengl() {
+    let text = message(ERROR, false);
+    assert!(text.contains("set WGPU_BACKEND=gl"), "a release build has no console to look this up from: {text}");
+}
+
+#[test]
+fn with_wgpu_backend_set_it_suggests_unsetting_it() {
+    let text = message(ERROR, true);
+    assert!(text.contains("unsetting"), "{text}");
+    assert!(!text.contains("graphics driver"), "the chosen backend is the likelier cause: {text}");
+}
@@ -16,3 +16,26 @@
 #
 # To remove your names, delete your entry (or set fields empty) in a PR. The next
 # contributors.py run, and the next build, drop them.
+
+[people.VanTan666]
+display_name = "VanTan"
+
+[people.tylerjenningsw]
+real_name = "Tyler Jennings"
+display_name = "tylerjenningsw"
+
+[people.Silvertree2010]
+display_name = "Netter"
+sync_github_name = false
+
+[people.yyamandevrim]
+real_name = "Yaman Devrim"
+sync_github_name = true
+
+[people.justinjohn0306]
+real_name = "Justin John"
+
+[people.Losminek]
+
+[people.RevDonz]
+sync_github_name = true
@@ -0,0 +1,53 @@
+//! Addresses removed from a file are kept only while its session lasts, so a long-running server
+//! doesn't collect them for every file it ever had open.
+
+use std::collections::HashMap;
+use std::net::{IpAddr, Ipv4Addr};
+
+use figcraft_collab::{Limits, Server};
+use figcraft_doc::Document;
+
+use super::{Admission, Backend, Closing, Hub, InFlight, Room};
+
+/// A backend that closes a file as soon as everyone left it.
+struct Closes;
+
+impl Backend for Closes {
+    fn admit(&mut self, _file: &str, _token: &str) -> Result<Admission, String> {
+        Err("no".into())
+    }
+
+    fn open(&mut self, _file: &str) -> Result<Server, String> {
+        Err("no".into())
+    }
+
+    fn idle(&mut self, _file: &str, _server: &mut Server) -> bool {
+        true
+    }
+
+    fn closing(&self) -> Closing {
+        Closing::Restarting
+    }
+}
+
+#[test]
+fn a_closed_file_forgets_whom_it_barred() {
+    let mut doc = Document::new("File");
+    doc.repair();
+    let mut hub = Hub {
+        in_flight: InFlight(Default::default()),
+        backend: Closes,
+        rooms: HashMap::from([("f".to_string(), Room::new(Server::new(doc, "", Limits::default())))]),
+        conns: HashMap::new(),
+        local: None,
+        outbox: Vec::new(),
+        barred: HashMap::new(),
+    };
+    let ip = IpAddr::V4(Ipv4Addr::new(10, 0, 0, 7));
+    hub.barred.entry("f".into()).or_default().insert(ip);
+    hub.barred.entry("other".into()).or_default().insert(ip);
+    hub.close_if_empty("f");
+    assert!(!hub.rooms.contains_key("f"), "everyone left: the file closed");
+    assert!(!hub.barred.contains_key("f"), "and its barred addresses went with it");
+    assert!(hub.barred.contains_key("other"), "another file's stay");
+}
@@ -11,6 +11,7 @@ use figcraft_collab::{Outgoing, Server, same_secret};
 use figcraft_doc::Document;
 use figcraft_engine::live::{Event, PEOPLE};

+pub use crate::hub::REMOVED;
 use crate::hub::{Admission, Backend, Closing, Hosting, Local, clean_name, to_local};
 use crate::inbox::Inbox;
 pub use crate::join::ENDED;
@@ -129,6 +130,12 @@ impl Host {
        self.hosting.send(msg);
    }

+    /// Remove client `id` from the session: they are disconnected and can't join again from
+    /// their address while it runs. The host can't remove themselves.
+    pub fn remove(&self, id: u32) {
+        self.hosting.remove(id);
+    }
+
    /// Cut every connection as a network failure would (no close frame).
    #[cfg(test)]
    pub(crate) fn cut_connections(&self) {
@@ -21,7 +21,7 @@
 //! backend may refuse addresses or limit what they do. A plain `GET /healthz` on the same port is
 //! answered `200 ok` for uptime checks.

-use std::collections::{BTreeMap, HashMap};
+use std::collections::{BTreeMap, HashMap, HashSet};
 use std::io::{self, Read, Write};
 use std::net::{IpAddr, Ipv6Addr, SocketAddr, TcpListener, TcpStream};
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
@@ -413,6 +413,8 @@ enum HubIn {
    },
    Local(Presence),
    LocalMsg(ClientMsg),
+    /// The person hosting removes client `id` from their file (app sessions).
+    Remove(u32),
    /// Cut every connection without a word (tests: a network failure).
    #[cfg(test)]
    Cut,
@@ -461,7 +463,15 @@ impl Hosting {
    pub(crate) fn start<B: Backend>(listener: TcpListener, backend: B, limits: NetLimits, local: Option<Local>) -> io::Result<Hosting> {
        let addr = listener.local_addr()?;
        let in_flight = InFlight(Arc::default());
-        let mut hub = Hub { backend, rooms: HashMap::new(), conns: HashMap::new(), local: None, outbox: Vec::new(), in_flight: in_flight.clone() };
+        let mut hub = Hub {
+            backend,
+            rooms: HashMap::new(),
+            conns: HashMap::new(),
+            local: None,
+            outbox: Vec::new(),
+            in_flight: in_flight.clone(),
+            barred: HashMap::new(),
+        };
        if let Some(l) = local {
            let mut room = Room::new(l.server);
            room.local = Some((l.id, l.inbox));
@@ -551,6 +561,12 @@ impl Hosting {
        let _ = self.hub.send(HubIn::LocalMsg(msg));
    }

+    /// The hosting person removes client `id` from their file (app sessions; see
+    /// [`HubIn::Remove`]).
+    pub(crate) fn remove(&self, id: u32) {
+        let _ = self.hub.send(HubIn::Remove(id));
+    }
+
    /// Cut every connection as a network failure would (no close frame).
    #[cfg(test)]
    pub(crate) fn cut_connections(&self) {
@@ -1108,6 +1124,16 @@ fn unsupported(protocol: u32) -> String {
 /// sharing): the session's end for them.
 pub const STOPPED: &str = "Sharing was stopped: the link you joined with no longer works. Your copy stays open";

+/// What someone removed from a file is told: the session's end for them (they keep their copy;
+/// nothing retries).
+pub const REMOVED: &str = "You were removed from this session. Your copy stays open";
+
+/// Why a removed person's address can't join the file again.
+const BARRED: &str = "you were removed from this session";
+
+/// The most addresses one file keeps barred.
+const MAX_BARRED: usize = 256;
+
 /// What everyone in a file is told when its changes couldn't be saved (they reconnect).
 const UNSAVED: &str = "The server couldn't save the latest changes; reconnecting";

@@ -1121,6 +1147,9 @@ struct Hub<B> {
    local: Option<String>,
    /// What the servers said, sent once the backend made what changed durable.
    outbox: Vec<(String, Outgoing)>,
+    /// Addresses ([`ip_key`]) removed from each open file: they can't join it again until its
+    /// session closes (the file is closed or removed; the entry goes with it).
+    barred: HashMap<String, HashSet<IpAddr>>,
 }

 impl<B: Backend> Hub<B> {
@@ -1208,6 +1237,13 @@ impl<B: Backend> Hub<B> {
                    self.client_message(&file, id, msg, None);
                }
            }
+            HubIn::Remove(id) => {
+                if let Some(file) = self.local.clone()
+                    && let Err(why) = self.remove_peer(&file, id)
+                {
+                    log::info!("live session: couldn't remove client {id}: {why}");
+                }
+            }
            #[cfg(test)]
            HubIn::Cut => {
                for c in self.conns.values() {
@@ -1232,6 +1268,14 @@ impl<B: Backend> Hub<B> {
                self.client_message(&file, id, msg, Some(bytes));
            }
            Some(Kind::Hosting { owns }) => match msg {
+                ClientMsg::Admin(Admin::RemovePeer { file, client }) => {
+                    let reply = if owns.as_deref() == Some(file.as_str()) {
+                        self.removed_reply(&file, client)
+                    } else {
+                        AdminReply::Failed { reason: "an owner token manages only its own file".into() }
+                    };
+                    self.answer(conn, &ServerMsg::Admin(Box::new(reply)));
+                }
                ClientMsg::Admin(req) => {
                    let owns = owns.clone();
                    let rooms = &self.rooms;
@@ -1243,6 +1287,10 @@ impl<B: Backend> Hub<B> {
                _ => self.kick(&[conn], "only publishing and managing your own files are spoken on this connection"),
            },
            Some(Kind::Managing) => match msg {
+                ClientMsg::Admin(Admin::RemovePeer { file, client }) => {
+                    let reply = self.removed_reply(&file, client);
+                    self.answer(conn, &ServerMsg::Admin(Box::new(reply)));
+                }
                ClientMsg::Admin(req) => self.admin(conn, req),
                ClientMsg::Ping => self.answer(conn, &ServerMsg::Pong),
                _ => self.kick(&[conn], "only requests to manage files are spoken on this connection"),
@@ -1305,6 +1353,10 @@ impl<B: Backend> Hub<B> {
            Ok(a) => a,
            Err(why) => return refuse(&c.out, &why),
        };
+        if self.barred.get(&hello.file).is_some_and(|b| b.contains(&c.ip)) {
+            log::info!("event=refused ip={} reason=removed", c.ip);
+            return refuse(&c.out, BARRED);
+        }
        let hosting = reads_hosting(&hello.client_version);
        // The backend checked the secret: the sessions don't keep it.
        hello.token.clear();
@@ -1362,6 +1414,34 @@ impl<B: Backend> Hub<B> {
        }
    }

+    /// Remove client `id` from `file`: they are told the session is over for them and
+    /// disconnected, and their address can't join the file again while its session lasts. The
+    /// person hosting can't be removed.
+    fn remove_peer(&mut self, file: &str, id: u32) -> Result<(), String> {
+        let room = self.rooms.get(file).ok_or("nobody is in this file")?;
+        if room.local.as_ref().is_some_and(|(local, _)| *local == id) {
+            return Err("the person hosting can't be removed".into());
+        }
+        let conn = *room.ids.get(&id).ok_or_else(|| format!("nobody with client id {id} is in this file"))?;
+        let c = self.conns.get(&conn).ok_or_else(|| format!("nobody with client id {id} is in this file"))?;
+        let barred = self.barred.entry(file.to_string()).or_default();
+        if barred.len() < MAX_BARRED {
+            barred.insert(c.ip);
+        }
+        log::info!("event=removed file={file} client={id} ip={}", c.ip);
+        let _ = c.out.tx.try_send(Out::Close(CloseCode::Away, REMOVED.into()));
+        self.gone(conn);
+        Ok(())
+    }
+
+    /// [`remove_peer`](Self::remove_peer) as a managing connection's answer.
+    fn removed_reply(&mut self, file: &str, id: u32) -> AdminReply {
+        match self.remove_peer(file, id) {
+            Ok(()) => AdminReply::Done,
+            Err(reason) => AdminReply::Failed { reason },
+        }
+    }
+
    /// Take in connection `c` as `kind` and send it `first`.
    fn take_in(&mut self, conn: u64, c: Pending, kind: Kind, first: &ServerMsg) {
        self.conns.insert(conn, Conn { out: c.out, sock: c.sock, kind, ip: c.ip });
@@ -1479,6 +1559,7 @@ impl<B: Backend> Hub<B> {
                .collect();
            // Closed without saving: the file is gone.
            self.rooms.remove(&file);
+            self.barred.remove(&file);
            self.kick(&users, "this file was removed from the server");
        }
        if let Some(ip) = handled.blocked {
@@ -1556,6 +1637,7 @@ impl<B: Backend> Hub<B> {
        let Some(room) = self.rooms.get_mut(file).filter(|r| r.empty()) else { return };
        if self.backend.idle(file, &mut room.server) {
            self.rooms.remove(file);
+            self.barred.remove(file);
        }
    }

@@ -1661,3 +1743,7 @@ pub(crate) fn to_local(inbox: &Inbox, local: u32, msg: &ServerMsg) {
 #[cfg(test)]
 #[path = "queue_tests.rs"]
 mod queue_tests;
+
+#[cfg(test)]
+#[path = "barred_tests.rs"]
+mod barred_tests;
@@ -243,6 +243,18 @@ impl LiveLink for NetLink {
        }
    }

+    fn remove(&mut self, session: SessionId, client: u32) -> Result<(), String> {
+        match self.sessions.get(session) {
+            Some(Active::Host(h)) if h.me().client_id == client => Err("you can't remove yourself: stop the session instead".into()),
+            Some(Active::Host(h)) => {
+                h.remove(client);
+                Ok(())
+            }
+            Some(Active::Guest(_)) => Err("only the person hosting can remove people from this session".into()),
+            None => Err("this session is over".into()),
+        }
+    }
+
    fn leave(&mut self, session: SessionId) {
        if let Some(active) = self.sessions.remove(session) {
            active.end();
@@ -15,7 +15,7 @@ use tungstenite::protocol::WebSocket;
 use tungstenite::{Bytes, Message};

 use crate::guest::{Guest, GuestConfig};
-use crate::host::{ENDED, Host, HostConfig};
+use crate::host::{ENDED, Host, HostConfig, REMOVED};
 use crate::inbox::Inbox;
 use crate::invite::Invite;
 use crate::net::{Bucket, NetLimits};
@@ -611,3 +611,34 @@ fn until_presence_or_pong(r: &mut Raw) -> Option<ServerMsg> {
        }
    }
 }
+
+#[test]
+fn the_host_removes_someone_and_they_cant_come_back() {
+    let (mut host, mut hp, invite) = start();
+    let (_a, mut ap) = join(&invite, "Ada");
+    let (b, mut bp) = join(&invite, "Bo");
+    ap.wait("welcome", welcomed);
+    bp.wait("welcome", welcomed);
+    let (ada, bo) = (ap.me(), bp.me());
+    connections_settle(&host, 2);
+    // The host can't remove themselves, nor someone who isn't there: nothing happens.
+    host.remove(host.me().client_id);
+    host.remove(9999);
+    host.remove(ada);
+    // Ada is told the session is over for her (no reconnecting); the others see her leave.
+    ap.wait("Ada removed", |e| e.iter().any(|e| matches!(e, Event::Ended { reason } if reason == REMOVED)));
+    hp.wait("the host sees Ada leave", |e| e.iter().any(|e| matches!(e, Event::PeerLeft(id) if *id == ada)));
+    bp.wait("Bo sees Ada leave", |e| e.iter().any(|e| matches!(e, Event::PeerLeft(id) if *id == ada)));
+    connections_settle(&host, 1);
+    assert!(!ap.events.iter().any(|e| matches!(e, Event::Status(Status::Reconnecting { .. }))), "a removed guest doesn't reconnect");
+    assert!(!hp.left().contains(&bo), "only Ada was removed");
+    // Her address can't join again with the same invite (every guest here comes from 127.0.0.1).
+    let (_again, mut againp) = join(&invite, "Ada");
+    againp.wait("a refusal", |e| e.iter().any(|e| matches!(e, Event::Status(Status::Failed { reason }) if reason.contains("removed"))));
+    assert!(!welcomed(&againp.events));
+    // Bo, already in, stays and can still talk to the host.
+    b.presence(presence(3.0, 4.0));
+    hp.wait("Bo's cursor", |e| e.iter().any(|e| matches!(e, Event::Presence(id, _) if *id == bo)));
+    host.stop();
+    assert_eq!(host.connections(), 0);
+}
@@ -307,7 +307,8 @@ impl Client {
    /// Queue `changes` as a new batch (already shown in the view).
    fn queue(&mut self, changes: Vec<Change>, kind: BatchKind, step: Option<u64>) {
        let batch_id = self.next_batch;
-        self.next_batch += 1;
+        // `next_batch` starts from the welcome's `last_batch`, the host's word: saturate.
+        self.next_batch = self.next_batch.saturating_add(1);
        self.pending.push_back(Pending { batch_id, base_seq: self.seq, changes, kind, step, rebased: false, sent: false });
    }

@@ -484,7 +485,11 @@ impl Client {

    /// A batch the server accepted (in order). Follow-ups it causes are queued.
    fn accepted(&mut self, acc: Accepted, recompute: &dyn Recompute) -> Result<(), Error> {
-        if acc.seq != self.seq + 1 {
+        // The host's sequence number is untrusted: at `u64::MAX` it can't step past it.
+        let Some(next) = self.seq.checked_add(1) else {
+            return Err(Error::Protocol(format!("sequence {} after {}", acc.seq, self.seq)));
+        };
+        if acc.seq != next {
            return Err(Error::Protocol(format!("sequence {} after {}", acc.seq, self.seq)));
        }
        if acc.author != self.id {
@@ -0,0 +1,43 @@
+//! A client's handling of the host's messages: sequence numbers and batch ids come from the host,
+//! so they are treated as hostile input (they must never overflow).
+
+use figcraft_doc::NodeKind;
+
+use crate::message::{Accepted, ClientMsg, Hello, ServerMsg};
+use crate::sim_tests::base;
+use crate::{Client, Limits, NoRecompute, Outgoing, Server};
+
+fn hello() -> Hello {
+    let ClientMsg::Hello(h) = Client::hello("f", "tok", "Ada", "#FF8800") else { panic!("not a hello") };
+    h
+}
+
+/// A welcome whose sequence numbers are what a lying host would send.
+fn hostile_welcome(seq: u64, last_batch: u64) -> ServerMsg {
+    let mut s = Server::new(base(), "tok", Limits::default());
+    let (_, out) = s.join(hello()).unwrap();
+    let mut welcome = out
+        .into_iter()
+        .find_map(|o| match o {
+            Outgoing::To(_, m) => Some(m),
+            _ => None,
+        })
+        .unwrap();
+    let ServerMsg::Welcome { seq: seq0, processed, .. } = &mut welcome else { panic!("no welcome") };
+    *seq0 = seq;
+    processed.last_batch = last_batch;
+    welcome
+}
+
+#[test]
+fn hostile_sequence_numbers_do_not_overflow_the_client() {
+    let mut c = Client::join(hostile_welcome(u64::MAX, u64::MAX)).unwrap();
+    // This client's own first batch must not overflow its batch counter.
+    let mut d = c.document().clone();
+    let page = d.first_page().unwrap();
+    d.create(page, NodeKind::Rectangle, "R", 0.0, 0.0, 10.0, 10.0).unwrap();
+    assert!(c.edit(&d).unwrap().is_some(), "the edit is batched");
+    // A batch the host claims follows `u64::MAX` can't exist: refuse it, don't overflow.
+    let acc = Accepted { seq: 0, author: c.id().wrapping_add(1), batch_id: 0, changes: Vec::new() };
+    assert!(c.receive(ServerMsg::Changes(acc), &NoRecompute).is_err());
+}
@@ -75,6 +75,7 @@ fn samples() -> (Vec<ClientMsg>, Vec<ServerMsg>) {
        ClientMsg::Admin(Admin::Block { ip: "203.0.113.9".into() }),
        ClientMsg::Admin(Admin::Unblock { ip: "2001:db8::".into() }),
        ClientMsg::Admin(Admin::Blocked),
+        ClientMsg::Admin(Admin::RemovePeer { file: "f".into(), client: 7 }),
        ClientMsg::Report { reason: "Spam ☕".into() },
    ];
    let snapshot = Replica::new(Document::new("Snap")).snapshot().unwrap();
@@ -123,6 +123,8 @@ impl Recompute for NoRecompute {
    fn recompute(&self, _: &mut Document, _: &Document, _: &BTreeSet<NodeId>) {}
 }

+#[cfg(test)]
+mod client_tests;
 #[cfg(test)]
 mod codec_tests;
 #[cfg(test)]
@@ -274,6 +274,10 @@ pub enum Admin {
    /// these `(file id, owner token)` pairs own, at most [`MAX_OWNED`] of them:
    /// [`AdminReply::Owned`]. Servers older than this request can't read it.
    Owned { files: Vec<(String, String)> },
+    /// Remove client `client` from `file`'s session: they are disconnected and their address
+    /// can't join the file again while its session lasts. With the server key, or on an open
+    /// hosting connection with `file`'s owner token. Servers older than this request can't read it.
+    RemovePeer { file: String, client: u32 },
 }

 /// The most files one [`Admin::Owned`] asks about.
@@ -903,15 +903,22 @@ impl Document {
    /// A unique name like "Frame 3" for a new node of a kind.
    pub fn next_name(&self, base: &str) -> String {
        let mut max = 0u64;
+        let mut taken = std::collections::BTreeSet::new();
        for n in self.nodes() {
            if let Some(rest) = n.name.strip_prefix(base)
                && let Some(num) = rest.strip_prefix(' ')
                && let Ok(k) = num.parse::<u64>()
            {
                max = max.max(k);
+                taken.insert(k);
            }
        }
-        format!("{base} {}", max + 1)
+        let next = match max.checked_add(1) {
+            Some(next) => next,
+            // The counter is spent: the lowest free number instead of wrapping onto a name.
+            None => (1u64..).find(|k| !taken.contains(k)).unwrap_or(1),
+        };
+        format!("{base} {next}")
    }

    pub fn style(&self, id: &str) -> Option<&Style> {
@@ -335,6 +335,16 @@ fn next_name_increments() {
    assert_eq!(d.next_name("Ellipse"), "Ellipse 1");
 }

+#[test]
+fn next_name_never_overflows() {
+    let mut d = Document::new("x");
+    let p = page(&d);
+    d.create(p, NodeKind::Frame, "Frame 18446744073709551615", 0.0, 0.0, 1.0, 1.0).unwrap();
+    assert_eq!(d.next_name("Frame"), "Frame 1", "the counter can't step past u64::MAX");
+    d.create(p, NodeKind::Frame, "Frame 1", 0.0, 0.0, 1.0, 1.0).unwrap();
+    assert_eq!(d.next_name("Frame"), "Frame 2");
+}
+
 #[test]
 fn custom_easings() {
    use crate::proto::Easing;
@@ -73,3 +73,52 @@ fn autosaves_keep_their_flag_in_the_file() {
    assert!(!autosave(&mut t));
    let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn files_that_save_themselves_still_get_checkpoints() {
+    let dir = std::env::temp_dir().join(format!("figcraft-autosave-on-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("auto.figcraft").to_string_lossy().to_string();
+    let mut s = Session::new();
+    s.execute("pref.autoSave", &json!({"on": true})).unwrap();
+    rect(&mut s, 0.0);
+    s.execute("file.save", &json!({"path": path})).unwrap();
+    assert!(autosave(&mut s), "saved, but changed since the last version");
+    assert!(!autosave(&mut s), "no change since the checkpoint");
+    // Just opened: nothing to checkpoint.
+    let mut t = Session::empty();
+    t.execute("pref.autoSave", &json!({"on": true})).unwrap();
+    t.execute("file.open", &json!({"path": path})).unwrap();
+    assert!(!autosave(&mut t));
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+#[test]
+fn a_file_encoded_elsewhere_is_saved_as_of_its_snapshot() {
+    use crate::cmd::file::FileSnapshot;
+    let dir = std::env::temp_dir().join(format!("figcraft-snapshot-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("snap.figcraft").to_string_lossy().to_string();
+    let mut s = Session::new();
+    s.execute("file.save", &json!({"path": path})).unwrap();
+    rect(&mut s, 0.0);
+    let file = FileSnapshot::of(s.ds().unwrap());
+    let bytes = file.encode().unwrap();
+    rect(&mut s, 50.0);
+    assert!(file.save(&mut s, &bytes).unwrap());
+    assert!(s.ds().unwrap().is_dirty(), "the edit since the snapshot is still unsaved");
+    let mut t = Session::empty();
+    t.execute("file.open", &json!({"path": path})).unwrap();
+    assert_eq!(t.ds().unwrap().doc.page_content_bounds(t.ds().unwrap().page).unwrap().x1, 10.0, "the file is the snapshot");
+    // Saved meanwhile: the older bytes never overwrite the newer file.
+    let file = FileSnapshot::of(s.ds().unwrap());
+    let bytes = file.encode().unwrap();
+    rect(&mut s, 100.0);
+    s.execute("file.save", &json!({})).unwrap();
+    assert!(!file.save(&mut s, &bytes).unwrap());
+    assert!(!s.ds().unwrap().is_dirty());
+    let mut t = Session::empty();
+    t.execute("file.open", &json!({"path": path})).unwrap();
+    assert_eq!(t.ds().unwrap().doc.page_content_bounds(t.ds().unwrap().page).unwrap().x1, 110.0);
+    let _ = std::fs::remove_dir_all(&dir);
+}
@@ -61,3 +61,25 @@ fn failed_plugin_run_restores_each_document_without_restoring_unrelated_state()
    assert_eq!(s.journal, before_journal);
    assert_eq!(s.message, before_message);
 }
+
+#[test]
+fn failed_group_keeps_the_redo_steps() {
+    let mut s = Session::new();
+    s.execute("shape.rectangle", &json!({"x": 0, "y": 0, "width": 10, "height": 10})).unwrap();
+    assert!(s.undo().unwrap());
+    assert_eq!(s.undo_depth().1, 1);
+
+    let result = s.execute(
+        "command.batch",
+        &json!({
+            "commands": [
+                {"command": "shape.rectangle", "params": {"x": 20, "y": 20, "width": 10, "height": 10}},
+                {"command": "node.set", "params": {"id": 999999, "props": {"name": "must fail"}}}
+            ]
+        }),
+    );
+
+    assert!(result.is_err());
+    assert_eq!(s.undo_depth().1, 1, "the redo step survives the failed batch");
+    assert!(s.redo().unwrap());
+}
@@ -0,0 +1,112 @@
+use serde_json::json;
+
+use crate::{EngineError, Session};
+
+fn id(value: &serde_json::Value) -> crate::NodeId {
+    crate::params::id_of(&value["id"]).unwrap()
+}
+
+#[test]
+fn later_steps_target_layers_created_by_earlier_steps() {
+    let mut s = Session::new();
+    let results = s
+        .execute(
+            "command.batch",
+            &json!({
+                "label": "Card",
+                "commands": [
+                    {"command": "node.create", "params": {"type": "frame", "x": 0, "y": 0, "width": 200, "height": 100}},
+                    {"command": "node.create", "params": {"type": "rectangle", "parent": {"$step": 0}, "x": 10, "y": 10, "width": 20, "height": 20}},
+                    {"command": "node.set", "params": {"ids": [{"$step": 1}], "props": {"name": "Swatch"}}}
+                ]
+            }),
+        )
+        .unwrap();
+
+    let frame = id(&results[0]);
+    let rect = id(&results[1]);
+    let doc = s.doc().unwrap();
+    assert_eq!(doc.node(rect).unwrap().parent, Some(frame));
+    assert_eq!(doc.node(rect).unwrap().name, "Swatch");
+    assert_eq!(s.ds().unwrap().history.undo.len(), 1, "still one undo step");
+}
+
+#[test]
+fn field_picks_another_part_of_the_result() {
+    let mut s = Session::new();
+    let results = s
+        .execute(
+            "command.batch",
+            &json!({"commands": [
+                {"command": "node.create", "params": {"type": "frame", "width": 50, "height": 50}},
+                {"command": "node.create", "params": {"type": "text", "text": "hi", "parent": {"$step": 0, "field": "id"}}}
+            ]}),
+        )
+        .unwrap();
+    assert_eq!(s.doc().unwrap().node(id(&results[1])).unwrap().parent, Some(id(&results[0])));
+}
+
+#[test]
+fn bad_references_fail_and_roll_back() {
+    let mut s = Session::new();
+    let before = s.doc().unwrap().node(s.page().unwrap()).unwrap().children.len();
+    let frame = json!({"command": "node.create", "params": {"type": "frame", "width": 10, "height": 10}});
+    for (bad, needle) in [
+        (json!({"$step": 1}), "earlier step"),
+        (json!({"$step": 5}), "earlier step"),
+        (json!({"$step": -1}), "step index"),
+        (json!({"$step": "0"}), "step index"),
+        (json!({"$step": 0, "field": "nope"}), "no `nope`"),
+        (json!({"$step": 0, "field": 3}), "`field` must be a string"),
+        (json!({"$step": 0, "extra": true}), "not `extra`"),
+    ] {
+        let r = s.execute("command.batch", &json!({"commands": [frame, {"command": "node.set", "params": {"ids": [bad], "props": {"name": "x"}}}]}));
+        match r {
+            Err(EngineError::BadParams { msg, .. }) => assert!(msg.contains(needle), "{msg} should mention {needle}"),
+            other => panic!("expected BadParams for {bad}, got {other:?}"),
+        }
+        assert_eq!(s.doc().unwrap().node(s.page().unwrap()).unwrap().children.len(), before, "rolled back");
+    }
+}
+
+#[test]
+fn deep_params_are_refused_not_overflowed() {
+    let mut s = Session::new();
+    let mut deep = json!(1);
+    for _ in 0..200 {
+        deep = json!([deep]);
+    }
+    let r = s.execute("command.batch", &json!({"commands": [{"command": "select.none", "params": {"x": deep}}]}));
+    assert!(matches!(r, Err(EngineError::BadParams { .. })));
+}
+
+#[test]
+fn text_that_looks_like_a_reference_is_left_alone() {
+    let mut s = Session::new();
+    let results = s
+        .execute("command.batch", &json!({"commands": [{"command": "node.create", "params": {"type": "text", "text": "$step 0 {\"$step\": 0}"}}]}))
+        .unwrap();
+    let n = s.doc().unwrap().node(id(&results[0])).unwrap().clone();
+    assert!(matches!(n.kind, figcraft_doc::NodeKind::Text(t) if t.characters == "$step 0 {\"$step\": 0}"));
+}
+
+#[test]
+fn a_nested_batch_refers_to_its_own_steps() {
+    let mut s = Session::new();
+    let frame = |name: &str| json!({"command": "node.create", "params": {"type": "frame", "name": name, "width": 100, "height": 100}});
+    let results = s
+        .execute(
+            "command.batch",
+            &json!({"commands": [
+                frame("Outer"),
+                {"command": "command.batch", "params": {"commands": [
+                    frame("Inner"),
+                    {"command": "node.create", "params": {"type": "rectangle", "parent": {"$step": 0}, "width": 10, "height": 10}}
+                ]}}
+            ]}),
+        )
+        .unwrap();
+    let inner = &results[1];
+    let rect = s.doc().unwrap().node(id(&inner[1])).unwrap().clone();
+    assert_eq!(rect.parent, Some(id(&inner[0])), "in the nested batch's own first frame, not the outer one");
+}
@@ -156,6 +156,22 @@ pub(crate) fn sync(s: &mut Session) {
    }
 }

+/// The branches of the file in tab `uid` as saving it now would write them: [`sync`] only puts a
+/// branch tab's latest edits in before the next command.
+pub fn current(s: &Session, uid: u64) -> Vec<Branch> {
+    let Some(ds) = s.docs.iter().find(|d| d.uid == uid) else { return Vec::new() };
+    let mut branches = ds.branches.clone();
+    for d in &s.docs {
+        let Some((_, id)) = d.branch_of.as_ref().filter(|(main, _)| *main == uid) else { continue };
+        let Some(b) = branches.iter_mut().find(|b| b.id == *id) else { continue };
+        b.head = d.document_itself().clone();
+        if d.versions_changed {
+            b.versions = d.versions.clone();
+        }
+    }
+    branches
+}
+
 /// The tab a save writes: the main file's for a branch tab, else the active tab.
 pub fn file_tab(s: &Session) -> usize {
    s.ds().ok().and_then(|d| d.branch_of.as_ref()).and_then(|(m, _)| s.docs.iter().position(|d| d.uid == *m)).unwrap_or(s.active)
@@ -145,21 +145,28 @@ pub fn rotate_world(doc: &mut Document, id: NodeId, pivot: Point, deg: f64) -> R
    Ok(())
 }

+/// Whether aligning `ids` would move anything: a layer alone on the page has nothing to align to.
+pub fn can_align(doc: &Document, ids: &[NodeId]) -> bool {
+    align_target(doc, &roots(doc, ids)).is_some()
+}
+
+/// What `roots` align to: one layer to its parent frame, several to their combined bounds.
+fn align_target(doc: &Document, roots: &[NodeId]) -> Option<Rect> {
+    match roots {
+        [] => None,
+        [id] => {
+            let parent = doc.node(*id)?.parent.filter(|pp| !doc.node(*pp).is_some_and(Node::is_page))?;
+            Some(doc.world_bounds(parent).unwrap_or_default())
+        }
+        _ => Some(doc.bounds_of(roots).unwrap_or_default()),
+    }
+}
+
 fn align(s: &mut Session, p: &Value, a: Al) -> Result<Value> {
    let ids = req_targets("align", s, p)?;
    let doc = s.doc_mut()?;
    let ids = roots(doc, &ids);
-    // One layer aligns within its parent frame; several align to their combined bounds.
-    let target: Rect = if ids.len() == 1 {
-        let Some(id) = ids.first() else { return ok() };
-        let parent = doc.get(*id)?.parent;
-        match parent.filter(|pp| !doc.node(*pp).is_some_and(Node::is_page)) {
-            Some(pp) => doc.world_bounds(pp).unwrap_or_default(),
-            None => return ok(),
-        }
-    } else {
-        doc.bounds_of(&ids).unwrap_or_default()
-    };
+    let Some(target) = align_target(doc, &ids) else { return ok() };
    for i in ids {
        let Some(b) = doc.world_bounds(i) else { continue };
        let (dx, dy) = match a {
@@ -325,8 +332,12 @@ fn zorder(s: &mut Session, p: &Value, z: Z) -> Result<Value> {
        }
    }
    if matches!(z, Z::Back) {
-        for (k, i) in ids.iter().enumerate() {
-            doc.reorder(*i, k)?;
+        let mut next: std::collections::HashMap<NodeId, usize> = std::collections::HashMap::new();
+        for i in &ids {
+            let Some(pp) = doc.get(*i)?.parent else { continue };
+            let k = next.entry(pp).or_insert(0);
+            doc.reorder(*i, *k)?;
+            *k += 1;
        }
    }
    ok()
@@ -242,7 +242,7 @@ pub fn create(s: &mut Session, p: &Value) -> Result<Value> {
    let doc = ds.doc_mut();
    let nid = doc.alloc_id();
    let mut node = if base == "Section" { Node::new_section(nid, name, w, h) } else { Node::new(nid, kind, name, w, h) };
-    if app_text && let Some(fills) = crate::tools::readable_text_fills(doc, doc.page_of(parent).unwrap_or(page)) {
+    if app_text && let Some(fills) = crate::tools::readable_text_fills(doc, parent) {
        node.fills = fills;
    }
    node.transform = space.inverse() * figcraft_geom::Affine::translate((x + offset.0, y + offset.1));
@@ -18,7 +18,7 @@ pub fn specs() -> Vec<CommandSpec> {
        spec!(
            "edit.duplicate",
            "Duplicate",
-            "{ids?, dx?, dy? (offset; default 0 for frames-in-place... Figma offsets top-level frames to the right)}",
+            "{ids?, dx?, dy? (page offset; default: the offset of the last duplicate when ids are its copies, still selected; else top-level frames to the right with a 100 gap, everything else in place)}",
            true,
            duplicate
        ),
@@ -253,7 +253,7 @@ pub fn specs() -> Vec<CommandSpec> {
            ok()
        }),
        spec!("effect.set", "Set effect", "{ids?, index, effect {..}}", true, |s, p| {
-            let i = req_num("effect.set", p, "index")? as usize;
+            let i = req_index("effect.set", p, "index")?;
            let e: Effect = parse("effect.set", p, "effect")?.ok_or_else(|| bad("effect.set", "`effect` required"))?;
            for id in req_targets("effect.set", s, p)? {
                let n = s.doc_mut()?.get_mut(id)?;
@@ -302,7 +302,7 @@ pub fn specs() -> Vec<CommandSpec> {
            true,
            |s, p| {
                let cmd = "export.update";
-                let i = req_num(cmd, p, "index")? as usize;
+                let i = req_index(cmd, p, "index")?;
                super::file::export_setting(cmd, ExportSetting::default(), p)?;
                for id in req_targets(cmd, s, p)? {
                    let n = s.doc_mut()?.get_mut(id)?;
@@ -314,7 +314,7 @@ pub fn specs() -> Vec<CommandSpec> {
            }
        ),
        spec!("export.remove", "Remove export setting", "{ids?, index}", true, |s, p| {
-            let i = req_num("export.remove", p, "index")? as usize;
+            let i = req_index("export.remove", p, "index")?;
            for id in req_targets("export.remove", s, p)? {
                let n = s.doc_mut()?.get_mut(id)?;
                if i < n.exports.len() {
@@ -412,13 +412,48 @@ fn delete(s: &mut Session, p: &Value) -> Result<Value> {
    Ok(json!({"deleted": ids}))
 }

+/// Layers duplicated last (Duplicate or Alt-drag) and their copies, in the same order. While the
+/// copies are the selection, Duplicate places the next copies as far from them as they are from
+/// their sources, measured then: so moving the copies first sets the step.
+#[derive(Clone, Debug)]
+pub struct Duplicated {
+    pub sources: Vec<NodeId>,
+    pub copies: Vec<NodeId>,
+}
+
+impl Duplicated {
+    pub fn is_selection(&self, sel: &[NodeId]) -> bool {
+        let set = |v: &[NodeId]| v.iter().copied().collect::<BTreeSet<_>>();
+        !self.copies.is_empty() && set(&self.copies) == set(sel)
+    }
+
+    /// The page offset from the sources to the copies, if both are still there and the copies move
+    /// freely (an auto layout places its own).
+    fn offset(&self, doc: &Document) -> Option<(f64, f64)> {
+        let free = self
+            .copies
+            .iter()
+            .all(|c| doc.node(*c).is_some_and(|n| n.child_layout.absolute || n.parent.and_then(|p| doc.node(p)).is_none_or(|p| p.layout.is_none())));
+        if !free || self.sources.iter().chain(&self.copies).any(|i| !doc.contains(*i)) {
+            return None;
+        }
+        let (a, b) = (doc.bounds_of(&self.sources)?, doc.bounds_of(&self.copies)?);
+        let d = (b.x0 - a.x0, b.y0 - a.y0);
+        (d.0.is_finite() && d.1.is_finite() && (d.0 != 0.0 || d.1 != 0.0)).then_some(d)
+    }
+}
+
 fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
    let ids = req_targets("edit.duplicate", s, p)?;
    let rename = s.prefs.rename_duplicates;
+    let explicit = num(p, "dx").is_some() || num(p, "dy").is_some();
+    let ds = s.ds()?;
+    let roots_now = z_sorted(&ds.doc, &roots(&ds.doc, &ids));
+    let repeat = ds.last_duplicate.as_ref().filter(|d| !explicit && d.is_selection(&roots_now)).and_then(|d| d.offset(&ds.doc));
    let doc = s.doc_mut()?;
-    let ids = z_sorted(doc, &roots(doc, &ids));
+    let ids = roots_now;
    let mut out = Vec::new();
-    for i in ids {
+    for i in ids.iter().copied() {
        let n = doc.get(i)?;
        let parent = n.parent.ok_or_else(|| bad("edit.duplicate", "pages are duplicated with page.duplicate"))?;
        let top_frame = doc.node(parent).is_some_and(Node::is_page) && n.kind.is_frame_like();
@@ -432,22 +467,30 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
            _ if top_frame => (w + 100.0, 0.0),
            _ => (0.0, 0.0),
        };
-        let nn = doc.get_mut(nid)?;
-        nn.transform = Affine::translate((dx, dy)) * nn.transform;
+        match repeat {
+            Some((rx, ry)) => super::arrange::move_world(doc, nid, rx, ry)?,
+            None => {
+                let nn = doc.get_mut(nid)?;
+                nn.transform = Affine::translate((dx, dy)) * nn.transform;
+            }
+        }
        if rename {
+            let nn = doc.get_mut(nid)?;
            nn.name = bump_name(&nn.name);
        }
        out.push(nid);
    }
    s.set_selection(out.clone());
+    s.ds_mut()?.last_duplicate = Some(Duplicated { sources: ids, copies: out.clone() });
    Ok(json!({"ids": out}))
 }

 fn bump_name(n: &str) -> String {
    if let Some((base, num)) = n.rsplit_once(' ')
        && let Ok(k) = num.parse::<u64>()
+        && let Some(next) = k.checked_add(1)
    {
-        return format!("{base} {}", k + 1);
+        return format!("{base} {next}");
    }
    format!("{n} 2")
 }
@@ -803,7 +846,8 @@ pub fn opacity_from_digits(digits: &str) -> Option<f32> {
    let mut n = 0u32;
    let mut count = 0;
    for c in digits.chars() {
-        n = n * 10 + c.to_digit(10)?;
+        // Input-derived: a number that outgrows `u32` stops the scan (None); it never wraps.
+        n = n.checked_mul(10)?.checked_add(c.to_digit(10)?)?;
        count += 1;
    }
    match count {
@@ -944,6 +988,16 @@ fn batch_rename(s: &mut Session, p: &Value) -> Result<Value> {
    Ok(json!({"names": names.iter().map(|(i, n)| json!({"id": i, "name": n})).collect::<Vec<_>>()}))
 }

+/// Char index of the first case-insensitive occurrence of `needle` in `hay` at or after `from`.
+/// Works on char indices (what `replace_range` takes), so lowercasing never shifts offsets.
+fn find_ci(hay: &[char], needle: &[char], from: usize) -> Option<usize> {
+    if needle.is_empty() {
+        return None;
+    }
+    (from..hay.len())
+        .find(|&i| hay.get(i..i + needle.len()).is_some_and(|w| w.iter().zip(needle).all(|(a, b)| a == b || a.to_lowercase().eq(b.to_lowercase()))))
+}
+
 fn find_replace(s: &mut Session, p: &Value) -> Result<Value> {
    let find = req_string("edit.findReplace", p, "find")?;
    if find.is_empty() {
@@ -954,11 +1008,16 @@ fn find_replace(s: &mut Session, p: &Value) -> Result<Value> {
    let page = s.page()?;
    let doc = s.doc_mut()?;
    let mut hits = Vec::new();
-    let lower = find.to_lowercase();
+    let needle: Vec<char> = find.chars().collect();
+    let r_chars: Vec<char> = replace.as_deref().map(|r| r.chars().collect()).unwrap_or_default();
    for i in doc.subtree(page) {
        let Some(n) = doc.node(i) else { continue };
-        let text_hit = matches!(&n.kind, NodeKind::Text(t) if t.characters.to_lowercase().contains(&lower));
-        let name_hit = names && n.name.to_lowercase().contains(&lower);
+        let text: Option<Vec<char>> = match &n.kind {
+            NodeKind::Text(t) => Some(t.characters.chars().collect()),
+            _ => None,
+        };
+        let text_hit = text.as_deref().is_some_and(|c| find_ci(c, &needle, 0).is_some());
+        let name_hit = names && find_ci(&n.name.chars().collect::<Vec<_>>(), &needle, 0).is_some();
        if !(text_hit || name_hit) || n.is_page() {
            continue;
        }
@@ -966,19 +1025,27 @@ fn find_replace(s: &mut Session, p: &Value) -> Result<Value> {
        if let Some(r) = &replace {
            let n = doc.get_mut(i)?;
            if names && name_hit {
-                n.name = n.name.replace(find.as_str(), r);
+                let chars: Vec<char> = n.name.chars().collect();
+                let mut out = String::new();
+                let mut at = 0;
+                while let Some(pos) = find_ci(&chars, &needle, at) {
+                    out.extend(chars.get(at..pos).unwrap_or_default());
+                    out.push_str(r);
+                    at = pos + needle.len();
+                }
+                out.extend(chars.get(at..).unwrap_or_default());
+                n.name = out;
            }
-            if let NodeKind::Text(t) = &mut n.kind {
-                // Replace occurrence by occurrence so styles shift correctly.
-                let mut guard = 0;
-                while let Some(pos) = t.characters.find(find.as_str()) {
-                    let start = t.characters.get(..pos).map(|x| x.chars().count()).unwrap_or(0);
-                    let len = find.chars().count();
-                    t.replace_range(start, start + len, r);
-                    guard += 1;
-                    if guard > 10_000 || r.contains(find.as_str()) {
-                        break;
-                    }
+            if let (NodeKind::Text(t), Some(mut chars)) = (&mut n.kind, text) {
+                // Replace occurrence by occurrence so styles shift correctly. The search resumes
+                // after each inserted replacement, so a replacement that matches `find` (in any
+                // case) neither loops forever nor stops the other occurrences.
+                let mut cursor = 0;
+                for _ in 0..10_000 {
+                    let Some(start) = find_ci(&chars, &needle, cursor) else { break };
+                    t.replace_range(start, start + needle.len(), r);
+                    chars.splice(start..start + needle.len(), r_chars.iter().copied());
+                    cursor = start + r_chars.len();
                }
            }
        }
@@ -37,7 +37,7 @@ pub fn specs() -> Vec<CommandSpec> {
        spec!(
            "file.openRecent",
            "Open recent",
-            "{path? | index? (into the list), clear? (forget them all)}  opens a recent file; a file that no longer exists is dropped from the list. Returns the list, newest first: {files: [{path, name, exists}]} (opening returns what `file.open` does)",
+            "{path? | index? (into the list), clear? (forget them all), remove? (a path: forget that one)}  opens a recent file; a file that no longer exists is dropped from the list. Returns the list, newest first: {files: [{path, name, exists}]} (opening returns what `file.open` does)",
            false,
            open_recent
        ),
@@ -195,7 +195,7 @@ pub fn specs() -> Vec<CommandSpec> {
        spec!(
            "version.autosave",
            "Autosave version",
-            "{}  save an automatic checkpoint when the document has unsaved changes since the last version (the app does this every 30 minutes); keeps the newest 20 autosaves → {saved, version?}",
+            "{}  save an automatic checkpoint when the document has unsaved changes since the last version (with `pref.autoSave` on: changes made since it was opened); the app does this every 30 minutes; keeps the newest 20 autosaves → {saved, version?}",
            false,
            autosave
        ),
@@ -219,7 +219,7 @@ pub fn specs() -> Vec<CommandSpec> {
            }
        ),
        spec!("doc.switch", "Switch document", "{index}", false, |s, p| {
-            let i = req_num("doc.switch", p, "index")? as usize;
+            let i = req_index("doc.switch", p, "index")?;
            if i >= s.docs.len() {
                return Err(bad("doc.switch", "no such document"));
            }
@@ -257,8 +257,11 @@ pub const MAX_AUTOSAVES: usize = 20;

 /// `version.autosave`: a checkpoint of a document with unsaved changes since the last version.
 fn autosave(s: &mut Session, _: &Value) -> Result<Value> {
+    let auto_save = s.prefs.auto_save;
    let ds = s.ds_mut()?;
-    if ds.preview.is_some() || !ds.is_dirty() || !ds.changed_since_checkpoint() {
+    // A file that saves itself is rarely unsaved: edits since it was opened count then.
+    let edited = ds.is_dirty() || (auto_save && !ds.history.undo.is_empty());
+    if ds.preview.is_some() || !edited || !ds.changed_since_checkpoint() {
        return Ok(json!({"saved": false}));
    }
    Ok(match add_version(ds, AUTOSAVE, "", true) {
@@ -437,15 +440,12 @@ pub(crate) fn read_capped(path: &str, max: u64) -> Result<Vec<u8>> {
    read(path)
 }

+/// Write `bytes` to `path` through a uniquely named, exclusively created staging file and one
+/// atomic rename (see [`figcraft_format::write_file_atomic`]): a failed or interrupted write never
+/// truncates `path`, and no file or symlink at a staging name is ever written through.
 #[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn write(path: &str, bytes: &[u8]) -> Result<()> {
-    let tmp = format!("{path}.tmp-figcraft");
-    std::fs::write(&tmp, bytes).map_err(|e| EngineError::Other(format!("{tmp}: {e}")))?;
-    std::fs::rename(&tmp, path).map_err(|e| {
-        // Leave nothing behind when the file can't take its place.
-        let _ = std::fs::remove_file(&tmp);
-        EngineError::Other(format!("{path}: {e}"))
-    })
+    figcraft_format::write_file_atomic(std::path::Path::new(path), bytes).map_err(|e| EngineError::Other(format!("{path}: {e}")))
 }

 #[cfg(target_arch = "wasm32")]
@@ -625,6 +625,9 @@ fn open_recent(s: &mut Session, p: &Value) -> Result<Value> {
    if p.get("clear").and_then(Value::as_bool) == Some(true) {
        s.prefs.recent_files.clear();
    }
+    if let Some(gone) = string(p, "remove") {
+        s.prefs.recent_files.retain(|r| *r != gone);
+    }
    let path = match (string(p, "path"), num(p, "index")) {
        (Some(path), _) => Some(path),
        (None, Some(i)) => Some(s.prefs.recent_files.get(i.max(0.0) as usize).cloned().ok_or_else(|| bad(CMD, "no such recent file"))?),
@@ -693,10 +696,71 @@ pub fn thumbnail(doc: &Document) -> Option<Vec<u8>> {

 /// The `.figcraft` file for a document: content, thumbnail and version history.
 pub fn file_bytes(ds: &DocState) -> Result<Vec<u8>> {
-    let mut doc = (*ds.doc).clone();
-    doc.current_page = Some(ds.page);
-    let thumb = thumbnail(&doc);
-    figcraft_format::save_bytes_with_history(&doc, thumb.as_deref(), &ds.versions, &ds.branches).map_err(|e| EngineError::Other(e.to_string()))
+    FileSnapshot::of(ds).encode()
+}
+
+/// A document's file as it is at one moment, so the slow part of saving it (the thumbnail and the
+/// encoding) can run on another thread while editing goes on: [`encode`](Self::encode) there, then
+/// [`save`](Self::save) the bytes back on the session's thread.
+pub struct FileSnapshot {
+    uid: u64,
+    path: Option<String>,
+    revision: u64,
+    doc: Arc<Document>,
+    /// The document as last saved when the snapshot was taken: another save since makes it stale.
+    saved: Arc<Document>,
+    page: NodeId,
+    versions: Vec<Version>,
+    branches: Vec<figcraft_format::Branch>,
+}
+
+impl FileSnapshot {
+    pub fn of(ds: &DocState) -> Self {
+        Self {
+            uid: ds.uid,
+            path: ds.path.clone(),
+            revision: ds.revision,
+            doc: ds.doc.clone(),
+            saved: ds.saved_doc.clone(),
+            page: ds.page,
+            versions: ds.versions.clone(),
+            branches: ds.branches.clone(),
+        }
+    }
+
+    /// The file's bytes: content, thumbnail and version history.
+    pub fn encode(&self) -> Result<Vec<u8>> {
+        let mut doc = (*self.doc).clone();
+        doc.current_page = Some(self.page);
+        let thumb = thumbnail(&doc);
+        figcraft_format::save_bytes_with_history(&doc, thumb.as_deref(), &self.versions, &self.branches)
+            .map_err(|e| EngineError::Other(e.to_string()))
+    }
+
+    /// Write `bytes` (this snapshot's [`encode`](Self::encode)) to the document's file: it is saved
+    /// as of the snapshot, and edits since stay unsaved. False (nothing written) when the document
+    /// was closed, saved, reverted or given another path since: the bytes are out of date.
+    pub fn save(self, s: &mut Session, bytes: &[u8]) -> Result<bool> {
+        let Some(ds) = s.docs.iter_mut().find(|d| d.uid == self.uid && d.path == self.path && Arc::ptr_eq(&d.saved_doc, &self.saved)) else {
+            return Ok(false);
+        };
+        write(self.path.as_deref().ok_or(EngineError::NoDocument)?, bytes)?;
+        // The history or branches may have changed since: then they still count as unsaved.
+        if ds.revision == self.revision {
+            ds.versions_changed = false;
+        }
+        ds.saved_doc = self.doc;
+        ds.revision += 1;
+        branch_tabs_saved(s, self.uid);
+        Ok(true)
+    }
+}
+
+/// The branch tabs of the file in tab `uid` were saved with it.
+fn branch_tabs_saved(s: &mut Session, uid: u64) {
+    for tab in s.docs.iter_mut().filter(|d| d.branch_of.as_ref().is_some_and(|(m, _)| *m == uid)) {
+        tab.mark_saved();
+    }
 }

 fn color_profile(s: &mut Session, p: &Value) -> Result<Value> {
@@ -721,9 +785,7 @@ fn save_to(s: &mut Session, path: String) -> Result<Value> {
    ds.mark_saved();
    ds.revision += 1;
    let uid = ds.uid;
-    for tab in s.docs.iter_mut().filter(|d| d.branch_of.as_ref().is_some_and(|(m, _)| *m == uid)) {
-        tab.mark_saved();
-    }
+    branch_tabs_saved(s, uid);
    remember(s, &path);
    Ok(json!({"path": path, "bytes": bytes.len()}))
 }
@@ -1324,3 +1386,126 @@ mod rest_import_tests {
        let _ = std::fs::remove_dir_all(&dir);
    }
 }
+
+#[cfg(test)]
+mod staging_write_tests {
+    use super::*;
+
+    fn dir(name: &str) -> std::path::PathBuf {
+        let d = std::env::temp_dir().join(format!("figcraft-engine-staging-{name}-{}", std::process::id()));
+        std::fs::create_dir_all(&d).unwrap();
+        d
+    }
+
+    /// A symlink `from` → `to`; false when the platform won't make one (Windows needs privileges).
+    #[cfg(unix)]
+    fn symlink(from: &std::path::Path, to: &std::path::Path) -> bool {
+        std::os::unix::fs::symlink(to, from).is_ok()
+    }
+
+    #[cfg(windows)]
+    fn symlink(from: &std::path::Path, to: &std::path::Path) -> bool {
+        std::os::windows::fs::symlink_file(to, from).is_ok()
+    }
+
+    #[test]
+    fn an_existing_staging_file_is_never_written_through() {
+        let d = dir("existing");
+        let path = d.join("shot.svg");
+        // The old deterministic staging name, held by an unrelated file: the write must pick its
+        // own staging name instead of truncating this one.
+        let old = d.join("shot.svg.tmp-figcraft");
+        std::fs::write(&old, b"not yours").unwrap();
+        write(&path.to_string_lossy(), b"<svg/>").unwrap();
+        assert_eq!(std::fs::read(&path).unwrap(), b"<svg/>");
+        assert_eq!(std::fs::read(&old).unwrap(), b"not yours", "an unrelated file at a staging name is untouched");
+        // Just the file and the untouched staging file: no new staging leftovers.
+        assert_eq!(std::fs::read_dir(&d).unwrap().count(), 2);
+        let _ = std::fs::remove_dir_all(&d);
+    }
+
+    #[test]
+    fn a_staging_symlink_is_never_followed() {
+        let d = dir("symlink");
+        let path = d.join("shot.svg");
+        let victim = d.join("victim.txt");
+        std::fs::write(&victim, b"innocent").unwrap();
+        let old = d.join("shot.svg.tmp-figcraft");
+        if !symlink(&old, &victim) {
+            return; // Making a symlink needs privileges on some Windows setups.
+        }
+        write(&path.to_string_lossy(), b"<svg/>").unwrap();
+        assert_eq!(std::fs::read(&victim).unwrap(), b"innocent", "the symlink was never written through");
+        assert_eq!(std::fs::read(&path).unwrap(), b"<svg/>");
+        let _ = std::fs::remove_dir_all(&d);
+    }
+
+    #[test]
+    fn concurrent_writers_of_one_file_never_interleave() {
+        let d = dir("concurrent");
+        let path = d.join("shot.svg");
+        for round in 0..5u8 {
+            let mut handles = Vec::new();
+            for w in 0u8..4 {
+                let (path, bytes) = (path.clone(), vec![b'0' + w; 8192]);
+                handles.push(std::thread::spawn(move || write(&path.to_string_lossy(), &bytes)));
+            }
+            let mut wins = 0;
+            for h in handles {
+                // On Windows a rename over a file another writer just replaced can lose the race.
+                if h.join().unwrap().is_ok() {
+                    wins += 1;
+                }
+            }
+            assert!(wins > 0, "round {round}: every writer lost");
+            // Whatever landed is one writer's complete payload, never a mix.
+            let got = std::fs::read(&path).unwrap();
+            assert_eq!(got.len(), 8192, "round {round}: a complete payload landed");
+            assert!(got.windows(2).all(|w| w[0] == w[1]), "round {round}: one writer's payload, not a mix");
+        }
+        // No staging file was left stuck (a failed writer removes its own).
+        let left = std::fs::read_dir(&d).unwrap().count();
+        assert!(left <= if cfg!(windows) { 5 } else { 1 }, "{left} files left in the staging directory");
+        let _ = std::fs::remove_dir_all(&d);
+    }
+
+    #[test]
+    fn a_failed_write_leaves_the_destination_alone_and_cleans_up() {
+        let d = dir("failure");
+        // The destination is a directory: the rename fails, our staging file is removed and the
+        // directory is untouched.
+        let taken = d.join("over-a-directory");
+        std::fs::create_dir_all(&taken).unwrap();
+        assert!(write(&taken.to_string_lossy(), b"payload").is_err());
+        assert!(taken.is_dir());
+        assert_eq!(std::fs::read_dir(&d).unwrap().count(), 1, "no staging file left behind");
+        // A missing parent directory fails without creating anything anywhere.
+        assert!(write(&d.join("no").join("such.svg").to_string_lossy(), b"payload").is_err());
+        assert!(!d.join("no").exists());
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            // A read-only directory refuses the staging file, and the old destination stays.
+            let ro = d.join("read-only");
+            std::fs::create_dir_all(&ro).unwrap();
+            let dest = ro.join("keep.svg");
+            std::fs::write(&dest, b"keep").unwrap();
+            let mut perms = std::fs::metadata(&ro).unwrap().permissions();
+            perms.set_mode(0o500);
+            std::fs::set_permissions(&ro, perms).unwrap();
+            // Running as root would defeat the read-only directory: skip instead of failing.
+            let probe = ro.join(".probe");
+            if std::fs::write(&probe, b"").is_ok() {
+                let _ = std::fs::remove_file(&probe);
+            } else {
+                assert!(write(&dest.to_string_lossy(), b"payload").is_err());
+                assert_eq!(std::fs::read(&dest).unwrap(), b"keep");
+                assert_eq!(std::fs::read_dir(&ro).unwrap().count(), 1, "no staging file left behind");
+            }
+            let mut perms = std::fs::metadata(&ro).unwrap().permissions();
+            perms.set_mode(0o700);
+            std::fs::set_permissions(&ro, perms).unwrap();
+        }
+        let _ = std::fs::remove_dir_all(&d);
+    }
+}
@@ -26,7 +26,12 @@ fn settle(s: &mut Session, cmd: &str) -> crate::Result<()> {
 pub fn specs() -> Vec<CommandSpec> {
    vec![
        spec!("page.add", "Add page", "{name?} (a name starting with a hyphen adds a divider)", true, |s, p| {
-            let background = s.new_page_background();
+            // An added page takes the current page's colour; the theme only decides new files.
+            let current = s.page().ok().and_then(|p| match s.doc().ok()?.node(p)?.kind {
+                NodeKind::Page { background, .. } => Some(background),
+                _ => None,
+            });
+            let background = current.unwrap_or_else(|| s.new_page_background());
            let doc = s.doc_mut()?;
            let name = string(p, "name").unwrap_or_else(|| format!("Page {}", doc.pages.len() + 1));
            let id = doc.add_page(&name);
@@ -47,7 +52,7 @@ pub fn specs() -> Vec<CommandSpec> {
            let id = match id(p, "id") {
                Some(i) => i,
                None => {
-                    let k = req_num("page.select", p, "index")? as usize;
+                    let k = req_index("page.select", p, "index")?;
                    *doc.pages.get(k).ok_or_else(|| bad("page.select", "no such page"))?
                }
            };
@@ -102,6 +107,9 @@ pub fn specs() -> Vec<CommandSpec> {
            let id = id(p, "id").unwrap_or(s.page()?);
            let k = req_num("page.move", p, "index")?.max(0.0) as usize;
            let doc = s.doc_mut()?;
+            if !doc.pages.contains(&id) {
+                return Err(bad("page.move", format!("{id} is not a page")));
+            }
            doc.pages.retain(|x| *x != id);
            let k = k.min(doc.pages.len());
            doc.pages.insert(k, id);
@@ -13,7 +13,7 @@ pub const STROKE_SIDES: [&str; 4] = ["strokeTopWeight", "strokeRightWeight", "st

 /// Keys `node.set` understands (documented for agents).
 pub const KEYS: &str = "name, visible, locked, opacity (0-1), blend, x, y (relative to the parent frame; groups don't count), width, height, rotation (degrees), \
-fills (paints or colours), fill (colour), strokes, stroke (colour), strokeWeight, strokeAlign (inside|center|outside), strokeSides [t,r,b,l], strokeTopWeight / strokeRightWeight / strokeBottomWeight / strokeLeftWeight (one side; turns on individual strokes), \
+fills (paints or colours; gradients as {type: linearGradient|radialGradient|angularGradient|diamondGradient, stops: [\"#hex\", ...], from?, to?} too), fill (colour), strokes, stroke (colour), strokeWeight, strokeAlign (inside|center|outside), strokeSides [t,r,b,l], strokeTopWeight / strokeRightWeight / strokeBottomWeight / strokeLeftWeight (one side; turns on individual strokes), \
 strokeCap / startCap / endCap, strokeJoin, miterAngle (degrees: sharper joins bevel; or miterLimit as a ratio), dashes [..], widthProfile (preset uniform|wedge|taper|eye|rounded|pinch, [[t, scale], ...] or null), brush (preset id, {preset, spacing, sizeJitter, rotationJitter, scatter, seed} or null), cornerRadius (n or [tl,tr,br,bl]), cornerSmoothing (0-1), effects, \
 clip, isMask, layout (null|horizontal|vertical|grid|{...}), gap, crossGap, padding (n or [t,r,b,l]), paddingTop/Right/Bottom/Left, \
 mainAlign (min|center|max, or the auto gaps spaceBetween|spaceAround|spaceEvenly), crossAlign (min|center|max|baseline: first text baselines, horizontal layouts), contentAlign (wrapped lines: auto = packed where crossAlign says | spaceBetween), wrap (rows of a horizontal layout, columns of a vertical one), strokesIncluded (the frame's inside stroke takes up space), reverseZ (canvas stacking: true = first on top), \
@@ -362,9 +362,9 @@ fn flatten(s: &mut Session, p: &Value) -> Result<Value> {

 fn outline_stroke(s: &mut Session, p: &Value) -> Result<Value> {
    let ids = req_targets("vector.outlineStroke", s, p)?;
-    let doc = s.doc_mut()?;
    let mut out = Vec::new();
    for i in ids {
+        let doc = s.doc_mut()?;
        let n = doc.get(i)?.clone();
        if !n.has_visible_stroke() {
            continue;
@@ -409,7 +409,7 @@ fn outline_stroke(s: &mut Session, p: &Value) -> Result<Value> {
            if let Some(g) = id_of(&r["id"]) {
                out.push(g);
            }
-            return Ok(json!({"ids": out}));
+            continue;
        }
        // Standing in for the layer, the outline keeps how it is drawn and placed.
        (v.opacity, v.blend, v.effects, v.styles.effect) = (n.opacity, n.blend, n.effects.clone(), n.styles.effect);
@@ -334,6 +334,7 @@ pub fn specs() -> Vec<CommandSpec> {
        spec!("pref.showDimensions", "Show dimensions on objects", "{on?}", false, |s, p| pref(s, p, |x| &mut x.show_dimensions)),
        spec!("pref.numberKeysOpacity", "Use number keys for opacity", "{on?}", false, |s, p| pref(s, p, |x| &mut x.number_keys_opacity)),
        spec!("pref.reduceMotion", "Reduce motion", "{on?}", false, |s, p| pref(s, p, |x| &mut x.reduce_motion)),
+        spec!("pref.autoSave", "Save files automatically", "{on?}", false, |s, p| pref(s, p, |x| &mut x.auto_save)),
        spec!("pref.nudge", "Nudge amount", "{small?, big?}", false, |s, p| {
            s.prefs.nudge_small = num(p, "small").unwrap_or(s.prefs.nudge_small).clamp(0.01, 1000.0);
            s.prefs.nudge_big = num(p, "big").unwrap_or(s.prefs.nudge_big).clamp(0.01, 10000.0);
@@ -369,18 +370,24 @@ pub fn specs() -> Vec<CommandSpec> {
                Ok(json!({"url": s.prefs.publish_server, "default": crate::live::DEFAULT_SERVER}))
            }
        ),
-        spec!("pref.language", "Interface language", "{language: system|en|es|es-419|fr|de|pt-BR|ja|ko|zh-Hans|…; else English}", false, |s, p| {
-            let lang = req_string("pref.language", p, "language")?;
-            let lang = lang.trim();
-            // A BCP 47-style tag ("es", "pt-BR", "zh_Hans") or "system".
-            let tag = lang.len() <= 35
-                && lang.split(['-', '_']).all(|part| !part.is_empty() && part.len() <= 8 && part.chars().all(|c| c.is_ascii_alphanumeric()));
-            if !tag {
-                return Err(bad("pref.language", format!("`{lang}` is not a language code")));
+        spec!(
+            "pref.language",
+            "Interface language",
+            "{language: system|en|cs|ru|es|es-419|fr|de|pt-BR|ja|ko|zh-Hans|…; else English}",
+            false,
+            |s, p| {
+                let lang = req_string("pref.language", p, "language")?;
+                let lang = lang.trim();
+                // A BCP 47-style tag ("es", "pt-BR", "zh_Hans") or "system".
+                let tag = lang.len() <= 35
+                    && lang.split(['-', '_']).all(|part| !part.is_empty() && part.len() <= 8 && part.chars().all(|c| c.is_ascii_alphanumeric()));
+                if !tag {
+                    return Err(bad("pref.language", format!("`{lang}` is not a language code")));
+                }
+                s.prefs.language = lang.to_string();
+                Ok(json!({"language": s.prefs.language}))
            }
-            s.prefs.language = lang.to_string();
-            Ok(json!({"language": s.prefs.language}))
-        }),
+        ),
        spec!("app.preferences", "Preferences", "{}", false, |s, _| ui(s, "dialog.preferences")),
        spec!("app.actions", "Actions", "{}", false, |s, _| ui(s, "palette.actions")),
        spec!("help.shortcuts", "Keyboard shortcuts", "{}", false, |s, _| ui(s, "panel.shortcuts")),
@@ -58,6 +58,9 @@ fn close(a: f64, b: f64) -> bool {

 /// A square (100,100)–(200,200), selected, and the text "Hello" at (400, 100), not selected.
 fn scene() -> (Session, NodeId, NodeId) {
+    // The text is measured with a font: without craft-fonts that is a system one, scanned here
+    // rather than by whichever test happens to run first (#333).
+    figcraft_text::scan_system_fonts();
    let mut s = Session::new();
    let r = id(&ex(&mut s, "shape.rectangle", json!({"x": 100, "y": 100, "width": 100, "height": 100})));
    let t = id(&ex(&mut s, "text.create", json!({"text": "Hello", "x": 400, "y": 100, "props": {"fontSize": 40}})));
@@ -1,6 +1,6 @@
-//! Text made by commands in the app (the interface reported its theme) is readable on its page
-//! like text drawn with the Text tool: white on a dark page unless a fill is named. A session
-//! without an interface (CLI, MCP, exports) keeps the model's black everywhere.
+//! Text made by commands in the app (the interface reported its theme) is readable where it is
+//! drawn, like text drawn with the Text tool: white on a dark page or a dark frame unless a fill is
+//! named. A session without an interface (CLI, MCP, exports) keeps the model's black everywhere.

 use figcraft_color::{Color, Paint};
 use figcraft_doc::NodeId;
@@ -62,12 +62,51 @@ fn text_made_by_commands_is_readable_on_its_page() {
 }

 #[test]
-fn text_in_a_frame_follows_the_page_it_is_on() {
-    // As with the Text tool: the page decides, also inside a frame; made in one undo step.
+fn text_in_a_frame_is_readable_on_the_frame() {
+    // #362: what the text is drawn on decides: the nearest layer around it with a solid fill (a
+    // new frame's white too), else its page; made in one undo step.
+    let (white, black) = (vec![Paint::solid(Color::WHITE)], vec![Paint::solid(Color::BLACK)]);
    let mut s = session(Some(true));
-    let frame: NodeId = id_of(&ex(&mut s, "frame.create", json!({"x": 0, "y": 0, "width": 200, "height": 100}))["id"]).unwrap();
-    let t = ex(&mut s, "text.create", json!({"text": "Hi", "x": 10, "y": 10, "parent": frame}));
-    assert_eq!(fills(&s, &t), vec![Paint::solid(Color::WHITE)]);
+    let frame = |s: &mut Session, x: i64, parent: Option<NodeId>, fills: Option<Value>| -> NodeId {
+        let mut p = json!({"x": x, "y": 0, "width": 200, "height": 100});
+        if let Some(parent) = parent {
+            p["parent"] = json!(parent);
+        }
+        let f = id_of(&ex(s, "frame.create", p)["id"]).unwrap();
+        if let Some(fills) = fills {
+            ex(s, "node.set", json!({"id": f, "props": {"fills": fills}}));
+        }
+        f
+    };
+    let light = frame(&mut s, 0, None, None);
+    let dark = frame(&mut s, 300, None, Some(json!([{"type": "solid", "color": "#202020"}])));
+    let bare = frame(&mut s, 600, None, Some(json!([])));
+    let inner = frame(&mut s, 0, Some(light), Some(json!([])));
+    let faint = frame(&mut s, 900, None, Some(json!([{"type": "solid", "color": "#FFFFFF", "opacity": 0.2}])));
+    let stacked = frame(&mut s, 1200, None, Some(json!([{"type": "solid", "color": "#202020"}, {"type": "solid", "color": "#FFFFFF"}])));
+    let cases = [
+        (light, &black, "a white frame on a dark page: black text"),
+        (dark, &white, "a dark frame: white"),
+        (bare, &white, "a frame without a fill: the page decides"),
+        (inner, &black, "a frame without a fill in a white one: the white one"),
+        (faint, &white, "a faint fill lets the page show through: the page decides"),
+        (stacked, &black, "the fill on top counts"),
+    ];
+    for (parent, want, why) in cases {
+        let t = ex(&mut s, "text.create", json!({"text": "Hi", "x": 10, "y": 10, "parent": parent}));
+        assert_eq!(&fills(&s, &t), want, "{why}");
+    }
+    // The Text tool reads it the same way.
+    use crate::tools::{PointerEvent, PointerKind, ToolId};
+    let at = s.doc().unwrap().world_bounds(light).unwrap().center();
+    s.set_tool(ToolId::Text);
+    for kind in [PointerKind::Down, PointerKind::Up] {
+        s.pointer(&PointerEvent::at(kind, at.x, at.y, 1.0)).unwrap();
+    }
+    let typed = s.ds().unwrap().text_edit.as_ref().unwrap().id;
+    assert_eq!(s.doc().unwrap().node(typed).unwrap().fills, black, "the Text tool in a white frame");
+    crate::textedit::end(&mut s).unwrap();
+    let t = ex(&mut s, "text.create", json!({"text": "Hi", "x": 10, "y": 10, "parent": light}));
    ex(&mut s, "edit.undo", json!({}));
    assert!(s.doc().unwrap().node(id_of(&t["id"]).unwrap()).is_none());
 }
@@ -15,6 +15,9 @@ fn ex(s: &mut Session, cmd: &str, p: Value) -> Value {

 /// A frame holding a group of a rectangle and a text layer at (60, 60); returns (group, text).
 fn scene(s: &mut Session) -> (NodeId, NodeId) {
+    // The text is measured with a font: without craft-fonts that is a system one, scanned here
+    // rather than by whichever test happens to run first (#333).
+    figcraft_text::scan_system_fonts();
    let f = id_of(&ex(s, "frame.create", json!({"x": 0, "y": 0, "width": 400, "height": 300}))["id"]).unwrap();
    let r = id_of(&ex(s, "shape.rectangle", json!({"x": 40, "y": 40, "width": 200, "height": 60, "parent": f}))["id"]).unwrap();
    let t = id_of(&ex(s, "text.create", json!({"text": "Hi there", "x": 60, "y": 60, "parent": f, "props": {"fontSize": 16}}))["id"]).unwrap();
@@ -74,6 +77,26 @@ fn double_clicks_reach_and_edit_text_in_a_group_wherever_they_land() {
    }
 }

+#[test]
+fn editing_text_keeps_other_document_changes_since_open() {
+    let mut s = Session::new();
+    let first = id_of(&ex(&mut s, "shape.rectangle", json!({"x": 20, "y": 20, "width": 80, "height": 40}))["id"]).unwrap();
+    let deleted = id_of(&ex(&mut s, "shape.rectangle", json!({"x": 120, "y": 20, "width": 80, "height": 40}))["id"]).unwrap();
+    let text = id_of(&ex(&mut s, "text.create", json!({"text": "A", "x": 20, "y": 100}))["id"]).unwrap();
+    ex(&mut s, "node.set", json!({"ids": [first], "props": {"x": 650}}));
+    ex(&mut s, "edit.delete", json!({"ids": [deleted]}));
+
+    let bounds = s.doc().unwrap().world_bounds(text).unwrap();
+    double_click(&mut s, bounds.center().x, bounds.center().y, 0.0, 1.0);
+    assert_eq!(editing(&s), Some(text));
+    crate::textedit::insert(&mut s, "B").unwrap();
+    crate::textedit::end(&mut s).unwrap();
+
+    assert_eq!(s.doc().unwrap().world_bounds(first).unwrap().x0, 650.0);
+    assert!(!s.doc().unwrap().contains(deleted));
+    assert_eq!(s.doc().unwrap().node(text).unwrap().kind.text().unwrap().characters, "B");
+}
+
 #[test]
 fn a_press_drags_only_past_the_threshold_in_screen_pixels() {
    for (zoom, by, moves) in [(1.0, 2.0, false), (1.0, 4.0, true), (4.0, 0.5, false), (4.0, 1.0, true), (0.25, 8.0, false), (0.25, 16.0, true)] {
@@ -0,0 +1,159 @@
+//! Duplicating at a spacing: a copy Alt-dragged off a layer snaps to that layer too (its edges,
+//! centres and equal spacing), and Duplicate repeats the last duplicate's offset while its copies
+//! are selected, so Alt-drag (or Duplicate and move) then Cmd+D steps out evenly spaced copies.
+
+use serde_json::{Value, json};
+
+use crate::Session;
+use crate::params::id_of;
+use crate::tools::{PointerEvent, PointerKind};
+use figcraft_doc::NodeId;
+
+fn ex(s: &mut Session, cmd: &str, p: Value) -> Value {
+    s.execute(cmd, &p).unwrap_or_else(|e| panic!("{cmd}: {e}"))
+}
+
+fn rect(s: &mut Session, x: f64, y: f64) -> NodeId {
+    id_of(&ex(s, "shape.rectangle", json!({"x": x, "y": y, "width": 100, "height": 100}))["id"]).unwrap()
+}
+
+/// Alt-drag from `from` to `to`: returns the copy (the selection afterwards).
+fn alt_drag(s: &mut Session, from: (f64, f64), to: (f64, f64)) -> NodeId {
+    let ev = |kind, (x, y): (f64, f64)| PointerEvent { alt: true, ..PointerEvent::at(kind, x, y, 1.0) };
+    s.pointer(&ev(PointerKind::Down, from)).unwrap();
+    for k in 1..=4 {
+        let t = f64::from(k) / 4.0;
+        s.pointer(&ev(PointerKind::Move, (from.0 + (to.0 - from.0) * t, from.1 + (to.1 - from.1) * t))).unwrap();
+    }
+    s.pointer(&ev(PointerKind::Up, to)).unwrap();
+    let sel = s.selection();
+    assert_eq!(sel.len(), 1, "one copy selected");
+    sel[0]
+}
+
+/// Duplicate the selection: the copy.
+fn cmd_d(s: &mut Session) -> NodeId {
+    let out = ex(s, "edit.duplicate", json!({}));
+    id_of(&out["ids"][0]).unwrap()
+}
+
+fn at(s: &Session, id: NodeId) -> (f64, f64) {
+    let b = s.doc().unwrap().world_bounds(id).unwrap();
+    (b.x0, b.y0)
+}
+
+#[test]
+fn an_alt_dragged_copy_snaps_to_the_layer_it_came_from() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0, 0.0);
+    // 2 px below the original's top edge: within the snap distance.
+    let copy = alt_drag(&mut s, (50.0, 50.0), (250.0, 52.0));
+    assert_ne!(copy, a);
+    assert_eq!(at(&s, copy), (200.0, 0.0), "the copy's top lines up with the original's");
+    assert_eq!(at(&s, a), (0.0, 0.0), "the original stays");
+}
+
+#[test]
+fn an_alt_dragged_copy_spaces_equally_with_the_layer_it_came_from() {
+    let mut s = Session::new();
+    rect(&mut s, 0.0, 0.0);
+    rect(&mut s, 200.0, 0.0);
+    // B's copy dropped 2 px short of the 100 gap that A and B have.
+    let copy = alt_drag(&mut s, (250.0, 50.0), (448.0, 50.0));
+    assert_eq!(at(&s, copy), (400.0, 0.0));
+}
+
+#[test]
+fn duplicate_repeats_the_step_set_by_moving_the_copy() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0, 0.0);
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    let c1 = cmd_d(&mut s);
+    assert_eq!(at(&s, c1), (0.0, 0.0), "the first copy lands in place");
+    ex(&mut s, "node.set", json!({"ids": [c1], "props": {"x": 150, "y": 20}}));
+    let c2 = cmd_d(&mut s);
+    assert_eq!(at(&s, c2), (300.0, 40.0), "the next one as far again");
+    let c3 = cmd_d(&mut s);
+    assert_eq!(at(&s, c3), (450.0, 60.0), "and again");
+}
+
+#[test]
+fn duplicate_after_an_alt_drag_repeats_its_step() {
+    let mut s = Session::new();
+    rect(&mut s, 0.0, 0.0);
+    let copy = alt_drag(&mut s, (50.0, 50.0), (180.0, 50.0));
+    assert_eq!(at(&s, copy), (130.0, 0.0));
+    let next = cmd_d(&mut s);
+    assert_eq!(at(&s, next), (260.0, 0.0));
+}
+
+#[test]
+fn duplicate_only_repeats_for_the_last_copies() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0, 0.0);
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    let c1 = cmd_d(&mut s);
+    ex(&mut s, "node.set", json!({"ids": [c1], "props": {"x": 150}}));
+    // Another selection forgets it: the original duplicates in place.
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    ex(&mut s, "select.set", json!({"ids": [c1]}));
+    let c2 = cmd_d(&mut s);
+    assert_eq!(at(&s, c2), (150.0, 0.0), "the step was forgotten when the selection changed");
+    // An offset given explicitly wins over a remembered one.
+    ex(&mut s, "node.set", json!({"ids": [c2], "props": {"x": 300}}));
+    let out = ex(&mut s, "edit.duplicate", json!({"dx": 10}));
+    let c3 = id_of(&out["ids"][0]).unwrap();
+    assert_eq!(at(&s, c3), (310.0, 0.0));
+}
+
+#[test]
+fn undo_doesnt_let_a_new_layer_take_a_remembered_step() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0, 0.0);
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    let c1 = cmd_d(&mut s);
+    ex(&mut s, "node.set", json!({"ids": [c1], "props": {"x": 150}}));
+    ex(&mut s, "edit.undo", json!({}));
+    ex(&mut s, "edit.undo", json!({}));
+    assert!(!s.doc().unwrap().contains(c1));
+    // Undo gives ids back: the new rectangle may well get the undone copy's.
+    let r = rect(&mut s, 500.0, 500.0);
+    ex(&mut s, "select.set", json!({"ids": [r]}));
+    let c = cmd_d(&mut s);
+    assert_eq!(at(&s, c), (500.0, 500.0), "a plain duplicate, in place");
+}
+
+#[test]
+fn the_step_is_measured_in_page_space_inside_a_rotated_frame() {
+    let mut s = Session::new();
+    let f = id_of(&ex(&mut s, "frame.create", json!({"x": 0, "y": 0, "width": 600, "height": 600}))["id"]).unwrap();
+    ex(&mut s, "node.set", json!({"ids": [f], "props": {"rotation": 30}}));
+    let a = id_of(&ex(&mut s, "shape.rectangle", json!({"x": 50, "y": 50, "width": 40, "height": 40, "parent": f}))["id"]).unwrap();
+    ex(&mut s, "select.set", json!({"ids": [a]}));
+    let c1 = cmd_d(&mut s);
+    ex(&mut s, "node.set", json!({"ids": [c1], "props": {"x": 150}}));
+    let (p0, p1) = (at(&s, a), at(&s, c1));
+    let c2 = cmd_d(&mut s);
+    let p2 = at(&s, c2);
+    let close = |a: f64, b: f64| (a - b).abs() < 1e-6;
+    assert!(close(p2.0 - p1.0, p1.0 - p0.0) && close(p2.1 - p1.1, p1.1 - p0.1), "{p0:?} {p1:?} {p2:?}");
+}
+
+#[test]
+fn an_alt_drag_into_auto_layout_sets_no_step() {
+    let mut s = Session::new();
+    let f = id_of(&ex(&mut s, "frame.create", json!({"x": 0, "y": 0, "width": 400, "height": 100}))["id"]).unwrap();
+    for i in 0..2 {
+        ex(&mut s, "shape.rectangle", json!({"x": i * 60, "y": 0, "width": 50, "height": 30, "parent": f}));
+    }
+    ex(&mut s, "layout.add", json!({"ids": [f]}));
+    ex(&mut s, "select.none", json!({}));
+    let kids = s.doc().unwrap().node(f).unwrap().children.clone();
+    let b = s.doc().unwrap().world_bounds(kids[0]).unwrap();
+    let from = (b.center().x, b.center().y);
+    alt_drag(&mut s, from, (from.0 + 70.0, from.1));
+    assert!(s.ds().unwrap().last_duplicate.is_none(), "the layout placed the copy: no step to repeat");
+    let n = s.doc().unwrap().node(f).unwrap().children.len();
+    cmd_d(&mut s);
+    assert_eq!(s.doc().unwrap().node(f).unwrap().children.len(), n + 1, "Duplicate still adds one to the flow");
+}
@@ -85,3 +85,24 @@ fn inspect_and_css_show_the_new_effects() {
    let css = code_for(doc, r, CodeLang::Css);
    assert!(css.contains("backdrop-filter: blur(2px);"), "{css}");
 }
+
+#[test]
+fn negative_or_fractional_index_is_refused_not_item_zero() {
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    s.execute("effect.add", &json!({"ids": [r], "type": "layerBlur"})).unwrap();
+    s.execute("export.add", &json!({"ids": [r]})).unwrap();
+    s.execute("export.add", &json!({"ids": [r]})).unwrap();
+    let before = s.doc().unwrap().node(r).unwrap().clone();
+    assert_eq!(before.exports.len(), 2);
+    for index in [json!(-1), json!(-0.5), json!(1.5)] {
+        let set = json!({"ids": [r], "index": index, "effect": {"type": "dropShadow"}});
+        assert!(s.execute("effect.set", &set).is_err(), "effect.set index {index}");
+        let upd = json!({"ids": [r], "index": index, "format": "svg"});
+        assert!(s.execute("export.update", &upd).is_err(), "export.update index {index}");
+        assert!(s.execute("export.remove", &json!({"ids": [r], "index": index})).is_err(), "export.remove index {index}");
+        let n = s.doc().unwrap().node(r).unwrap();
+        assert_eq!(n.effects, before.effects, "index {index}");
+        assert_eq!(n.exports, before.exports, "index {index}");
+    }
+}
@@ -0,0 +1,107 @@
+//! The documented gradient shorthand (`{"type":"linearGradient","stops":["#hex",…]}`) works
+//! through every route into the engine, not only MCP (#252): `figcraft-cli run` and the control
+//! channel send params straight to `Session::execute`.
+
+use figcraft_color::Paint;
+use figcraft_doc::NodeId;
+use serde_json::{Value, json};
+
+use crate::Session;
+use crate::params::{id_of, paint_of};
+
+/// The red→blue left-to-right gradient as written in the docs.
+fn short() -> Value {
+    json!({"type": "linearGradient", "stops": ["#ff0000", "#0000ff"], "from": [0, 0.5], "to": [1, 0.5]})
+}
+
+/// The same gradient in the engine's own form.
+fn long() -> Value {
+    json!({"type": "gradient", "kind": "linear",
+        "stops": [{"position": 0, "color": {"r": 1, "g": 0, "b": 0, "a": 1}},
+                  {"position": 1, "color": {"r": 0, "g": 0, "b": 1, "a": 1}}],
+        "from": [0, 0.5], "to": [1, 0.5], "width": [0, 1.5]})
+}
+
+fn rect(s: &mut Session) -> NodeId {
+    id_of(&s.execute("shape.rectangle", &json!({"x": 0, "y": 0, "width": 200, "height": 100})).unwrap()["id"]).unwrap()
+}
+
+fn fills(s: &Session, id: NodeId) -> Vec<Paint> {
+    s.doc().unwrap().node(id).unwrap().fills.clone()
+}
+
+#[test]
+fn the_shorthand_reads_as_the_long_form() {
+    assert_eq!(paint_of(&short()).expect("the documented shorthand is a paint"), paint_of(&long()).unwrap());
+}
+
+#[test]
+fn node_set_takes_the_shorthand() {
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    s.execute("node.set", &json!({"ids": [r], "fills": [short()]})).unwrap();
+    s.execute("node.set", &json!({"ids": [r], "strokes": [short()]})).unwrap();
+    let want = paint_of(&long()).unwrap();
+    assert_eq!(fills(&s, r), vec![want.clone()]);
+    assert_eq!(s.doc().unwrap().node(r).unwrap().strokes, vec![want]);
+}
+
+#[test]
+fn node_create_fill_add_and_fill_set_take_the_shorthand() {
+    let want = paint_of(&long()).unwrap();
+    let mut s = Session::new();
+    let v = s.execute("node.create", &json!({"type": "rectangle", "width": 200, "height": 100, "props": {"fills": [short()]}})).unwrap();
+    let r = id_of(&v["id"]).unwrap();
+    assert_eq!(fills(&s, r), vec![want.clone()]);
+    s.execute("fill.add", &json!({"ids": [r], "paint": short()})).unwrap();
+    assert_eq!(fills(&s, r), vec![want.clone(), want.clone()]);
+    let r2 = rect(&mut s);
+    s.execute("fill.set", &json!({"ids": [r2], "index": 0, "paint": short()})).unwrap();
+    assert_eq!(fills(&s, r2), vec![want]);
+}
+
+#[test]
+fn shorthand_defaults_match_the_mcp_server() {
+    // No handles: top to bottom, with a square width handle.
+    let p = paint_of(&json!({"type": "linearGradient", "stops": ["#000000", "#ffffff"]})).unwrap();
+    let v = serde_json::to_value(&p).unwrap();
+    assert_eq!(
+        (v["kind"].clone(), v["from"].clone(), v["to"].clone(), v["width"].clone()),
+        (json!("linear"), json!([0.5, 0.0]), json!([0.5, 1.0]), json!([-0.5, 0.0]))
+    );
+    // Plain colour stops are spread evenly.
+    let p = paint_of(&json!({"type": "radialGradient", "stops": ["#000000", "#808080", "#ffffff"]})).unwrap();
+    let v = serde_json::to_value(&p).unwrap();
+    assert_eq!(v["kind"], "radial");
+    let pos: Vec<f64> = v["stops"].as_array().unwrap().iter().map(|s| s["position"].as_f64().unwrap()).collect();
+    assert_eq!(pos, vec![0.0, 0.5, 1.0]);
+    for kind in ["angular", "diamond"] {
+        let p = paint_of(&json!({"type": format!("{kind}Gradient"), "stops": ["#000000", "#ffffff"]})).unwrap();
+        assert_eq!(serde_json::to_value(&p).unwrap()["kind"], kind);
+    }
+    // A CSS colour inside a solid paint or a positioned stop is read too.
+    assert_eq!(paint_of(&json!({"type": "solid", "color": "#00ff00"})), paint_of(&json!("#00ff00")));
+    let p = paint_of(&json!({"type": "gradient", "stops": [{"position": 0, "color": "#ff0000"}, {"position": 1, "color": "#0000ff"}], "from": [0, 0.5], "to": [1, 0.5]})).unwrap();
+    assert_eq!(p, paint_of(&long()).unwrap());
+}
+
+#[test]
+fn junk_is_still_refused() {
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    for junk in [
+        json!({"type": "linearGradient", "stops": "red"}),
+        json!({"type": "linearGradient", "stops": [42]}),
+        json!({"type": "fooGradient", "stops": ["#ff0000"]}),
+        json!({"type": "linearGradient", "stops": ["#ff0000"], "from": "left"}),
+    ] {
+        let e = s.execute("node.set", &json!({"ids": [r], "fills": [junk.clone()]})).unwrap_err().to_string();
+        assert!(e.contains("`fills` must be paints or colours"), "{junk}: {e}");
+    }
+    // Deep nesting doesn't overflow the stack.
+    let mut deep = json!("#ff0000");
+    for _ in 0..200 {
+        deep = json!({"type": "linearGradient", "stops": [{"position": 0, "color": deep}]});
+    }
+    assert!(paint_of(&deep).is_none());
+}
@@ -0,0 +1,67 @@
+//! A command that fails part-way (a property that applies, then one that doesn't) leaves nothing
+//! behind — also during an interaction, whose last valid preview and own snapshot survive it.
+
+use serde_json::json;
+
+use crate::Session;
+use crate::params::id_of;
+
+fn rect(s: &mut Session) -> crate::NodeId {
+    id_of(&s.execute("shape.rectangle", &json!({"x": 0, "y": 0, "width": 80, "height": 60})).unwrap()["id"]).unwrap()
+}
+
+/// `width` applies (geometry keys go first), then `visible` fails validation.
+fn partially_applicable(s: &mut Session, id: crate::NodeId) -> crate::Result<serde_json::Value> {
+    s.execute("node.set", &json!({"id": id, "width": 123, "visible": "yes"}))
+}
+
+#[test]
+fn a_failed_command_during_an_interaction_keeps_the_prior_preview() {
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    s.begin_interaction("Move").unwrap();
+    let props = serde_json::Map::from_iter([("x".to_string(), json!(20.0))]);
+    s.preview(|d, _| crate::cmd::props::apply("node.set", d, r, &props)).unwrap();
+    let (previewed, selection, page) = {
+        let ds = s.ds().unwrap();
+        (ds.doc.clone(), ds.selection.clone(), ds.page)
+    };
+    let before_journal = s.journal.clone();
+    let before_history = s.ds().unwrap().history.undo.len();
+
+    assert!(partially_applicable(&mut s, r).is_err());
+
+    // The rejected edit is gone: the command-entry state (the valid preview) is back.
+    let ds = s.ds().unwrap();
+    assert_eq!(*ds.doc, *previewed, "the document is what the preview showed");
+    assert_eq!(ds.doc.node(r).unwrap().width, 80.0);
+    assert_eq!(ds.selection, selection);
+    assert_eq!(ds.page, page);
+    assert_eq!(ds.history.undo.len(), before_history);
+    assert_eq!(s.journal, before_journal);
+
+    // The interaction is alive and commits the preview, not the rejected mutation.
+    s.commit_interaction().unwrap();
+    let n = s.doc().unwrap().node(r).unwrap();
+    assert_eq!((n.width, n.visible), (80.0, true));
+    assert_eq!(n.transform.as_coeffs()[4], 20.0, "the previewed move is committed");
+    assert_eq!(s.undo_depth(), (before_history + 1, 0));
+    assert_eq!(s.undo_labels(1), vec!["Move".to_string()]);
+    s.undo().unwrap();
+    assert_eq!(s.doc().unwrap().node(r).unwrap().transform.as_coeffs()[4], 0.0);
+}
+
+#[test]
+fn a_failed_command_without_an_interaction_still_rolls_back() {
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    let before_journal = s.journal.clone();
+    let before_history = s.ds().unwrap().history.undo.len();
+
+    assert!(partially_applicable(&mut s, r).is_err());
+
+    let n = s.doc().unwrap().node(r).unwrap();
+    assert_eq!((n.width, n.visible), (80.0, true));
+    assert_eq!(s.ds().unwrap().history.undo.len(), before_history);
+    assert_eq!(s.journal, before_journal);
+}
@@ -4,11 +4,11 @@

 use serde_json::{Value, json};

-use crate::Session;
 use crate::cmd::edit::opacity_from_digits;
 use crate::keymap::{Context, GESTURES, Group, KEYS, Mods, Platform, display, lookup, matches, normalize, parse, primary};
 use crate::params::id_of;
 use crate::tools::ToolId;
+use crate::{EngineError, Session};
 use figcraft_doc::NodeId;

 const PLATFORMS: [Platform; 2] = [Platform::Mac, Platform::Other];
@@ -186,6 +186,7 @@ fn opacity_digits() {
    assert_eq!(opacity_from_digits("00"), Some(0.0));
    assert_eq!(opacity_from_digits(""), None);
    assert_eq!(opacity_from_digits("123"), None);
+    assert_eq!(opacity_from_digits("9999999999"), None, "ten digits must not overflow u32");
    assert_eq!(opacity_from_digits("4x"), None);
    assert_eq!(opacity_from_digits("٣"), None, "ASCII digits only");

@@ -201,6 +202,10 @@ fn opacity_digits() {
    ex(&mut s, "edit.undo", json!({}));
    assert_eq!(op(&s, a), 0.3, "one undo step");
    assert!(s.execute("object.opacityKeys", &json!({"digits": "123"})).is_err());
+    assert!(
+        matches!(s.execute("object.opacityKeys", &json!({"digits": "9999999999"})), Err(EngineError::BadParams { .. })),
+        "an overflowing digit string is a parameter error, not a panic"
+    );
    assert!(s.execute("object.opacityKeys", &json!({})).is_err());
    ex(&mut s, "select.none", json!({}));
    assert!(s.execute("object.opacityKeys", &json!({"digits": "1"})).is_err(), "nothing selected");
@@ -107,6 +107,47 @@ pub fn bad(cmd: &str, msg: impl Into<String>) -> EngineError {
    EngineError::BadParams { cmd: cmd.to_string(), msg: msg.into() }
 }

+/// Deepest params nesting `resolve_step_refs` walks before giving up.
+const STEP_REF_MAX_DEPTH: usize = 64;
+
+/// Replace every `{"$step": n}` / `{"$step": n, "field": "…"}` in `v` with that field (default
+/// `id`) of `results[n]`, the result of an earlier batch step.
+fn resolve_step_refs(v: &Value, results: &[Value], step: usize, depth: usize) -> Result<Value> {
+    if depth > STEP_REF_MAX_DEPTH {
+        return Err(bad("command.batch", format!("step {step}: params nest deeper than {STEP_REF_MAX_DEPTH} levels")));
+    }
+    match v {
+        Value::Object(o) if o.contains_key("$step") => {
+            if let Some(k) = o.keys().find(|k| *k != "$step" && *k != "field") {
+                return Err(bad("command.batch", format!("step {step}: a `$step` reference takes only `field`, not `{k}`")));
+            }
+            let n = o
+                .get("$step")
+                .and_then(Value::as_u64)
+                .ok_or_else(|| bad("command.batch", format!("step {step}: `$step` must be a step index (0, 1, …)")))?;
+            let field = match o.get("field") {
+                None => "id",
+                Some(Value::String(f)) => f.as_str(),
+                Some(_) => return Err(bad("command.batch", format!("step {step}: `field` must be a string"))),
+            };
+            let Some(result) = usize::try_from(n).ok().and_then(|n| results.get(n)) else {
+                let range = if step == 0 { "there is none before step 0".to_string() } else { format!("0 to {}", step - 1) };
+                return Err(bad("command.batch", format!("step {step}: `$step` {n} must be an earlier step ({range})")));
+            };
+            result.get(field).cloned().ok_or_else(|| bad("command.batch", format!("step {step}: step {n}'s result has no `{field}`")))
+        }
+        Value::Object(o) => {
+            let mut out = serde_json::Map::with_capacity(o.len());
+            for (k, x) in o {
+                out.insert(k.clone(), resolve_step_refs(x, results, step, depth + 1)?);
+            }
+            Ok(Value::Object(out))
+        }
+        Value::Array(a) => a.iter().map(|x| resolve_step_refs(x, results, step, depth + 1)).collect::<Result<Vec<_>>>().map(Value::Array),
+        _ => Ok(v.clone()),
+    }
+}
+
 /// One undo step.
 #[derive(Clone, Debug)]
 pub struct HistoryEntry {
@@ -328,6 +369,9 @@ pub struct DocState {
    pub guide: Option<(NodeId, usize)>,
    /// The selection's rotation origin, when moved or shown (see [`rotation_origin`]; not saved).
    pub(crate) rotation_origin: Option<rotation_origin::RotationOrigin>,
+    /// The last duplicate while its copies are the selection: Duplicate repeats its offset (see
+    /// [`cmd::edit::Duplicated`]; not saved).
+    pub(crate) last_duplicate: Option<cmd::edit::Duplicated>,
 }

 /// A version shown on the canvas in place of the document: read-only until it's restored or the
@@ -383,6 +427,7 @@ impl DocState {
            focus: None,
            guide: None,
            rotation_origin: None,
+            last_duplicate: None,
        };
        st.zoom_to_fit();
        st
@@ -538,6 +583,10 @@ impl DocState {
        if self.rotation_origin.as_ref().is_some_and(|o| o.ids != self.selection) {
            self.rotation_origin = None;
        }
+        // So does the last duplicate (undo reuses ids: a new layer could take a copy's).
+        if self.last_duplicate.as_ref().is_some_and(|d| !d.is_selection(&self.selection)) {
+            self.last_duplicate = None;
+        }
    }
 }

@@ -552,6 +601,7 @@ pub struct Prefs {
    pub highlight_on_hover: bool,
    pub number_keys_opacity: bool,
    pub show_dimensions: bool,
+    /// "system" by default; an explicit "light" or "dark" choice stays saved.
    pub theme: String,
    /// The widths of the main window's left and right panels (the interface keeps them within its
    /// limits; other windows have their own while they are open).
@@ -564,6 +614,9 @@ pub struct Prefs {
    /// Reduce motion: the interface's own animations are off (the system's setting turns them off
    /// too). Prototype transitions still play.
    pub reduce_motion: bool,
+    /// Files that have a path are saved by themselves a few seconds after they change (the app's
+    /// timer; off: only File ▸ Save writes them).
+    pub auto_save: bool,
    /// `figcraft://` invite links open this app (`collab.registerLinks`); `None`: on for installed
    /// builds, off for development builds.
    pub invite_links: Option<bool>,
@@ -591,6 +644,14 @@ pub struct Prefs {
    /// The Getting started tips on the home screen were closed (Help ▸ Getting started shows them
    /// again).
    pub getting_started_dismissed: bool,
+    /// How each home screen section shows its files, by section id (`"recents"`): `"grid"` (cards
+    /// with the picture each file carries) or `"list"` (a table). Missing: the grid.
+    #[serde(skip_serializing_if = "BTreeMap::is_empty")]
+    pub home_views: BTreeMap<String, String>,
+    /// What the home screen's recent files are ordered by: `"modified"`, `"name"` or `"created"`.
+    pub home_sort: String,
+    /// Which way: `"desc"` (newest first, Z to A) or `"asc"`.
+    pub home_order: String,
 }

 impl Default for Prefs {
@@ -603,11 +664,12 @@ impl Default for Prefs {
            highlight_on_hover: true,
            number_keys_opacity: true,
            show_dimensions: true,
-            theme: "light".into(),
+            theme: "system".into(),
            panel_widths: (240.0, 240.0),
            language: "system".into(),
            user_name: cmd::comment::DEFAULT_AUTHOR.into(),
            reduce_motion: false,
+            auto_save: false,
            invite_links: None,
            plugins: Vec::new(),
            plugin_settings: BTreeMap::new(),
@@ -616,6 +678,9 @@ impl Default for Prefs {
            recent_files: Vec::new(),
            online_files: Vec::new(),
            getting_started_dismissed: false,
+            home_views: BTreeMap::new(),
+            home_sort: "modified".into(),
+            home_order: "desc".into(),
        }
    }
 }
@@ -652,8 +717,8 @@ pub struct Session {
    pub prefs: Prefs,
    pub tool: tools::ToolState,
    pub ui_requests: Vec<UiRequest>,
-    /// The interface's theme once the UI knows it ([`Session::set_ui_dark`]): new files and pages
-    /// get the dark page colour while it is dark. Headless sessions (CLI, MCP, exports) have no
+    /// The interface's theme once the UI knows it ([`Session::set_ui_dark`]): new files get the
+    /// dark page colour while it is dark (added pages take the current page's). Headless sessions (CLI, MCP, exports) have no
    /// theme, so what scripts make is the same everywhere.
    pub ui_dark: Option<bool>,
    /// Command log (id + params) for actions/automation.
@@ -710,7 +775,7 @@ impl Session {
        }
    }

-    /// The background new pages get: the dark page colour while the interface is dark.
+    /// The background a new file's page gets: the dark page colour while the interface is dark.
    pub fn new_page_background(&self) -> figcraft_color::Color {
        if self.ui_dark == Some(true) { figcraft_color::Color::DARK_PAGE } else { figcraft_color::Color::DEFAULT_PAGE }
    }
@@ -826,10 +891,11 @@ impl Session {
                }
            }
            Err(_) => {
-                // Roll back any partial edit.
+                // Roll back any partial edit — also during an interaction, where `before` is the
+                // interaction's last valid preview: restore it and leave the gesture itself (its
+                // own snapshot) alone.
                if let Some((doc, sel, page, uid)) = before
                    && let Some(ds) = self.docs.iter_mut().find(|d| d.uid == uid)
-                    && ds.interaction.is_none()
                {
                    ds.doc = doc;
                    ds.selection = sel;
@@ -1060,9 +1126,20 @@ impl Session {
        self.ui_requests.push(UiRequest { kind: kind.to_string(), data });
    }

-    /// Run several commands as one undo step.
+    /// Run several commands as one undo step. A param value `{"$step": n}` is replaced by the `id`
+    /// in the result of the earlier step `n` (`{"$step": n, "field": "…"}` picks another field),
+    /// so a step can target a layer that an earlier step of the same batch created. Any object
+    /// with a `$step` key in a step's params is such a reference, except inside a nested
+    /// `command.batch` step: its references are to its own steps.
    pub fn batch(&mut self, label: &str, cmds: &[(String, Value)]) -> Result<Vec<Value>> {
-        self.grouped(label, |s| cmds.iter().map(|(id, p)| s.execute(id, p)).collect())
+        self.grouped(label, |s| {
+            let mut results: Vec<Value> = Vec::with_capacity(cmds.len());
+            for (step, (id, p)) in cmds.iter().enumerate() {
+                let p = if id == "command.batch" { p.clone() } else { resolve_step_refs(p, &results, step, 0)? };
+                results.push(s.execute(id, &p)?);
+            }
+            Ok(results)
+        })
    }

    /// Run `f` as one undo step called `label`: the commands it executes push no steps of their
@@ -1071,6 +1148,8 @@ impl Session {
        self.ds()?;
        let before: Vec<_> =
            self.docs.iter().map(|ds| (ds.uid, ds.doc.clone(), ds.selection.clone(), ds.page, ds.history.undo.len(), ds.history.limit)).collect();
+        // An edit inside clears the redo steps; a failed group has to bring them back.
+        let redo_before: Vec<_> = self.docs.iter().map(|ds| ds.history.redo.clone()).collect();
        let active = self.active;
        let journal_len = self.journal.len();

@@ -1088,8 +1167,9 @@ impl Session {

        if result.is_err() {
            self.docs.retain(|ds| before.iter().any(|(uid, _, _, _, _, _)| *uid == ds.uid));
-            for (uid, doc, selection, page, undo_len, limit) in &before {
+            for ((uid, doc, selection, page, undo_len, limit), redo) in before.iter().zip(redo_before) {
                if let Some(ds) = self.docs.iter_mut().find(|ds| ds.uid == *uid) {
+                    ds.history.redo = redo;
                    ds.doc = doc.clone();
                    ds.selection = selection.clone();
                    ds.page = *page;
@@ -1382,6 +1462,8 @@ mod autosave_tests;
 #[cfg(test)]
 mod batch_rollback_tests;
 #[cfg(test)]
+mod batch_step_ref_tests;
+#[cfg(test)]
 mod binding_lists_tests;
 #[cfg(test)]
 mod booleans_tests;
@@ -1430,6 +1512,8 @@ mod double_click_tests;
 #[cfg(test)]
 mod draw_tools_tests;
 #[cfg(test)]
+mod duplicate_spacing_tests;
+#[cfg(test)]
 mod effects_tests;
 #[cfg(test)]
 mod export_behaviour_tests;
@@ -1456,6 +1540,8 @@ mod fx_behaviour_tests;
 #[cfg(test)]
 mod gesture_preview_tests;
 #[cfg(test)]
+mod gradient_shorthand_tests;
+#[cfg(test)]
 mod hide_publishing_tests;
 #[cfg(test)]
 mod history_behaviour_tests;
@@ -1466,6 +1552,8 @@ mod import_export_tests;
 #[cfg(test)]
 mod inspect_behaviour_tests;
 #[cfg(test)]
+mod interaction_rollback_tests;
+#[cfg(test)]
 mod invite_links_tests;
 #[cfg(test)]
 mod keymap_tests;
@@ -1506,6 +1594,8 @@ mod panels_behaviour_tests;
 #[cfg(test)]
 mod pdf_print_tests;
 #[cfg(test)]
+mod pen_overlay_tests;
+#[cfg(test)]
 mod pixel_preview_tests;
 #[cfg(test)]
 mod playground_tests;
@@ -517,6 +517,11 @@ pub trait LiveLink: Send {
    fn background(&mut self, _job: u64, _req: NetRequest) -> bool {
        false
    }
+    /// Remove client `client` from session `session`, which this link hosts: they are
+    /// disconnected and can't join again from their address while it runs. Returns at once.
+    fn remove(&mut self, _session: SessionId, _client: u32) -> std::result::Result<(), String> {
+        Err("removing people needs the desktop app or the MCP server".into())
+    }
    /// End session `session` (stop hosting or leave); the others go on. Nothing for a session
    /// that is over already.
    fn leave(&mut self, session: SessionId);
@@ -1889,6 +1894,59 @@ fn follow(s: &mut Session, p: &Value) -> Result<Value> {
    Ok(json!({"follow": s.live().follow}))
 }

+/// Remove someone from the open file's session: in a session this app hosts, the hub drops them;
+/// in a file of yours on a server, the server does (with the file's owner token). They are told
+/// the session is over for them, keep their copy, and can't join again from their address while
+/// the session (or the server) runs.
+fn remove_person(s: &mut Session, p: &Value) -> Result<Value> {
+    const CMD: &str = "collab.removePerson";
+    let client =
+        get(p, "client").and_then(Value::as_u64).and_then(|n| u32::try_from(n).ok()).ok_or_else(|| bad(CMD, "`client` must be a client id"))?;
+    let live = s.live();
+    if live.status != Status::Live {
+        return Err(bad(CMD, "the open file isn't in a live session"));
+    }
+    let name =
+        live.peers.get(&client).map(|p| p.name.clone()).ok_or_else(|| bad(CMD, format!("nobody with client id {client} is in the session")))?;
+    let (id, role, server_file) = (live.id, live.role(), live.server_file());
+    match (role, server_file) {
+        (Some(Role::Host), _) => {
+            let link = s.live.link.as_deref_mut().ok_or_else(|| unavailable(CMD))?;
+            link.remove(id, client).map_err(EngineError::Other)?;
+        }
+        (Some(Role::Guest), Some((server, file))) => {
+            let owner =
+                s.live().published.as_ref().and_then(|p| p.owner.clone()).or_else(|| s.online_owner(&server, &file)).filter(|o| !o.is_empty());
+            let owner = owner.ok_or_else(|| bad(CMD, "only the file's owner can remove people from it"))?;
+            let req = Some(Admin::RemovePeer { file: file.clone(), client });
+            match hosting_request(s, CMD, &server, &file, &owner, req) {
+                Ok((_, Some(AdminReply::Done))) => {}
+                Ok(_) => return Err(EngineError::Other(format!("couldn't remove {name}: the server answered something else"))),
+                // A server older than this request can't read it.
+                Err(e) => return Err(EngineError::Other(format!("couldn't remove {name}: {e} (the server may be older than removing people)"))),
+            }
+        }
+        _ => return Err(bad(CMD, "only the person hosting the session, or the file's owner, can remove people")),
+    }
+    s.message = Some(format!("{name} was removed from the session"));
+    Ok(json!({"removed": client, "name": name}))
+}
+
+/// You may remove others from the open file's session: you host it, or it is your file on a
+/// server.
+pub fn can_remove_people(s: &Session) -> bool {
+    let live = s.live();
+    live.status == Status::Live
+        && match live.role() {
+            Some(Role::Host) => true,
+            Some(Role::Guest) => live.server_file().is_some_and(|(server, file)| {
+                live.published.as_ref().and_then(|p| p.owner.as_deref()).is_some_and(|o| !o.is_empty())
+                    || s.online_owner(&server, &file).is_some_and(|o| !o.is_empty())
+            }),
+            None => false,
+        }
+}
+
 fn cursor(s: &mut Session, p: &Value) -> Result<Value> {
    let at = match (num(p, "x"), num(p, "y")) {
        (Some(x), Some(y)) => Some((x, y)),
@@ -1997,6 +2055,13 @@ pub fn specs() -> Vec<CommandSpec> {
            |s, _| Ok(s.live_summary())
        ),
        spec!("collab.follow", "Follow", "{client? (a peer's id; omit to stop following)} → {follow}", false, follow),
+        spec!(
+            "collab.removePerson",
+            "Remove from session",
+            "{client (a peer's id)} → {removed, name}: they are disconnected (they keep their copy) and can't join again from their address while the session runs; only the person hosting, or the owner of a file on a server, can do it",
+            false,
+            remove_person
+        ),
        spec!(
            "collab.cursor",
            "Show cursor at",
@@ -28,6 +28,8 @@ pub(crate) struct Script {
    /// The session each presence in `sent` and each message in `msgs` was for.
    pub(crate) sent_to: Vec<u64>,
    pub(crate) msgs_to: Vec<u64>,
+    /// The people removed: `(session, client)`.
+    pub(crate) removed: Vec<(u64, u32)>,
 }

 pub(crate) struct Mock(pub(crate) Arc<Mutex<Script>>);
@@ -62,6 +64,10 @@ impl LiveLink for Mock {
        s.published.push(opts);
        Ok(())
    }
+    fn remove(&mut self, session: u64, client: u32) -> Result<(), String> {
+        self.0.lock().unwrap().removed.push((session, client));
+        Ok(())
+    }
    fn leave(&mut self, session: u64) {
        let mut s = self.0.lock().unwrap();
        s.left += 1;
@@ -314,6 +320,43 @@ fn the_host_ending_resets_everything() {
    assert_eq!(s.message.as_deref(), Some("The host ended the session"));
 }

+#[test]
+fn the_host_removes_people_and_guests_cant() {
+    let (mut s, script) = session();
+    let remove = |s: &mut Session, client: serde_json::Value| s.execute("collab.removePerson", &json!({ "client": client }));
+    // Not in a session: nobody to remove.
+    assert!(matches!(remove(&mut s, json!(2)), Err(EngineError::BadParams { .. })));
+    assert!(!crate::live::can_remove_people(&s));
+    s.execute("collab.host", &json!({})).unwrap();
+    let id = s.live().id;
+    push(&script, vec![Event::PeerJoined(peer(2, "Ada")), Event::PeerJoined(peer(3, "Bo"))]);
+    s.live_poll();
+    assert!(crate::live::can_remove_people(&s));
+    // Only someone who is here, by a client id.
+    for bad in [json!(9), json!(1), json!(-2), json!("2"), json!(4_294_967_296u64)] {
+        assert!(matches!(remove(&mut s, bad.clone()), Err(EngineError::BadParams { .. })), "{bad}");
+    }
+    let r = remove(&mut s, json!(2)).unwrap();
+    assert_eq!((r["removed"].as_u64(), r["name"].as_str()), (Some(2), Some("Ada")));
+    assert_eq!(script.lock().unwrap().removed, [(id, 2)]);
+    assert_eq!(s.message.as_deref(), Some("Ada was removed from the session"));
+    // The host's own session tells them she left.
+    push(&script, vec![Event::PeerLeft(2)]);
+    s.live_poll();
+    assert_eq!(s.live().peers.keys().copied().collect::<Vec<_>>(), [3]);
+    s.execute("collab.stop", &json!({})).unwrap();
+
+    // A guest in someone else's session can't remove anyone.
+    let (mut s, script) = session();
+    s.execute("collab.join", &json!({"link": "figcraft://join?host=a:1&file=f&token=t"})).unwrap();
+    push(&script, vec![Event::Welcome { info: info(Role::Guest, 2), peers: vec![peer(1, "Hana"), peer(3, "Bo")] }]);
+    s.live_poll();
+    assert!(!crate::live::can_remove_people(&s));
+    let e = remove(&mut s, json!(3)).unwrap_err().to_string();
+    assert!(e.contains("only the person hosting"), "{e}");
+    assert!(script.lock().unwrap().removed.is_empty());
+}
+
 #[test]
 fn collab_commands_survive_junk() {
    let junk = [
@@ -196,16 +196,17 @@ fn alt_drag_shows_live_distances_to_the_neighbours() {
        e
    };
    s.pointer(&ev(PointerKind::Down, 30.0)).unwrap();
-    // Alt duplicates: the copy moves to 110..160, between the original and the other layer.
+    // Alt duplicates: the copy, dragged to 110..160, snaps to equal spacing between the original
+    // and the other layer (105..155).
    s.pointer(&ev(PointerKind::Move, 130.0)).unwrap();
    let g = s.tool.overlay.guides.clone();
    assert_eq!(
        labelled(&g),
        vec![
-            ("30".into(), [135, 0, 135, 30]),
-            ("30".into(), [135, 70, 135, 100]),
-            ("40".into(), [160, 50, 200, 50]),
-            ("50".into(), [60, 50, 110, 50])
+            ("30".into(), [130, 0, 130, 30]),
+            ("30".into(), [130, 70, 130, 100]),
+            ("45".into(), [60, 50, 105, 50]),
+            ("45".into(), [155, 50, 200, 50])
        ]
    );
    s.pointer(&ev(PointerKind::Up, 130.0)).unwrap();
@@ -33,6 +33,19 @@ fn open_recent_lists_opens_prunes_and_clears() {
    let _ = std::fs::remove_dir_all(&dir);
 }

+#[test]
+fn one_recent_file_is_forgotten_and_nothing_opens() {
+    let mut s = Session::empty();
+    s.prefs.recent_files = vec!["/tmp/a.figcraft".into(), "/tmp/b.fig".into(), "/tmp/c.svg".into()];
+    let list = s.execute("file.openRecent", &json!({"remove": "/tmp/b.fig"})).unwrap();
+    assert_eq!(s.prefs.recent_files, vec!["/tmp/a.figcraft".to_string(), "/tmp/c.svg".to_string()]);
+    assert_eq!(list["files"].as_array().map(Vec::len), Some(2), "the list as it is now");
+    assert!(s.docs.is_empty(), "nothing opens");
+    // A path that isn't in the list changes nothing.
+    s.execute("file.openRecent", &json!({"remove": "/tmp/zzz.fig"})).unwrap();
+    assert_eq!(s.prefs.recent_files.len(), 2);
+}
+
 #[test]
 fn recent_files_are_capped() {
    let dir = std::env::temp_dir().join(format!("figcraft-recent-cap-{}", std::process::id()));
@@ -337,6 +337,34 @@ fn pages_by_the_documented_rules() {
    assert_ne!(s.page().unwrap(), div, "deleting the open page opens a page, never a divider");
 }

+#[test]
+fn page_move_refuses_what_is_not_a_page() {
+    let mut s = Session::new();
+    let r = rect(&mut s, "r", 30.0, 40.0, None);
+    let before = pages(&mut s);
+    assert!(s.execute("page.move", &json!({"id": r, "index": 0})).is_err(), "a layer id is not a page");
+    assert!(s.execute("page.move", &json!({"id": 999999, "index": 0})).is_err(), "a page that isn't there is not a page");
+    assert_eq!(pages(&mut s), before, "the page list is untouched");
+    assert!(s.doc().unwrap().validate().is_empty(), "the document still checks out");
+}
+
+#[test]
+fn page_select_and_doc_switch_refuse_negative_or_fractional_indexes() {
+    let mut s = Session::new();
+    let p2 = id(&ex(&mut s, "page.add", json!({})));
+    for bad_index in [json!(-1), json!(0.5)] {
+        assert!(s.execute("page.select", &json!({"index": bad_index})).is_err(), "page.select index {bad_index} must fail");
+        assert_eq!(s.page().unwrap(), p2, "page.select index {bad_index} leaves the open page alone");
+    }
+    ex(&mut s, "file.new", json!({}));
+    let active = s.active;
+    assert_eq!(active, 1);
+    for bad_index in [json!(-1), json!(0.5)] {
+        assert!(s.execute("doc.switch", &json!({"index": bad_index})).is_err(), "doc.switch index {bad_index} must fail");
+        assert_eq!(s.active, active, "doc.switch index {bad_index} leaves the active tab alone");
+    }
+}
+
 #[test]
 fn assets_panel_lists_files_and_drops_by_the_documented_rules() {
    let mut s = Session::new();
@@ -386,3 +414,14 @@ fn assets_panel_lists_files_and_drops_by_the_documented_rules() {
    assert_eq!(kids(&s, row).first(), Some(&into), "an asset dropped in an auto layout frame joins the flow where it is dropped");
    assert_eq!(s.doc().unwrap().page_of(into), Some(page));
 }
+
+#[test]
+fn duplicating_a_layer_named_past_the_counter_does_not_overflow() {
+    let mut s = Session::new();
+    ex(&mut s, "pref.renameDuplicates", json!({"on": true}));
+    let r = rect(&mut s, "r", 30.0, 40.0, None);
+    ex(&mut s, "node.set", json!({"id": r, "props": {"name": "Layer 18446744073709551615"}}));
+    let dup = id_of(&ex(&mut s, "edit.duplicate", json!({"ids": [r]}))["ids"][0]).unwrap();
+    assert_eq!(name(&s, dup), "Layer 18446744073709551615 2");
+    assert!(s.doc().unwrap().validate().is_empty(), "the document still checks out");
+}
@@ -3,7 +3,7 @@

 use figcraft_color::{BlendMode, Color, Paint};
 use figcraft_doc::NodeId;
-use serde_json::Value;
+use serde_json::{Value, json};

 use crate::{EngineError, Result, Session, bad};

@@ -135,12 +135,80 @@ pub fn color(p: &Value, key: &str) -> Option<Color> {
    get(p, key).and_then(color_of)
 }

-/// A paint from JSON: a colour string/object (solid) or a full paint object.
+/// Read the friendlier paint/effect JSON that the docs and MCP tools describe as the engine's own
+/// form: any `"color"` given as a CSS string ("#RRGGBB[AA]", "rgb(…)") becomes {r,g,b,a},
+/// `{"type":"linearGradient"}` becomes `{"type":"gradient","kind":"linear"}`, gradients get default
+/// handles (top to bottom) when `from`/`to`/`width` are missing, and stops given as plain colours
+/// are spread evenly. Anything else is left for serde to refuse.
+pub fn normalize_paint(v: &mut Value) {
+    normalize_paintish(v, 0);
+}
+
+fn normalize_paintish(v: &mut Value, depth: usize) {
+    if depth > 16 {
+        return;
+    }
+    match v {
+        Value::Array(a) => {
+            for x in a {
+                normalize_paintish(x, depth + 1);
+            }
+        }
+        Value::Object(o) => {
+            if let Some(c) = o.get("color").filter(|c| c.is_string()).and_then(color_of) {
+                o.insert("color".into(), serde_json::to_value(c).unwrap_or(Value::Null));
+            }
+            let is_gradient = o.get("type").and_then(Value::as_str).is_some_and(|t| t.to_ascii_lowercase().contains("gradient"));
+            if is_gradient {
+                // Accept {"type":"linearGradient"} as well as {"type":"gradient","kind":"linear"}.
+                if let Some(t) = o.get("type").and_then(Value::as_str).map(str::to_ascii_lowercase)
+                    && t != "gradient"
+                {
+                    let kind = t.trim_end_matches("gradient").to_string();
+                    o.insert("type".into(), json!("gradient"));
+                    o.entry("kind").or_insert(json!(if kind.is_empty() { "linear".to_string() } else { kind }));
+                }
+                o.entry("kind").or_insert(json!("linear"));
+                let linear = o.get("kind").and_then(Value::as_str) == Some("linear");
+                let (from, to, width) = if linear { ([0.5, 0.0], [0.5, 1.0], [-0.5, 0.0]) } else { ([0.5, 0.5], [0.5, 1.0], [1.0, 0.5]) };
+                o.entry("from").or_insert(json!(from));
+                o.entry("to").or_insert(json!(to));
+                // A linear gradient's width handle goes square to its axis (else its bands skew,
+                // or vanish when the handle lies on the axis).
+                let pt = |k: &str| o.get(k).and_then(Value::as_array).and_then(|a| Some((a.first()?.as_f64()?, a.get(1)?.as_f64()?)));
+                if linear
+                    && !o.contains_key("width")
+                    && let (Some(f), Some(t)) = (pt("from"), pt("to"))
+                {
+                    o.insert("width".into(), json!([f.0 - (t.1 - f.1), f.1 + (t.0 - f.0)]));
+                }
+                o.entry("width").or_insert(json!(width));
+                if let Some(Value::Array(stops)) = o.get_mut("stops") {
+                    let n = stops.len();
+                    for (i, s) in stops.iter_mut().enumerate() {
+                        if let Some(c) = color_of(s).filter(|_| s.is_string()) {
+                            let pos = if n > 1 { i as f64 / (n - 1) as f64 } else { 0.0 };
+                            *s = json!({"position": pos, "color": c});
+                        } else {
+                            normalize_paintish(s, depth + 1);
+                        }
+                    }
+                }
+            }
+        }
+        _ => {}
+    }
+}
+
+/// A paint from JSON: a colour string/object (solid), a full paint object or its shorthand
+/// ([`normalize_paint`]).
 pub fn paint_of(v: &Value) -> Option<Paint> {
    if let Some(c) = color_of(v) {
        return Some(Paint::solid(c));
    }
-    let mut p: Paint = serde_json::from_value(v.clone()).ok()?;
+    let mut v = v.clone();
+    normalize_paint(&mut v);
+    let mut p: Paint = serde_json::from_value(v).ok()?;
    p.opacity = if p.opacity.is_finite() { p.opacity.clamp(0.0, 1.0) } else { 1.0 };
    Some(p)
 }
@@ -0,0 +1,65 @@
+//! What the Pen tool shows while a path is drawn (`tool.overlay`): the handles shaping the segments
+//! at the pen, and the rubber band to the pointer, which follows the last anchor's out handle.
+
+use crate::Session;
+use crate::tools::{PointerEvent, PointerKind, ToolId};
+
+fn at(s: &mut Session, kind: PointerKind, x: f64, y: f64) {
+    s.pointer(&PointerEvent::at(kind, x, y, 1.0)).unwrap();
+}
+
+/// A press at (x, y) dragged to (to_x, to_y) and released: a smooth point with out handle
+/// (to - p).
+fn drag_point(s: &mut Session, x: f64, y: f64, to_x: f64, to_y: f64) {
+    at(s, PointerKind::Down, x, y);
+    at(s, PointerKind::Move, to_x, to_y);
+    at(s, PointerKind::Up, to_x, to_y);
+}
+
+#[test]
+fn the_dragged_point_shows_its_handles_and_the_one_before_its_out_handle() {
+    let mut s = Session::new();
+    s.set_tool(ToolId::Pen);
+    drag_point(&mut s, 100.0, 100.0, 140.0, 100.0);
+    assert_eq!(s.tool.overlay.pen_handles, vec![[100.0, 100.0, 60.0, 100.0], [100.0, 100.0, 140.0, 100.0]], "in and out of the first point");
+    // The second point, mid-drag.
+    at(&mut s, PointerKind::Down, 200.0, 200.0);
+    assert_eq!(s.tool.overlay.rubber, None, "the press shows the segment itself, not a straight band");
+    at(&mut s, PointerKind::Move, 200.0, 240.0);
+    assert_eq!(
+        s.tool.overlay.pen_handles,
+        vec![[100.0, 100.0, 140.0, 100.0], [200.0, 200.0, 200.0, 160.0], [200.0, 200.0, 200.0, 240.0]],
+        "the one before's out handle, then the dragged point's in and out"
+    );
+    at(&mut s, PointerKind::Up, 200.0, 240.0);
+    // Moving on: the band leaves along the last out handle.
+    at(&mut s, PointerKind::Hover, 300.0, 200.0);
+    assert_eq!(s.tool.overlay.rubber, Some([200.0, 200.0, 300.0, 200.0]));
+    assert_eq!(s.tool.overlay.rubber_handle, Some([200.0, 240.0]));
+}
+
+#[test]
+fn corner_points_have_no_handles_and_a_straight_band() {
+    let mut s = Session::new();
+    s.set_tool(ToolId::Pen);
+    for (x, y) in [(100.0, 100.0), (200.0, 100.0)] {
+        at(&mut s, PointerKind::Down, x, y);
+        at(&mut s, PointerKind::Up, x, y);
+    }
+    at(&mut s, PointerKind::Hover, 250.0, 200.0);
+    assert!(s.tool.overlay.pen_handles.is_empty());
+    assert_eq!(s.tool.overlay.rubber, Some([200.0, 100.0, 250.0, 200.0]));
+    assert_eq!(s.tool.overlay.rubber_handle, None, "straight");
+}
+
+#[test]
+fn finishing_the_path_clears_its_handles_and_band() {
+    let mut s = Session::new();
+    s.set_tool(ToolId::Pen);
+    drag_point(&mut s, 100.0, 100.0, 140.0, 100.0);
+    drag_point(&mut s, 200.0, 200.0, 200.0, 240.0);
+    at(&mut s, PointerKind::Hover, 300.0, 200.0);
+    s.pen_finish().unwrap();
+    let ov = &s.tool.overlay;
+    assert!(ov.pen.is_empty() && ov.pen_handles.is_empty() && ov.rubber.is_none() && ov.rubber_handle.is_none());
+}
@@ -431,3 +431,31 @@ fn flatten_and_outline_stroke() {
    let (path, _) = figcraft_render::node_outline(s.doc().unwrap(), &n).unwrap();
    assert!((path.bounding_box().height() - 10.0).abs() < 1e-6, "the outline is as thick as the stroke was");
 }
+
+#[test]
+fn outline_stroke_outlines_every_selected_layer() {
+    // Fixed (#378): with several filled, stroked shapes selected, only the first was outlined.
+    for by_selection in [false, true] {
+        let mut s = Session::new();
+        let a = create(&mut s, "shape.rectangle", json!({"x": 0, "y": 0, "width": 50, "height": 50}));
+        let b = create(&mut s, "shape.rectangle", json!({"x": 100, "y": 0, "width": 50, "height": 50}));
+        let line = create(&mut s, "shape.line", json!({"x": 0, "y": 100, "width": 100, "props": {"strokeWeight": 4}}));
+        ex(&mut s, "node.set", json!({"ids": [a, b], "props": {"strokes": ["#000000"], "strokeWeight": 4}}));
+        let out = if by_selection {
+            s.set_selection(vec![a, b, line]);
+            ex(&mut s, "vector.outlineStroke", json!({}))
+        } else {
+            ex(&mut s, "vector.outlineStroke", json!({"ids": [a, b, line]}))
+        };
+        let ids: Vec<NodeId> = out["ids"].as_array().unwrap().iter().filter_map(id_of).collect();
+        assert_eq!(ids.len(), 3, "one result per layer: {out}");
+        assert!(matches!(node(&s, ids[0]).kind, NodeKind::Group), "filled shape a becomes a group");
+        assert!(matches!(node(&s, ids[1]).kind, NodeKind::Group), "filled shape b becomes a group");
+        assert!(matches!(node(&s, ids[2]).kind, NodeKind::Vector { .. }), "the line becomes a vector");
+        for id in [a, b] {
+            assert!(node(&s, id).strokes.is_empty(), "{id:?} still has its stroke");
+        }
+        assert!(s.doc().unwrap().node(line).is_none(), "the line was replaced by its outline");
+        assert_eq!(s.selection(), ids, "the results are selected");
+    }
+}
@@ -74,15 +74,6 @@ impl Targets {
        // A layer's box in snap space.
        let bbox = |id: NodeId| doc.node(id).map(|n| transform_rect_bbox(to * doc.world_transform(id), n.local_rect())).filter(|b| b.is_finite());
        let mut t = Targets { space, moving: moving.iter().filter_map(|m| bbox(*m)).reduce(|a, b| a.union(b)), ..Default::default() };
-        let push = |r: Rect, t: &mut Targets| {
-            for x in [r.x0, r.center().x, r.x1] {
-                t.xs.push((x, r.y0, r.y1));
-            }
-            for y in [r.y0, r.center().y, r.y1] {
-                t.ys.push((y, r.x0, r.x1));
-            }
-            t.boxes.push(r);
-        };
        let parent = parent_of(doc, page, moving);
        // The parent frame's own box (and its layout grids).
        if parent != page
@@ -109,7 +100,7 @@ impl Targets {
                    continue;
                }
                if let Some(b) = bbox(*c) {
-                    push(b, &mut t);
+                    t.add_box(b);
                }
            }
        }
@@ -136,6 +127,17 @@ impl Targets {
        t
    }

+    /// A box to snap to (in snap space): its edges and centre lines, and equal spacing with it.
+    pub fn add_box(&mut self, r: Rect) {
+        for x in [r.x0, r.center().x, r.x1] {
+            self.xs.push((x, r.y0, r.y1));
+        }
+        for y in [r.y0, r.center().y, r.y1] {
+            self.ys.push((y, r.x0, r.x1));
+        }
+        self.boxes.push(r);
+    }
+
    /// A point to snap onto (a vector point, a segment midpoint): lines through it on both axes,
    /// and a marker when a moving point lands on it.
    pub fn add_point(&mut self, p: Point) {
@@ -161,6 +161,28 @@ fn text_create_autosize_and_edit() {
    assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, "Hello");
 }

+#[test]
+fn find_replace_replaces_every_occurrence_when_replacement_contains_find() {
+    for (text, find, replace, want) in [
+        ("cat and cat", "cat", "cats", "cats and cats"),
+        ("cat and cat", "cat", "category", "category and category"),
+        ("banana", "a", "aa", "baanaanaa"),
+    ] {
+        let mut s = sess();
+        let t = id(&s.execute("text.create", &json!({"text": text, "x": 0, "y": 0})).unwrap());
+        s.execute("edit.findReplace", &json!({"find": find, "replace": replace})).unwrap();
+        assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, want, "{text}: {find} -> {replace}");
+    }
+}
+
+#[test]
+fn find_replace_rejects_empty_find() {
+    let mut s = sess();
+    let t = id(&s.execute("text.create", &json!({"text": "cat", "x": 0, "y": 0})).unwrap());
+    assert!(s.execute("edit.findReplace", &json!({"find": "", "replace": "x"})).is_err());
+    assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, "cat");
+}
+
 #[test]
 fn components_and_instances_sync() {
    let mut s = sess();
@@ -253,6 +275,49 @@ fn align_distribute_zorder() {
    assert_eq!(s.doc().unwrap().node(page).unwrap().children[0], c);
 }

+#[test]
+fn a_layer_alone_on_the_page_has_nothing_to_align_to() {
+    use crate::cmd::arrange::can_align;
+    let mut s = sess();
+    let f = id(&s.execute("frame.create", &json!({"x": 0, "y": 0, "width": 200, "height": 100})).unwrap());
+    let inner = id(&s.execute("shape.rectangle", &json!({"x": 20, "y": 30, "width": 10, "height": 10, "parent": f})).unwrap());
+    let loose = id(&s.execute("shape.rectangle", &json!({"x": 300, "y": 5, "width": 10, "height": 10})).unwrap());
+    let doc = s.doc().unwrap();
+    assert!(!can_align(doc, &[]));
+    assert!(!can_align(doc, &[loose]), "alone on the page");
+    assert!(!can_align(doc, &[f, inner]), "a frame with its own child is the frame alone");
+    assert!(can_align(doc, &[inner]), "one in a frame aligns to it");
+    assert!(can_align(doc, &[f, loose]), "two align to each other");
+    // Where the buttons are off, the command still does nothing (and no harm).
+    let before = doc.world_bounds(loose);
+    s.execute("align.right", &json!({"ids": [loose]})).unwrap();
+    assert_eq!(s.doc().unwrap().world_bounds(loose), before);
+    s.execute("align.right", &json!({"ids": [inner]})).unwrap();
+    assert_eq!(s.doc().unwrap().world_bounds(inner).unwrap().x1, 200.0);
+}
+
+#[test]
+fn send_to_back_across_frames_counts_per_parent() {
+    let mut s = sess();
+    let make = |s: &mut Session, p: Value| id(&s.execute("node.create", &p).unwrap());
+    let fa = make(&mut s, json!({"type": "frame", "x": 0, "y": 0, "width": 200, "height": 200}));
+    let fb = make(&mut s, json!({"type": "frame", "x": 300, "y": 0, "width": 200, "height": 200}));
+    let rect = |parent: NodeId| json!({"type": "rectangle", "parent": parent, "x": 10, "y": 10, "width": 20, "height": 20});
+    let a: Vec<NodeId> = (0..2).map(|_| make(&mut s, rect(fa))).collect();
+    let b: Vec<NodeId> = (0..3).map(|_| make(&mut s, rect(fb))).collect();
+    let idx = |s: &Session, n: NodeId| s.doc().unwrap().index_in_parent(n);
+    assert_eq!(idx(&s, a[1]), Some(1));
+    assert_eq!(idx(&s, b[2]), Some(2));
+    s.execute("arrange.back", &json!({"ids": [a[1], b[2]]})).unwrap();
+    assert_eq!(idx(&s, a[1]), Some(0), "top of frame A at the back");
+    assert_eq!(idx(&s, b[2]), Some(0), "top of frame B at the back");
+    // Two from B plus one from A: each parent's selection ends at 0..n in its original order.
+    s.execute("arrange.back", &json!({"ids": [b[1], a[0], b[0]]})).unwrap();
+    let kids = |s: &Session, f: NodeId| s.doc().unwrap().node(f).unwrap().children.clone();
+    assert_eq!(kids(&s, fa), vec![a[0], a[1]]);
+    assert_eq!(kids(&s, fb), vec![b[0], b[1], b[2]]);
+}
+
 #[test]
 fn copy_paste_and_duplicate() {
    let mut s = sess();
@@ -532,3 +597,27 @@ fn guides_add_move_remove() {
    s.execute("guide.clear", &json!({})).unwrap();
    assert!(guides(&s).is_empty());
 }
+
+#[test]
+fn find_replace_matches_and_replaces_case_insensitively() {
+    let mut s = sess();
+    let t = id(&s.execute("text.create", &json!({"text": "Hello", "x": 0, "y": 0})).unwrap());
+    let u = id(&s.execute("text.create", &json!({"text": "İ HELLO hello", "x": 0, "y": 40})).unwrap());
+    let f = id(&s.execute("frame.create", &json!({"x": 0, "y": 80, "width": 50, "height": 50, "name": "HELLO box"})).unwrap());
+    let chars = |s: &Session, i| s.doc().unwrap().node(i).unwrap().kind.text().unwrap().characters.clone();
+    let r = s.execute("edit.findReplace", &json!({"find": "hello", "replace": "bye", "layerNames": true})).unwrap();
+    assert_eq!(r["matches"], json!([t, u, f]));
+    assert_eq!(chars(&s, t), "bye");
+    assert_eq!(chars(&s, u), "İ bye bye");
+    assert_eq!(s.doc().unwrap().node(f).unwrap().name, "bye box");
+}
+
+#[test]
+fn find_replace_changing_only_the_case_replaces_every_occurrence() {
+    let mut s = sess();
+    let t = id(&s.execute("text.create", &json!({"text": "figcraft and FIGCRAFT, figcraft", "x": 0, "y": 0})).unwrap());
+    let f = id(&s.execute("frame.create", &json!({"x": 0, "y": 80, "width": 50, "height": 50, "name": "figcraft / figcraft"})).unwrap());
+    s.execute("edit.findReplace", &json!({"find": "figcraft", "replace": "FigCraft", "layerNames": true})).unwrap();
+    assert_eq!(s.doc().unwrap().node(t).unwrap().kind.text().unwrap().characters, "FigCraft and FigCraft, FigCraft");
+    assert_eq!(s.doc().unwrap().node(f).unwrap().name, "FigCraft / FigCraft");
+}
@@ -192,3 +192,40 @@ fn paragraph_indent_only_moves_left_aligned_text() {
    let (x, w2) = first_x(&s);
    assert!((w2 - (w - 30.0)).abs() < 1e-6 && x.abs() < 1e-6, "centered auto-width text: no indent, the box shrinks by it");
 }
+
+/// A new text made with the Text tool by a press at `from`, a drag to `to` and a release, holding
+/// `chars`: its box and resize mode.
+fn text_tool(from: (f64, f64), to: (f64, f64), chars: &str) -> (figcraft_geom::Rect, figcraft_doc::TextAutoResize) {
+    use crate::tools::{PointerEvent, PointerKind, ToolId};
+    let mut s = Session::new();
+    s.set_tool(ToolId::Text);
+    s.pointer(&PointerEvent::at(PointerKind::Down, from.0, from.1, 1.0)).unwrap();
+    s.pointer(&PointerEvent::at(PointerKind::Move, to.0, to.1, 1.0)).unwrap();
+    s.pointer(&PointerEvent::at(PointerKind::Up, to.0, to.1, 1.0)).unwrap();
+    crate::textedit::insert(&mut s, chars).unwrap();
+    let t = s.ds().unwrap().text_edit.as_ref().unwrap().id;
+    let doc = s.doc().unwrap();
+    let NodeKind::Text(td) = &doc.node(t).unwrap().kind else { panic!("not a text") };
+    (doc.world_bounds(t).unwrap(), td.auto_resize)
+}
+
+#[test]
+fn a_drag_with_the_text_tool_makes_a_fixed_size_box() {
+    // #360: the drag's size, its top-left where the drag started, and its text wraps in it; a
+    // click, or a drag within a few pixels, still makes auto-width text.
+    use figcraft_doc::TextAutoResize;
+    figcraft_text::scan_system_fonts();
+    let long = "A sentence much longer than eighty pixels";
+    let (line, auto) = text_tool((100.0, 100.0), (100.0, 100.0), long);
+    assert_eq!(auto, TextAutoResize::WidthAndHeight);
+    assert_eq!(text_tool((100.0, 100.0), (101.0, 101.0), long).1, TextAutoResize::WidthAndHeight, "a slip of the hand is a click");
+    let (b, auto) = text_tool((100.0, 100.0), (180.0, 400.0), long);
+    assert_eq!(auto, TextAutoResize::None);
+    assert_eq!((b.x0, b.y0, b.width(), b.height()), (100.0, 100.0, 80.0, 300.0), "the text wraps in a box that keeps its size");
+    // Dragged up and to the left, the box is the same.
+    let (b2, _) = text_tool((180.0, 400.0), (100.0, 100.0), long);
+    assert_eq!((b2.x0, b2.y0, b2.width(), b2.height()), (100.0, 100.0, 80.0, 300.0));
+    // A flat drag still makes a box one line tall.
+    let (b3, _) = text_tool((100.0, 100.0), (180.0, 101.0), "A");
+    assert_eq!((b3.width(), b3.height()), (80.0, line.height()));
+}
@@ -1,7 +1,7 @@
-//! The page colour of new files and pages follows the interface's theme when they are made (dark:
-//! #1E1E1E, light: #F5F5F5) and is the page's own from then on; a session without an interface
-//! (CLI, MCP, exports) has no theme and keeps the light default. Text drawn with the Text tool is
-//! white on a dark page and black on a light one.
+//! The page colour of a new file follows the interface's theme when it is made (dark: #1E1E1E,
+//! light: #F5F5F5) and is the page's own from then on; an added page takes the colour of the page
+//! it was added from. A session without an interface (CLI, MCP, exports) has no theme and keeps the
+//! light default. Text drawn with the Text tool is white on a dark page and black on a light one.

 use figcraft_color::{Color, Paint};
 use figcraft_doc::{NodeId, NodeKind};
@@ -38,8 +38,8 @@ fn draw_text(s: &mut Session, x: f64, y: f64) -> NodeId {
 }

 #[test]
-fn new_files_and_pages_take_the_theme_they_are_made_in() {
-    // (theme the interface reported, colour of a new file's page and of an added page)
+fn new_files_take_the_theme_they_are_made_in_and_added_pages_follow() {
+    // (theme the interface reported, colour of a new file's page and of a page added to it)
    for (dark, want) in [(None, "#F5F5F5"), (Some(false), "#F5F5F5"), (Some(true), "#1E1E1E")] {
        let mut s = Session::empty();
        if let Some(d) = dark {
@@ -62,8 +62,10 @@ fn a_change_of_theme_leaves_existing_pages_alone() {
    ex(&mut s, "file.new", json!({}));
    s.set_ui_dark(false);
    ex(&mut s, "page.add", json!({}));
+    assert_eq!(backgrounds(&s), ["#1E1E1E", "#1E1E1E"], "an added page follows its page, not the theme");
+    ex(&mut s, "page.setBackground", json!({"color": "#F5F5F5"}));
    s.set_ui_dark(true);
-    assert_eq!(backgrounds(&s), ["#1E1E1E", "#F5F5F5"], "each page keeps the colour it was made with");
+    assert_eq!(backgrounds(&s), ["#1E1E1E", "#F5F5F5"], "each page keeps its colour");
    // A copy of a page is that page's colour, whatever the theme.
    let first = s.doc().unwrap().pages[0];
    s.set_ui_dark(false);
@@ -71,6 +73,57 @@ fn a_change_of_theme_leaves_existing_pages_alone() {
    assert_eq!(background(&s, copy), Color::DARK_PAGE);
 }

+#[test]
+fn an_added_page_takes_the_current_pages_colour() {
+    // Whatever the theme, and headless too: the page it was added from decides.
+    for dark in [None, Some(false), Some(true)] {
+        let mut s = Session::empty();
+        if let Some(d) = dark {
+            s.set_ui_dark(d);
+        }
+        ex(&mut s, "file.new", json!({}));
+        ex(&mut s, "page.setBackground", json!({"color": "#336699"}));
+        ex(&mut s, "page.add", json!({}));
+        assert_eq!(backgrounds(&s), ["#336699", "#336699"], "theme {dark:?}");
+        // From the second page, now current, after giving it its own colour.
+        ex(&mut s, "page.setBackground", json!({"color": "#FFE08A"}));
+        ex(&mut s, "page.add", json!({"name": "Third"}));
+        assert_eq!(backgrounds(&s), ["#336699", "#FFE08A", "#FFE08A"], "theme {dark:?}");
+        // One undo step, the colour with it.
+        ex(&mut s, "edit.undo", json!({}));
+        assert_eq!(backgrounds(&s), ["#336699", "#FFE08A"], "theme {dark:?} after undo");
+        ex(&mut s, "edit.redo", json!({}));
+        assert_eq!(backgrounds(&s), ["#336699", "#FFE08A", "#FFE08A"], "theme {dark:?} after redo");
+    }
+    // From a page other than the first: go there, then add.
+    let mut s = Session::new();
+    s.set_ui_dark(true);
+    ex(&mut s, "page.add", json!({}));
+    ex(&mut s, "page.setBackground", json!({"color": "#0B1F3A"}));
+    ex(&mut s, "page.select", json!({"index": 0}));
+    ex(&mut s, "page.add", json!({}));
+    assert_eq!(backgrounds(&s), ["#1E1E1E", "#0B1F3A", "#1E1E1E"], "the current page decides, not the last");
+}
+
+#[test]
+fn added_page_colours_survive_save_and_reopen() {
+    let dir = std::env::temp_dir().join(format!("figcraft-added-pages-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("pages.figcraft");
+    let mut s = Session::new();
+    ex(&mut s, "page.setBackground", json!({"color": "#336699"}));
+    ex(&mut s, "page.add", json!({}));
+    ex(&mut s, "file.saveAs", json!({"path": path.to_string_lossy()}));
+    let mut s = Session::empty();
+    s.set_ui_dark(true);
+    ex(&mut s, "file.open", json!({"path": path.to_string_lossy()}));
+    assert_eq!(backgrounds(&s), ["#336699", "#336699"]);
+    // And a page added to the reopened file in the dark theme follows the file, not the theme.
+    ex(&mut s, "page.add", json!({}));
+    assert_eq!(backgrounds(&s), ["#336699", "#336699", "#336699"]);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
 #[test]
 fn the_file_the_app_opened_with_takes_the_theme_once_it_is_known() {
    // Made before the interface knew its theme, nothing done to it yet.
@@ -118,13 +171,14 @@ fn text_drawn_on_a_dark_page_is_white_and_on_a_light_page_black() {
        let t = draw_text(&mut s, 40.0, 40.0);
        assert_eq!(s.doc().unwrap().node(t).unwrap().fills, vec![Paint::solid(want)], "text drawn on {page}");
    }
-    // In a frame on a dark page too; so is text a command makes in the app (`dark_page_text_tests`).
+    // In a (white) frame on a dark page, readable on the frame (#362); so is text a command makes
+    // in the app (`dark_page_text_tests`).
    let mut s = Session::empty();
    s.set_ui_dark(true);
    ex(&mut s, "file.new", json!({}));
    ex(&mut s, "frame.create", json!({"x": 0, "y": 0, "width": 200, "height": 200}));
    let t = draw_text(&mut s, 50.0, 50.0);
-    assert_eq!(s.doc().unwrap().node(t).unwrap().fills, vec![Paint::solid(Color::WHITE)]);
+    assert_eq!(s.doc().unwrap().node(t).unwrap().fills, vec![Paint::solid(Color::BLACK)]);
    let made = id_of(&ex(&mut s, "text.create", json!({"text": "Hi", "x": 0, "y": 300}))["id"]).unwrap();
    assert_eq!(s.doc().unwrap().node(made).unwrap().fills, vec![Paint::solid(Color::WHITE)]);
 }
@@ -266,6 +266,12 @@ pub struct Overlay {
    /// Pen tool: the in-progress path's anchor points and the rubber band to the pointer.
    pub pen: Vec<[f64; 2]>,
    pub rubber: Option<[f64; 4]>,
+    /// Pen tool: the handles shaping the segments at the pen (anchor x, y, handle x, y): the last
+    /// anchor's in and out handles and the one before's out handle.
+    pub pen_handles: Vec<[f64; 4]>,
+    /// Pen tool: where the last anchor's out handle ends, when it has one: the rubber band is the
+    /// curve a click would make, leaving along it.
+    pub rubber_handle: Option<[f64; 2]>,
    /// Frame/section the pointer is drawing or dropping into (highlighted).
    pub drop_target: Option<NodeId>,
    /// Auto layout insertion indicator (x0, y0, x1, y1).
@@ -370,6 +376,13 @@ pub(crate) enum Gesture {
    TextSelect {
        id: NodeId,
    },
+    /// A new text from the Text tool, still pressed: a drag makes it a box the size of the drag
+    /// (at least `line`, the height of its first line, tall).
+    TextBox {
+        id: NodeId,
+        start: Point,
+        line: f64,
+    },
    PenDrag {
        anchor: Point,
    },
@@ -397,6 +410,14 @@ pub(crate) enum Gesture {
    },
 }

+/// The handles a pen path shows while it is drawn ([`Overlay::pen_handles`]): the last anchor's in
+/// and out handles and the one before's out handle, those that aren't zero.
+fn pen_handles(points: &[(Point, Vec2, Vec2)]) -> Vec<[f64; 4]> {
+    let last = points.last().into_iter().flat_map(|(p, i, o)| [(p, i), (p, o)]);
+    let before = points.len().checked_sub(2).and_then(|k| points.get(k)).into_iter().map(|(p, _, o)| (p, o));
+    before.chain(last).filter(|(_, h)| h.hypot() > 0.0).map(|(p, h)| [p.x, p.y, p.x + h.x, p.y + h.y]).collect()
+}
+
 /// The pen tool's in-progress path (page coordinates).
 #[derive(Clone, Debug, Default)]
 pub struct PenPath {
@@ -530,12 +551,16 @@ pub fn anchor_name(a: (u8, u8)) -> &'static str {
    ANCHORS.get(usize::from(a.1.min(2)) * 3 + usize::from(a.0.min(2))).copied().unwrap_or("tl")
 }

-/// The fill new text takes to be readable where it is drawn: white on a dark `page` (None: the
-/// model's default, black). For text made in the app: by the Text tool, or by a command that
-/// names no fill while the interface is up.
-pub(crate) fn readable_text_fills(doc: &Document, page: NodeId) -> Option<Vec<figcraft_color::Paint>> {
-    matches!(doc.node(page).map(|p| &p.kind), Some(NodeKind::Page { background, .. }) if background.is_dark())
-        .then(|| vec![figcraft_color::Paint::solid(figcraft_color::Color::WHITE)])
+/// The fill new text takes to be readable where it is drawn, in `parent`: white on a dark
+/// background (None: the model's default, black). The background is the nearest layer from `parent`
+/// out whose top visible fill is a mostly opaque solid colour, else the page (#362). For text made
+/// in the app: by the Text tool, or by a command that names no fill while the interface is up.
+pub(crate) fn readable_text_fills(doc: &Document, parent: NodeId) -> Option<Vec<figcraft_color::Paint>> {
+    let dark = std::iter::once(parent).chain(doc.ancestors(parent)).filter_map(|id| doc.node(id)).find_map(|n| match &n.kind {
+        NodeKind::Page { background, .. } => Some(background.is_dark()),
+        _ => n.fills.iter().rev().find(|p| p.visible).and_then(|p| p.solid_color()).filter(|c| c.a >= 0.5).map(|c| c.is_dark()),
+    });
+    dark.unwrap_or(false).then(|| vec![figcraft_color::Paint::solid(figcraft_color::Color::WHITE)])
 }

 const ANCHORS: [&str; 9] = ["tl", "t", "tr", "l", "c", "r", "bl", "b", "br"];
@@ -617,6 +642,18 @@ pub fn handle_at(doc: &Document, sel: &[NodeId], p: Point, zoom: f64) -> Option<
    handle_at_corners(&corners, p, zoom, is_line)
 }

+/// Half the side of the square the canvas draws on each corner of the handle box (screen pixels,
+/// upright whatever the box's rotation).
+const CORNER_SQUARE_PX: f64 = 4.0;
+
+/// Whether `p` is on a corner square of the selection's handle box as drawn: there the corner
+/// resizes, although a corner-radius handle 10 px in reaches that far too.
+fn on_corner_square(doc: &Document, sel: &[NodeId], p: Point, zoom: f64) -> bool {
+    let reach = CORNER_SQUARE_PX / zoom.max(1e-6);
+    matches!(handle_at(doc, sel, p, zoom), Some(Handle::Corner(_)))
+        && selection_box(doc, sel).is_some_and(|c| c.iter().any(|c| (c.x - p.x).abs() <= reach && (c.y - p.y).abs() <= reach))
+}
+
 /// A box whose sides are both shorter than this on screen (pixels) would be covered by its
 /// handles: the canvas draws just its outline (the handles still answer just outside it).
 pub const SMALL_BOX_PX: f64 = 16.0;
@@ -685,7 +722,18 @@ pub(crate) fn handle_cursor(c: &[Point; 4], h: Handle) -> Cursor {
        Handle::Corner(i) => {
            let a = c.get(i as usize).copied().unwrap_or_default();
            let b = c.get((i as usize + 2) % 4).copied().unwrap_or_default();
-            Cursor::Resize(angle(a, b))
+            // Along the box's own axes at 45°, not the diagonal, so wide or tall boxes still get a
+            // diagonal cursor. A box with no width or height falls back to the diagonal.
+            let unit = |v: figcraft_geom::kurbo::Vec2| {
+                let len = v.hypot();
+                (len.is_finite() && len > 1e-9).then(|| v / len)
+            };
+            let next = c.get((i as usize + 1) % 4).copied().unwrap_or_default();
+            let prev = c.get((i as usize + 3) % 4).copied().unwrap_or_default();
+            match (unit(next - a), unit(prev - a)) {
+                (Some(u), Some(v)) => Cursor::Resize((u + v).atan2().to_degrees()),
+                _ => Cursor::Resize(angle(a, b)),
+            }
        }
        Handle::Edge(i) => {
            let a = c.get(i as usize).copied().unwrap_or_default();
@@ -982,7 +1030,11 @@ impl Session {
        let mut measure_box = None;
        let arc_hover = if self.arc_handles_shown() { crate::arc_handles::hit(&doc, &sel, ev.p(), ev.zoom).map(|(_, h)| h) } else { None };
        self.tool.overlay.arc_hover = arc_hover;
-        let shape_hover = if self.arc_handles_shown() { crate::shape_handles::hit(&doc, &sel, ev.p(), ev.zoom).map(|(_, h)| h) } else { None };
+        let shape_hover = if self.arc_handles_shown() && !on_corner_square(&doc, &sel, ev.p(), ev.zoom) {
+            crate::shape_handles::hit(&doc, &sel, ev.p(), ev.zoom).map(|(_, h)| h)
+        } else {
+            None
+        };
        self.tool.overlay.shape_hover = shape_hover;
        if matches!(tool, ToolId::Move | ToolId::Scale) && on_edited {
            cursor = Cursor::Text;
@@ -1026,8 +1078,9 @@ impl Session {
            let (to, g) = if ev.shift { (ev.p(), Vec::new()) } else { self.snap_pen_tool(ev)? };
            guides = g;
            self.tool.overlay.cursor = Cursor::Pen(self.pen_cursor(&doc, &sel, to, ev.zoom));
-            if let Some((last, _, _)) = self.tool.pen.as_ref().and_then(|pen| pen.points.last()) {
+            if let Some((last, _, out)) = self.tool.pen.as_ref().and_then(|pen| pen.points.last()) {
                self.tool.overlay.rubber = Some([last.x, last.y, to.x, to.y]);
+                self.tool.overlay.rubber_handle = (out.hypot() > 0.0).then_some([last.x + out.x, last.y + out.y]);
            }
        }
        self.tool.overlay.guides = guides;
@@ -1090,6 +1143,7 @@ impl Session {
            return Ok(());
        }
        if self.arc_handles_shown()
+            && !on_corner_square(&doc, &sel, ev.p(), ev.zoom)
            && let Some((id, handle)) = crate::shape_handles::hit(&doc, &sel, ev.p(), ev.zoom)
        {
            self.begin_interaction("Corner radius")?;
@@ -1164,7 +1218,13 @@ impl Session {
                if ids.is_empty() {
                    return Ok(());
                }
-                let targets = Targets::gather(&doc, page, &ids);
+                let mut targets = Targets::gather(&doc, page, &ids);
+                // A copy dragged out with Alt snaps to the layers it came from too (they stay put).
+                if ev.alt
+                    && let Some(b) = targets.moving
+                {
+                    targets.add_box(b);
+                }
                self.begin_interaction(if ev.alt { "Duplicate" } else { "Move" })?;
                self.tool.gesture = Gesture::Move { start: ev.p(), ids, targets, duplicate: ev.alt, moved: false };
                self.tool.overlay.cursor = if ev.alt { Cursor::Copy } else { Cursor::Default };
@@ -1347,6 +1407,11 @@ impl Session {
                self.tool.gesture = g;
                return self.draw_drag(ev, start, id, parent, &targets);
            }
+            Gesture::TextBox { id, start, line } => {
+                let (id, start, line) = (*id, *start, *line);
+                self.tool.gesture = g;
+                return self.text_box_drag(ev, id, start, line);
+            }
            Gesture::Arc { id, handle, arc } => {
                let (id, handle, arc) = (*id, *handle, *arc);
                self.tool.gesture = g;
@@ -1675,6 +1740,7 @@ impl Session {
                    // dropped; layers in an auto layout frame already sit in their slot.
                    let page = self.page()?;
                    let sel = self.selection();
+                    let sources = if duplicate { ids.clone() } else { Vec::new() };
                    let moving = if duplicate { sel } else { ids };
                    let doc = self.doc()?.clone();
                    let in_al =
@@ -1703,6 +1769,10 @@ impl Session {
                        self.cancel_interaction()?;
                    } else {
                        self.commit_interaction()?;
+                        // Duplicate repeats a free Alt-drag's step (an auto layout places its own).
+                        if duplicate && !in_al && moving.len() == sources.len() {
+                            self.ds_mut()?.last_duplicate = Some(crate::cmd::edit::Duplicated { sources, copies: moving });
+                        }
                    }
                } else {
                    self.cancel_interaction()?;
@@ -1760,7 +1830,7 @@ impl Session {
                self.tool.overlay.pen.clear();
                self.pencil_finish(&points, &pressure)?;
            }
-            Gesture::TextSelect { .. } | Gesture::Marquee { .. } | Gesture::None => {}
+            Gesture::TextSelect { .. } | Gesture::TextBox { .. } | Gesture::Marquee { .. } | Gesture::None => {}
            Gesture::PenDrag { .. } | Gesture::ShapeBuild { .. } | Gesture::Origin => {}
            Gesture::Vector(_) => self.commit_interaction()?,
        }
@@ -1878,22 +1948,46 @@ impl Session {
        let at = Point::new(ev.x.round(), (ev.y - 7.0).round());
        n.transform = pw.inverse() * Affine::translate(at.to_vec2());
        n.name = String::new();
-        if let Some(fills) = readable_text_fills(d, page) {
+        if let Some(fills) = readable_text_fills(d, parent) {
            n.fills = fills;
        }
        if let Some((w, h)) = figcraft_text::auto_size(&n) {
            n.width = w.max(1.0);
            n.height = h;
        }
+        let line = n.height;
        d.insert(n, parent, None)?;
        ds.selection = vec![id];
        textedit::begin(self, id, Some(0), true)?;
+        self.tool.gesture = Gesture::TextBox { id, start: ev.p(), line };
        if !self.prefs.keep_tool {
            self.tool.tool = ToolId::Move;
        }
        Ok(())
    }

+    /// Drag out a new text box: past the drag slop it has the drag's size (at least one line
+    /// tall) and its top-left, and that size is fixed.
+    fn text_box_drag(&mut self, ev: &PointerEvent, id: NodeId, start: Point, line: f64) -> Result<()> {
+        if within_slop(ev, start) {
+            return Ok(());
+        }
+        let r = Rect::from_points(start, ev.p());
+        let d = self.ds_mut()?.doc_mut();
+        let pw = d.node(id).and_then(|n| n.parent).map(|p| d.world_transform(p)).unwrap_or_default();
+        let n = d.get_mut(id)?;
+        n.transform = pw.inverse() * Affine::translate((r.x0.round(), r.y0.round()));
+        n.width = r.width().round().max(1.0);
+        n.height = r.height().round().max(line);
+        n.child_layout.sizing_h = Sizing::Fixed;
+        n.child_layout.sizing_v = Sizing::Fixed;
+        if let NodeKind::Text(t) = &mut n.kind {
+            t.auto_resize = TextAutoResize::None;
+        }
+        self.ds_mut()?.revision += 1;
+        Ok(())
+    }
+
    fn eyedrop(&mut self, ev: &PointerEvent) -> Result<()> {
        let ds = self.ds()?;
        let doc = ds.doc.clone();
@@ -1931,6 +2025,9 @@ impl Session {

    fn pen_down(&mut self, ev: &PointerEvent) -> Result<()> {
        self.tool.overlay.guides.clear();
+        // The segment being placed shows as itself while the press lasts.
+        self.tool.overlay.rubber = None;
+        self.tool.overlay.rubber_handle = None;
        let p = if ev.shift { ev.p() } else { self.snap_pen_tool(ev)?.0 };
        let (doc, page) = {
            let ds = self.ds()?;
@@ -1985,6 +2082,7 @@ impl Session {
    fn pen_update(&mut self) -> Result<()> {
        let Some(pen) = self.tool.pen.clone() else { return Ok(()) };
        self.tool.overlay.pen = pen.points.iter().map(|(p, _, _)| [p.x, p.y]).collect();
+        self.tool.overlay.pen_handles = pen_handles(&pen.points);
        if pen.points.len() < 2 {
            if let Ok(ds) = self.ds_mut() {
                ds.revision += 1;
@@ -2067,7 +2165,9 @@ impl Session {
    pub fn pen_finish(&mut self) -> Result<()> {
        let pen = self.tool.pen.take();
        self.tool.overlay.pen.clear();
+        self.tool.overlay.pen_handles.clear();
        self.tool.overlay.rubber = None;
+        self.tool.overlay.rubber_handle = None;
        self.tool.gesture = Gesture::None;
        if pen.as_ref().is_some_and(|p| p.id.is_some()) {
            self.commit_interaction()?;
@@ -277,6 +277,35 @@ fn constrain_proportions_keeps_the_other_side_in_ratio() {
    assert_eq!(size(&s, z), (20.0, 0.0), "a zero height leaves nothing to scale");
 }

+#[test]
+fn a_press_anywhere_on_a_corner_handle_resizes() {
+    // The canvas draws each corner handle as an 8 px square centred on the corner, and the
+    // corner-radius handle sits 10 px in along the diagonal: a press on the square's inner half
+    // resizes (both sides, in ratio with the link on), it doesn't pick the radius handle.
+    let radii = |s: &Session, r: NodeId| s.doc().unwrap().node(r).unwrap().corners.radii;
+    for lock in [false, true] {
+        let mut s = session();
+        let r = rect(&mut s, 0.0, 0.0, 1000.0, 600.0, None);
+        set(&mut s, &[r], json!({"constrainProportions": lock}));
+        ex(&mut s, "select.set", json!({"ids": [r]}));
+        let on_square = Point::new(997.0, 597.0);
+        s.pointer(&ev(PointerKind::Hover, on_square, NONE)).unwrap();
+        assert!(matches!(s.tool.overlay.cursor, Cursor::Resize(_)), "lock {lock}: {:?}", s.tool.overlay.cursor);
+        drag(&mut s, on_square, Point::new(1197.0, 637.0), NONE);
+        let (w, h) = size(&s, r);
+        let want_h = if lock { 718.2 } else { 637.0 };
+        assert!(near(w, 1197.0) && near(h, want_h), "lock {lock}: both sides follow the corner, got {w}×{h}");
+        assert_eq!(radii(&s, r), [0.0; 4]);
+    }
+    // Further in, past the square, the radius handle still answers.
+    let mut s = session();
+    let r = rect(&mut s, 0.0, 0.0, 1000.0, 600.0, None);
+    ex(&mut s, "select.set", json!({"ids": [r]}));
+    drag(&mut s, Point::new(993.0, 593.0), Point::new(980.0, 580.0), NONE);
+    assert_eq!(size(&s, r), (1000.0, 600.0));
+    assert!(radii(&s, r)[0] > 0.0, "the radius handle rounds the corners");
+}
+
 #[test]
 fn frames_resize_with_constraints_and_cmd_ignores_them() {
    let mut s = session();
@@ -378,6 +407,30 @@ fn smart_guides_snap_to_edges_centres_and_equal_spacing() {
    assert_eq!(bounds(&s, b).origin(), Point::new(198.0, 2.0));
 }

+#[test]
+fn corner_cursors_stay_diagonal_whatever_the_proportions() {
+    let mut s = session();
+    let mod180 = |a: f64, b: f64| near((a - b).rem_euclid(180.0).min((b - a).rem_euclid(180.0)), 0.0);
+    for (w, h) in [(65.0, 15.0), (100.0, 100.0), (60.0, 200.0), (200.0, 50.0)] {
+        let r = rect(&mut s, 0.0, 0.0, w, h, None);
+        let doc = s.doc().unwrap().clone();
+        let q = selection_box(&doc, &[r]).unwrap();
+        for (i, want) in [(0u8, 45.0), (1, 135.0), (2, 45.0), (3, 135.0)] {
+            let Cursor::Resize(a) = handle_cursor(&q, Handle::Corner(i)) else { panic!() };
+            assert!(mod180(a, want), "{w}x{h} corner {i}: {a}, want {want}");
+        }
+        // Turned, the corner cursors turn with the layer's own axes.
+        set(&mut s, &[r], json!({"rotation": 30}));
+        let doc = s.doc().unwrap().clone();
+        let q = selection_box(&doc, &[r]).unwrap();
+        let axis = (q[1] - q[0]).atan2().to_degrees();
+        for (i, off) in [(0u8, 45.0), (1, 135.0), (2, 45.0), (3, 135.0)] {
+            let Cursor::Resize(a) = handle_cursor(&q, Handle::Corner(i)) else { panic!() };
+            assert!(mod180(a, axis + off), "{w}x{h} turned corner {i}: {a}, want {}", axis + off);
+        }
+    }
+}
+
 #[test]
 fn the_transform_box_and_its_handles() {
    let mut s = session();
@@ -25,6 +25,8 @@ const MAX_DEPTH: usize = 256;
 const MAX_COMMANDS: usize = 200_000;
 /// Id of "no style".
 const NO_STYLE: &str = "4294967295:4294967295";
+/// Longest asset `key` or `version` kept for resolving references given as assets.
+const MAX_ASSET_PART: usize = 256;

 /// The REST API file JSON for message `msg`, with the warnings about what was skipped.
 pub(super) fn to_rest(msg: &Kv, name: &str) -> (Value, Vec<String>) {
@@ -86,6 +88,10 @@ fn vec2(v: &Kv) -> Option<Value> {
    Some(json!({"x": num(v, "x")?, "y": num(v, "y")?}))
 }

+fn size(v: &Kv) -> Option<(f64, f64)> {
+    Some((num(v, "x")?, num(v, "y")?))
+}
+
 fn matrix(m: &Kv) -> Option<Affine> {
    let c = |k: &str| num(m, k);
    let a = Affine::new([c("m00")?, c("m10")?, c("m01")?, c("m11")?, c("m02")?, c("m12")?]);
@@ -113,11 +119,21 @@ fn copy_str(o: &mut Obj, n: &View, from: &str, to: &str) {
 #[derive(Clone)]
 struct View<'a> {
    layers: Vec<&'a Kv<'a>>,
+    /// Size and transform worked out from the constraints, over the layers' own.
+    fitted: Option<((f64, f64), Affine)>,
 }

 impl<'a> View<'a> {
    fn of(n: &'a Kv<'a>) -> Self {
-        Self { layers: vec![n] }
+        Self { layers: vec![n], fitted: None }
+    }
+
+    fn size(&self) -> Option<(f64, f64)> {
+        self.fitted.map(|f| f.0).or_else(|| self.get("size").and_then(size))
+    }
+
+    fn transform(&self) -> Option<Affine> {
+        self.fitted.map(|f| f.1).or_else(|| self.get("transform").and_then(matrix))
    }

    fn with(&self, top: impl IntoIterator<Item = &'a Kv<'a>>) -> Self {
@@ -147,13 +163,83 @@ impl<'a> View<'a> {
    }
 }

+/// How the layers of a resized container follow it when the file gives no derived layout for
+/// them: a frame's by their constraints, from its main's size to its own; a group's scale with it.
+#[derive(Clone, Copy)]
+enum Fit {
+    Frame { from: (f64, f64), to: (f64, f64) },
+    Scale(f64, f64),
+}
+
+impl Fit {
+    fn frame(from: Option<(f64, f64)>, to: Option<(f64, f64)>) -> Option<Self> {
+        let (from, to) = (from?, to?);
+        ((from.0 - to.0).abs() > 1e-9 || (from.1 - to.1).abs() > 1e-9).then_some(Fit::Frame { from, to })
+    }
+
+    fn scale(from: Option<(f64, f64)>, to: Option<(f64, f64)>) -> Option<Self> {
+        let (from, to) = (from?, to?);
+        let k = |a: f64, b: f64| if a > 1e-9 { b / a } else { 1.0 };
+        let (kx, ky) = (k(from.0, to.0), k(from.1, to.1));
+        ((kx - 1.0).abs() > 1e-9 || (ky - 1.0).abs() > 1e-9).then_some(Fit::Scale(kx, ky))
+    }
+
+    /// The size and transform (in the parent's coordinates) of a `w` × `h` layer at `t` with
+    /// constraints `h_con`, `v_con`. Like the editor's constraint solver, a layer keeps its
+    /// rotation and flip and stretches along its own axes.
+    fn apply(self, w: f64, h: f64, t: Affine, h_con: Option<&str>, v_con: Option<&str>) -> ((f64, f64), Affine) {
+        let [a, b, c, d, _, _] = t.as_coeffs();
+        let lin = Affine::new([a, b, c, d, 0.0, 0.0]);
+        let bb = figcraft_doc::geom::transform_rect_bbox(t, figcraft_doc::geom::Rect::new(0.0, 0.0, w, h));
+        // Where the new box goes: its top-left (constraints) or its centre (a group's scale).
+        let (kx, ky, x0, y0, centred) = match self {
+            Fit::Frame { from, to } => {
+                let axis = |con: Option<&str>, lo: f64, hi: f64, old: f64, new: f64| match con {
+                    Some("MAX" | "FIXED_MAX") => (lo + new - old, hi + new - old),
+                    Some("STRETCH") => (lo, hi + new - old),
+                    Some("CENTER") => (lo + (new - old) / 2.0, hi + (new - old) / 2.0),
+                    Some("SCALE") if old > 1e-9 => (lo * new / old, hi * new / old),
+                    _ => (lo, hi),
+                };
+                let (x0, x1) = axis(h_con, bb.x0, bb.x1, from.0, to.0);
+                let (y0, y1) = axis(v_con, bb.y0, bb.y1, from.1, to.1);
+                let k = |new: f64, old: f64| if old > 1e-9 { (new / old).max(0.0) } else { 1.0 };
+                (k(x1 - x0, bb.width()), k(y1 - y0, bb.height()), x0, y0, false)
+            }
+            Fit::Scale(kx, ky) => (kx, ky, bb.center().x * kx, bb.center().y * ky, true),
+        };
+        let along = |x: f64, y: f64, fallback: f64| {
+            let len = x.hypot(y);
+            let k = (kx * x).hypot(ky * y) / len;
+            if len > 1e-12 && k.is_finite() { k } else { fallback }
+        };
+        let size = (w * along(a, b, kx), h * along(c, d, ky));
+        let nb = figcraft_doc::geom::transform_rect_bbox(lin, figcraft_doc::geom::Rect::new(0.0, 0.0, size.0, size.1));
+        let at = if centred { nb.center() } else { figcraft_doc::geom::Point::new(nb.x0, nb.y0) };
+        (size, Affine::translate((x0 - at.x, y0 - at.y)) * lin)
+    }
+}
+
+/// Overrides and derived layout by id path.
+type Overrides<'a> = BTreeMap<Vec<String>, Vec<(Entry, &'a Kv<'a>)>>;
+
+/// Where an override entry comes from.
+#[derive(Clone, Copy, PartialEq)]
+enum Entry {
+    Override,
+    Derived,
+    /// Derived layout of a nested instance for a size it no longer has: its size and place no
+    /// longer hold, the rest (resolved colours, text) still does.
+    Stale,
+}
+
 /// Where an instance's expanded layers are: the overrides and derived layout of the outermost
 /// instance (by id path), the path of the instance being expanded, and the property values.
 #[derive(Clone)]
 struct Inst<'a> {
    root: String,
    path: Vec<String>,
-    overrides: Rc<BTreeMap<Vec<String>, Vec<&'a Kv<'a>>>>,
+    overrides: Rc<Overrides<'a>>,
    props: Rc<BTreeMap<String, &'a Kv<'a>>>,
    /// Mains being expanded (an instance inside its own main stops there).
    symbols: Vec<String>,
@@ -165,6 +251,10 @@ struct Mapper<'a> {
    blobs: Vec<&'a [u8]>,
    /// Component property definitions: id → (REST name "Name#id", type).
    prop_defs: BTreeMap<String, (String, &'a str)>,
+    /// File nodes by asset `key` and `version`: references can name a collection, variable or
+    /// style as the asset instead of the guid, and the file carries the resources to resolve
+    /// them (the collection node itself says the same `key`).
+    assets: BTreeMap<String, BTreeMap<String, String>>,
    styles: Obj,
    /// Descriptions of components and component sets (REST `components` / `componentSets`).
    components: Obj,
@@ -203,7 +293,37 @@ impl<'a> Mapper<'a> {
        }
        let blobs =
            msg.get("blobs").map(Kv::list).unwrap_or_default().iter().map(|b| b.get("bytes").and_then(Kv::bytes).unwrap_or_default()).collect();
-        Self { nodes, kids, blobs, prop_defs, styles: Obj::new(), components: Obj::new(), sets: Obj::new(), warnings: Vec::new(), count: 0 }
+        let mut assets: BTreeMap<String, BTreeMap<String, String>> = BTreeMap::new();
+        for n in msg.get("nodeChanges").map(Kv::list).unwrap_or_default() {
+            let (Some(key), Some(id)) = (n.get("key").and_then(Kv::str), n.get("guid").and_then(guid)) else { continue };
+            if key.is_empty() || key.len() > MAX_ASSET_PART {
+                continue;
+            }
+            let version = n.get("version").and_then(Kv::str).filter(|v| !v.is_empty() && v.len() <= MAX_ASSET_PART).unwrap_or("");
+            assets.entry(key.to_string()).or_default().entry(version.to_string()).or_insert(id);
+        }
+        Self { nodes, kids, blobs, prop_defs, assets, styles: Obj::new(), components: Obj::new(), sets: Obj::new(), warnings: Vec::new(), count: 0 }
+    }
+
+    /// The id of the resource a `VariableSetID` (or `VariableID`, `StyleId`) names: its `guid`,
+    /// else the file node its asset `key` and `version` names (a collection from a library is
+    /// referenced as the asset, and the file's own node for it says the same `key`). `None` when
+    /// the reference has neither or the asset names nothing (or ambiguously) in the file.
+    /// Original code for this importer: the field names are those of the schema each file embeds.
+    fn resource_id(&self, v: &Kv) -> Option<String> {
+        if let Some(g) = v.get("guid").and_then(guid).filter(|g| *g != NO_STYLE) {
+            return Some(g);
+        }
+        let asset = v.get("assetRef")?;
+        let key = asset.get("key").and_then(Kv::str)?;
+        let versions = self.assets.get(key)?;
+        let version = asset.get("version").and_then(Kv::str);
+        match version {
+            Some(v) => versions.get(v),
+            // Without a version: an unversioned record, else the file's only one.
+            None => versions.get("").or_else(|| (versions.len() == 1).then(|| versions.values().next()).flatten()),
+        }
+        .cloned()
    }

    fn warn(&mut self, w: impl Into<String>) {
@@ -263,7 +383,7 @@ impl<'a> Mapper<'a> {
                let name = sp.get("name").and_then(Kv::str).filter(|s| !s.is_empty()).unwrap_or("Flow");
                flows.push((sp.get("position").and_then(Kv::str).unwrap_or(""), json!({"nodeId": c, "name": name})));
            }
-            kids.extend(self.layer(&c, None, Affine::IDENTITY, None, 0));
+            kids.extend(self.layer(&c, None, Affine::IDENTITY, None, None, 0));
        }
        flows.sort_by(|a, b| a.0.cmp(b.0));
        if !flows.is_empty() {
@@ -276,7 +396,15 @@ impl<'a> Mapper<'a> {
    /// Layer `id` (inside instance `inst` when expanding one) and its subtree. `space`: from the
    /// parent's coordinates to the enclosing frame's (groups and booleans place their children in
    /// the frame's space, like the REST JSON). `parent`: the parent's view (grid tracks).
-    fn layer(&mut self, id: &str, inst: Option<&Inst<'a>>, space: Affine, parent: Option<&View<'a>>, depth: usize) -> Option<Value> {
+    fn layer(
+        &mut self,
+        id: &str,
+        inst: Option<&Inst<'a>>,
+        space: Affine,
+        parent: Option<&View<'a>>,
+        fit: Option<Fit>,
+        depth: usize,
+    ) -> Option<Value> {
        if depth > MAX_DEPTH {
            self.warn(format!("layers nested deeper than {MAX_DEPTH} levels were skipped"));
            return None;
@@ -287,10 +415,28 @@ impl<'a> Mapper<'a> {
        }
        let base = *self.nodes.get(id)?;
        let path = inst.map(|i| [i.path.as_slice(), &[id.to_string()]].concat());
-        let view = match (inst, &path) {
-            (Some(i), Some(p)) => View::of(base).with(i.overrides.get(p).into_iter().flatten().copied()),
-            _ => View::of(base),
+        let entries = match (inst, &path) {
+            (Some(i), Some(p)) => i.overrides.get(p).map(Vec::as_slice).unwrap_or_default(),
+            _ => &[],
        };
+        let mut view = View::of(base).with(entries.iter().map(|e| e.1));
+        // A layer of a resized instance the file gives no derived layout for follows its
+        // constraints from the main's geometry, then takes the size and place overridden on it
+        // (auto layout places the others, as in the editor).
+        let derived = entries.iter().any(|(d, l)| *d == Entry::Derived && (l.get("size").is_some() || l.get("transform").is_some()));
+        let stacked = parent.and_then(|p| p.str("stackMode")).is_some_and(|m| matches!(m, "HORIZONTAL" | "VERTICAL" | "GRID"))
+            && view.str("stackPositioning") != Some("ABSOLUTE");
+        let main = View::of(base);
+        let set = |k: &str| entries.iter().rev().filter(|e| e.0 != Entry::Stale).find_map(|(_, l)| l.get(k));
+        if let (Some(f), false, false, Some((w, h))) = (fit, derived, stacked, main.size()) {
+            let t = main.transform().unwrap_or_default();
+            let (fw, ft) = f.apply(w, h, t, view.str("horizontalConstraint"), view.str("verticalConstraint"));
+            view.fitted = Some((set("size").and_then(size).unwrap_or(fw), set("transform").and_then(matrix).unwrap_or(ft)));
+        } else if entries.iter().any(|(d, l)| *d == Entry::Stale && (l.get("size").is_some() || l.get("transform").is_some()))
+            && let Some(s) = set("size").and_then(size).or_else(|| main.size())
+        {
+            view.fitted = Some((s, set("transform").and_then(matrix).or_else(|| main.transform()).unwrap_or_default()));
+        }
        let rest_id = match (inst, &path) {
            (Some(i), Some(p)) => format!("I{};{}", i.root, p.join(";")),
            _ => id.to_string(),
@@ -338,21 +484,26 @@ impl<'a> Mapper<'a> {
            self.component(&mut o, &view, &rest_id);
        }
        self.prop_refs(&mut o, &view, inst);
-        let child_space = if matches!(ty, "GROUP" | "BOOLEAN_OPERATION") {
-            space * view.get("transform").and_then(matrix).unwrap_or_default()
-        } else {
-            Affine::IDENTITY
-        };
+        let child_space = if matches!(ty, "GROUP" | "BOOLEAN_OPERATION") { space * view.transform().unwrap_or_default() } else { Affine::IDENTITY };
        let mut kids = Vec::new();
        if ty == "INSTANCE" {
            if let Some((sub, sym)) = self.instance(&mut o, &view, id, inst, &rest_id) {
+                let main = self.nodes.get(&sym).map(|m| View::of(m));
+                let fit = Fit::frame(main.and_then(|m| m.size()), view.size());
                for c in self.children(&sym) {
-                    kids.extend(self.layer(&c, Some(&sub), child_space, Some(&view), depth + 1));
+                    kids.extend(self.layer(&c, Some(&sub), child_space, Some(&view), fit, depth + 1));
                }
            }
        } else {
+            // Inside an instance a layer's children are its main's: they follow it from the main's
+            // size to its own.
+            let fit = match (inst, ty) {
+                (None, _) => None,
+                (Some(_), "GROUP" | "BOOLEAN_OPERATION") => Fit::scale(View::of(base).size(), view.size()),
+                (Some(_), _) => Fit::frame(View::of(base).size(), view.size()),
+            };
            for c in self.children(id) {
-                kids.extend(self.layer(&c, inst, child_space, Some(&view), depth + 1));
+                kids.extend(self.layer(&c, inst, child_space, Some(&view), fit, depth + 1));
            }
        }
        if stand.is_some_and(|s| s.0 == "FRAME") {
@@ -487,10 +638,10 @@ impl<'a> Mapper<'a> {
        if let Some(b) = v.str("blendMode").filter(|b| *b != "UNSET") {
            o.insert("blendMode".into(), json!(b));
        }
-        if let Some(s) = v.get("size").and_then(vec2) {
-            o.insert("size".into(), s);
+        if let Some((x, y)) = v.size() {
+            o.insert("size".into(), json!({"x": x, "y": y}));
        }
-        let t = v.get("transform").and_then(matrix).unwrap_or_default();
+        let t = v.transform().unwrap_or_default();
        o.insert("relativeTransform".into(), rows(space * t));
        // Paints, from the shared style when one is linked (the layer's own copy can be stale).
        let mut styles = Obj::new();
@@ -739,7 +890,8 @@ impl<'a> Mapper<'a> {
            vd.get("styleOverrideTable").map(Kv::list).unwrap_or_default().iter().filter_map(|s| Some((num(s, "styleID")? as u64, s))).collect();
        let style = |id: u32| styles.get(&u64::from(id)).copied().filter(|_| id != 0);
        let scale = |k: &str| {
-            let (size, norm) = (v.get("size").and_then(|s| num(s, k)), vd.get("normalizedSize").and_then(|s| num(s, k)));
+            let size = v.size().map(|s| if k == "x" { s.0 } else { s.1 });
+            let norm = vd.get("normalizedSize").and_then(|s| num(s, k));
            size.zip(norm).filter(|(s, n)| s.is_finite() && *n > 1e-9).map_or(1.0, |(s, n)| s / n)
        };
        let (sx, sy) = (scale("x"), scale("y"));
@@ -908,7 +1060,15 @@ impl<'a> Mapper<'a> {
        }
        // Overrides by id path below this instance (the instance itself is addressed by its main's id).
        let own_path: Vec<String> = outer.map(|i| [i.path.as_slice(), &[id.to_string()]].concat()).unwrap_or_default();
-        let mut overrides: BTreeMap<Vec<String>, Vec<&'a Kv<'a>>> = outer.map(|i| (*i.overrides).clone()).unwrap_or_default();
+        let mut overrides: Overrides<'a> = outer.map(|i| (*i.overrides).clone()).unwrap_or_default();
+        // A nested instance's derived layout is for the size it has in its main: resized here, the
+        // sizes and places in it no longer hold and its layers follow their constraints instead.
+        let differs = |a: f64, b: f64| (a - b).abs() > 1e-6 * a.abs().max(b.abs()).max(1.0);
+        let resized = outer.is_some()
+            && match (self.nodes.get(id).and_then(|b| View::of(b).size()), v.size()) {
+                (Some(a), Some(b)) => differs(a.0, b.0) || differs(a.1, b.1),
+                (a, b) => a.is_some() != b.is_some(),
+            };
        let lists = [sd.and_then(|s| s.get("symbolOverrides")).map(Kv::list).unwrap_or_default(), v.list("derivedSymbolData")];
        for (layer, list) in lists.into_iter().enumerate() {
            for ov in list {
@@ -920,9 +1080,16 @@ impl<'a> Mapper<'a> {
                let e = overrides.entry([own_path.as_slice(), &rel].concat()).or_default();
                // The outer instance's overrides win over this one's own; derived layout comes last.
                if layer == 0 && outer.is_some() {
-                    e.insert(0, ov);
+                    e.insert(0, (Entry::Override, ov));
                } else {
-                    e.push(ov);
+                    e.push((
+                        match (layer, resized) {
+                            (0, _) => Entry::Override,
+                            (_, false) => Entry::Derived,
+                            (_, true) => Entry::Stale,
+                        },
+                        ov,
+                    ));
                }
            }
        }
@@ -1105,11 +1272,21 @@ impl<'a> Mapper<'a> {
            o.insert("style".into(), json!({"boundVariables": text_bound}));
        }
        let mut modes = Obj::new();
+        let mut lost = false;
        for e in v.get("variableModeBySetMap").and_then(|m| m.get("entries")).map(Kv::list).unwrap_or_default() {
-            if let (Some(set), Some(mode)) = (e.get("variableSetID").and_then(ref_guid), e.get("variableModeID").and_then(guid)) {
-                modes.insert(set, json!(mode));
+            let (Some(set), Some(mode)) = (e.get("variableSetID"), e.get("variableModeID").and_then(guid)) else { continue };
+            match self.resource_id(set) {
+                Some(id) => {
+                    modes.insert(id, json!(mode));
+                }
+                // A mode of a collection neither named by guid nor resolvable in the file.
+                None if set.get("guid").is_some() || set.get("assetRef").is_some() => lost = true,
+                None => {}
            }
        }
+        if lost {
+            self.warn("variable modes of collections that aren't in the file were skipped");
+        }
        if !modes.is_empty() {
            o.insert("explicitVariableModes".into(), Value::Object(modes));
        }
@@ -1128,7 +1305,7 @@ impl<'a> Mapper<'a> {
        found.sort_by(|a, b| (a.0, &a.1).cmp(&(b.0, &b.1)));
        let mut out = Vec::new();
        for (_, id, n) in found {
-            let Some(node) = self.layer(&id, None, Affine::IDENTITY, None, 0) else { break };
+            let Some(node) = self.layer(&id, None, Affine::IDENTITY, None, None, 0) else { break };
            let name = n.get("name").and_then(Kv::str).unwrap_or("Style");
            let desc = n.get("styleDescription").or_else(|| n.get("description")).and_then(Kv::str).unwrap_or("");
            let ty = n.get("styleType").and_then(Kv::str).unwrap_or("");
@@ -1174,7 +1351,7 @@ impl<'a> Mapper<'a> {
        let mut variable_order = Vec::new();
        let mut variables = Obj::new();
        for (id, n) in of_type("VARIABLE", "sortPosition") {
-            let Some(set) = n.get("variableSetID").and_then(ref_guid).filter(|s| collections.contains_key(s)) else { continue };
+            let Some(set) = n.get("variableSetID").and_then(|s| self.resource_id(s)).filter(|s| collections.contains_key(s)) else { continue };
            let ty = n.get("variableResolvedType").and_then(Kv::str).unwrap_or("");
            if !matches!(ty, "BOOLEAN" | "FLOAT" | "STRING" | "COLOR") {
                continue;
@@ -32,18 +32,20 @@ enum ExpressionFunction ADDITION SUBTRACTION RESOLVE_VARIANT MULTIPLY DIVIDE EQU
 enum NavigationType NAVIGATE OVERLAY
 enum TransitionType INSTANT_TRANSITION DISSOLVE SMART_ANIMATE
 enum EasingType IN_CUBIC OUT_CUBIC
+enum ConstraintType MIN CENTER MAX STRETCH SCALE
 struct GUID uint sessionID, uint localID
 struct Color float r, float g, float b, float a
 struct Vector float x, float y
 struct Matrix float m00, float m01, float m02, float m10, float m11, float m12
 struct ColorStop Color color, float position
 message Image byte[] hash, string name
-message VariableID GUID guid
+message AssetRef string key, string version
+message VariableID GUID guid, AssetRef assetRef
 message PropRefValue GUID defId
 message AnyValue bool boolValue, float floatValue, VariableID alias, Color colorValue, PropRefValue propRefValue, TextData textDataValue, string textValue, Expression expressionValue
 message Expression ExpressionFunction expressionFunction, VariableData[] expressionArguments
 message VariableTarget VariableID id
-message VariableSetID GUID guid
+message VariableSetID GUID guid, AssetRef assetRef
 message ConditionalActions Action[] actions, VariableData condition
 message VectorData uint vectorNetworkBlob, Vector normalizedSize, NodeChange[] styleOverrideTable
 message ConnectorEndpoint GUID endpointNodeID, Vector position, Vector relativePosition
@@ -70,7 +72,7 @@ message Event InteractionType interactionType
 message Action GUID transitionNodeID, TransitionType transitionType, float transitionDuration, EasingType easingType, ConnectionType connectionType, NavigationType navigationType, VariableTarget targetVariable, VariableData targetVariableData, VariableSetID targetVariableSetID, GUID targetVariableModeID, ConditionalActions[] conditionalActions
 message Interaction Event event, Action[] actions
 message StartingPoint string name, string position
-message NodeChange GUID guid, ParentIndex parentIndex, NodeType type, string name, bool visible, float opacity, Vector size, Matrix transform, Paint[] fillPaints, Paint[] strokePaints, float strokeWeight, float cornerRadius, bool resizeToFit, bool internalOnly, float fontSize, FontName fontName, TextData textData, uint styleID, Path[] fillGeometry, Path[] strokeGeometry, StyleType styleType, StyleId styleIdForFill, SymbolData symbolData, PropDef[] componentPropDefs, PropAssignment[] componentPropAssignments, VariableDataMap parameterConsumptionMap, SetMode[] variableSetModes, VariableID variableSetID, ResolvedType variableResolvedType, Values variableDataValues, ModeMap variableModeBySetMap, Interaction[] prototypeInteractions, StartingPoint prototypeStartingPoint, GUIDPath guidPath, StackMode stackMode, float stackSpacing, float stackHorizontalPadding, float stackVerticalPadding, uint count, float starInnerScale, VectorData vectorData, StrokeCap strokeCap, StrokeJoin strokeJoin, VectorMirror handleMirroring, ShapeWithTextType shapeWithTextType, ConnectorEndpoint connectorStart, ConnectorEndpoint connectorEnd, StrokeCap connectorStartCap, StrokeCap connectorEndCap, ConnectorLineStyle connectorLineStyle
+message NodeChange GUID guid, ParentIndex parentIndex, NodeType type, string name, bool visible, float opacity, Vector size, Matrix transform, Paint[] fillPaints, Paint[] strokePaints, float strokeWeight, float cornerRadius, bool resizeToFit, bool internalOnly, float fontSize, FontName fontName, TextData textData, uint styleID, Path[] fillGeometry, Path[] strokeGeometry, StyleType styleType, StyleId styleIdForFill, SymbolData symbolData, PropDef[] componentPropDefs, PropAssignment[] componentPropAssignments, VariableDataMap parameterConsumptionMap, SetMode[] variableSetModes, VariableID variableSetID, ResolvedType variableResolvedType, Values variableDataValues, ModeMap variableModeBySetMap, Interaction[] prototypeInteractions, StartingPoint prototypeStartingPoint, GUIDPath guidPath, StackMode stackMode, float stackSpacing, float stackHorizontalPadding, float stackVerticalPadding, uint count, float starInnerScale, VectorData vectorData, StrokeCap strokeCap, StrokeJoin strokeJoin, VectorMirror handleMirroring, ShapeWithTextType shapeWithTextType, ConnectorEndpoint connectorStart, ConnectorEndpoint connectorEnd, StrokeCap connectorStartCap, StrokeCap connectorEndCap, ConnectorLineStyle connectorLineStyle, ConstraintType horizontalConstraint, ConstraintType verticalConstraint, NodeChange[] derivedSymbolData, string key, string version
 message Blob byte[] bytes
 message Message NodeChange[] nodeChanges, Blob[] blobs
 ";
@@ -665,6 +667,209 @@ fn instances_inside_their_own_main_stop() {
    assert!(doc.nodes().any(|n| n.name == "Self"));
 }

+/// A collection from a library is named by its asset key, not a guid — also in the explicit mode
+/// map of the frames, components and instances set it on, and in the variables' collection link.
+#[test]
+fn modes_of_collections_named_by_asset_import() {
+    let modes = arr(vec![
+        o(vec![("id", g(90)), ("name", s("Dark")), ("sortPosition", s("!"))]),
+        o(vec![("id", g(91)), ("name", s("Light")), ("sortPosition", s("\""))]),
+    ]);
+    let color_value = |c| o(vec![("value", o(vec![("colorValue", c)])), ("dataType", e("COLOR"))]);
+    let values = o(vec![(
+        "entries",
+        arr(vec![
+            o(vec![("modeID", g(90)), ("variableData", color_value(rgb(0.0, 0.0, 0.0)))]),
+            o(vec![("modeID", g(91)), ("variableData", color_value(rgb(1.0, 1.0, 1.0)))]),
+        ]),
+    )]);
+    let by_asset = |key: &'static str, version: Option<&'static str>| {
+        let mut r = vec![("key", s(key))];
+        r.extend(version.map(|v| ("version", s(v))));
+        o(vec![("assetRef", o(r))])
+    };
+    let mode_map = |set: Kv<'static>| o(vec![("entries", arr(vec![o(vec![("variableSetID", set), ("variableModeID", g(91))])]))]);
+    let nodes = vec![
+        node(0, None, "DOCUMENT", "Document", vec![]),
+        node(1, Some((0, "!")), "CANVAS", "Page A", vec![]),
+        node(2, Some((0, "~")), "CANVAS", "Internal", vec![("internalOnly", Kv::Bool(true))]),
+        // The collection itself says the asset key its references name.
+        node(4, Some((2, "!")), "VARIABLE_SET", "Schema", vec![("variableSetModes", modes), ("key", s("schema-collection")), ("version", s("7"))]),
+        node(
+            5,
+            Some((2, "\"")),
+            "VARIABLE",
+            "surface",
+            vec![("variableSetID", by_asset("schema-collection", Some("7"))), ("variableResolvedType", e("COLOR")), ("variableDataValues", values)],
+        ),
+        node(
+            10,
+            Some((1, "!")),
+            "FRAME",
+            "Light section",
+            vec![("size", xy(400.0, 300.0)), ("variableModeBySetMap", mode_map(by_asset("schema-collection", Some("7"))))],
+        ),
+        node(
+            20,
+            Some((1, "\"")),
+            "SYMBOL",
+            "Button",
+            vec![("size", xy(100.0, 40.0)), ("variableModeBySetMap", mode_map(by_asset("schema-collection", None)))],
+        ),
+        node(
+            21,
+            Some((1, "#")),
+            "INSTANCE",
+            "Button copy",
+            vec![
+                ("size", xy(100.0, 40.0)),
+                ("symbolData", o(vec![("symbolID", g(20))])),
+                ("variableModeBySetMap", mode_map(by_asset("schema-collection", Some("7")))),
+            ],
+        ),
+        // One names a collection that isn't in the file: its mode is skipped, with a warning.
+        node(11, Some((1, "$")), "FRAME", "Gone", vec![("size", xy(400.0, 300.0)), ("variableModeBySetMap", mode_map(by_asset("gone", None)))]),
+    ];
+    let (doc, warnings) = import(&canvas(&schema(), &o(vec![("nodeChanges", arr(nodes))])), "x").unwrap();
+    assert_eq!(doc.variables.collections.len(), 1);
+    assert_eq!(doc.variables.variables.len(), 1);
+    assert_eq!(doc.variables.variables[0].collection, "1:4");
+    for name in ["Light section", "Button", "Button copy"] {
+        let n = named(&doc, name);
+        assert_eq!(n.var_modes.get("1:4").map(String::as_str), Some("1:91"), "{name}");
+    }
+    assert!(named(&doc, "Gone").var_modes.is_empty());
+    assert!(warnings.iter().any(|w| w.contains("variable modes of collections that aren't in the file")), "{warnings:?}");
+}
+
+#[test]
+fn resized_instances_lay_their_layers_out_by_their_constraints() {
+    let pin = |h: &'static str, v: &'static str| vec![("horizontalConstraint", e(h)), ("verticalConstraint", e(v))];
+    let layer = |id, pos, ty, name, w, h, x, y, c: Vec<(&'static str, Kv<'static>)>| {
+        node(id, Some((5, pos)), ty, name, [vec![("size", xy(w, h)), ("transform", at(x, y))], c].concat())
+    };
+    let nodes = vec![
+        node(0, None, "DOCUMENT", "D", vec![]),
+        node(1, Some((0, "!")), "CANVAS", "P", vec![]),
+        node(5, Some((1, "!")), "SYMBOL", "Logo", vec![("size", xy(132.0, 22.0)), ("transform", at(0.0, 0.0))]),
+        layer(6, "!", "ROUNDED_RECTANGLE", "Mark", 132.0, 22.0, 0.0, 0.0, pin("SCALE", "SCALE")),
+        layer(7, "\"", "ROUNDED_RECTANGLE", "Badge", 32.0, 10.0, 100.0, 12.0, pin("MAX", "MAX")),
+        layer(8, "#", "ROUNDED_RECTANGLE", "Bar", 112.0, 2.0, 10.0, 0.0, pin("STRETCH", "MIN")),
+        // A group scales its layers with it.
+        layer(11, "$", "FRAME", "Wordmark", 66.0, 22.0, 66.0, 0.0, [pin("SCALE", "SCALE"), vec![("resizeToFit", Kv::Bool(true))]].concat()),
+        node(12, Some((11, "!")), "ROUNDED_RECTANGLE", "Letter", vec![("size", xy(66.0, 22.0)), ("transform", at(0.0, 0.0))]),
+        node(
+            9,
+            Some((1, "\"")),
+            "INSTANCE",
+            "Small logo",
+            vec![("size", xy(90.0, 15.0)), ("transform", at(0.0, 100.0)), ("symbolData", o(vec![("symbolID", g(5))]))],
+        ),
+        // Derived layout the file gives wins over the constraints.
+        node(
+            10,
+            Some((1, "#")),
+            "INSTANCE",
+            "Derived logo",
+            vec![
+                ("size", xy(90.0, 15.0)),
+                ("transform", at(0.0, 200.0)),
+                ("symbolData", o(vec![("symbolID", g(5))])),
+                ("derivedSymbolData", arr(vec![o(vec![("guidPath", o(vec![("guids", arr(vec![g(6)]))])), ("size", xy(50.0, 5.0))])])),
+            ],
+        ),
+        // A size the instance overrides: the place still follows the constraints.
+        node(
+            13,
+            Some((1, "$")),
+            "INSTANCE",
+            "Resized badge",
+            vec![
+                ("size", xy(90.0, 15.0)),
+                ("transform", at(0.0, 300.0)),
+                (
+                    "symbolData",
+                    o(vec![
+                        ("symbolID", g(5)),
+                        ("symbolOverrides", arr(vec![o(vec![("guidPath", o(vec![("guids", arr(vec![g(7)]))])), ("size", xy(20.0, 10.0))])])),
+                    ]),
+                ),
+            ],
+        ),
+    ];
+    let (doc, _) = import(&canvas(&schema(), &o(vec![("nodeChanges", arr(nodes))])), "x").unwrap();
+    let box_of = |inst: &str, name: &str| {
+        let i = named(&doc, inst);
+        let n = i.children.iter().map(|c| doc.node(*c).unwrap()).find(|n| n.name == name).unwrap();
+        let t = n.transform.translation();
+        [t.x, t.y, n.width, n.height].map(|x| (x * 1e3).round() / 1e3)
+    };
+    assert_eq!(box_of("Small logo", "Mark"), [0.0, 0.0, 90.0, 15.0]);
+    assert_eq!(box_of("Small logo", "Badge"), [58.0, 5.0, 32.0, 10.0]);
+    assert_eq!(box_of("Small logo", "Bar"), [10.0, 0.0, 70.0, 2.0]);
+    // The main's own, then the instances'.
+    let mut letters: Vec<[f64; 2]> =
+        doc.nodes().filter(|n| n.name == "Letter").map(|n| [n.width, n.height].map(|x| (x * 1e3).round() / 1e3)).collect();
+    letters.sort_by(|a, b| a[0].total_cmp(&b[0]));
+    assert_eq!(letters, [[45.0, 15.0], [45.0, 15.0], [45.0, 15.0], [66.0, 22.0]]);
+    assert_eq!(box_of("Derived logo", "Mark")[2..], [50.0, 5.0]);
+    assert_eq!(box_of("Resized badge", "Badge"), [58.0, 5.0, 20.0, 10.0]);
+}
+
+#[test]
+fn nested_instances_resized_again_drop_the_layout_derived_for_their_old_size() {
+    let stretch = || vec![("horizontalConstraint", e("STRETCH")), ("verticalConstraint", e("MIN"))];
+    let nodes = vec![
+        node(0, None, "DOCUMENT", "D", vec![]),
+        node(1, Some((0, "!")), "CANVAS", "P", vec![]),
+        node(20, Some((1, "!")), "SYMBOL", "Track", vec![("size", xy(100.0, 10.0)), ("transform", at(0.0, 0.0))]),
+        node(21, Some((20, "!")), "ROUNDED_RECTANGLE", "Fill", [vec![("size", xy(100.0, 10.0)), ("transform", at(0.0, 0.0))], stretch()].concat()),
+        node(30, Some((1, "\"")), "SYMBOL", "Slider", vec![("size", xy(200.0, 50.0)), ("transform", at(0.0, 100.0))]),
+        // The nested instance is 150 wide in its main, with the layout derived for that.
+        node(
+            31,
+            Some((30, "!")),
+            "INSTANCE",
+            "Inner",
+            [
+                vec![
+                    ("size", xy(150.0, 10.0)),
+                    ("transform", at(0.0, 0.0)),
+                    ("symbolData", o(vec![("symbolID", g(20))])),
+                    (
+                        "derivedSymbolData",
+                        arr(vec![o(vec![
+                            ("guidPath", o(vec![("guids", arr(vec![g(21)]))])),
+                            ("size", xy(150.0, 10.0)),
+                            ("fillPaints", arr(vec![solid(1.0, 0.0, 0.0)])),
+                        ])]),
+                    ),
+                ],
+                stretch(),
+            ]
+            .concat(),
+        ),
+        node(
+            40,
+            Some((1, "#")),
+            "INSTANCE",
+            "Wide slider",
+            vec![("size", xy(300.0, 50.0)), ("transform", at(0.0, 200.0)), ("symbolData", o(vec![("symbolID", g(30))]))],
+        ),
+    ];
+    let (doc, _) = import(&canvas(&schema(), &o(vec![("nodeChanges", arr(nodes))])), "x").unwrap();
+    let width = |outer: &str| {
+        let inner = doc.node(named(&doc, outer).children[0]).unwrap();
+        (inner.width, doc.node(inner.children[0]).unwrap().width)
+    };
+    // In its main the derived layout holds; stretched to 250 it no longer does.
+    assert_eq!(width("Slider"), (150.0, 150.0));
+    assert_eq!(width("Wide slider"), (250.0, 250.0));
+    // What else the derived data gives (the colour a variable resolves to, say) still holds.
+    let fill = doc.node(doc.node(named(&doc, "Wide slider").children[0]).unwrap().children[0]).unwrap();
+    assert!(matches!(fill.fills.first().map(|p| &p.kind), Some(figcraft_doc::color::PaintKind::Solid { color }) if color.r == 1.0 && color.g == 0.0));
+}
+
 #[path = "tail_tests.rs"]
 mod tail;

@@ -0,0 +1,93 @@
+//! The images of a native file within a budget (#189): however many members each within the
+//! per-member limit a file holds, the images read from it together stay within a byte and a count
+//! budget. The document's own images are read first, and the ones past the budget are reported.
+
+use std::io::Write;
+
+use figcraft_doc::Document;
+
+use super::*;
+
+fn png(k: u8) -> Vec<u8> {
+    let img = image::RgbaImage::from_pixel(2, 2, image::Rgba([k, 7, 0, 255]));
+    let mut out = Vec::new();
+    img.write_to(&mut std::io::Cursor::new(&mut out), image::ImageFormat::Png).unwrap();
+    out
+}
+
+/// A saved document with `n` images, and their hashes and total size.
+fn file_with_images(n: u8) -> (Vec<u8>, Vec<String>, u64) {
+    let mut d = Document::new("File");
+    let mut hashes = Vec::new();
+    let mut total = 0;
+    for k in 0..n {
+        let bytes = png(k);
+        total += bytes.len() as u64;
+        hashes.push(add_image(&mut d, bytes).unwrap().0);
+    }
+    (save_bytes(&d, None).unwrap(), hashes, total)
+}
+
+/// `bytes` with one more member, `name` holding `data`.
+fn with_member(bytes: &[u8], name: &str, data: &[u8]) -> Vec<u8> {
+    let mut z = zip::ZipArchive::new(std::io::Cursor::new(bytes)).unwrap();
+    let names: Vec<String> = z.file_names().map(str::to_string).collect();
+    let mut buf = std::io::Cursor::new(Vec::new());
+    let mut w = zip::ZipWriter::new(&mut buf);
+    let stored = zip::write::SimpleFileOptions::default().compression_method(zip::CompressionMethod::Stored);
+    for n in names {
+        let member = read_member(&mut z, &n, u64::MAX).unwrap();
+        w.start_file(n, stored).unwrap();
+        w.write_all(&member).unwrap();
+    }
+    w.start_file(name, stored).unwrap();
+    w.write_all(data).unwrap();
+    w.finish().unwrap();
+    buf.into_inner()
+}
+
+#[test]
+fn images_exactly_within_the_budget_all_load() {
+    let (bytes, hashes, total) = file_with_images(3);
+    let loaded = load_within(&bytes, ImageBudget { images: 3, bytes: total }).unwrap();
+    assert!(loaded.issues.is_empty(), "{:?}", loaded.issues);
+    assert!(hashes.iter().all(|h| loaded.doc.images.contains_key(h)));
+}
+
+#[test]
+fn images_past_the_byte_budget_are_left_out_and_reported() {
+    let (bytes, hashes, total) = file_with_images(3);
+    let loaded = load_within(&bytes, ImageBudget { images: 100, bytes: total - 1 }).unwrap();
+    let held: u64 = loaded.doc.images.values().map(|i| i.bytes.len() as u64).sum();
+    assert!(held < total, "{held} bytes held");
+    assert_eq!(loaded.doc.images.len(), 2);
+    let lost: Vec<&String> = hashes.iter().filter(|h| !loaded.doc.images.contains_key(*h)).collect();
+    assert_eq!(lost.len(), 1);
+    assert!(loaded.issues.iter().any(|i| i.contains(lost[0].as_str()) && i.contains("together")), "{:?}", loaded.issues);
+}
+
+#[test]
+fn images_past_the_count_budget_are_left_out_and_reported() {
+    let (bytes, _, _) = file_with_images(4);
+    let loaded = load_within(&bytes, ImageBudget { images: 3, bytes: u64::MAX }).unwrap();
+    assert_eq!(loaded.doc.images.len(), 3);
+    assert!(loaded.issues.iter().any(|i| i.contains("more than 3 images")), "{:?}", loaded.issues);
+}
+
+#[test]
+fn the_documents_own_images_are_read_before_others() {
+    let (bytes, hashes, total) = file_with_images(2);
+    // An image the document doesn't list, named to come first in the archive's order.
+    let extra = with_member(&bytes, "images/0000", &png(99));
+    let loaded = load_within(&extra, ImageBudget { images: 2, bytes: total }).unwrap();
+    assert!(hashes.iter().all(|h| loaded.doc.images.contains_key(h)), "{:?}", loaded.issues);
+    assert!(!loaded.issues.iter().any(|i| hashes.iter().any(|h| i.contains(h.as_str()))), "{:?}", loaded.issues);
+}
+
+#[test]
+fn a_file_within_the_shipped_budget_loads_as_before() {
+    let (bytes, hashes, _) = file_with_images(3);
+    let loaded = load_bytes_with_versions(&bytes).unwrap();
+    assert!(loaded.issues.is_empty(), "{:?}", loaded.issues);
+    assert!(hashes.iter().all(|h| loaded.doc.images.contains_key(h)));
+}
@@ -20,6 +20,7 @@
 pub mod fig;
 pub mod library;
 pub mod rest;
+pub mod thumbnail;

 pub use library::{is_valid_library_id, read_library, read_library_within};

@@ -46,6 +47,8 @@ pub const MAX_VERSION_DESCRIPTION: usize = 2000;
 /// Largest version index and total size of the version snapshots read from one file.
 const MAX_VERSION_INDEX: u64 = 16 * 1024 * 1024;
 const MAX_VERSION_BYTES: u64 = 1024 * 1024 * 1024;
+/// Most images, and image bytes together, read from one file (members past it are left out).
+const IMAGE_BUDGET: ImageBudget = ImageBudget { images: 20_000, bytes: 4 * 1024 * 1024 * 1024 };
 const BRANCH_INDEX: &str = "branches/index.json";
 /// Most branches a file keeps: making more is refused, extra entries in a file are skipped.
 pub const MAX_BRANCHES: usize = 100;
@@ -452,8 +455,20 @@ pub(crate) fn read_member<R: Read + Seek>(z: &mut zip::ZipArchive<R>, name: &str
    Ok(data)
 }

+/// How many images, and how many bytes of them together, one file may give.
+#[derive(Clone, Copy, Debug)]
+pub(crate) struct ImageBudget {
+    pub images: usize,
+    pub bytes: u64,
+}
+
 /// Read a `.figcraft` archive (or bare JSON) with its version history.
 pub fn load_bytes_with_versions(bytes: &[u8]) -> Result<Loaded, FormatError> {
+    load_within(bytes, IMAGE_BUDGET)
+}
+
+/// [`load_bytes_with_versions`] reading at most `budget` of images.
+pub(crate) fn load_within(bytes: &[u8], budget: ImageBudget) -> Result<Loaded, FormatError> {
    let trimmed = bytes.iter().position(|b| !b.is_ascii_whitespace()).and_then(|i| bytes.get(i));
    if trimmed == Some(&b'{') {
        let text = std::str::from_utf8(bytes).map_err(|e| FormatError::Corrupt(e.to_string()))?;
@@ -463,18 +478,7 @@ pub fn load_bytes_with_versions(bytes: &[u8]) -> Result<Loaded, FormatError> {
    let mut z = zip::ZipArchive::new(std::io::Cursor::new(bytes)).map_err(|e| FormatError::Corrupt(e.to_string()))?;
    let text = String::from_utf8(read_member(&mut z, "document.json", MAX_MEMBER)?).map_err(|e| FormatError::Corrupt(e.to_string()))?;
    let (mut doc, mut issues, own_images) = parse_json(&text)?;
-    let names: Vec<String> = z.file_names().filter(|n| n.starts_with("images/")).map(str::to_string).collect();
-    let mut images = BTreeMap::new();
-    let mut unread = Vec::new();
-    for name in names {
-        let hash = name.trim_start_matches("images/").to_string();
-        match read_member(&mut z, &name, MAX_MEMBER) {
-            Ok(data) => {
-                images.insert(hash, image_data(data));
-            }
-            Err(e) => unread.push((hash, e)),
-        }
-    }
+    let (images, unread) = read_images(&mut z, own_images.as_ref(), budget);
    report_lost_images(&mut issues, &unread, own_images.as_ref(), &images);
    match library::read(&mut z, &images, u64::MAX) {
        Ok(lib) => doc.published = lib.map(Arc::new),
@@ -496,6 +500,41 @@ pub fn load_bytes_with_versions(bytes: &[u8]) -> Result<Loaded, FormatError> {
    Ok(Loaded { doc, issues, versions, branches })
 }

+/// The archive's `images/` members by hash, within `budget`, and the ones that couldn't be read
+/// with why. The document's own images (`own`) are read first, so a file past the budget loses
+/// the images only its history uses before its own.
+fn read_images<R: Read + Seek>(
+    z: &mut zip::ZipArchive<R>,
+    own: Option<&BTreeSet<String>>,
+    budget: ImageBudget,
+) -> (BTreeMap<String, ImageData>, Vec<(String, FormatError)>) {
+    let mut hashes: Vec<String> = z.file_names().filter_map(|n| n.strip_prefix("images/")).map(str::to_string).collect();
+    hashes.sort_by_key(|h| !own.is_some_and(|o| o.contains(h)));
+    let mut images = BTreeMap::new();
+    let mut unread = Vec::new();
+    let mut left = budget.bytes;
+    for (i, hash) in hashes.into_iter().enumerate() {
+        let name = format!("images/{hash}");
+        if i >= budget.images {
+            unread.push((hash, FormatError::Corrupt(format!("the file has more than {} images", budget.images))));
+            continue;
+        }
+        if z.by_name(&name).is_ok_and(|f| f.size() > left) {
+            let mb = budget.bytes / (1024 * 1024);
+            unread.push((hash, FormatError::Corrupt(format!("the file's images together pass {mb} MB"))));
+            continue;
+        }
+        match read_member(z, &name, left.min(MAX_MEMBER)) {
+            Ok(data) => {
+                left = left.saturating_sub(data.len() as u64);
+                images.insert(hash, image_data(data));
+            }
+            Err(e) => unread.push((hash, e)),
+        }
+    }
+    (images, unread)
+}
+
 /// Most lost images reported one by one (the rest as a count).
 const MAX_IMAGE_ISSUES: usize = 20;

@@ -653,14 +692,53 @@ fn read_branches<R: Read + Seek>(z: &mut zip::ZipArchive<R>, images: &BTreeMap<S
    out
 }

-/// Save atomically: write a temp file next to `path`, then rename over it.
+/// Save atomically: write a staging file next to `path`, then rename over it.
 #[cfg(not(target_arch = "wasm32"))]
 pub fn save_file(doc: &Document, path: &std::path::Path, thumbnail_png: Option<&[u8]>) -> Result<(), FormatError> {
    let bytes = save_bytes(doc, thumbnail_png)?;
-    let tmp = path.with_extension("figcraft.tmp");
-    std::fs::write(&tmp, &bytes).map_err(|e| FormatError::Io(format!("{}: {e}", tmp.display())))?;
-    std::fs::rename(&tmp, path).map_err(|e| FormatError::Io(format!("{}: {e}", path.display())))?;
-    Ok(())
+    write_file_atomic(path, &bytes).map_err(|e| FormatError::Io(format!("{}: {e}", path.display())))
+}
+
+/// Write `bytes` to `path` through a staging file and one atomic rename, so a reader of `path`
+/// sees either the previous file or the complete new one, never a partial write. The staging file
+/// is a uniquely named sibling (`<path>.tmp-figcraft-<process id>-<counter>`) created exclusively
+/// (`create_new`) and written through its own handle: a file or symlink that already exists at a
+/// staging name is never truncated or followed, and separate writers (also of separate processes)
+/// never share a staging file. On failure only the staging file this call created is removed, and
+/// `path` is replaced only on success. The rename replaces an existing destination on every
+/// platform (`std::fs::rename` uses `MoveFileEx` with `MOVEFILE_REPLACE_EXISTING` on Windows).
+/// (No `sync_all` yet: nothing around here promises durability across a power cut.)
+#[cfg(not(target_arch = "wasm32"))]
+pub fn write_file_atomic(path: &std::path::Path, bytes: &[u8]) -> std::io::Result<()> {
+    use std::sync::atomic::{AtomicU64, Ordering::Relaxed};
+
+    static STAGING: AtomicU64 = AtomicU64::new(0);
+    // Three tries at a fresh name: the counter is unique within this process, so only a leftover
+    // of a dead process that now shares our process id can collide, and the next counter won't.
+    for _ in 0..3 {
+        let mut name = path.as_os_str().to_os_string();
+        name.push(format!(".tmp-figcraft-{}-{}", std::process::id(), STAGING.fetch_add(1, Relaxed)));
+        let tmp = std::path::PathBuf::from(name);
+        match std::fs::OpenOptions::new().write(true).create_new(true).open(&tmp) {
+            Ok(mut file) => {
+                if let Err(e) = file.write_all(bytes) {
+                    let _ = std::fs::remove_file(&tmp);
+                    return Err(e);
+                }
+                return match std::fs::rename(&tmp, path) {
+                    Ok(()) => Ok(()),
+                    // Leave nothing behind when the file can't take its place.
+                    Err(e) => {
+                        let _ = std::fs::remove_file(&tmp);
+                        Err(e)
+                    }
+                };
+            }
+            Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => continue,
+            Err(e) => return Err(e),
+        }
+    }
+    Err(std::io::Error::new(std::io::ErrorKind::AlreadyExists, "no free staging name next to the file"))
 }

 #[cfg(not(target_arch = "wasm32"))]
@@ -672,10 +750,16 @@ pub fn load_file(path: &std::path::Path) -> Result<(Document, Vec<String>), Form
 #[cfg(test)]
 mod branch_tests;
 #[cfg(test)]
+mod image_budget_tests;
+#[cfg(test)]
 mod image_tests;
 #[cfg(test)]
 mod large_tests;
 #[cfg(test)]
+mod staging_tests;
+#[cfg(test)]
+mod thumbnail_tests;
+#[cfg(test)]
 mod version_tests;

 #[cfg(test)]
@@ -0,0 +1,125 @@
+//! The staging write behind `save_file`: a pre-existing file or symlink at a staging name is never
+//! truncated or followed, concurrent savers of one file never corrupt it, and a failed write
+//! cleans up after itself and leaves the destination alone.
+
+use figcraft_doc::Document;
+
+use crate::{save_file, write_file_atomic};
+
+fn dir(name: &str) -> std::path::PathBuf {
+    let d = std::env::temp_dir().join(format!("figcraft-staging-tests-{name}-{}", std::process::id()));
+    std::fs::create_dir_all(&d).unwrap();
+    d
+}
+
+/// A symlink `from` → `to`; false when the platform won't make one (Windows needs privileges).
+#[cfg(unix)]
+fn symlink(from: &std::path::Path, to: &std::path::Path) -> bool {
+    std::os::unix::fs::symlink(to, from).is_ok()
+}
+
+#[cfg(windows)]
+fn symlink(from: &std::path::Path, to: &std::path::Path) -> bool {
+    std::os::windows::fs::symlink_file(to, from).is_ok()
+}
+
+#[test]
+fn an_existing_staging_file_is_never_written_through() {
+    let d = dir("existing");
+    let path = d.join("a.figcraft");
+    // The old deterministic staging name, held by an unrelated file: saving must pick its own
+    // staging name instead of truncating this one.
+    let old = d.join("a.figcraft.tmp");
+    std::fs::write(&old, b"not yours").unwrap();
+    save_file(&Document::new("Mine"), &path, None).unwrap();
+    assert_eq!(std::fs::read(&old).unwrap(), b"not yours", "an unrelated file at a staging name is untouched");
+    assert_eq!(crate::load_file(&path).unwrap().0.name, "Mine");
+    // Just the file and the untouched staging file: no new staging leftovers.
+    assert_eq!(std::fs::read_dir(&d).unwrap().count(), 2);
+    let _ = std::fs::remove_dir_all(&d);
+}
+
+#[test]
+fn a_staging_symlink_is_never_followed() {
+    let d = dir("symlink");
+    let path = d.join("a.figcraft");
+    let victim = d.join("victim.txt");
+    std::fs::write(&victim, b"innocent").unwrap();
+    let old = d.join("a.figcraft.tmp");
+    if !symlink(&old, &victim) {
+        return; // Making a symlink needs privileges on some Windows setups.
+    }
+    save_file(&Document::new("Mine"), &path, None).unwrap();
+    assert_eq!(std::fs::read(&victim).unwrap(), b"innocent", "the symlink was never written through");
+    assert_eq!(crate::load_file(&path).unwrap().0.name, "Mine");
+    let _ = std::fs::remove_dir_all(&d);
+}
+
+#[test]
+fn concurrent_savers_of_one_file_never_interleave() {
+    let d = dir("concurrent");
+    let path = d.join("a.figcraft");
+    let names = ["W0", "W1", "W2", "W3"];
+    for round in 0..5 {
+        let mut handles = Vec::new();
+        for name in names {
+            let (path, doc) = (path.clone(), Document::new(name));
+            handles.push(std::thread::spawn(move || save_file(&doc, &path, None)));
+        }
+        for h in handles {
+            // On Windows a rename over a file another writer just replaced can lose the race.
+            if cfg!(windows) {
+                let _ = h.join().unwrap();
+            } else {
+                h.join().unwrap().unwrap();
+            }
+        }
+        // Whatever landed is one writer's complete file, never a mix: a torn archive wouldn't load.
+        let (doc, _) = crate::load_file(&path).unwrap();
+        assert!(names.contains(&doc.name.as_str()), "round {round}: {:?}", doc.name);
+    }
+    // No staging file was left stuck.
+    assert_eq!(std::fs::read_dir(&d).unwrap().count(), 1);
+    let _ = std::fs::remove_dir_all(&d);
+}
+
+#[test]
+fn a_failed_write_leaves_the_destination_alone_and_cleans_up() {
+    let d = dir("failure");
+    // The destination is a directory: the rename fails, our staging file is removed, the
+    // directory is untouched.
+    let taken = d.join("folder.figcraft");
+    std::fs::create_dir_all(&taken).unwrap();
+    assert!(save_file(&Document::new("Mine"), &taken, None).is_err());
+    assert!(write_file_atomic(&taken, b"payload").is_err());
+    assert!(taken.is_dir());
+    assert_eq!(std::fs::read_dir(&d).unwrap().count(), 1, "no staging file left behind");
+    // A missing parent directory fails without creating anything anywhere.
+    assert!(write_file_atomic(&d.join("no").join("such.figcraft"), b"payload").is_err());
+    assert!(!d.join("no").exists());
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        // A read-only directory refuses the staging file, and the old destination stays.
+        let ro = d.join("read-only");
+        std::fs::create_dir_all(&ro).unwrap();
+        let dest = ro.join("keep.figcraft");
+        std::fs::write(&dest, b"keep").unwrap();
+        let mut perms = std::fs::metadata(&ro).unwrap().permissions();
+        perms.set_mode(0o500);
+        std::fs::set_permissions(&ro, perms).unwrap();
+        // Running as root would defeat the read-only directory: skip instead of failing.
+        let probe = ro.join(".probe");
+        if std::fs::write(&probe, b"").is_ok() {
+            let _ = std::fs::remove_file(&probe);
+        } else {
+            assert!(write_file_atomic(&dest, b"payload").is_err());
+            assert_eq!(std::fs::read(&dest).unwrap(), b"keep");
+            assert_eq!(std::fs::read_dir(&ro).unwrap().count(), 1, "no staging file left behind");
+        }
+        let mut perms = std::fs::metadata(&ro).unwrap().permissions();
+        perms.set_mode(0o700);
+        std::fs::set_permissions(&ro, perms).unwrap();
+    }
+    let _ = std::fs::remove_dir_all(&d);
+}
@@ -0,0 +1,170 @@
+//! The picture a saved file carries of itself: `thumbnail.png` inside a `.figcraft` or `.fig` zip
+//! (the home screen's recent files show it), and the colour of the page it sits on. Image files are
+//! their own picture. Everything is read within caps: a missing, damaged or oversized picture gives
+//! `None`, never an error or a panic.
+
+use std::io::{Read, Seek};
+use std::path::Path;
+
+/// Largest `thumbnail.png` read from an archive.
+pub const MAX_THUMBNAIL_BYTES: u64 = 8 * 1024 * 1024;
+/// Largest image file read as its own picture.
+pub const MAX_IMAGE_FILE_BYTES: u64 = 32 * 1024 * 1024;
+/// Widest or tallest picture decoded (pixels); a larger one gives none.
+pub const MAX_THUMBNAIL_SIDE: u32 = 8192;
+/// Largest `document.json` read for its page colour, and `.fig` `meta.json`.
+const MAX_DOCUMENT_BYTES: u64 = 64 * 1024 * 1024;
+const MAX_META_BYTES: u64 = 1024 * 1024;
+/// Most memory one decode may take.
+const MAX_DECODE_ALLOC: u64 = 256 * 1024 * 1024;
+
+/// A decoded picture: straight (unpremultiplied) RGBA, `width * height * 4` bytes.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Thumbnail {
+    pub width: u32,
+    pub height: u32,
+    pub rgba: Vec<u8>,
+}
+
+/// The bytes of `thumbnail.png` in a zip archive (`.figcraft`, `.fig`); `None` when it isn't a zip,
+/// has no thumbnail, or the thumbnail is larger than [`MAX_THUMBNAIL_BYTES`].
+pub fn thumbnail_png<R: Read + Seek>(archive: R) -> Option<Vec<u8>> {
+    let mut z = zip::ZipArchive::new(archive).ok()?;
+    crate::read_member(&mut z, "thumbnail.png", MAX_THUMBNAIL_BYTES).ok()
+}
+
+/// Decode a picture (PNG, JPEG, WebP, GIF, BMP or TIFF) no larger than [`MAX_THUMBNAIL_SIDE`] on
+/// either side, scaled down to at most `fit` pixels on its longer side (never up).
+pub fn decode_thumbnail(bytes: &[u8], fit: u32) -> Option<Thumbnail> {
+    let mut reader = image::ImageReader::new(std::io::Cursor::new(bytes)).with_guessed_format().ok()?;
+    let mut limits = image::Limits::default();
+    limits.max_image_width = Some(MAX_THUMBNAIL_SIDE);
+    limits.max_image_height = Some(MAX_THUMBNAIL_SIDE);
+    limits.max_alloc = Some(MAX_DECODE_ALLOC);
+    reader.limits(limits);
+    let mut picture = reader.decode().ok()?;
+    let fit = fit.clamp(1, MAX_THUMBNAIL_SIDE);
+    if picture.width() > fit || picture.height() > fit {
+        picture = picture.thumbnail(fit, fit);
+    }
+    let rgba = picture.to_rgba8();
+    let (width, height) = rgba.dimensions();
+    (width > 0 && height > 0).then(|| Thumbnail { width, height, rgba: rgba.into_raw() })
+}
+
+/// What kind of file `path` is, for its picture and its icon.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum FileKind {
+    /// `.figcraft`
+    FigCraft,
+    /// `.fig`
+    Fig,
+    /// `.svg`
+    Svg,
+    /// A raster image (`.png`, `.jpg`, `.webp`, …).
+    Image,
+    Other,
+}
+
+impl FileKind {
+    pub fn of(path: &Path) -> FileKind {
+        let ext = path.extension().map(|e| e.to_string_lossy().to_ascii_lowercase()).unwrap_or_default();
+        match ext.as_str() {
+            "figcraft" => FileKind::FigCraft,
+            "fig" => FileKind::Fig,
+            "svg" => FileKind::Svg,
+            "png" | "jpg" | "jpeg" | "webp" | "gif" | "bmp" | "tif" | "tiff" => FileKind::Image,
+            _ => FileKind::Other,
+        }
+    }
+}
+
+/// The picture of the file at `path`, at most `fit` pixels on its longer side: the thumbnail a
+/// `.figcraft` or `.fig` file carries, or an image file itself (up to [`MAX_IMAGE_FILE_BYTES`]).
+/// `None` for anything else, and for a file that is missing, unreadable or damaged.
+pub fn file_thumbnail(path: &Path, fit: u32) -> Option<Thumbnail> {
+    match FileKind::of(path) {
+        FileKind::FigCraft | FileKind::Fig => {
+            let file = std::fs::File::open(path).ok()?;
+            let png = thumbnail_png(std::io::BufReader::new(file))?;
+            decode_thumbnail(&png, fit)
+        }
+        FileKind::Image => {
+            let file = std::fs::File::open(path).ok()?;
+            let mut bytes = Vec::new();
+            file.take(MAX_IMAGE_FILE_BYTES.saturating_add(1)).read_to_end(&mut bytes).ok()?;
+            if bytes.len() as u64 > MAX_IMAGE_FILE_BYTES {
+                return None;
+            }
+            decode_thumbnail(&bytes, fit)
+        }
+        FileKind::Svg | FileKind::Other => None,
+    }
+}
+
+/// How a file looks on the home screen: the colour of its first page (straight RGBA, 0 to 1) and
+/// the picture it carries. Either may be missing: a file with nothing on it has a page colour and no
+/// picture; an image file has a picture and no page.
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct Preview {
+    pub page: Option<[f32; 4]>,
+    pub picture: Option<Thumbnail>,
+}
+
+/// The [`Preview`] of the file at `path`, its picture at most `fit` pixels on its longer side.
+/// Empty for a file that is missing, unreadable, damaged or of another kind.
+pub fn file_preview(path: &Path, fit: u32) -> Preview {
+    match FileKind::of(path) {
+        FileKind::FigCraft | FileKind::Fig => {
+            let Ok(file) = std::fs::File::open(path) else { return Preview::default() };
+            archive_preview(std::io::BufReader::new(file), fit)
+        }
+        FileKind::Image => Preview { page: None, picture: file_thumbnail(path, fit) },
+        FileKind::Svg | FileKind::Other => Preview::default(),
+    }
+}
+
+/// The [`Preview`] of a `.figcraft` or `.fig` archive: `thumbnail.png`, and the first page's colour
+/// from `document.json` (`.figcraft`) or `meta.json` (`.fig`).
+pub fn archive_preview<R: Read + Seek>(archive: R, fit: u32) -> Preview {
+    let Ok(mut z) = zip::ZipArchive::new(archive) else { return Preview::default() };
+    let picture = crate::read_member(&mut z, "thumbnail.png", MAX_THUMBNAIL_BYTES).ok().and_then(|png| decode_thumbnail(&png, fit));
+    let page = if z.file_names().any(|n| n == "document.json") {
+        crate::read_member(&mut z, "document.json", MAX_DOCUMENT_BYTES).ok().and_then(|json| figcraft_page(&json))
+    } else {
+        crate::read_member(&mut z, "meta.json", MAX_META_BYTES).ok().and_then(|json| fig_page(&json))
+    };
+    Preview { page, picture }
+}
+
+/// The first page's background in a `.figcraft` `document.json`.
+fn figcraft_page(json: &[u8]) -> Option<[f32; 4]> {
+    #[derive(serde::Deserialize)]
+    struct Head {
+        #[serde(default)]
+        pages: Vec<u64>,
+        #[serde(default)]
+        nodes: std::collections::BTreeMap<String, Node>,
+    }
+    #[derive(serde::Deserialize)]
+    struct Node {
+        #[serde(default)]
+        background: Option<serde_json::Value>,
+    }
+    let head: Head = serde_json::from_slice(json).ok()?;
+    let first = head.pages.first()?;
+    rgba(head.nodes.get(&first.to_string())?.background.as_ref()?)
+}
+
+/// The canvas colour a `.fig` file's `meta.json` gives (`client_meta.background_color`).
+fn fig_page(json: &[u8]) -> Option<[f32; 4]> {
+    let meta: serde_json::Value = serde_json::from_slice(json).ok()?;
+    rgba(meta.get("client_meta")?.get("background_color")?)
+}
+
+/// `{r, g, b, a?}` (0 to 1) as a colour; `None` unless every channel is a finite number.
+fn rgba(v: &serde_json::Value) -> Option<[f32; 4]> {
+    let channel = |k: &str| v.get(k).and_then(serde_json::Value::as_f64).filter(|x| x.is_finite()).map(|x| x.clamp(0.0, 1.0) as f32);
+    let a = if v.get("a").is_some() { channel("a")? } else { 1.0 };
+    Some([channel("r")?, channel("g")?, channel("b")?, a])
+}
@@ -0,0 +1,178 @@
+//! Reading the picture a saved file carries: from `.figcraft` and `.fig` archives and image files,
+//! and `None` (never a panic) for missing, damaged, oversized and non-zip input.
+
+use std::io::{Cursor, Write};
+
+use figcraft_doc::Document;
+
+use crate::thumbnail::{FileKind, MAX_THUMBNAIL_BYTES, MAX_THUMBNAIL_SIDE, decode_thumbnail, file_thumbnail, thumbnail_png};
+
+fn png(w: u32, h: u32) -> Vec<u8> {
+    let img = image::RgbaImage::from_pixel(w, h, image::Rgba([10, 20, 30, 255]));
+    let mut out = Vec::new();
+    img.write_to(&mut Cursor::new(&mut out), image::ImageFormat::Png).unwrap();
+    out
+}
+
+/// A zip holding `members` (stored).
+fn zip(members: &[(&str, &[u8])]) -> Vec<u8> {
+    let mut buf = Cursor::new(Vec::new());
+    let mut z = zip::ZipWriter::new(&mut buf);
+    let stored = zip::write::SimpleFileOptions::default().compression_method(zip::CompressionMethod::Stored);
+    for (name, bytes) in members {
+        z.start_file(*name, stored).unwrap();
+        z.write_all(bytes).unwrap();
+    }
+    z.finish().unwrap();
+    buf.into_inner()
+}
+
+fn dir(name: &str) -> std::path::PathBuf {
+    let d = std::env::temp_dir().join(format!("figcraft-thumbnail-tests-{name}-{}", std::process::id()));
+    std::fs::create_dir_all(&d).unwrap();
+    d
+}
+
+#[test]
+fn a_figcraft_file_gives_its_thumbnail() {
+    let thumb = png(40, 20);
+    let bytes = crate::save_bytes(&Document::new("File"), Some(&thumb)).unwrap();
+    assert_eq!(thumbnail_png(Cursor::new(&bytes)).as_deref(), Some(thumb.as_slice()));
+    let t = decode_thumbnail(&thumb, 640).unwrap();
+    assert_eq!((t.width, t.height, t.rgba.len()), (40, 20, 40 * 20 * 4));
+    assert_eq!(t.rgba.get(..4), Some([10, 20, 30, 255].as_slice()));
+    // And from disk.
+    let path = dir("figcraft").join("a.figcraft");
+    std::fs::write(&path, &bytes).unwrap();
+    assert_eq!(file_thumbnail(&path, 640), Some(t));
+}
+
+#[test]
+fn a_fig_file_gives_its_thumbnail() {
+    let thumb = png(30, 60);
+    let (bytes, _) = crate::fig::export(&Document::new("File"), Some(&thumb)).unwrap();
+    assert_eq!(thumbnail_png(Cursor::new(&bytes)).as_deref(), Some(thumb.as_slice()));
+    let path = dir("fig").join("b.fig");
+    std::fs::write(&path, &bytes).unwrap();
+    let t = file_thumbnail(&path, 640).unwrap();
+    assert_eq!((t.width, t.height), (30, 60));
+}
+
+#[test]
+fn large_pictures_are_scaled_down_to_fit_never_up() {
+    let t = decode_thumbnail(&png(800, 400), 200).unwrap();
+    assert_eq!((t.width, t.height), (200, 100));
+    let t = decode_thumbnail(&png(300, 900), 300).unwrap();
+    assert_eq!((t.width, t.height), (100, 300));
+    let t = decode_thumbnail(&png(16, 8), 640).unwrap();
+    assert_eq!((t.width, t.height), (16, 8));
+}
+
+#[test]
+fn missing_damaged_oversized_and_non_zip_input_give_none() {
+    // No thumbnail in the archive.
+    let bytes = crate::save_bytes(&Document::new("File"), None).unwrap();
+    assert_eq!(thumbnail_png(Cursor::new(&bytes)), None);
+    // Not a zip: bare JSON, an old-style `.fig`, nothing at all.
+    assert_eq!(thumbnail_png(Cursor::new(b"{\"format\":\"figcraft\"}".as_slice())), None);
+    assert_eq!(thumbnail_png(Cursor::new(b"fig-kiwi\x0f\0\0\0".as_slice())), None);
+    assert_eq!(thumbnail_png(Cursor::new(Vec::new())), None);
+    // A thumbnail that isn't a picture, or is cut short.
+    let damaged = zip(&[("thumbnail.png", b"\x89PNG\r\n\x1a\nnot really")]);
+    let png_bytes = thumbnail_png(Cursor::new(&damaged)).unwrap();
+    assert_eq!(decode_thumbnail(&png_bytes, 640), None);
+    let whole = png(20, 20);
+    assert_eq!(decode_thumbnail(&whole[..whole.len() / 2], 640), None);
+    assert_eq!(decode_thumbnail(b"", 640), None);
+    // Too many bytes for a thumbnail.
+    let big = vec![0u8; MAX_THUMBNAIL_BYTES as usize + 1];
+    assert_eq!(thumbnail_png(Cursor::new(zip(&[("thumbnail.png", &big)]))), None);
+    // Too many pixels on a side, however small the file.
+    assert_eq!(decode_thumbnail(&png(MAX_THUMBNAIL_SIDE + 1, 1), 640), None);
+    // A zip with a damaged central directory.
+    let mut cut = crate::save_bytes(&Document::new("File"), Some(&png(4, 4))).unwrap();
+    cut.truncate(cut.len() - 10);
+    assert_eq!(thumbnail_png(Cursor::new(cut)), None);
+}
+
+#[test]
+fn files_on_disk_by_kind() {
+    let d = dir("kinds");
+    // An image is its own picture; an svg and a missing file have none.
+    let image = d.join("photo.PNG");
+    std::fs::write(&image, png(12, 6)).unwrap();
+    assert_eq!(file_thumbnail(&image, 640).map(|t| (t.width, t.height)), Some((12, 6)));
+    let svg = d.join("icon.svg");
+    std::fs::write(&svg, "<svg xmlns='http://www.w3.org/2000/svg'/>").unwrap();
+    assert_eq!(file_thumbnail(&svg, 640), None);
+    assert_eq!(file_thumbnail(&d.join("gone.figcraft"), 640), None);
+    // A `.figcraft` that is plain JSON, and one that is junk.
+    let json = d.join("plain.figcraft");
+    std::fs::write(&json, "{}").unwrap();
+    assert_eq!(file_thumbnail(&json, 640), None);
+    let junk = d.join("junk.fig");
+    std::fs::write(&junk, [0xFFu8; 64]).unwrap();
+    assert_eq!(file_thumbnail(&junk, 640), None);
+    // A folder named like a file.
+    let folder = d.join("folder.figcraft");
+    std::fs::create_dir_all(&folder).unwrap();
+    assert_eq!(file_thumbnail(&folder, 640), None);
+    let kinds: Vec<FileKind> =
+        ["a.figcraft", "a.FIG", "a.svg", "a.jpeg", "a.webp", "a.txt", "noext"].iter().map(|p| FileKind::of(std::path::Path::new(p))).collect();
+    assert_eq!(kinds, [FileKind::FigCraft, FileKind::Fig, FileKind::Svg, FileKind::Image, FileKind::Image, FileKind::Other, FileKind::Other]);
+}
+
+/// A document whose first page is `rgb`.
+fn doc_on(rgb: [f32; 3]) -> Document {
+    let mut d = Document::new("File");
+    let p = d.first_page().unwrap();
+    if let Some(figcraft_doc::NodeKind::Page { background, .. }) = d.node_mut(p).map(|n| &mut n.kind) {
+        *background = figcraft_doc::color::Color { r: rgb[0], g: rgb[1], b: rgb[2], a: 1.0 };
+    }
+    d
+}
+
+#[test]
+fn previews_carry_the_first_pages_colour() {
+    use crate::thumbnail::{Preview, archive_preview, file_preview};
+    let thumb = png(8, 4);
+    // `.figcraft`: the first page's background from document.json.
+    let bytes = crate::save_bytes(&doc_on([0.1, 0.2, 0.3]), Some(&thumb)).unwrap();
+    let p = archive_preview(Cursor::new(&bytes), 640);
+    assert_eq!(p.page, Some([0.1, 0.2, 0.3, 1.0]));
+    assert_eq!(p.picture.map(|t| (t.width, t.height)), Some((8, 4)));
+    // `.fig`: the canvas colour from meta.json.
+    let (bytes, _) = crate::fig::export(&doc_on([0.5, 0.25, 0.75]), Some(&thumb)).unwrap();
+    let p = archive_preview(Cursor::new(&bytes), 640);
+    assert_eq!(p.page, Some([0.5, 0.25, 0.75, 1.0]));
+    assert!(p.picture.is_some());
+    // A file with nothing on it: its colour, no picture.
+    let bytes = crate::save_bytes(&doc_on([0.9, 0.9, 0.9]), None).unwrap();
+    assert_eq!(archive_preview(Cursor::new(&bytes), 640), Preview { page: Some([0.9, 0.9, 0.9, 1.0]), picture: None });
+    // Damaged or odd metadata: no colour, never a panic.
+    for meta in [&b"{"[..], b"{\"client_meta\":{\"background_color\":{\"r\":\"x\",\"g\":0,\"b\":0}}}", b"[]", b"{\"client_meta\":7}"] {
+        assert_eq!(archive_preview(Cursor::new(zip(&[("meta.json", meta)])), 640).page, None, "{}", String::from_utf8_lossy(meta));
+    }
+    for doc in [
+        &b"{\"pages\":[5],\"nodes\":{}}"[..],
+        b"{\"pages\":[],\"nodes\":{}}",
+        b"{\"pages\":\"x\"}",
+        b"{\"pages\":[1],\"nodes\":{\"1\":{\"background\":[1,2]}}}",
+    ] {
+        assert_eq!(archive_preview(Cursor::new(zip(&[("document.json", doc)])), 640).page, None, "{}", String::from_utf8_lossy(doc));
+    }
+    // Out-of-range channels are clamped; alpha defaults to opaque.
+    let doc = b"{\"pages\":[1],\"nodes\":{\"1\":{\"background\":{\"r\":2,\"g\":-1,\"b\":0.5}}}}";
+    assert_eq!(archive_preview(Cursor::new(zip(&[("document.json", doc)])), 640).page, Some([1.0, 0.0, 0.5, 1.0]));
+    // Not an archive, or no file at all.
+    assert_eq!(archive_preview(Cursor::new(b"junk".to_vec()), 640), Preview::default());
+    assert_eq!(file_preview(std::path::Path::new("/nonexistent/x.figcraft"), 640), Preview::default());
+    let d = dir("preview");
+    let svg = d.join("a.svg");
+    std::fs::write(&svg, "<svg/>").unwrap();
+    assert_eq!(file_preview(&svg, 640), Preview::default());
+    let image = d.join("a.png");
+    std::fs::write(&image, png(5, 5)).unwrap();
+    let p = file_preview(&image, 640);
+    assert!(p.page.is_none() && p.picture.is_some());
+}
@@ -0,0 +1,95 @@
+//! Deeply nested layers and a resize (#210): constraints, group scaling and auto layout fill
+//! follow a resize down to [`MAX_NESTING`] levels and stop there, instead of running out of stack.
+//! Each case runs on a 1 MB stack, the main thread's on Windows; thousands of levels overflowed it.
+
+use super::*;
+use figcraft_doc::{AutoLayout, Constraints, Document, HConstraint, NodeKind, VConstraint};
+
+/// Far deeper than the nesting the layout follows.
+const DEEP: usize = 5000;
+
+fn on_small_stack(f: impl FnOnce() + Send + 'static) {
+    std::thread::Builder::new().stack_size(1 << 20).spawn(f).unwrap().join().unwrap();
+}
+
+fn width(d: &Document, id: NodeId) -> f64 {
+    d.node(id).unwrap().width
+}
+
+/// A 100 × 100 frame holding `depth` frames, each inside the last and stretching with it; the
+/// root and the chain from the top.
+fn stretching_frames(depth: usize) -> (Document, NodeId, Vec<NodeId>) {
+    let mut d = Document::new("deep");
+    let page = d.first_page().unwrap();
+    let root = d.create(page, NodeKind::Frame, "F", 0.0, 0.0, 100.0, 100.0).unwrap();
+    let mut chain = Vec::new();
+    let mut parent = root;
+    for _ in 0..depth {
+        let f = d.create(parent, NodeKind::Frame, "F", 0.0, 0.0, 100.0, 100.0).unwrap();
+        d.get_mut(f).unwrap().constraints = Constraints { horizontal: HConstraint::LeftRight, vertical: VConstraint::TopBottom };
+        chain.push(f);
+        parent = f;
+    }
+    (d, root, chain)
+}
+
+#[test]
+fn deeply_nested_frames_follow_their_constraints_without_running_out_of_stack() {
+    on_small_stack(|| {
+        let (mut d, root, chain) = stretching_frames(DEEP);
+        set_size(&mut d, root, 200.0, 200.0);
+        apply_constraints(&mut d, root, 100.0, 100.0);
+        assert_eq!(width(&d, chain[0]), 200.0);
+        assert_eq!(width(&d, chain[MAX_NESTING - 2]), 200.0);
+        assert_eq!(width(&d, chain[DEEP - 1]), 100.0, "past the nesting the layout follows, layers stay");
+    });
+}
+
+#[test]
+fn a_shallow_chain_follows_all_the_way_down() {
+    let (mut d, root, chain) = stretching_frames(20);
+    set_size(&mut d, root, 200.0, 200.0);
+    apply_constraints(&mut d, root, 100.0, 100.0);
+    assert!(chain.iter().all(|f| width(&d, *f) == 200.0));
+}
+
+#[test]
+fn deeply_nested_groups_scale_without_running_out_of_stack() {
+    on_small_stack(|| {
+        let mut d = Document::new("deep");
+        let mut parent = d.first_page().unwrap();
+        let root = d.create(parent, NodeKind::Group, "G", 0.0, 0.0, 100.0, 100.0).unwrap();
+        parent = root;
+        let mut chain = Vec::new();
+        for _ in 0..DEEP {
+            parent = d.create(parent, NodeKind::Group, "G", 0.0, 0.0, 100.0, 100.0).unwrap();
+            chain.push(parent);
+        }
+        scale_group_children(&mut d, root, 2.0, 2.0);
+        assert_eq!(width(&d, chain[0]), 200.0);
+    });
+}
+
+#[test]
+fn deeply_nested_fill_frames_lay_out_without_running_out_of_stack() {
+    on_small_stack(|| {
+        let mut d = Document::new("deep");
+        let page = d.first_page().unwrap();
+        let root = d.create(page, NodeKind::Frame, "F", 0.0, 0.0, 100.0, 100.0).unwrap();
+        d.get_mut(root).unwrap().layout = Some(AutoLayout { padding: [0.0; 4], ..AutoLayout::default() });
+        let mut parent = root;
+        let mut chain = Vec::new();
+        for _ in 0..DEEP {
+            let f = d.create(parent, NodeKind::Frame, "F", 0.0, 0.0, 10.0, 10.0).unwrap();
+            let n = d.get_mut(f).unwrap();
+            n.layout = Some(AutoLayout { padding: [0.0; 4], ..AutoLayout::default() });
+            n.child_layout.sizing_h = Sizing::Fill;
+            chain.push(f);
+            parent = f;
+        }
+        d.get_mut(root).unwrap().width = 300.0;
+        layout_frame(&mut d, root, &NoMeasure);
+        assert_eq!(width(&d, chain[0]), 300.0);
+        assert_eq!(width(&d, chain[DEEP - 1]), 10.0, "past the nesting the layout follows, layers stay");
+    });
+}
@@ -20,6 +20,30 @@ use figcraft_doc::{
 };
 use figcraft_geom::{Affine, Point, Rect};

+/// Most layout calls nested in one another (about one per level of layers): deeper layers don't
+/// follow a resize, so a deeply nested document can't run the stack out (#210).
+pub const MAX_NESTING: usize = 256;
+
+thread_local! {
+    static NESTING: std::cell::Cell<usize> = const { std::cell::Cell::new(0) };
+}
+
+/// One level of nested layout calls, released when dropped.
+struct Nested;
+
+impl Nested {
+    /// Enter one more level; `None` when [`MAX_NESTING`] are in progress.
+    fn enter() -> Option<Self> {
+        NESTING.with(|n| (n.get() < MAX_NESTING).then(|| n.set(n.get() + 1)).map(|()| Self))
+    }
+}
+
+impl Drop for Nested {
+    fn drop(&mut self) {
+        NESTING.with(|n| n.set(n.get().saturating_sub(1)));
+    }
+}
+
 /// Measures text for a given width (auto-height text inside a Fill container).
 pub trait Measure {
    /// The height a text node needs at `width`.
@@ -311,6 +335,7 @@ struct Item {

 /// Lay out one auto layout frame's children and size the frame if it hugs.
 pub fn layout_frame(doc: &mut Document, frame: NodeId, m: &dyn Measure) {
+    let Some(_nested) = Nested::enter() else { return };
    let Some(f) = doc.node(frame) else { return };
    let Some(al) = f.layout.clone() else { return };
    let horizontal = matches!(al.mode, LayoutMode::Horizontal);
@@ -893,6 +918,7 @@ fn layout_grid(doc: &mut Document, frame: NodeId, al: &AutoLayout, m: &dyn Measu
 /// (recursively for children frames that resize). In an auto layout frame only the children that
 /// ignore auto layout (absolute position) follow constraints; the layout places the others.
 pub fn apply_constraints(doc: &mut Document, id: NodeId, ow: f64, oh: f64) {
+    let Some(_nested) = Nested::enter() else { return };
    let Some(f) = doc.node(id) else { return };
    let absolute_only = f.layout.is_some();
    let (nw, nh) = (f.width, f.height);
@@ -977,6 +1003,7 @@ pub fn apply_constraints(doc: &mut Document, id: NodeId, ow: f64, oh: f64) {
 /// Each child keeps its rotation and flip and scales along its own axes ([`axis_factors`]), its
 /// centre following the group's scale.
 pub fn scale_group_children(doc: &mut Document, id: NodeId, kx: f64, ky: f64) {
+    let Some(_nested) = Nested::enter() else { return };
    let Some(n) = doc.node(id) else { return };
    for c in n.children.clone() {
        let Some(cn) = doc.node(c) else { continue };
@@ -1101,6 +1128,8 @@ mod behaviour_tests;
 #[cfg(test)]
 mod content_align_tests;
 #[cfg(test)]
+mod depth_tests;
+#[cfg(test)]
 mod nested_tests;
 #[cfg(test)]
 mod tests;
@@ -3,6 +3,7 @@
 //! behave the same.

 use base64::Engine as _;
+use figcraft_engine::params::normalize_paint;
 use serde_json::{Map, Value, json};

 use crate::backend::{Backend, decode_data, page_children};
@@ -127,7 +128,7 @@ pub fn tool_definitions() -> Vec<Value> {
        tool(
            "batch",
            "Run commands as one step",
-            "Run several commands in order as ONE undo step (engine `command.batch`). If any command fails, everything is rolled back and the error names the failing step. Returns an array of the results in order. Note: later commands cannot reference ids created by earlier ones in the same batch (ids are only known afterwards), so create containers first, then batch the edits.",
+            "Run several commands in order as ONE undo step (engine `command.batch`). If any command fails, everything is rolled back and the error names the failing step. Returns an array of the results in order. A later step can use a layer an earlier step created: anywhere in its params, {\"$step\": n} stands for the `id` in step n's result (zero-based; {\"$step\": n, \"field\": \"…\"} picks another field). Example: [{\"command\":\"node.create\",\"params\":{\"type\":\"frame\"}}, {\"command\":\"node.create\",\"params\":{\"type\":\"text\",\"text\":\"Hi\",\"parent\":{\"$step\":0}}}] builds a frame and a text inside it in one call.",
            obj(
                json!({
                    "commands": {"type": "array", "minItems": 1, "description": "Steps to run", "items": obj(json!({"command": string("Command id"), "params": {"type": "object"}}), &["command"])},
@@ -369,74 +370,17 @@ fn bounds_of(b: &mut dyn Backend, ids: &[u64]) -> Option<(f64, f64, f64, f64)> {
    acc
 }

-/// Make paint/effect JSON friendlier than the engine's strict serde: any `"color"` given as a CSS
-/// string ("#RRGGBB[AA]", "rgb(…)") becomes the engine's {r,g,b,a} object, gradient paints get
-/// default handles (top-to-bottom) when `from`/`to`/`width` are missing, and gradient stops given
-/// as plain colours are spread evenly.
+/// Make paint/effect JSON friendlier than the engine's strict serde (see
+/// [`figcraft_engine::params::normalize_paint`]). The engine reads paints this way itself; effects
+/// still need it here.
 pub fn normalize_props(props: &mut Map<String, Value>) {
    for k in ["fills", "strokes", "effects"] {
        if let Some(v) = props.get_mut(k) {
-            normalize_paintish(v, 0);
+            normalize_paint(v);
        }
    }
 }

-fn normalize_paintish(v: &mut Value, depth: usize) {
-    if depth > 16 {
-        return;
-    }
-    match v {
-        Value::Array(a) => {
-            for x in a {
-                normalize_paintish(x, depth + 1);
-            }
-        }
-        Value::Object(o) => {
-            if let Some(c) = o.get("color").filter(|c| c.is_string()).and_then(figcraft_engine::params::color_of) {
-                o.insert("color".into(), serde_json::to_value(c).unwrap_or(Value::Null));
-            }
-            let is_gradient = o.get("type").and_then(Value::as_str).is_some_and(|t| t.to_ascii_lowercase().contains("gradient"));
-            if is_gradient {
-                // Accept {"type":"linearGradient"} as well as {"type":"gradient","kind":"linear"}.
-                if let Some(t) = o.get("type").and_then(Value::as_str).map(str::to_ascii_lowercase)
-                    && t != "gradient"
-                {
-                    let kind = t.trim_end_matches("gradient").to_string();
-                    o.insert("type".into(), json!("gradient"));
-                    o.entry("kind").or_insert(json!(if kind.is_empty() { "linear".to_string() } else { kind }));
-                }
-                o.entry("kind").or_insert(json!("linear"));
-                let linear = o.get("kind").and_then(Value::as_str) == Some("linear");
-                let (from, to, width) = if linear { ([0.5, 0.0], [0.5, 1.0], [-0.5, 0.0]) } else { ([0.5, 0.5], [0.5, 1.0], [1.0, 0.5]) };
-                o.entry("from").or_insert(json!(from));
-                o.entry("to").or_insert(json!(to));
-                // A linear gradient's width handle goes square to its axis (else its bands skew,
-                // or vanish when the handle lies on the axis).
-                let pt = |k: &str| o.get(k).and_then(Value::as_array).and_then(|a| Some((a.first()?.as_f64()?, a.get(1)?.as_f64()?)));
-                if linear
-                    && !o.contains_key("width")
-                    && let (Some(f), Some(t)) = (pt("from"), pt("to"))
-                {
-                    o.insert("width".into(), json!([f.0 - (t.1 - f.1), f.1 + (t.0 - f.0)]));
-                }
-                o.entry("width").or_insert(json!(width));
-                if let Some(Value::Array(stops)) = o.get_mut("stops") {
-                    let n = stops.len();
-                    for (i, s) in stops.iter_mut().enumerate() {
-                        if let Some(c) = figcraft_engine::params::color_of(s).filter(|_| s.is_string()) {
-                            let pos = if n > 1 { i as f64 / (n - 1) as f64 } else { 0.0 };
-                            *s = json!({"position": pos, "color": c});
-                        } else {
-                            normalize_paintish(s, depth + 1);
-                        }
-                    }
-                }
-            }
-        }
-        _ => {}
-    }
-}
-
 /// [`normalize_props`] for command params: `props`, flat node.set keys, `paint`, `effect`.
 fn friendly_params(p: &mut Value) {
    let Some(o) = p.as_object_mut() else { return };
@@ -446,7 +390,7 @@ fn friendly_params(p: &mut Value) {
    normalize_props(o);
    for k in ["paint", "effect"] {
        if let Some(v) = o.get_mut(k) {
-            normalize_paintish(v, 0);
+            normalize_paint(v);
        }
    }
 }
@@ -307,3 +307,40 @@ fn task_vector_edit_keys() {
    assert_eq!(c.page_children().len(), 1);
    assert!(c.call("run_command", json!({"command": "vector.edit.state", "params": {}}))["isError"] == true, "Enter left edit mode");
 }
+
+/// A whole card in one `batch` call: later steps reach the frames earlier steps created through
+/// `{"$step": n}`, so the tree is built in one round-trip and one undo step.
+#[test]
+fn task_card_in_one_batch() {
+    let mut c = Client::new();
+    let out = c.ok(
+        "batch",
+        json!({"label": "Card", "commands": [
+            {"command": "node.create", "params": {"type": "frame", "name": "Card", "width": 320, "height": 50,
+                "props": {"layout": "vertical", "padding": 24, "gap": 12, "sizingV": "hug"}}},
+            {"command": "node.create", "params": {"type": "text", "parent": {"$step": 0}, "text": "Ada Lovelace"}},
+            {"command": "node.create", "params": {"type": "frame", "parent": {"$step": 0}, "name": "Button", "height": 44,
+                "props": {"layout": "horizontal", "sizingH": "fill"}}},
+            {"command": "node.create", "params": {"type": "text", "parent": {"$step": 2}, "text": "Follow"}},
+            {"command": "node.set", "params": {"ids": [{"$step": 2}], "props": {"fill": "#3B5BDB"}}},
+        ]}),
+    );
+    let results = ids(&out);
+    assert_eq!(results.len(), 5);
+    let (card, button) = (results[0]["id"].clone(), results[2]["id"].clone());
+    let n = c.node(&card);
+    assert_eq!(ids(&n["children"]).len(), 2, "title and button are inside the card");
+    let b = c.node(&button);
+    assert_eq!(ids(&b["children"]).len(), 1, "the label is inside the button");
+    assert_eq!(b["fills"][0]["color"].as_str().unwrap().to_ascii_uppercase(), "#3B5BDB");
+    assert_eq!(c.doc()["history"]["undo"][0], "Card", "one undo step");
+    // A forward reference fails the whole batch and names the step.
+    let e = c.err(
+        "batch",
+        json!({"commands": [
+            {"command": "node.create", "params": {"type": "frame", "parent": {"$step": 1}}},
+            {"command": "node.create", "params": {"type": "frame"}},
+        ]}),
+    );
+    assert!(e.contains("step 0") && e.contains("earlier step"), "{e}");
+}
@@ -0,0 +1,79 @@
+//! A drop shadow under a layer with a background blur (#255): the shadow is cast by what the layer
+//! paints (a translucent fill casts a faint one), not by the blurred backdrop drawn through its
+//! shape, and the blur reads what lies under the layer with its own shadow there, so a shadow
+//! that shows behind transparent areas is seen, blurred, through the layer.
+
+use figcraft_color::{Color, Paint};
+use figcraft_doc::{Blur, Document, Effect, EffectKind, NodeId, NodeKind, Shadow};
+
+use super::*;
+
+/// A white 240 × 200 frame with blue and green stripes and, on top, a pane at (60, 40) 120 × 80
+/// filled 20% black, with a hard black drop shadow 40 down (below it and under its lower half)
+/// and, when `blur`, a background blur.
+fn scene(show_behind: bool, blur: bool) -> (Document, NodeId) {
+    let mut d = Document::new("shadow behind blur");
+    let p = d.first_page().unwrap();
+    let f = d.create(p, NodeKind::Frame, "Frame", 0.0, 0.0, 240.0, 200.0).unwrap();
+    d.get_mut(f).unwrap().fills = vec![Paint::solid(Color::from_hex("FFFFFF").unwrap())];
+    for (i, x) in [20.0, 80.0, 140.0, 200.0].into_iter().enumerate() {
+        let s = d.create(f, NodeKind::Rectangle, "Stripe", x, 0.0, 20.0, 200.0).unwrap();
+        d.get_mut(s).unwrap().fills = vec![Paint::solid(Color::from_hex(if i % 2 == 0 { "2040E0" } else { "20C060" }).unwrap())];
+    }
+    let pane = d.create(f, NodeKind::Rectangle, "Pane", 60.0, 40.0, 120.0, 80.0).unwrap();
+    let n = d.get_mut(pane).unwrap();
+    n.fills = vec![Paint::solid(Color::new(0.0, 0.0, 0.0, 0.2))];
+    let shadow = Shadow { color: Color::new(0.0, 0.0, 0.0, 1.0), offset: (0.0, 40.0), radius: 0.0, show_behind, ..Shadow::default() };
+    n.effects = vec![Effect { kind: EffectKind::DropShadow(shadow), visible: true }];
+    if blur {
+        n.effects.push(Effect { kind: EffectKind::BackgroundBlur(Blur::uniform(8.0)), visible: true });
+    }
+    (d, f)
+}
+
+fn px(p: &Pixmap, x: u32, y: u32) -> [u8; 4] {
+    let i = ((y * p.width() + x) * 4) as usize;
+    [p.data()[i], p.data()[i + 1], p.data()[i + 2], p.data()[i + 3]]
+}
+
+/// The largest channel difference between `a` and `b` over the shadow below the pane
+/// (60..180 × 122..160).
+fn max_diff_below_pane(a: &Pixmap, b: &Pixmap) -> u8 {
+    let mut worst = 0;
+    for y in 122..160 {
+        for x in 60..180 {
+            worst = worst.max(px(a, x, y).iter().zip(px(b, x, y)).map(|(c, d)| c.abs_diff(d)).max().unwrap());
+        }
+    }
+    worst
+}
+
+#[test]
+fn a_background_blur_doesnt_change_the_shadow_its_layer_casts() {
+    for show_behind in [false, true] {
+        let (with_blur, f) = scene(show_behind, true);
+        let (without, _) = scene(show_behind, false);
+        let got = render_node(&with_blur, f, 1.0).unwrap();
+        let want = render_node(&without, f, 1.0).unwrap();
+        let diff = max_diff_below_pane(&got, &want);
+        assert!(diff <= 2, "show behind {show_behind}: the shadow below the pane differs by {diff}");
+        // A 20% fill casts a faint shadow: the white between the stripes stays light.
+        let light = px(&got, 120, 140);
+        assert!(light[0] > 180, "show behind {show_behind}: {light:?}");
+    }
+}
+
+#[test]
+fn a_shadow_showing_behind_is_seen_through_the_background_blur() {
+    let (d, f) = scene(true, true);
+    let got = render_node(&d, f, 1.0).unwrap();
+    // Between the stripes, the pane's top (no shadow under it) and its lower half (its own shadow
+    // under it, from y = 80).
+    let (top, low) = (px(&got, 120, 50), px(&got, 120, 110));
+    assert!(top[0] > low[0] + 20, "the shadow under the pane doesn't show through: top {top:?}, lower half {low:?}");
+    // Hidden behind the layer, it doesn't.
+    let (d, f) = scene(false, true);
+    let got = render_node(&d, f, 1.0).unwrap();
+    let (top, low) = (px(&got, 120, 50), px(&got, 120, 110));
+    assert!(top[0].abs_diff(low[0]) <= 2, "a hidden shadow shows: top {top:?}, lower half {low:?}");
+}
@@ -423,16 +423,18 @@ pub fn draw_node(ctx: &Ctx, pix: &mut Pixmap, id: NodeId, parent_xf: Affine, dep
    let shape = node_outline(ctx.doc, n);
    // Background blur and glass: the whole backdrop under the layer (every surface below this
    // one, composited), through the shape, under the content.
-    if backdrop::has_effects(n)
-        && let Some(sh) = &backdrop::outline(ctx.doc, n)
-    {
-        let pad = backdrop::pad(n, ctx.scale);
-        let p = i32::try_from(pad).unwrap_or(0);
-        if let Some(back) = backdrop::backdrop(pix, ctx.under, lx.saturating_sub(p), ly.saturating_sub(p), lw + pad * 2, lh + pad * 2)
-            && let Some(b) = backdrop::effects(n, sh, &back, pad, lw, lh, lxf, ctx.scale)
-        {
-            layer.draw_pixmap(0, 0, b.as_ref(), &PixmapPaint::default(), Transform::identity(), None);
-        }
+    let back_shape = if backdrop::has_effects(n) { backdrop::outline(ctx.doc, n) } else { None };
+    let read_backdrop = |pix: &Pixmap| back_shape.as_ref().and_then(|sh| backdrop_layer(ctx, pix, n, sh, (lx, ly), (lw, lh), lxf));
+    // With drop shadows too, the layer casts them from what it paints, not from the backdrop, and
+    // the backdrop is read again once they lie under it (a shadow showing behind is seen through
+    // it). Until then, the layer's content sees the backdrop read first under it (#255).
+    let casts = back_shape.is_some() && n.effects.iter().any(|e| e.visible && matches!(e.kind, EffectKind::DropShadow(_)));
+    // Kept apart, the first read is only what backdrop effects inside the content see: without
+    // any, the backdrop (blur or glass, the costly part) is computed once, after the shadows.
+    let nested = || ctx.doc.subtree(id).iter().skip(1).any(|c| ctx.doc.node(*c).is_some_and(backdrop::has_effects));
+    let first_back = if !casts || nested() { read_backdrop(pix) } else { None };
+    if !casts && let Some(b) = &first_back {
+        layer.draw_pixmap(0, 0, b.as_ref(), &PixmapPaint::default(), Transform::identity(), None);
    }
    let op = n.opacity.clamp(0.0, 1.0);
    {
@@ -448,9 +450,12 @@ pub fn draw_node(ctx: &Ctx, pix: &mut Pixmap, id: NodeId, parent_xf: Affine, dep
            }
        };
        let has_inner = shape.is_some() && n.effects.iter().any(|e| e.visible && matches!(e.kind, EffectKind::InnerShadow(_)));
-        // Backdrops further down see this layer composited onto `pix`.
+        // Backdrops further down see this layer composited onto `pix` (over its backdrop, when
+        // that is kept apart for now).
        let under = Under { opacity: op, blend: n.blend, ..Under::new(pix, (lx, ly), ctx.under) };
-        draw_content(&Ctx { under: Some(&under), ..*ctx }, &mut layer, n, lxf, depth, has_inner.then_some(&inner as &dyn Fn(&mut Pixmap)));
+        let over_back = first_back.as_ref().filter(|_| casts).map(|b| Under::new(b, (0, 0), Some(&under)));
+        let content_under = over_back.as_ref().unwrap_or(&under);
+        draw_content(&Ctx { under: Some(content_under), ..*ctx }, &mut layer, n, lxf, depth, has_inner.then_some(&inner as &dyn Fn(&mut Pixmap)));
    }
    // A group is no outline of its own: its inner shadows are cast from around what its layers
    // draw together, over them.
@@ -465,24 +470,60 @@ pub fn draw_node(ctx: &Ctx, pix: &mut Pixmap, id: NodeId, parent_xf: Affine, dep
        }
    }
    // Layer blur, noise and texture, in list order, over everything else.
+    if !casts {
+        layer_effects(ctx, &mut layer, n, id, lxf);
+    }
+    // Drop shadows go under the layer, in effect-list order.
+    {
+        // Kept apart, the backdrop isn't in the layer yet: the shadows are cast from the content
+        // with the layer effects it will get (a copy only when it gets some).
+        let layer_fx =
+            n.effects.iter().any(|e| e.visible && matches!(e.kind, EffectKind::LayerBlur(_) | EffectKind::Noise(_) | EffectKind::Texture(_)));
+        let content = (casts && layer_fx).then(|| {
+            let mut c = layer.clone();
+            layer_effects(ctx, &mut c, n, id, lxf);
+            c
+        });
+        let caster = shadow::Caster::new(ctx.doc, n, content.as_ref().unwrap_or(&layer), lxf, ctx.scale);
+        for e in n.effects.iter().filter(|e| e.visible) {
+            if let EffectKind::DropShadow(s) = &e.kind
+                && let Some(sh) = shadow::drop_shadow(&caster, s)
+            {
+                composite(pix, (lx, ly), &sh, op, s.blend);
+            }
+        }
+    }
+    if casts {
+        // The backdrop with the shadows under it, the content over it, then the layer effects.
+        if let Some(mut b) = read_backdrop(pix) {
+            b.draw_pixmap(0, 0, layer.as_ref(), &PixmapPaint::default(), Transform::identity(), None);
+            layer = b;
+        }
+        layer_effects(ctx, &mut layer, n, id, lxf);
+    }
+    composite(pix, (lx, ly), &layer, op, n.blend);
+}
+
+/// Node `n`'s backdrop effects through its backdrop outline `sh`, for its `size` layer at `at` on
+/// `pix` (local → layer pixels through `lxf`): what `pix` holds there now, over what lies under it.
+fn backdrop_layer(ctx: &Ctx, pix: &Pixmap, n: &Node, sh: &shadow::Outline, at: (i32, i32), size: (u32, u32), lxf: Affine) -> Option<Pixmap> {
+    let ((lx, ly), (lw, lh)) = (at, size);
+    let pad = backdrop::pad(n, ctx.scale);
+    let p = i32::try_from(pad).unwrap_or(0);
+    let back = backdrop::backdrop(pix, ctx.under, lx.saturating_sub(p), ly.saturating_sub(p), lw + pad * 2, lh + pad * 2)?;
+    backdrop::effects(n, sh, &back, pad, lw, lh, lxf, ctx.scale)
+}
+
+/// Node `n`'s layer blur, noise and texture on its `layer`, in list order.
+fn layer_effects(ctx: &Ctx, layer: &mut Pixmap, n: &Node, id: NodeId, lxf: Affine) {
    for e in n.effects.iter().filter(|e| e.visible) {
        match &e.kind {
-            EffectKind::LayerBlur(b) => blur::apply(&mut layer, b, (n.width, n.height), lxf, ctx.scale),
-            EffectKind::Noise(nz) => grain::noise(&mut layer, nz, lxf, id.0 as u32),
-            EffectKind::Texture(t) => grain::texture(&mut layer, t, lxf, ctx.scale, id.0 as u32),
+            EffectKind::LayerBlur(b) => blur::apply(layer, b, (n.width, n.height), lxf, ctx.scale),
+            EffectKind::Noise(nz) => grain::noise(layer, nz, lxf, id.0 as u32),
+            EffectKind::Texture(t) => grain::texture(layer, t, lxf, ctx.scale, id.0 as u32),
            _ => {}
        }
    }
-    // Drop shadows go under the layer, in effect-list order.
-    let caster = shadow::Caster::new(ctx.doc, n, &layer, lxf, ctx.scale);
-    for e in n.effects.iter().filter(|e| e.visible) {
-        if let EffectKind::DropShadow(s) = &e.kind
-            && let Some(sh) = shadow::drop_shadow(&caster, s)
-        {
-            composite(pix, (lx, ly), &sh, op, s.blend);
-        }
-    }
-    composite(pix, (lx, ly), &layer, op, n.blend);
 }

 fn draw_outline(ctx: &Ctx, pix: &mut Pixmap, n: &Node, xf: Affine, depth: usize) {
@@ -531,21 +572,50 @@ fn draw_content(ctx: &Ctx, pix: &mut Pixmap, n: &Node, xf: Affine, depth: usize,
        NodeKind::Text(t) => {
            let Some((layout, dy)) = figcraft_text::layout_node(n) else { return };
            let gxf = xf * Affine::translate((0.0, dy));
+            // Colour glyphs (emoji) carry their own ink, which draws instead of their outline: a
+            // bitmap the font ships, or COLR layers with a colour each.
+            let gs = gxf.determinant().abs().sqrt();
+            let mut ink: Vec<(usize, Ink)> = Vec::new();
            // Group glyphs by style so runs with their own fills paint with them.
            let mut by_style: HashMap<usize, BezPath> = HashMap::new();
            for g in &layout.glyphs {
-                by_style.entry(g.style).or_default().extend(g.path().elements().iter().copied());
+                match g.color(gs) {
+                    Some(figcraft_text::ColorInk::Bitmap(bitmap, place)) => ink.push((g.style, Ink::Bitmap(bitmap, place))),
+                    Some(figcraft_text::ColorInk::Layers(layers)) => {
+                        for layer in layers.iter() {
+                            ink.push((g.style, Ink::Layer(g.layer_path(layer.gid), layer.rgba)));
+                        }
+                    }
+                    None => by_style.entry(g.style).or_default().extend(g.path().elements().iter().copied()),
+                }
            }
            for d in &layout.decorations {
                by_style.entry(d.style).or_default().extend(d.path().elements().iter().copied());
            }
-            let mut keys: Vec<usize> = by_style.keys().copied().collect();
+            // A run can have ink and no outline at all (bitmap-only fonts).
+            let mut keys: Vec<usize> = by_style.keys().copied().chain(ink.iter().map(|(style, _)| *style)).collect();
            keys.sort_unstable();
-            // Every run's fills, then what paints over the fills, then the strokes on top.
+            keys.dedup();
+            // Every run's fills (its ink included), then what paints over the fills, then the
+            // strokes on top.
            for k in &keys {
-                let Some(tp) = by_style.get(k).and_then(ts_path) else { continue };
                let fills = layout.styles.get(*k).and_then(|s| s.fills.as_ref()).unwrap_or(&n.fills);
-                fill_with(pix, &tp, fills, w, h, gxf, FillRule::Winding, ctx, None);
+                if let Some(tp) = by_style.get(k).and_then(ts_path) {
+                    fill_with(pix, &tp, fills, w, h, gxf, FillRule::Winding, ctx, None);
+                }
+                for (_, item) in ink.iter().filter(|(style, _)| style == k) {
+                    match item {
+                        Ink::Bitmap(bitmap, place) => blit(pix, bitmap, ts_transform(gxf * *place)),
+                        Ink::Layer(path, rgba) => {
+                            if let Some(tp) = ts_path(path) {
+                                let mut paint = tiny_skia::Paint::default();
+                                paint.set_color_rgba8(rgba[0], rgba[1], rgba[2], rgba[3]);
+                                paint.anti_alias = true;
+                                pix.fill_path(&tp, &paint, FillRule::Winding, ts_transform(gxf), None);
+                            }
+                        }
+                    }
+                }
            }
            if let Some(f) = over_fills {
                f(pix);
@@ -687,6 +757,23 @@ fn draw_children_clipped(ctx: &Ctx, pix: &mut Pixmap, n: &Node, xf: Affine, dept
    backdrop::replace(pix, (lx, ly), &layer, mask.as_ref().map(|m| (m, (0, 0))));
 }

+/// Colour ink of a text run, in the order the run paints it. Strokes follow the outlines only: a
+/// bitmap-strike glyph has no outline to stroke.
+enum Ink {
+    /// An embedded bitmap and the transform from its pixels into layout coordinates.
+    Bitmap(Arc<figcraft_text::ColorBitmap>, Affine),
+    /// One COLR layer: its outline in layout coordinates and the colour to fill it with.
+    Layer(BezPath, [u8; 4]),
+}
+
+/// Draw a colour bitmap (premultiplied RGBA) under a transform, sampled smoothly when the
+/// transform scales it.
+fn blit(pix: &mut Pixmap, bitmap: &figcraft_text::ColorBitmap, transform: Transform) {
+    let Some(image) = tiny_skia::PixmapRef::from_bytes(&bitmap.rgba, bitmap.width, bitmap.height) else { return };
+    let paint = PixmapPaint { quality: tiny_skia::FilterQuality::Bilinear, ..Default::default() };
+    pix.draw_pixmap(0, 0, image, &paint, transform, None);
+}
+
 fn is_axis_aligned(xf: Affine) -> bool {
    let c = xf.as_coeffs();
    c[1].abs() < 1e-9 && c[2].abs() < 1e-9 && fract_ok(c[4]) && fract_ok(c[5])
@@ -0,0 +1,125 @@
+//! Decoded images within a memory budget (#203): an image too large is refused from its header,
+//! before its pixels are decoded, and the decoded-image caches hold a bounded number of bytes
+//! however many images, filters and colour profiles a document uses.
+
+use std::sync::Arc;
+
+use figcraft_color::ColorProfile;
+use tiny_skia::Pixmap;
+
+use super::*;
+
+fn png(w: u32, h: u32) -> Vec<u8> {
+    let img = image::RgbaImage::from_pixel(w, h, image::Rgba([200, 40, 40, 255]));
+    let mut out = Vec::new();
+    img.write_to(&mut std::io::Cursor::new(&mut out), image::ImageFormat::Png).unwrap();
+    out
+}
+
+/// A PNG whose header claims `w` × `h` but which holds no pixel data at all.
+fn png_header_only(w: u32, h: u32) -> Vec<u8> {
+    let mut ihdr = Vec::new();
+    ihdr.extend_from_slice(&w.to_be_bytes());
+    ihdr.extend_from_slice(&h.to_be_bytes());
+    ihdr.extend_from_slice(&[8, 6, 0, 0, 0]);
+    let mut out = b"\x89PNG\r\n\x1a\n".to_vec();
+    out.extend_from_slice(&13u32.to_be_bytes());
+    let chunk: Vec<u8> = b"IHDR".iter().copied().chain(ihdr).collect();
+    out.extend_from_slice(&chunk);
+    out.extend_from_slice(&crc32(&chunk).to_be_bytes());
+    out
+}
+
+fn crc32(data: &[u8]) -> u32 {
+    let mut crc = !0u32;
+    for b in data {
+        crc ^= u32::from(*b);
+        for _ in 0..8 {
+            crc = if crc & 1 == 1 { (crc >> 1) ^ 0xEDB8_8320 } else { crc >> 1 };
+        }
+    }
+    !crc
+}
+
+#[test]
+fn an_image_within_the_limits_decodes() {
+    let (p, _) = images::decode_within(&png(30, 20), ColorProfile::Srgb, 30, 30 * 20 * 4).unwrap();
+    assert_eq!((p.width(), p.height()), (30, 20));
+}
+
+#[test]
+fn an_image_wider_or_taller_than_the_limit_is_refused() {
+    assert!(images::decode_within(&png(30, 20), ColorProfile::Srgb, 29, u64::MAX).is_none());
+    assert!(images::decode_within(&png(20, 30), ColorProfile::Srgb, 29, u64::MAX).is_none());
+}
+
+#[test]
+fn an_image_whose_pixels_pass_the_byte_budget_is_refused() {
+    assert!(images::decode_within(&png(30, 20), ColorProfile::Srgb, 1000, 30 * 20 * 4 - 1).is_none());
+}
+
+#[test]
+fn a_huge_image_is_refused_from_its_header_alone() {
+    // 16 000 × 16 000 is within the side limit; its pixels (1 GB) aren't within a 1 MB budget, and
+    // the file has none to decode: only the header is read.
+    assert!(images::decode_within(&png_header_only(16_000, 16_000), ColorProfile::Srgb, 16_384, 1 << 20).is_none());
+    // Past the side limit, the shipped decode refuses it the same way.
+    assert!(images::decode(&png_header_only(20_000, 10)).is_none());
+}
+
+fn key(name: &str) -> images::Key {
+    (name.to_string(), [0; 7], ColorProfile::Srgb)
+}
+
+fn pixmap(side: u32) -> Arc<Pixmap> {
+    Arc::new(Pixmap::new(side, side).unwrap())
+}
+
+#[test]
+fn the_image_cache_keeps_within_its_byte_budget() {
+    // 10 × 10 pixmaps are 400 bytes; 1000 bytes hold two.
+    let mut c = images::PixmapCache::default();
+    for name in ["a", "b", "c", "d", "e"] {
+        c.insert(key(name), pixmap(10), 1000);
+        assert!(c.bytes() <= 1000, "{} bytes held", c.bytes());
+        assert!(c.get(&key(name)).is_some(), "{name} was just added");
+    }
+}
+
+#[test]
+fn a_full_image_cache_drops_the_least_recently_used_image_only() {
+    // 1000 bytes hold two 400-byte pixmaps: the third drops the one used longest ago.
+    let mut c = images::PixmapCache::default();
+    c.insert(key("a"), pixmap(10), 1000);
+    c.insert(key("b"), pixmap(10), 1000);
+    assert!(c.get(&key("a")).is_some());
+    c.insert(key("c"), pixmap(10), 1000);
+    assert!(c.get(&key("a")).is_some(), "used since b: kept");
+    assert!(c.get(&key("b")).is_none(), "used longest ago: dropped");
+    assert!(c.get(&key("c")).is_some());
+    assert_eq!(c.bytes(), 800);
+}
+
+#[test]
+fn an_image_larger_than_the_budget_is_held_alone() {
+    let mut c = images::PixmapCache::default();
+    c.insert(key("small"), pixmap(10), 1000);
+    c.insert(key("big"), pixmap(20), 1000);
+    assert!(c.get(&key("big")).is_some());
+    assert!(c.get(&key("small")).is_none());
+    assert_eq!(c.bytes(), 20 * 20 * 4);
+    // The next image takes its place.
+    c.insert(key("next"), pixmap(10), 1000);
+    assert_eq!(c.bytes(), 400);
+}
+
+#[test]
+fn filter_and_profile_variants_count_against_one_budget() {
+    let mut c = images::PixmapCache::default();
+    for (i, profile) in [ColorProfile::Srgb, ColorProfile::DisplayP3].into_iter().enumerate() {
+        for f in 0..4 {
+            c.insert(("img".to_string(), [f, 0, 0, 0, 0, 0, i as i32], profile), pixmap(10), 1000);
+            assert!(c.bytes() <= 1000, "{} bytes held", c.bytes());
+        }
+    }
+}
@@ -13,11 +13,69 @@ use figcraft_color::{ColorProfile, ImageFilters, PaintKind};
 use figcraft_doc::{Document, ImageData, NodeId};
 use tiny_skia::Pixmap;

-type Key = (String, [i32; 7], ColorProfile);
+pub(crate) type Key = (String, [i32; 7], ColorProfile);

-fn cache() -> &'static Mutex<HashMap<Key, Arc<Pixmap>>> {
-    static C: OnceLock<Mutex<HashMap<Key, Arc<Pixmap>>>> = OnceLock::new();
-    C.get_or_init(|| Mutex::new(HashMap::new()))
+/// The largest image side decoded.
+const MAX_SIDE: u32 = 16_384;
+/// The most bytes one image's decoding may allocate: the image crate's own default limit (a
+/// larger image is refused from its header).
+const MAX_DECODED_BYTES: u64 = 512 << 20;
+/// The most bytes of pixels each decoded-image cache holds (one image larger than this is held
+/// alone).
+const MAX_CACHED_BYTES: u64 = 512 << 20;
+/// The most entries each decoded-image cache holds.
+const MAX_CACHED_IMAGES: usize = 256;
+
+/// Decoded pixmaps by image, filters and profile, holding at most a byte budget of pixels: adding
+/// one past the budget (or past [`MAX_CACHED_IMAGES`]) drops the least recently used first, so
+/// the images on screen stay while they fit.
+#[derive(Default)]
+pub(crate) struct PixmapCache {
+    /// Each pixmap and when it was last used.
+    map: HashMap<Key, (Arc<Pixmap>, u64)>,
+    bytes: u64,
+    tick: u64,
+}
+
+impl PixmapCache {
+    pub(crate) fn get(&mut self, key: &Key) -> Option<Arc<Pixmap>> {
+        self.tick += 1;
+        let tick = self.tick;
+        self.map.get_mut(key).map(|(p, used)| {
+            *used = tick;
+            p.clone()
+        })
+    }
+
+    /// Add `p` under `key`, keeping the cache within `max_bytes` (or holding `p` alone).
+    pub(crate) fn insert(&mut self, key: Key, p: Arc<Pixmap>, max_bytes: u64) {
+        let size = p.data().len() as u64;
+        self.remove(&key);
+        while self.bytes.saturating_add(size) > max_bytes || self.map.len() >= MAX_CACHED_IMAGES {
+            let Some(oldest) = self.map.iter().min_by_key(|(_, (_, used))| *used).map(|(k, _)| k.clone()) else { break };
+            self.remove(&oldest);
+        }
+        self.tick += 1;
+        self.map.insert(key, (p, self.tick));
+        self.bytes = self.bytes.saturating_add(size);
+    }
+
+    fn remove(&mut self, key: &Key) {
+        if let Some((p, _)) = self.map.remove(key) {
+            self.bytes = self.bytes.saturating_sub(p.data().len() as u64);
+        }
+    }
+
+    /// The bytes of pixels held.
+    #[cfg(test)]
+    pub(crate) fn bytes(&self) -> u64 {
+        self.bytes
+    }
+}
+
+fn cache() -> &'static Mutex<PixmapCache> {
+    static C: OnceLock<Mutex<PixmapCache>> = OnceLock::new();
+    C.get_or_init(|| Mutex::new(PixmapCache::default()))
 }

 fn fkey(f: &ImageFilters) -> [i32; 7] {
@@ -34,7 +92,23 @@ pub fn decode(bytes: &[u8]) -> Option<Pixmap> {
 /// image's own profile into `target` (`false`), or as sRGB when it has none (`true`: the sRGB →
 /// `target` conversion is still to do).
 fn decode_in(bytes: &[u8], target: ColorProfile) -> Option<(Pixmap, bool)> {
-    let mut dec = image::ImageReader::new(std::io::Cursor::new(bytes)).with_guessed_format().ok()?.into_decoder().ok()?;
+    decode_within(bytes, target, MAX_SIDE, MAX_DECODED_BYTES)
+}
+
+/// [`decode_in`] for images at most `max_side` wide and tall whose decoded pixels take at most
+/// `max_bytes`; larger ones are refused from their header, before any pixels are decoded.
+pub(crate) fn decode_within(bytes: &[u8], target: ColorProfile, max_side: u32, max_bytes: u64) -> Option<(Pixmap, bool)> {
+    use image::ImageDecoder;
+    let mut reader = image::ImageReader::new(std::io::Cursor::new(bytes)).with_guessed_format().ok()?;
+    let mut limits = image::Limits::default();
+    limits.max_image_width = Some(max_side);
+    limits.max_image_height = Some(max_side);
+    limits.max_alloc = Some(max_bytes);
+    reader.limits(limits);
+    let mut dec = reader.into_decoder().ok()?;
+    if dec.total_bytes() > max_bytes {
+        return None;
+    }
    let source = crate::image_profile::Source::read(bytes, &mut dec);
    let img = image::DynamicImage::from_decoder(dec).ok()?;
    match source.convert(&img, target) {
@@ -66,7 +140,7 @@ pub fn profile_name(hash: &str, data: Option<&ImageData>) -> Option<String> {
 /// Straight RGBA → a premultiplied pixmap (max 16k per side).
 fn premultiplied(rgba: &image::RgbaImage) -> Option<Pixmap> {
    let (w, h) = rgba.dimensions();
-    if w == 0 || h == 0 || w > 16_384 || h > 16_384 {
+    if w == 0 || h == 0 || w > MAX_SIDE || h > MAX_SIDE {
        return None;
    }
    let mut p = Pixmap::new(w, h)?;
@@ -87,17 +161,13 @@ fn premultiplied(rgba: &image::RgbaImage) -> Option<Pixmap> {
 pub fn get(hash: &str, data: Option<&ImageData>, filters: &ImageFilters, profile: ColorProfile) -> Option<Arc<Pixmap>> {
    let key = (hash.to_string(), fkey(filters), profile);
    if let Some(p) = cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner).get(&key) {
-        return Some(p.clone());
+        return Some(p);
    }
    let (mut p, srgb) = decode_in(&data?.bytes, profile)?;
    // Images with their own profile are in `profile` already (sRGB → sRGB is the identity).
    finish(&mut p, filters, if srgb { profile } else { ColorProfile::Srgb });
    let p = Arc::new(p);
-    let mut c = cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner);
-    if c.len() > 256 {
-        c.clear();
-    }
-    c.insert(key, p.clone());
+    cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner).insert(key, p.clone(), MAX_CACHED_BYTES);
    Some(p)
 }

@@ -166,7 +236,7 @@ pub fn decode_frames(bytes: &[u8]) -> Option<Vec<(Pixmap, f64)>> {
    let dec = image::codecs::gif::GifDecoder::new(std::io::Cursor::new(bytes)).ok()?;
    let (w, h) = dec.dimensions();
    let frame_bytes = u64::from(w) * u64::from(h) * 4;
-    if frame_bytes == 0 || w > 16_384 || h > 16_384 {
+    if frame_bytes == 0 || w > MAX_SIDE || h > MAX_SIDE {
        return None;
    }
    let most = (MAX_ANIMATION_BYTES / frame_bytes).min(MAX_FRAMES as u64) as usize;
@@ -304,22 +374,18 @@ pub fn pad(pm: &Pixmap) -> Option<Pixmap> {
    Some(out)
 }

-fn padded_cache() -> &'static Mutex<HashMap<Key, Arc<Pixmap>>> {
-    static C: OnceLock<Mutex<HashMap<Key, Arc<Pixmap>>>> = OnceLock::new();
-    C.get_or_init(|| Mutex::new(HashMap::new()))
+fn padded_cache() -> &'static Mutex<PixmapCache> {
+    static C: OnceLock<Mutex<PixmapCache>> = OnceLock::new();
+    C.get_or_init(|| Mutex::new(PixmapCache::default()))
 }

 /// `pm` with a transparent 1-pixel border (cached).
 pub fn padded(hash: &str, filters: &ImageFilters, profile: ColorProfile, pm: &Pixmap) -> Option<Arc<Pixmap>> {
    let key = (hash.to_string(), fkey(filters), profile);
    if let Some(p) = padded_cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner).get(&key) {
-        return Some(p.clone());
+        return Some(p);
    }
    let out = Arc::new(pad(pm)?);
-    let mut c = padded_cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner);
-    if c.len() > 256 {
-        c.clear();
-    }
-    c.insert(key, out.clone());
+    padded_cache().lock().unwrap_or_else(std::sync::PoisonError::into_inner).insert(key, out.clone(), MAX_CACHED_BYTES);
    Some(out)
 }
@@ -425,6 +425,8 @@ pub fn png_insert_chunk(png: Vec<u8>, kind: &[u8; 4], data: &[u8]) -> Vec<u8> {
    out
 }

+#[cfg(test)]
+mod backdrop_shadow_tests;
 #[cfg(test)]
 mod backdrop_tests;
 #[cfg(test)]
@@ -442,6 +444,8 @@ mod grain_tests;
 #[cfg(test)]
 mod group_effects_tests;
 #[cfg(test)]
+mod image_budget_tests;
+#[cfg(test)]
 mod image_profile_tests;
 #[cfg(test)]
 mod lod_tests;
@@ -217,6 +217,37 @@ fn text_renders_something() {
    }
 }

+/// The machine's colour emoji face, if it has one (this test skips without: no font ships here).
+fn emoji_face() -> Option<(String, String)> {
+    figcraft_text::scan_system_fonts();
+    let mut db = figcraft_text::db().write().unwrap();
+    db.emoji_fallbacks().into_iter().find(|f| f.has_color()).map(|f| (f.family.clone(), f.style.clone()))
+}
+
+#[test]
+fn colour_emoji_draw_their_pixels() {
+    let Some((family, style)) = emoji_face() else { return };
+    let mut d = figcraft_doc::Document::new("t");
+    let p = d.first_page().unwrap();
+    let mut td = TextData::new("\u{1F600}");
+    (td.style.font_family, td.style.font_style) = (family.clone(), style.clone());
+    td.style.font_size = 48.0;
+    d.create(p, NodeKind::Text(td), "T", 0.0, 0.0, 200.0, 64.0).unwrap();
+    let pix = render_view(&d, p, &view(100, 80), &Options { background: Some(Color::WHITE), ..Default::default() }).unwrap();
+    // The emoji is the only thing in this document that paints saturated colour.
+    let coloured = pix
+        .data()
+        .as_chunks::<4>()
+        .0
+        .iter()
+        .filter(|c| {
+            let (r, g, b) = (i16::from(c[0]), i16::from(c[1]), i16::from(c[2]));
+            c[3] == 255 && (r.max(g).max(b) - r.min(g).min(b)) > 60
+        })
+        .count();
+    assert!(coloured > 200, "{family} drew {coloured} coloured pixels");
+}
+
 #[test]
 fn export_png_roundtrip() {
    let (d, _, r) = doc_with_rect(Color::from_hex("00FF00").unwrap());
@@ -86,6 +86,12 @@ fn clip_attr(clip: &Option<String>) -> String {
    clip.as_ref().map(|c| format!(" clip-path=\"url(#{c})\"")).unwrap_or_default()
 }

+/// `el` in a group with `clip` (a ` clip-path` attribute, or nothing). A clip path is in page
+/// coordinates, and on an element with a `transform` it would be read after that transform.
+fn clipped(clip: &str, el: String) -> String {
+    if clip.is_empty() { el } else { format!("<g{clip}>{el}</g>") }
+}
+
 fn num(v: f64) -> String {
    if !v.is_finite() {
        return "0".into();
@@ -433,7 +439,8 @@ impl W<'_> {
            let fr = if *rule == figcraft_render::FillRule::EvenOdd { " fill-rule=\"evenodd\"" } else { "" };
            for p in &n.fills {
                if let Some(a) = self.paint_attr(p, w, h) {
-                    let _ = write!(self.body, "<path transform=\"{}\" d=\"{}\" {a}{fr}{paint_clip}/>", matrix(xf), path_d(path));
+                    let el = format!("<path transform=\"{}\" d=\"{}\" {a}{fr}/>", matrix(xf), path_d(path));
+                    self.body.push_str(&clipped(&paint_clip, el));
                }
            }
        }
@@ -505,7 +512,7 @@ impl W<'_> {
        if n.has_visible_stroke()
            && let Some(simple) = self.opts.simplify_stroke.then(|| self.simple_stroke(n, xf)).flatten()
        {
-            self.body.push_str(&simple);
+            self.body.push_str(&clipped(&paint_clip, simple));
        } else if n.has_visible_stroke() {
            let geom = match &n.kind {
                NodeKind::BooleanOp { .. } | NodeKind::Text(_) => outline.as_ref().map(|(p, _)| p.clone()),
@@ -517,7 +524,8 @@ impl W<'_> {
                let fr = if even { " fill-rule=\"evenodd\"" } else { "" };
                for p in &n.strokes {
                    if let Some(a) = self.paint_attr(p, w, h) {
-                        let _ = write!(self.body, "<path transform=\"{}\" d=\"{}\" {a}{fr}{paint_clip}/>", matrix(xf), path_d(&area));
+                        let el = format!("<path transform=\"{}\" d=\"{}\" {a}{fr}/>", matrix(xf), path_d(&area));
+                        self.body.push_str(&clipped(&paint_clip, el));
                    }
                }
            }
@@ -43,3 +43,42 @@ fn import_gradient_and_groups() {
    assert!(kinds.contains(&"GROUP"));
    assert!(kinds.contains(&"RECTANGLE") && kinds.contains(&"ELLIPSE"), "{kinds:?}");
 }
+
+/// #325: a frame with children inside a clipping frame keeps its own paint inside the clip. The
+/// clip path is in page coordinates, so it must sit on a group around the transformed path, never
+/// on the path itself (where it would be read after the path's transform, offset by it).
+#[test]
+fn nested_frame_paint_is_clipped_in_page_space() {
+    let mut d = Document::new("t");
+    let p = d.first_page().unwrap();
+    let page = d.create(p, NodeKind::Frame, "Page", 0.0, 0.0, 400.0, 300.0).unwrap();
+    d.get_mut(page).unwrap().fills = vec![Paint::solid(Color::from_hex("FFFFFF").unwrap())];
+    let card = d.create(page, NodeKind::Frame, "Card", 40.0, 60.0, 300.0, 120.0).unwrap();
+    let c = d.get_mut(card).unwrap();
+    c.fills = vec![Paint::solid(Color::from_hex("DDDDDD").unwrap())];
+    c.corners.radii = [12.0; 4];
+    c.clip = true;
+    let badge = d.create(card, NodeKind::Frame, "Badge", 200.0, 40.0, 80.0, 40.0).unwrap();
+    let b = d.get_mut(badge).unwrap();
+    b.fills = vec![Paint::solid(Color::from_hex("1E6F8E").unwrap())];
+    b.strokes = vec![Paint::solid(Color::from_hex("AA0000").unwrap())];
+    b.stroke.weight = 2.0;
+    let dot = d.create(badge, NodeKind::Rectangle, "Dot", 10.0, 10.0, 20.0, 20.0).unwrap();
+    d.get_mut(dot).unwrap().fills = vec![Paint::solid(Color::from_hex("FFFFFF").unwrap())];
+    for simplify_stroke in [true, false] {
+        let svg = export_svg(&d, &[page], &SvgOptions { simplify_stroke, ..SvgOptions::default() }).unwrap();
+        for tag in svg.split('<').filter(|t| t.contains(" clip-path=")) {
+            assert!(!tag.contains(" transform="), "clip-path on a transformed element: <{tag}\n{svg}");
+        }
+        // The card's clip: its rounded outline starts after the top-left radius.
+        let def = svg.find("<path d=\"M52 60").unwrap();
+        let open = svg[..def].rfind("<clipPath id=\"").unwrap() + "<clipPath id=\"".len();
+        let card_clip = &svg[open..open + svg[open..].find('"').unwrap()];
+        let wrapped = format!("<g clip-path=\"url(#{card_clip})\">");
+        for color in ["#1E6F8E", "#AA0000"] {
+            let at = svg.find(color).unwrap_or_else(|| panic!("{color} missing\n{svg}"));
+            let path = svg[..at].rfind("<path").unwrap();
+            assert!(svg[..path].ends_with(&wrapped), "{color} not in the card's clip\n{svg}");
+        }
+    }
+}
@@ -13,6 +13,8 @@ figcraft-geom = { workspace = true }
 figcraft-doc = { workspace = true }
 skrifa = { workspace = true }
 harfrust = { workspace = true }
+# Colour emoji: sbix/CBDT strikes are PNG images the text layer decodes for the renderer.
+png = { workspace = true }
 unicode-bidi = { workspace = true }
 unicode-segmentation = { workspace = true }
 log = { workspace = true }
@@ -0,0 +1,313 @@
+//! Colour glyphs: embedded bitmap strikes (sbix, CBDT/EBDT) and COLR v0 layers.
+//!
+//! Colour emoji fonts don't draw like other glyphs: the picture itself lives in a bitmap strike
+//! (sbix, CBDT/EBDT) or in a stack of coloured layers, not in the glyph's outline — in Apple Color
+//! Emoji most emoji are `sbix` bitmaps while the flags are drawn from outlines, and Noto Color
+//! Emoji has no outlines at all. This module gives the renderer either a
+//! premultiplied RGBA raster at the size it asked for, or the layer glyphs and the palette colours
+//! to fill with its own outlines. Anything else (COLR v1's paint graphs, alpha-only strikes) is
+//! left to the outline pipeline, which draws whatever outlines the face has, as before.
+
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::sync::PoisonError;
+
+use figcraft_geom::Affine;
+use skrifa::bitmap::{BitmapData, BitmapGlyph, BitmapStrikes, Origin};
+use skrifa::color::ColorPalettes;
+use skrifa::instance::Size;
+use skrifa::raw::TableProvider;
+use skrifa::{FontRef, GlyphId};
+
+use crate::fontdb::{Coords, Face};
+
+/// Colour rasters kept per face before the cache starts over, in bytes: they are pixels, and a
+/// canvas zoomed far in makes each one large.
+const MAX_RASTER_BYTES: usize = 32 * 1024 * 1024;
+/// Rasters kept per face (misses count too: a face whose strikes cover a few glyphs builds one
+/// per glyph and size, and the zoom changes the size).
+const MAX_RASTER_ENTRIES: usize = 8192;
+/// COLR layer lists kept per face (24 bytes a layer, so a count is enough).
+const MAX_LAYERS: usize = 4096;
+/// Widest and tallest PNG strike decoded (strikes are at most a few hundred pixels).
+const MAX_PNG_SIDE: u32 = 4096;
+/// Largest colour raster per em (device pixels). Past this the renderer scales one up instead.
+pub const MAX_PX_PER_EM: f64 = 512.0;
+
+/// A colour bitmap glyph: premultiplied RGBA at `size` px per em, and the offset of its top-left
+/// corner from the glyph's pen, in px at `size` (y down).
+#[derive(Debug)]
+pub struct ColorBitmap {
+    pub width: u32,
+    pub height: u32,
+    pub left: f64,
+    pub top: f64,
+    pub rgba: Arc<[u8]>,
+}
+
+/// One layer of a COLR v0 glyph: the glyph that draws the layer and the palette colour it fills
+/// with (straight RGBA: the renderer paints it).
+#[derive(Debug)]
+pub struct ColorLayer {
+    pub gid: u32,
+    pub rgba: [u8; 4],
+}
+
+/// A glyph's colour ink: what draws instead of its outline, placed in coordinates the caller
+/// supplies (a bitmap pixel maps through `place`; COLR layers are drawn like the glyph's outline).
+pub enum ColorInk {
+    Bitmap(Arc<ColorBitmap>, Affine),
+    Layers(Arc<Vec<ColorLayer>>),
+}
+
+/// Colour rasters cached per face, keyed by glyph, variations and size.
+#[derive(Default)]
+pub(crate) struct Rasters {
+    entries: HashMap<(u32, Coords, u64), Option<Arc<ColorBitmap>>>,
+    bytes: usize,
+}
+
+impl Rasters {
+    fn get(&self, key: &(u32, Coords, u64)) -> Option<Arc<ColorBitmap>> {
+        self.entries.get(key).and_then(Option::clone)
+    }
+
+    fn known(&self, key: &(u32, Coords, u64)) -> bool {
+        self.entries.contains_key(key)
+    }
+
+    fn insert(&mut self, key: (u32, Coords, u64), bitmap: Option<Arc<ColorBitmap>>) {
+        if let Some(b) = &bitmap {
+            self.bytes += b.rgba.len();
+        }
+        if self.bytes > MAX_RASTER_BYTES || self.entries.len() > MAX_RASTER_ENTRIES {
+            self.entries.clear();
+            self.bytes = bitmap.as_ref().map(|b| b.rgba.len()).unwrap_or(0);
+        }
+        self.entries.insert(key, bitmap);
+    }
+}
+
+impl Face {
+    /// Whether the face has colour glyphs at all: bitmaps (sbix, CBDT/EBDT) or COLR layers.
+    pub fn has_color(&self) -> bool {
+        self.has_bitmaps() || self.has_colr()
+    }
+
+    /// The face has bitmap strikes (`sbix`/`CBDT`/`EBDT`)
+    pub fn has_bitmaps(&self) -> bool {
+        self.bitmap_strikes
+    }
+
+    /// The face has a `COLR` table.
+    pub fn has_colr(&self) -> bool {
+        self.colr
+    }
+
+    /// The glyph's embedded bitmap, scaled to `size` px per em (premultiplied RGBA), with the offset
+    /// of its top-left corner from the pen in px at `size` (y down). `None` when the face has no
+    /// bitmap for the glyph.
+    pub fn color_bitmap(&self, gid: u32, coords: &Coords, size: f64) -> Option<Arc<ColorBitmap>> {
+        if !self.bitmap_strikes || !size.is_finite() || size <= 0.0 {
+            return None;
+        }
+        let size = size.clamp(1.0, MAX_PX_PER_EM);
+        let key = (gid, coords.clone(), size.to_bits());
+        let mut cache = self.rasters.lock().unwrap_or_else(PoisonError::into_inner);
+        if cache.known(&key) {
+            return cache.get(&key);
+        }
+        let made = self.read_bitmap(gid, size).map(Arc::new);
+        cache.insert(key, made.clone());
+        made
+    }
+
+    /// The glyph's COLR v0 layers (empty when the glyph has none: COLR v1 glyphs, or no COLR data).
+    pub fn color_layers(&self, gid: u32) -> Option<Arc<Vec<ColorLayer>>> {
+        if !self.colr {
+            return None;
+        }
+        let mut cache = self.layers.lock().unwrap_or_else(PoisonError::into_inner);
+        if let Some(hit) = cache.get(&gid) {
+            return hit.clone();
+        }
+        let made = self.read_layers(gid).map(Arc::new);
+        if cache.len() >= MAX_LAYERS {
+            cache.clear();
+        }
+        cache.insert(gid, made.clone());
+        made
+    }
+
+    /// Read a strike bitmap and place it the way Skia's fontations port does
+    /// (`src/ports/fontations/src/bitmap.rs`): the outer bearings are in font units and scale with
+    /// the em, the inner ones are pixels at the strike's ppem, and an sbix image is measured from
+    /// its lower-left corner (the spec places the graphic's origin at the glyph box's xMin, yMin).
+    fn read_bitmap(&self, gid: u32, size: f64) -> Option<ColorBitmap> {
+        let gid = GlyphId::new(gid);
+        let font = FontRef::from_index(self.bytes.data(), self.index).ok()?;
+        let strike = BitmapStrikes::new(&font).glyph_for_size(Size::new(size as f32), gid)?;
+        let (rgba, width, height) = decode(&strike)?;
+        if width == 0 || height == 0 || rgba.len() != width as usize * height as usize * 4 {
+            return None;
+        }
+        let (left, top) = placement(&strike, size, self.upem);
+        // Scale the strike's own pixels to the requested size (the caller blits them 1:1).
+        let scale = size / f64::from(strike.ppem_y.max(1.0));
+        let w = ((f64::from(width) * scale).round() as i64).clamp(1, MAX_PX_PER_EM as i64) as u32;
+        let h = ((f64::from(height) * scale).round() as i64).clamp(1, MAX_PX_PER_EM as i64) as u32;
+        let rgba = if (w, h) == (width, height) { rgba } else { scaled(&rgba, width, height, w, h)? };
+        Some(ColorBitmap { width: w, height: h, left, top, rgba: rgba.into() })
+    }
+
+    /// Read the COLR v0 layers of a glyph (`None` for a glyph the table doesn't cover, which is
+    /// every glyph of a COLR v1-only font).
+    fn read_layers(&self, gid: u32) -> Option<Vec<ColorLayer>> {
+        let font = FontRef::from_index(self.bytes.data(), self.index).ok()?;
+        let colr = font.colr().ok()?;
+        let range = colr.v0_base_glyph(GlyphId::new(gid))?;
+        let palettes = ColorPalettes::new(&font);
+        let palette = palettes.get(0);
+        let colors = palette.as_ref().map(|p| p.colors()).unwrap_or(&[]);
+        let mut out = Vec::new();
+        for index in range {
+            let (layer, color_index) = colr.v0_layer(index)?;
+            let rgba = colors.get(usize::from(color_index)).map(|c| [c.red(), c.green(), c.blue(), c.alpha()]).unwrap_or([0, 0, 0, 255]);
+            out.push(ColorLayer { gid: layer.to_u32(), rgba });
+        }
+        (!out.is_empty()).then_some(out)
+    }
+}
+
+/// Where a strike's image sits from the pen: the image's top-left corner in px at `size` (y down).
+fn placement(glyph: &BitmapGlyph, size: f64, upem: f64) -> (f64, f64) {
+    let units = size / upem.max(1.0);
+    let pixels = size / f64::from(glyph.ppem_y.max(1.0));
+    let left = f64::from(glyph.inner_bearing_x) * pixels + f64::from(glyph.bearing_x) * units;
+    let above = match glyph.placement_origin {
+        // sbix: the origin is the image's lower-left corner, so the whole image hangs above it.
+        Origin::BottomLeft => f64::from(glyph.inner_bearing_y) + f64::from(glyph.height),
+        Origin::TopLeft => f64::from(glyph.inner_bearing_y),
+    };
+    (left, -above * pixels - f64::from(glyph.bearing_y) * units)
+}
+
+/// A strike's pixels as premultiplied RGBA (what the renderer's pixmaps hold), with their size.
+fn decode(glyph: &BitmapGlyph<'_>) -> Option<(Vec<u8>, u32, u32)> {
+    match &glyph.data {
+        // The OpenType spec's PNG strikes are plain PNGs (straight alpha), so they are
+        // premultiplied here for the renderer.
+        BitmapData::Png(png) => {
+            let (rgba, width, height) = decode_png(png)?;
+            Some((premultiplied(rgba), width, height))
+        }
+        // Bit depth 32 without PNG is BGRA with premultiplied channels (the spec says so).
+        BitmapData::Bgra(bgra) => {
+            let (width, height) = (glyph.width, glyph.height);
+            let mut rgba = bgra.get(..width as usize * height as usize * 4)?.to_vec();
+            for px in rgba.chunks_exact_mut(4) {
+                px.swap(0, 2);
+            }
+            Some((rgba, width, height))
+        }
+        // Alpha-only strikes would be masks, not colour: the outline pipeline draws those glyphs.
+        BitmapData::Mask(_) => None,
+    }
+}
+
+#[cfg(test)]
+#[path = "color_tests.rs"]
+mod tests;
+
+/// A PNG strike as straight 8-bit RGBA.
+fn decode_png(png: &[u8]) -> Option<(Vec<u8>, u32, u32)> {
+    let mut decoder = png::Decoder::new(std::io::Cursor::new(png));
+    // Expand palettes, `tRNS` and sub-byte samples to 8-bit RGBA.
+    decoder.set_transformations(png::Transformations::normalize_to_color8() | png::Transformations::ALPHA);
+    let mut reader = decoder.read_info().ok()?;
+    // The header's size is checked before anything is allocated for it: a font can claim any size.
+    let (w, h) = reader.info().size();
+    if w == 0 || h == 0 || w > MAX_PNG_SIDE || h > MAX_PNG_SIDE {
+        return None;
+    }
+    let mut buf = vec![0u8; reader.output_buffer_size()?];
+    let info = reader.next_frame(&mut buf).ok()?;
+    let (width, height) = (info.width, info.height);
+    let data = buf.get(..info.buffer_size())?;
+    let rgba = match info.color_type {
+        png::ColorType::Rgba => data.to_vec(),
+        png::ColorType::Rgb => data.as_chunks::<3>().0.iter().flat_map(|p| [p[0], p[1], p[2], 255]).collect(),
+        png::ColorType::Grayscale => data.iter().flat_map(|g| [*g, *g, *g, 255]).collect(),
+        png::ColorType::GrayscaleAlpha => data.as_chunks::<2>().0.iter().flat_map(|p| [p[0], p[0], p[0], p[1]]).collect(),
+        png::ColorType::Indexed => return None,
+    };
+    Some((rgba, width, height))
+}
+
+/// Straight RGBA → premultiplied RGBA (in place).
+fn premultiplied(mut rgba: Vec<u8>) -> Vec<u8> {
+    for px in rgba.chunks_exact_mut(4) {
+        let a = u32::from(px[3]);
+        for c in &mut px[..3] {
+            *c = ((u32::from(*c) * a + 127) / 255) as u8;
+        }
+    }
+    rgba
+}
+
+/// Premultiplied RGBA scaled to `dw`×`dh`: a box average when shrinking, bilinear when growing.
+fn scaled(src: &[u8], sw: u32, sh: u32, dw: u32, dh: u32) -> Option<Vec<u8>> {
+    if sw == 0 || sh == 0 || dw == 0 || dh == 0 {
+        return None;
+    }
+    let sample = |x: u32, y: u32| -> [u8; 4] {
+        let i = ((y.min(sh - 1) * sw + x.min(sw - 1)) * 4) as usize;
+        match src.get(i..i + 4) {
+            Some(px) => [px[0], px[1], px[2], px[3]],
+            None => [0, 0, 0, 0],
+        }
+    };
+    let mut out = vec![0u8; dw as usize * dh as usize * 4];
+    if dw >= sw && dh >= sh {
+        let at = |v: f64, n: u32| ((v + 0.5) * f64::from(n) - 0.5).clamp(0.0, f64::from(n - 1));
+        for y in 0..dh {
+            let sy = at(f64::from(y) / f64::from(dh), sh);
+            let (y0, fy) = (sy.floor() as u32, sy.fract());
+            for x in 0..dw {
+                let sx = at(f64::from(x) / f64::from(dw), sw);
+                let (x0, fx) = (sx.floor() as u32, sx.fract());
+                let (p00, p10, p01, p11) = (sample(x0, y0), sample(x0 + 1, y0), sample(x0, y0 + 1), sample(x0 + 1, y0 + 1));
+                let o = ((y * dw + x) * 4) as usize;
+                for c in 0..4 {
+                    let top = f64::from(p00[c]) * (1.0 - fx) + f64::from(p10[c]) * fx;
+                    let bottom = f64::from(p01[c]) * (1.0 - fx) + f64::from(p11[c]) * fx;
+                    out[o + c] = (top * (1.0 - fy) + bottom * fy).round().clamp(0.0, 255.0) as u8;
+                }
+            }
+        }
+        return Some(out);
+    }
+    let (fx, fy) = (f64::from(sw) / f64::from(dw), f64::from(sh) / f64::from(dh));
+    for y in 0..dh {
+        let (y0, y1) = ((f64::from(y) * fy).floor() as u32, ((f64::from(y) + 1.0) * fy).ceil() as u32);
+        for x in 0..dw {
+            let (x0, x1) = ((f64::from(x) * fx).floor() as u32, ((f64::from(x) + 1.0) * fx).ceil() as u32);
+            let mut sum = [0.0f64; 4];
+            let mut n = 0.0f64;
+            for sy in y0..y1.clamp(y0 + 1, sh) {
+                for sx in x0..x1.clamp(x0 + 1, sw) {
+                    let px = sample(sx, sy);
+                    for c in 0..4 {
+                        sum[c] += f64::from(px[c]);
+                    }
+                    n += 1.0;
+                }
+            }
+            let o = ((y * dw + x) * 4) as usize;
+            for c in 0..4 {
+                out[o + c] = (sum[c] / n.max(1.0)).round().clamp(0.0, 255.0) as u8;
+            }
+        }
+    }
+    Some(out)
+}
@@ -0,0 +1,231 @@
+//! Colour glyph behaviour (colour emoji): bitmap strikes, COLR layers, and where they sit.
+//!
+//! The placement cases are pure numbers, so they run everywhere. The rest reads the machine's
+//! colour emoji face and skips (like the other suites) on a machine without one; which format it
+//! uses depends on the platform (Apple Color Emoji is sbix, Noto Color Emoji is CBDT, Segoe UI
+//! Emoji is COLR), so a machine exercises the paths its own font has.
+
+use super::*;
+use crate::fontdb::{db, no_coords, scan_system_fonts};
+use crate::layout::layout;
+use figcraft_doc::TextData;
+use skrifa::bitmap::{BitmapData, BitmapGlyph, MaskData, Origin};
+
+/// A strike glyph described by hand, for the placement cases.
+fn glyph(width: u32, height: u32, origin: Origin, bearing: (f32, f32), inner: (f32, f32), ppem: f32) -> BitmapGlyph<'static> {
+    BitmapGlyph {
+        data: BitmapData::Png(&[]),
+        bearing_x: bearing.0,
+        bearing_y: bearing.1,
+        inner_bearing_x: inner.0,
+        inner_bearing_y: inner.1,
+        ppem_x: ppem,
+        ppem_y: ppem,
+        advance: None,
+        width,
+        height,
+        placement_origin: origin,
+    }
+}
+
+/// A strike glyph with data, for the decoding cases (the fields they don't read stay neutral).
+fn strike(data: BitmapData<'_>, width: u32, height: u32) -> BitmapGlyph<'_> {
+    BitmapGlyph {
+        data,
+        bearing_x: 0.0,
+        bearing_y: 0.0,
+        inner_bearing_x: 0.0,
+        inner_bearing_y: 0.0,
+        ppem_x: 10.0,
+        ppem_y: 10.0,
+        advance: None,
+        width,
+        height,
+        placement_origin: Origin::TopLeft,
+    }
+}
+
+#[test]
+fn bitmap_placement_follows_the_strike() {
+    // CBDT: bearings are pixels from the origin to the bitmap's left and top edges, read at the
+    // strike's ppem and scaled to the size asked for: 2 px at ppem 10 in a 20 px run → 4 px.
+    let cbdt = glyph(100, 50, Origin::TopLeft, (0.0, 0.0), (2.0, 8.0), 10.0);
+    let (left, top) = placement(&cbdt, 20.0, 1000.0);
+    assert_eq!((left, top), (4.0, -16.0), "the left edge sits right of the pen, the top above it");
+
+    // sbix: bearings and origin offsets are font units, and the image is placed by its lower-left
+    // corner, so its top is the whole image above the origin.
+    let sbix = glyph(10, 10, Origin::BottomLeft, (-1.0, -3.0), (1.0, 2.0), 10.0);
+    let (left, top) = placement(&sbix, 20.0, 1000.0);
+    assert!((left - (2.0 - 0.02)).abs() < 1e-9, "{left}");
+    assert!((top - (-24.0 + 0.06)).abs() < 1e-9, "{top}");
+
+    // Doubling the size doubles the offset with it.
+    let scaled = glyph(10, 10, Origin::TopLeft, (0.0, 0.0), (1.0, 1.0), 10.0);
+    assert_eq!(placement(&scaled, 40.0, 1000.0).1, -4.0);
+    assert_eq!(placement(&scaled, 20.0, 1000.0).1, -2.0);
+}
+
+/// A 2×2 PNG with straight alpha, the format strikes carry: row 0 is (255,0,0,128) then
+/// (0,255,0,255), row 1 is (0,0,255,0) then (10,20,30,51).
+const PNG_STRAIGHT: &[u8] = &[
+    0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a, 0x00, 0x00, 0x00, 0x0d, 0x49, 0x48, 0x44, 0x52, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x02,
+    0x08, 0x06, 0x00, 0x00, 0x00, 0x72, 0xb6, 0x0d, 0x24, 0x00, 0x00, 0x00, 0x17, 0x49, 0x44, 0x41, 0x54, 0x78, 0xda, 0x63, 0xf8, 0xcf, 0xc0, 0xd0,
+    0xc0, 0xf0, 0x1f, 0x08, 0x19, 0x80, 0x98, 0x4b, 0x44, 0xce, 0x18, 0x00, 0x34, 0xb8, 0x04, 0xec, 0xa7, 0x3b, 0x38, 0x04, 0x00, 0x00, 0x00, 0x00,
+    0x49, 0x45, 0x4e, 0x44, 0xae, 0x42, 0x60, 0x82,
+];
+
+#[test]
+fn png_strikes_decode_to_premultiplied_rgba() {
+    let (rgba, width, height) = decode(&strike(BitmapData::Png(PNG_STRAIGHT), 2, 2)).unwrap();
+    assert_eq!((width, height), (2, 2));
+    assert_eq!(
+        rgba,
+        vec![128, 0, 0, 128, 0, 255, 0, 255, 0, 0, 0, 0, 2, 4, 6, 51],
+        "straight alpha times its own alpha, rounded: the renderer's surfaces are premultiplied"
+    );
+}
+
+#[test]
+fn a_png_strike_claiming_a_huge_size_is_refused_before_anything_is_allocated() {
+    // PNG_STRAIGHT with its header saying 1 048 576 × 1 048 576 pixels (4 TiB as RGBA).
+    let mut png = PNG_STRAIGHT.to_vec();
+    assert_eq!(crc32(&png[12..29]).to_be_bytes(), png[29..33], "the patched header passes its checksum");
+    png[16..24].copy_from_slice(&[0, 0x10, 0, 0, 0, 0x10, 0, 0]);
+    let crc = crc32(&png[12..29]);
+    png[29..33].copy_from_slice(&crc.to_be_bytes());
+    assert!(decode_png(&png).is_none());
+}
+
+/// The CRC-32 a PNG chunk ends with.
+fn crc32(bytes: &[u8]) -> u32 {
+    !bytes.iter().fold(!0u32, |c, b| (0..8).fold(c ^ u32::from(*b), |c, _| if c & 1 == 1 { 0xedb8_8320 ^ (c >> 1) } else { c >> 1 }))
+}
+
+#[test]
+fn raw_bgra_strikes_are_already_premultiplied() {
+    // BitmapData::Bgra is BGRA with premultiplied channels (the spec says so), so decoding only
+    // moves the red and blue channels.
+    let (rgba, width, height) = decode(&strike(BitmapData::Bgra(&[17, 34, 51, 255, 4, 8, 12, 16]), 2, 1)).unwrap();
+    assert_eq!((width, height), (2, 1));
+    assert_eq!(rgba, vec![51, 34, 17, 255, 12, 8, 4, 16]);
+}
+
+#[test]
+fn strikes_that_are_not_colour_decode_to_nothing() {
+    let mask = MaskData { bpp: 8, is_packed: false, data: &[0; 16] };
+    assert!(decode(&strike(BitmapData::Mask(mask), 2, 2)).is_none(), "alpha-only strikes are masks, not colour");
+    assert!(decode(&strike(BitmapData::Png(b"not a png"), 2, 2)).is_none(), "a broken PNG is skipped, not drawn");
+    assert!(decode(&strike(BitmapData::Bgra(&[1, 2, 3]), 2, 2)).is_none(), "a buffer shorter than the glyph is skipped");
+}
+
+#[test]
+fn scaling_keeps_the_pixels_premultiplied() {
+    // A 4×4 face: one straight colour over a falling alpha, premultiplied by hand.
+    let straight = [220u32, 180, 60];
+    let ramp = [255u32, 190, 128, 64, 0];
+    let mut src = Vec::new();
+    for y in 0..4 {
+        for x in 0..4 {
+            let a = ramp[(x + y) % ramp.len()];
+            src.extend(straight.iter().map(|c| ((c * a + 127) / 255) as u8));
+            src.push(a as u8);
+        }
+    }
+    for (dw, dh) in [(2, 2), (3, 4), (9, 7), (16, 16)] {
+        let out = scaled(&src, 4, 4, dw, dh).unwrap();
+        assert_eq!(out.len(), (dw * dh * 4) as usize);
+        for px in out.chunks_exact(4) {
+            assert!(px[0] <= px[3] && px[1] <= px[3] && px[2] <= px[3], "{dw}×{dh}: {px:?}");
+        }
+    }
+    assert!(scaled(&src, 4, 4, 0, 4).is_none() && scaled(&src, 0, 0, 4, 4).is_none(), "an empty side scales to nothing");
+}
+
+/// The machine's colour emoji face, if it has one (tests skip without: no font ships in the repo).
+fn emoji_face() -> Option<std::sync::Arc<Face>> {
+    scan_system_fonts();
+    let mut db = db().write().unwrap();
+    db.emoji_fallbacks().into_iter().find(|f| f.has_color())
+}
+
+#[test]
+fn colour_emoji_carry_their_own_pixels() {
+    let Some(face) = emoji_face() else { return };
+    // A grinning face: a bitmap strike (Apple, Noto) or COLR layers (Segoe) must cover it.
+    let gid = face.glyph_for('\u{1F600}');
+    assert_ne!(gid, 0, "U+1F600 is not in {}", face.family);
+    if let Some(layers) = face.color_layers(gid) {
+        assert!(!layers.is_empty());
+        assert!(layers.len() < 64, "{} layers", layers.len());
+        assert!(layers.iter().all(|l| l.gid != 0), "every layer names a glyph: {layers:?}");
+        return;
+    }
+    let Some(bitmap) = face.color_bitmap(gid, &no_coords(), 32.0) else {
+        panic!("{} has colour tables but draws nothing for U+1F600", face.family);
+    };
+    // The image is a sane size for 32 px of text and its pixels are premultiplied (what the
+    // renderer's surfaces hold), so no channel is brighter than its alpha.
+    assert!(bitmap.width >= 8 && bitmap.width <= 128, "{} px wide", bitmap.width);
+    assert!(bitmap.height >= 8 && bitmap.height <= 128, "{} px tall", bitmap.height);
+    assert_eq!(bitmap.rgba.len(), bitmap.width as usize * bitmap.height as usize * 4);
+    let mut opaque = 0;
+    for px in bitmap.rgba.chunks_exact(4) {
+        assert!(px[0] <= px[3] && px[1] <= px[3] && px[2] <= px[3], "premultiplied: {px:?}");
+        opaque += usize::from(px[3] == 255);
+    }
+    assert!(opaque > 20, "the glyph draws something: {opaque} opaque pixels");
+    // A bigger strike is scaled to a bigger image, and a smaller one to a smaller image.
+    let small = face.color_bitmap(gid, &no_coords(), 16.0);
+    let large = face.color_bitmap(gid, &no_coords(), 64.0);
+    if let (Some(small), Some(large)) = (small, large) {
+        assert!(small.width < bitmap.width && bitmap.width < large.width, "{} {} {}", small.width, bitmap.width, large.width);
+    }
+}
+
+#[test]
+fn emoji_in_plain_text_draw_from_a_colour_face() {
+    // The style's own face (DejaVu Sans on Linux) or a symbol font among the fallbacks (Windows has
+    // one) draws U+1F600 in one colour: the emoji face comes first for it.
+    if emoji_face().is_none() {
+        return;
+    }
+    let l = layout(&TextData::new("Hi \u{1F600}"), None, None);
+    assert!(l.glyphs.iter().any(|g| g.color(1.0).is_some()), "the emoji has colour ink");
+}
+
+#[test]
+fn glyphs_place_their_ink_at_a_scale() {
+    let Some(face) = emoji_face() else { return };
+    let mut t = TextData::new("\u{1F600}");
+    (t.style.font_family, t.style.font_style) = (face.family.clone(), face.style.clone());
+    t.style.font_size = 32.0;
+    let l = layout(&t, None, None);
+    let Some(g) = l.glyphs.first() else { return };
+    // Zoomed 2:1 the glyph asks for a 64 px raster and places it in layout coordinates.
+    let Some(ColorInk::Bitmap(bitmap, place)) = g.color(2.0) else {
+        assert!(g.color(2.0).is_some(), "the emoji glyph has ink");
+        return;
+    };
+    // Some emoji faces draw wider than the em (Noto Color Emoji's strikes are about 1.25 em).
+    assert!(bitmap.width >= 32 && bitmap.width <= 96, "{} px at 2:1", bitmap.width);
+    let corner = place * figcraft_geom::Point::new(0.0, 0.0);
+    assert!(corner.x >= g.x - g.size && corner.x <= g.x + g.size, "x {} vs pen {}", corner.x, g.x);
+    assert!(corner.y >= g.y - g.size && corner.y <= g.y + g.size, "y {} vs baseline {}", corner.y, g.y);
+    // Past the raster cap the image stops growing (a canvas zoomed far in).
+    let Some(ColorInk::Bitmap(huge, _)) = g.color(1000.0) else { return };
+    assert!(f64::from(huge.width) <= MAX_PX_PER_EM + 1.0, "{} px", huge.width);
+}
+
+#[test]
+fn text_without_colour_ink_keeps_its_outlines() {
+    // Faces without colour tables answer "no ink" without touching the font again, so plain text
+    // (the whole canvas, most of the time) pays one flag per glyph.
+    let Some(face) = crate::fontdb::find_face("Inter", "Regular") else { return };
+    if face.has_color() {
+        return;
+    }
+    let gid = face.glyph_for('A');
+    assert!(gid != 0, "Inter draws A");
+    assert!(face.color_layers(gid).is_none() && face.color_bitmap(gid, &no_coords(), 32.0).is_none());
+}
@@ -11,6 +11,8 @@ use skrifa::raw::{FileRef, TableProvider};
 use skrifa::string::StringId;
 use skrifa::{GlyphId, MetadataProvider};

+use crate::color::{ColorLayer, Rasters};
+
 /// A font from the optional craft-fonts build input (empty unless built with `CRAFT_FONTS_DIR`).
 pub struct CraftFont {
    pub family: &'static str,
@@ -107,6 +109,11 @@ pub struct Face {
    charmap: HashMap<u32, u32>,
    outlines: Mutex<HashMap<(u32, Coords), Arc<BezPath>>>,
    advances: Mutex<HashMap<(u32, Coords), f64>>,
+    /// Colour glyph tables (see [`crate::color`]): bitmap strikes and/or COLR layers.
+    pub(crate) bitmap_strikes: bool,
+    pub(crate) colr: bool,
+    pub(crate) rasters: Mutex<Rasters>,
+    pub(crate) layers: Mutex<HashMap<u32, Option<Arc<Vec<ColorLayer>>>>>,
 }

 impl std::fmt::Debug for Face {
@@ -139,6 +146,9 @@ impl Face {
        gsub_features.dedup();
        let charmap: HashMap<u32, u32> = f.charmap().mappings().map(|(c, g)| (c, g.to_u32())).collect();
        let (axes, instances) = variation_info(&f);
+        let has_table = |tag: &[u8; 4]| f.data_for_tag(skrifa::Tag::new(tag)).is_some();
+        let bitmap_strikes = has_table(b"sbix") || has_table(b"CBDT") || has_table(b"EBDT");
+        let colr = has_table(b"COLR");
        let under = m.underline.map(|d| (f64::from(d.offset), f64::from(d.thickness))).unwrap_or((-upem * 0.1, upem * 0.06));
        let strike = m.strikeout.map(|d| f64::from(d.offset)).unwrap_or(ascent * 0.3);
        let weight = {
@@ -169,6 +179,10 @@ impl Face {
            bytes,
            outlines: Mutex::new(HashMap::new()),
            advances: Mutex::new(HashMap::new()),
+            bitmap_strikes,
+            colr,
+            rasters: Mutex::new(Rasters::default()),
+            layers: Mutex::new(HashMap::new()),
        })
    }

@@ -613,7 +627,6 @@ impl FontDb {
            "PingFang SC",
            "Noto Sans CJK SC",
            "Microsoft YaHei",
-            "Apple Color Emoji",
            "Noto Sans Arabic",
            "Apple Symbols",
            "Segoe UI Symbol",
@@ -625,6 +638,19 @@ impl FontDb {
        out
    }

+    /// Colour emoji faces, for characters no other fallback covers. Kept out of
+    /// [`fallbacks`](Self::fallbacks) because the files are large (Apple Color Emoji is ~180 MB)
+    /// and only texts that actually show emoji need them; each family reads one face.
+    pub fn emoji_fallbacks(&mut self) -> Vec<Arc<Face>> {
+        let mut out = Vec::new();
+        for fam in ["Apple Color Emoji", "Segoe UI Emoji", "Noto Color Emoji"] {
+            if let Some(f) = self.find_one(fam, "Regular") {
+                out.push(f);
+            }
+        }
+        out
+    }
+
    pub fn face_count(&self) -> usize {
        self.faces.len()
    }
@@ -670,14 +696,27 @@ fn system_font_dirs() -> Vec<std::path::PathBuf> {
    {
        v.push("/usr/share/fonts".into());
        v.push("/usr/local/share/fonts".into());
-        if let Some(h) = std::env::var_os("HOME") {
-            v.push(std::path::PathBuf::from(&h).join(".fonts"));
-            v.push(std::path::PathBuf::from(h).join(".local/share/fonts"));
-        }
+        v.extend(unix_user_font_dirs(std::env::var_os("HOME"), std::env::var_os("XDG_DATA_HOME")));
    }
    v
 }

+// Fontconfig's default configuration uses $XDG_DATA_HOME/fonts for user fonts.
+// Ignore relative XDG paths, as required by the XDG Base Directory Specification.
+#[cfg(all(unix, not(target_os = "macos")))]
+fn unix_user_font_dirs(home: Option<std::ffi::OsString>, data_home: Option<std::ffi::OsString>) -> Vec<std::path::PathBuf> {
+    let home = home.map(std::path::PathBuf::from);
+    let data = data_home.map(std::path::PathBuf::from).filter(|p| p.is_absolute()).or_else(|| home.as_ref().map(|h| h.join(".local/share")));
+    let mut dirs = Vec::new();
+    if let Some(home) = home {
+        dirs.push(home.join(".fonts"));
+    }
+    if let Some(data) = data {
+        dirs.push(data.join("fonts"));
+    }
+    dirs
+}
+
 fn scan_dir(dir: &std::path::Path, depth: usize, out: &mut BTreeMap<String, (String, Vec<Pending>)>) {
    if depth > 6 {
        return;
@@ -699,8 +738,10 @@ fn scan_dir(dir: &std::path::Path, depth: usize, out: &mut BTreeMap<String, (Str
        if !matches!(ext.as_str(), "ttf" | "otf" | "ttc" | "otc") {
            continue;
        }
-        // Skip very large files (colour emoji); they are not outline fonts we can draw anyway.
-        let Some(bytes) = usize::try_from(meta.len()).ok().filter(|l| *l <= 64 * 1024 * 1024).and_then(|l| index_bytes(&path, l)) else { continue };
+        // Very large files are indexed all the same (Apple Color Emoji is ~180 MB and is where the
+        // system's colour emoji live): `index_bytes` reads headers and name tables out of a zeroed
+        // buffer, so only those parts are ever touched.
+        let Some(bytes) = usize::try_from(meta.len()).ok().filter(|l| *l <= 256 * 1024 * 1024).and_then(|l| index_bytes(&path, l)) else { continue };
        for (index, family, style) in faces_in(&bytes) {
            out.entry(family.to_lowercase()).or_insert_with(|| (family.clone(), Vec::new())).1.push(Pending { path: path.clone(), index, style });
        }
@@ -743,7 +784,8 @@ fn index_bytes(path: &std::path::Path, len: usize) -> Option<Vec<u8>> {
    Some(buf)
 }

-/// (index, family, style) of each outline face (one we can draw) in a font file.
+/// (index, family, style) of each face in a font file: outline fonts and colour fonts (Apple Color
+/// Emoji draws most emoji from `sbix`, Noto Color Emoji has no outlines at all).
 fn faces_in(bytes: &[u8]) -> Vec<(u32, String, String)> {
    let count = match FileRef::new(bytes) {
        Ok(FileRef::Collection(c)) => c.len(),
@@ -753,7 +795,10 @@ fn faces_in(bytes: &[u8]) -> Vec<(u32, String, String)> {
    (0..count.min(64))
        .filter_map(|i| {
            let f = skrifa::FontRef::from_index(bytes, i).ok()?;
-            [b"glyf", b"CFF ", b"CFF2"].iter().any(|t| f.data_for_tag(skrifa::Tag::new(t)).is_some()).then_some(())?;
+            [b"glyf", b"CFF ", b"CFF2", b"sbix", b"CBDT", b"EBDT", b"COLR"]
+                .iter()
+                .any(|t| f.data_for_tag(skrifa::Tag::new(t)).is_some())
+                .then_some(())?;
            let (family, style) = names(&f);
            let family = family.filter(|f| !f.starts_with('.'))?;
            Some((i, family, style.unwrap_or_else(|| "Regular".into())))
@@ -67,3 +67,29 @@ fn the_scan_reads_names_like_a_whole_file_read() {
        assert_eq!(faces_in(&index_bytes(&p, whole.len()).unwrap()), faces_in(&whole), "{}", p.display());
    }
 }
+
+#[cfg(all(unix, not(target_os = "macos")))]
+#[test]
+fn user_font_dirs_follow_xdg_data_home() {
+    use std::ffi::OsString;
+    use std::path::PathBuf;
+    let dirs = |home: Option<&str>, data: Option<&str>| unix_user_font_dirs(home.map(OsString::from), data.map(OsString::from));
+    let paths = |items: &[&str]| items.iter().map(PathBuf::from).collect::<Vec<_>>();
+    assert_eq!(dirs(Some("/home/user"), Some("/custom user data")), paths(&["/home/user/.fonts", "/custom user data/fonts"]));
+    for data in [None, Some(""), Some("relative/data")] {
+        assert_eq!(dirs(Some("/home/user"), data), paths(&["/home/user/.fonts", "/home/user/.local/share/fonts"]));
+    }
+    assert_eq!(dirs(None, Some("/custom-data")), paths(&["/custom-data/fonts"]));
+    assert_eq!(dirs(None, None), paths(&[]));
+    assert_eq!(dirs(None, Some("relative")), paths(&[]));
+}
+
+#[cfg(all(unix, not(target_os = "macos")))]
+#[test]
+fn user_font_dirs_preserve_non_utf8_paths() {
+    use std::ffi::OsString;
+    use std::os::unix::ffi::{OsStrExt, OsStringExt};
+    let dirs = unix_user_font_dirs(Some(OsString::from_vec(b"/home/\xff".to_vec())), Some(OsString::from_vec(b"/data/\xfe".to_vec())));
+    assert_eq!(dirs[0].as_os_str().as_bytes(), b"/home/\xff/.fonts");
+    assert_eq!(dirs[1].as_os_str().as_bytes(), b"/data/\xfe/fonts");
+}
@@ -10,6 +10,7 @@ use figcraft_doc::{
 use figcraft_geom::{Affine, BezPath, Rect};
 use harfrust::{Direction, Feature, ShapeOptions, ShaperInstance, Tag, UnicodeBuffer, Variation};

+use crate::color::{ColorInk, MAX_PX_PER_EM};
 use crate::fontdb::{Coords, Face, db, no_coords};

 /// A positioned glyph (pen position on the baseline, layout coordinates, y down).
@@ -37,11 +38,34 @@ pub struct Glyph {
 impl Glyph {
    /// The glyph outline placed in layout coordinates.
    pub fn path(&self) -> BezPath {
+        self.layer_path(self.gid)
+    }
+
+    /// The outline of one of the face's glyphs (a COLR layer), placed like this glyph.
+    pub fn layer_path(&self, gid: u32) -> BezPath {
        let s = self.size / self.face.upem;
-        let mut p = (*self.face.outline_at(self.gid, &self.coords)).clone();
+        let mut p = (*self.face.outline_at(gid, &self.coords)).clone();
        p.apply_affine(self.warp * Affine::new([s, 0.0, 0.0, s, self.x, self.y]));
        p
    }
+
+    /// The glyph's colour ink at `scale` device pixels per layout unit, placed in layout
+    /// coordinates (a bitmap's pixels map through the affine; COLR layers are drawn like the
+    /// outline). `None` — the usual case — means the outline is what draws.
+    pub fn color(&self, scale: f64) -> Option<ColorInk> {
+        if !scale.is_finite() || scale <= 0.0 {
+            return None;
+        }
+        if let Some(layers) = self.face.color_layers(self.gid) {
+            return Some(ColorInk::Layers(layers));
+        }
+        // Whole device pixels per em: rasters stay on the pixel grid and the cache stays small.
+        let px = (self.size * scale).round().clamp(1.0, MAX_PX_PER_EM);
+        let bitmap = self.face.color_bitmap(self.gid, &self.coords, px)?;
+        let s = px / self.size;
+        let place = self.warp * Affine::translate((self.x + bitmap.left / s, self.y + bitmap.top / s)) * Affine::scale(1.0 / s);
+        Some(ColorInk::Bitmap(bitmap, place))
+    }
 }

 #[derive(Clone, Debug)]
@@ -299,11 +323,16 @@ pub fn layout(text: &TextData, box_width: Option<f64>, box_height: Option<f64>)
        span_style.push(idx);
    }
    let mut dbw = db().write().unwrap_or_else(std::sync::PoisonError::into_inner);
-    let fallbacks = dbw.fallbacks();
+    let mut fallbacks = dbw.fallbacks();
    let mut faces: Vec<Option<Arc<Face>>> = Vec::with_capacity(styles.len());
    for s in &styles {
        faces.push(dbw.find(&s.font_family, &s.font_style).or_else(|| dbw.default_face()));
    }
+    // Colour emoji are their own, large faces (Apple Color Emoji is ~180 MB): they are read only
+    // for a text with emoji, or with characters nothing above covers.
+    let covered = |c: char| c == '\n' || faces.iter().flatten().any(|f| f.has_char(c)) || fallbacks.iter().any(|f| f.has_char(c));
+    let emoji = if chars.iter().any(|c| is_emoji(*c) || !covered(*c)) { dbw.emoji_fallbacks() } else { Vec::new() };
+    fallbacks.extend(emoji.iter().cloned());
    drop(dbw);

    // OpenType features the user toggled (global for the node).
@@ -331,6 +360,14 @@ pub fn layout(text: &TextData, box_width: Option<f64>, box_height: Option<f64>)
        let mut seg_start = *start;
        while seg_start < *end {
            let face_for = |c: char| -> Arc<Face> {
+                // Emoji take a colour face before a face without colour glyphs (the style's own or a
+                // symbol font), which would draw them in one colour.
+                if is_emoji(c)
+                    && !primary.has_color()
+                    && let Some(f) = emoji.iter().find(|f| f.has_char(c))
+                {
+                    return f.clone();
+                }
                if c == '\n' || primary.has_char(c) {
                    return primary.clone();
                }
@@ -958,6 +995,13 @@ fn sanitize_size(s: f64) -> f64 {
    if s.is_finite() { s.clamp(0.5, 5000.0) } else { 12.0 }
 }

+/// A character drawn as a colour emoji by default: flags and the pictograph blocks.
+/// shortcut: the older symbols (U+2600–U+27BF) keep their text look even before U+FE0F; read the
+/// emoji presentation data if they should turn colour too.
+fn is_emoji(c: char) -> bool {
+    matches!(c, '\u{1F1E6}'..='\u{1F1FF}' | '\u{1F300}'..='\u{1FAFF}')
+}
+
 /// One run of chars shaped with a single face and style.
 struct Segment<'a> {
    start: usize,
@@ -1213,7 +1257,8 @@ impl TextLayout {
            }
            let (x0, _) = self.caret(a.max(line.char_start));
            let x1 = if b >= line.char_end {
-                self.line_end_x(line) + if line.para_end && b > line.char_end.saturating_sub(1) { 4.0 } else { 0.0 }
+                // The last line has no paragraph break to show, so it ends at its glyphs.
+                self.line_end_x(line) + if line.para_end && li + 1 < self.lines.len() && b > line.char_end.saturating_sub(1) { 4.0 } else { 0.0 }
            } else {
                self.caret(b).0
            };
@@ -7,12 +7,14 @@
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]

 mod breaks;
+pub mod color;
 pub mod display;
 pub mod fontdb;
 mod layout;
 mod onpath;

 pub use breaks::grapheme_step;
+pub use color::{ColorBitmap, ColorInk, ColorLayer};
 pub use fontdb::{
    Axis, CRAFT_FONTS, Coords, Face, FontDb, NamedInstance, axis_label, db, face_with_char, family_names, family_styles, find_face, no_coords,
    scan_system_fonts, scan_system_fonts_on_demand, system_fonts_scanned,