Merge branch 'rb-578' into batch/t6

# Conflicts: # crates/text/src/fontdb_tests.rs
Merge branch 'rb-568' into batch/t6
2026-10-22 19:08:51 +00:00 · 2026-10-16 02:37:43 +07:00 · 2026-10-16 02:36:56 +07:00 · 2026-10-16 02:36:56 +07:00 · 2026-10-16 02:36:55 +07:00 · 2026-10-16 02:36:55 +07:00
257 changed files with 23209 additions and 1127 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:
@@ -43,8 +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
@@ -1418,6 +1418,7 @@ dependencies = [
 "figcraft-format",
 "figcraft-text",
 "figcraft-ui-egui",
+ "fmv-macos-events",
 "image",
 "log",
 "rfd",
@@ -1680,6 +1681,7 @@ dependencies = [
 "figcraft-geom",
 "harfrust 0.13.3",
 "log",
+ "png",
 "skrifa 0.47.0",
 "unicode-bidi",
 "unicode-segmentation",
@@ -1707,6 +1709,7 @@ dependencies = [
 "serde_json",
 "toml",
 "wat",
+ "web-time",
 ]

 [[package]]
@@ -1718,6 +1721,7 @@ dependencies = [
 "figcraft-collab-net",
 "figcraft-engine",
 "figcraft-ui-egui",
+ "js-sys",
 "log",
 "wasm-bindgen",
 "wasm-bindgen-futures",
@@ -1750,6 +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"
@@ -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 (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)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-15 · **Change:** minor (Typography spacing icons support scrubbing (#373); font scans skip named pipes; 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
@@ -111,7 +111,7 @@ native speakers' reviews of the six language drafts need people.
 | Korean | ko | 100% | draft (needs native review) |
 | Vietnamese | vi | 0% | none |

-No other languages. Figma ships English, Japanese, Korean, French, German, Spanish and Portuguese
+Also shipped: Swedish (`sv`: every UI string, 120 of 588 command labels and menu wordings; native review welcome). Figma ships English, Japanese, Korean, French, German, Spanish and Portuguese
 (Brazil); FigCraft has the localization layer, English and Spanish (Spain and Latin America),
 French, German, Brazilian Portuguese, Japanese, Korean and Simplified Chinese drafts (Preferences ▸
 Language; Traditional Chinese has no catalog; CJK UI
@@ -131,6 +131,7 @@ 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.
@@ -312,6 +313,9 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).

 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-15 | minor | M7: system font discovery skips entries observed as non-regular files before opening them, avoiding the reproduced named-pipe stall. Regular-file symlinks remain supported; directory depth, font limits and priorities are unchanged. Numbers unchanged. |
+| 2026-10-15 | minor | Typography spacing icons scrub with the shared number-field gesture, modifier rates and one Undo step per drag (#373). Units and selected-character targeting are preserved. Numbers unchanged. |
+| 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 |
@@ -38,7 +38,7 @@ fn write(path: &str, bytes: &[u8]) -> CliResult<()> {

 fn page_named(doc: &Document, name: Option<&str>) -> CliResult<NodeId> {
    match name {
-        None => doc.first_page().ok_or_else(|| CliError::Failed("the document has no pages".into())),
+        None => doc.first_open_page().or_else(|| doc.first_page()).ok_or_else(|| CliError::Failed("the document has no pages".into())),
        Some(n) => doc
            .pages
            .iter()
@@ -380,6 +380,22 @@ mod tests {
        assert_eq!(sanitize(""), "layer");
    }

+    #[test]
+    fn default_page_skips_leading_divider() {
+        let mut doc = Document::new("divider");
+        let page = doc.first_page().unwrap();
+        doc.create(page, figcraft_doc::NodeKind::Frame, "First", 0.0, 0.0, 40.0, 30.0).unwrap();
+        let divider = doc.add_page("- Divider");
+        doc.pages.retain(|p| *p != divider);
+        doc.pages.insert(0, divider);
+        assert!(doc.is_divider(divider));
+        assert_eq!(page_named(&doc, None).unwrap(), page);
+        assert_eq!(page_named(&doc, Some("- Divider")).unwrap(), divider);
+        let pm = render_page(&doc, page_named(&doc, None).unwrap(), 1.0).unwrap();
+        assert_eq!((pm.width(), pm.height()), (40, 30));
+        assert!(render_page(&doc, divider, 1.0).is_err());
+    }
+
    #[test]
    fn export_depth_errors_preserve_conversion_destinations() {
        let mut doc = Document::new("export depth");
@@ -438,44 +438,66 @@ fn measure_components(table: &mut Table, col: usize, instances: usize) -> CliRes
        mean(3, |i| exec(&mut s, "node.set", json!({"ids": labels, "props": {"fontSize": 13 + (i % 2) * 2}}))),
    );
    let doc = s.doc().map_err(failed)?.clone();
-    let (card, _) = instance_with(&doc, &inst, ds.card, &["Footer button", "Icon", "Glyph"]).ok_or_else(|| failed("no card"))?;
-    table.put(
-        col,
-        "switch a card's variant (nested overrides kept)",
-        mean(5, |i| {
-            exec(&mut s, "instance.setProperties", json!({"ids": [card], "properties": {"Size": if i % 2 == 0 { "Large" } else { "Small" }}}))
-        }),
-    );
-    let (nav, _) = instance_with(&doc, &inst, ds.nav, &["Profile"]).ok_or_else(|| failed("no nav"))?;
-    table.put(col, "reset all changes on a nav", timed(&mut s, "component.resetInstance", json!({"ids": [nav]}), true));
-    table.put(col, "detach a nav", timed(&mut s, "component.detach", json!({"ids": [nav]}), true));
-    let (button, bglyph) = instance_with(&doc, &inst, ds.button, &["Icon", "Glyph"]).ok_or_else(|| failed("no button"))?;
-    table.put(col, "push a button's changes to its main", timed(&mut s, "component.pushChanges", json!({"id": button}), true));
-    // A button glyph the drop really lands on: screens can overlap (text sizes differ without
-    // fonts), so ask the hit test the swap uses.
-    let now = s.doc().map_err(failed)?.clone();
-    let page = s.page().map_err(failed)?;
-    let b = std::iter::once(bglyph)
-        .chain(inst.iter().filter_map(|i| {
-            let NodeKind::Instance { component, .. } = &now.node(*i)?.kind else { return None };
-            (figcraft_engine::components::variant_set(&now, *component) == Some(ds.button)).then(|| find_path(&now, *i, &["Icon", "Glyph"]))?
-        }))
-        .filter_map(|g| now.world_bounds(g))
-        .find(|b| figcraft_engine::drop::swap_target(&now, page, b.center(), None, None).is_some())
-        .ok_or_else(|| failed("no button glyph to drop on"))?;
-    let other = ds.icons.get(5).copied().unwrap_or(icon0);
-    table.put(
-        col,
-        "Alt-drop swap onto an instance",
-        timed(&mut s, "instance.swapAt", json!({"component": other, "x": b.center().x, "y": b.center().y}), true),
-    );
-    exec(&mut s, "edit.copy", json!({"ids": [nav]}));
-    table.put(col, "copy + paste a nav", timed(&mut s, "edit.paste", json!({}), true));
+    // Small workloads may not contain every instance type; the rows needing a missing one stay empty.
+    if let Some((card, _)) = instance_with(&doc, &inst, ds.card, &["Footer button", "Icon", "Glyph"]) {
+        table.put(
+            col,
+            "switch a card's variant (nested overrides kept)",
+            mean(5, |i| {
+                exec(&mut s, "instance.setProperties", json!({"ids": [card], "properties": {"Size": if i % 2 == 0 { "Large" } else { "Small" }}}))
+            }),
+        );
+    } else {
+        table.put(col, "switch a card's variant (nested overrides kept)", f64::NAN);
+    }
+    let nav = instance_with(&doc, &inst, ds.nav, &["Profile"]).map(|(nav, _)| nav);
+    if let Some(nav) = nav {
+        table.put(col, "reset all changes on a nav", timed(&mut s, "component.resetInstance", json!({"ids": [nav]}), true));
+        table.put(col, "detach a nav", timed(&mut s, "component.detach", json!({"ids": [nav]}), true));
+    } else {
+        table.put(col, "reset all changes on a nav", f64::NAN);
+        table.put(col, "detach a nav", f64::NAN);
+    }
+    if let Some((button, bglyph)) = instance_with(&doc, &inst, ds.button, &["Icon", "Glyph"]) {
+        table.put(col, "push a button's changes to its main", timed(&mut s, "component.pushChanges", json!({"id": button}), true));
+        // A button glyph the drop really lands on: screens can overlap (text sizes differ without
+        // fonts), so ask the hit test the swap uses.
+        let now = s.doc().map_err(failed)?.clone();
+        let page = s.page().map_err(failed)?;
+        let drop_at = std::iter::once(bglyph)
+            .chain(inst.iter().filter_map(|i| {
+                let NodeKind::Instance { component, .. } = &now.node(*i)?.kind else { return None };
+                (figcraft_engine::components::variant_set(&now, *component) == Some(ds.button)).then(|| find_path(&now, *i, &["Icon", "Glyph"]))?
+            }))
+            .filter_map(|g| now.world_bounds(g))
+            .find(|b| figcraft_engine::drop::swap_target(&now, page, b.center(), None, None).is_some());
+        let other = ds.icons.get(5).copied().unwrap_or(icon0);
+        table.put(
+            col,
+            "Alt-drop swap onto an instance",
+            match drop_at {
+                Some(b) => timed(&mut s, "instance.swapAt", json!({"component": other, "x": b.center().x, "y": b.center().y}), true),
+                None => f64::NAN,
+            },
+        );
+    } else {
+        table.put(col, "push a button's changes to its main", f64::NAN);
+        table.put(col, "Alt-drop swap onto an instance", f64::NAN);
+    }
+    if let Some(nav) = nav {
+        exec(&mut s, "edit.copy", json!({"ids": [nav]}));
+        table.put(col, "copy + paste a nav", timed(&mut s, "edit.paste", json!({}), true));
+    } else {
+        table.put(col, "copy + paste a nav", f64::NAN);
+    }
    table.put(col, "undo (deep main edit)", mean(10, |_| _ = s.undo()));
    table.put(col, "redo", mean(10, |_| _ = s.redo()));

    // As a library: publish it, use it from another file, publish a change, accept the update.
-    let dir = std::env::temp_dir().join(format!("figcraft-perf-{}", std::process::id()));
+    // One directory per run, so concurrent runs in a process don't delete each other's files.
+    static RUNS: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
+    let run = RUNS.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+    let dir = std::env::temp_dir().join(format!("figcraft-perf-{}-{run}", std::process::id()));
    std::fs::create_dir_all(&dir).map_err(failed)?;
    let path = dir.join("design-system.figcraft").to_string_lossy().into_owned();
    let (lib_doc, lib_ds) = design_system_document(&spec).map_err(failed)?;
@@ -533,6 +555,14 @@ mod tests {
        assert!(t.rows.iter().all(|r| r.1.len() == 1 && r.1[0].is_finite()), "{:?}", t.rows);
    }

+    #[test]
+    fn measures_components_with_a_single_instance() {
+        let mut t = super::Table { rows: Vec::new() };
+        super::measure_components(&mut t, 0, 1).unwrap();
+        assert!(t.rows.iter().all(|r| r.1.len() == 1), "{:?}", t.rows);
+        assert!(t.rows.iter().any(|r| r.0.starts_with("build design system") && r.1[0].is_finite()), "{:?}", t.rows);
+    }
+
    #[test]
    fn measures_a_small_document() {
        let mut t = super::Table { rows: Vec::new() };
@@ -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,
@@ -343,14 +347,14 @@ impl Store {
        let key = load_key(root)?;
        let dir = root.join(FILES);
        fs::create_dir_all(&dir).map_err(|e| format!("can't create {}: {e}", dir.display()))?;
-        let (directory, problems) = Directory::open(root, cfg.directory);
+        let (directory, startup_problems) = Directory::open(root, cfg.directory);
        let abuse = Abuse::new(cfg.hosting.abuse);
        let mut store = Store {
            root: root.to_path_buf(),
            cfg,
            key,
            files: BTreeMap::new(),
-            problems,
+            problems: Vec::new(),
            directory,
            abuse,
            served: figcraft_collab_net::net::Bucket::new(LIBRARY_RATE, LIBRARY_BURST),
@@ -360,9 +364,13 @@ impl Store {
            gone_codes: VecDeque::new(),
            next_sweep: 0,
            compactions: 0,
+            cut_short: Vec::new(),
            free: None,
            _lock: lock,
        };
+        for problem in startup_problems {
+            store.note(problem);
+        }
        store.scan(&dir);
        store.blocked = store.read_list::<String>(BLOCKED).iter().filter_map(|s| s.parse().ok()).map(ip_key).collect();
        store.reports = store.read_list(REPORTS);
@@ -380,7 +388,7 @@ impl Store {
        match disk::read_capped(&path, 16 << 20).and_then(|b| serde_json::from_slice(&b).map_err(|e| format!("{name} is damaged ({e})"))) {
            Ok(list) => list,
            Err(e) => {
-                self.problems.push(e);
+                self.note(e);
                Vec::new()
            }
        }
@@ -389,7 +397,7 @@ impl Store {
    fn scan(&mut self, dir: &Path) {
        let entries = match fs::read_dir(dir) {
            Ok(e) => e,
-            Err(e) => return self.problems.push(format!("can't list {}: {e}", dir.display())),
+            Err(e) => return self.note(format!("can't list {}: {e}", dir.display())),
        };
        let mut ids: Vec<(String, PathBuf)> = entries.flatten().map(|e| (e.file_name().to_string_lossy().into_owned(), e.path())).collect();
        ids.sort();
@@ -398,18 +406,18 @@ impl Store {
                continue;
            }
            if !valid_id(&id) {
-                self.problems.push(format!("skipped {}: not a file folder of this server", path.display()));
+                self.note(format!("skipped {}: not a file folder of this server", path.display()));
                continue;
            }
            if self.files.len() >= self.cfg.max_files {
-                self.problems.push(format!("skipped file {id}: over the {}-file cap", self.cfg.max_files));
+                self.note(format!("skipped file {id}: over the {}-file cap", self.cfg.max_files));
                continue;
            }
            match self.check(&path) {
                Ok(entry) => {
                    self.files.insert(id, entry);
                }
-                Err(why) => self.problems.push(format!("skipped file {id}: {why}")),
+                Err(why) => self.note(format!("skipped file {id}: {why}")),
            }
        }
    }
@@ -919,11 +927,12 @@ 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 +974,24 @@ 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 +1143,7 @@ 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 +1156,24 @@ 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 +1226,19 @@ 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 +1246,7 @@ 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 +1262,13 @@ 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 +1289,18 @@ 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 +1368,8 @@ 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 +1492,8 @@ 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:?}");
+}
@@ -0,0 +1,40 @@
+use figcraft_server::config::Config;
+use figcraft_server::store::{FILES, Store};
+
+#[test]
+fn startup_problem_retention() {
+    let root = std::env::temp_dir().join(format!("figcraft-problem-cap-{}", std::process::id()));
+    assert!(!root.exists());
+    let result = (|| -> Result<(), String> {
+        for count in [3u32, 200, 201] {
+            let data = root.join(count.to_string());
+            for i in 0..count {
+                std::fs::create_dir_all(data.join(FILES).join(format!("{i:016x}"))).map_err(|e| e.to_string())?;
+            }
+            let cfg = Config { open_publish: true, data: data.clone(), ..Config::default() };
+            cfg.check()?;
+            let store = Store::open(&data, cfg.store())?;
+            let expected = (count as usize).min(200);
+            let problems = store.problems().to_vec();
+            let no_loaded_files = store.is_empty();
+            drop(store);
+            if !problems.iter().all(|p| p.contains("meta.json")) || !no_loaded_files {
+                return Err("unexpected diagnostic or loaded file".into());
+            }
+            if problems.len() != expected {
+                return Err(format!("expected {expected} retained problems, got {}", problems.len()));
+            }
+            // The latest problems stay, in scan order: the first folder's is the one dropped.
+            let first_kept = count as usize - expected;
+            for (n, p) in problems.iter().enumerate() {
+                let id = format!("{:016x}", first_kept + n);
+                if !p.contains(&id) {
+                    return Err(format!("problem {n} should be about {id}: {p}"));
+                }
+            }
+        }
+        Ok(())
+    })();
+    std::fs::remove_dir_all(&root).unwrap();
+    assert!(result.is_ok(), "{}", result.unwrap_err());
+}
@@ -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);
+}
@@ -107,11 +107,17 @@ 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?)"})
                    }
                }
            }
-            Err(e) => json!({"id": null, "ok": false, "error": format!("bad JSON: {e}")}),
+            Err(e) => {
+                // A line that isn't JSON ends the connection: a web page can make the browser send
+                // an HTTP request here, and its header lines must not let the JSON lines of its body
+                // through as commands.
+                writeln!(out, "{}", json!({"id": null, "ok": false, "error": format!("bad JSON: {e}")}))?;
+                break;
+            }
        };
        writeln!(out, "{reply}")?;
    }
@@ -53,9 +53,8 @@ fn valid_frames_keep_their_order_ids_and_parameters() {
    let pending = queue();
    let q = pending.clone();
    let worker = std::thread::spawn(move || serve(server, q, context(), Duration::from_secs(5)));
-    client.write_all(b"\r\n{bad JSON}\n{\"id\":\"test\",\"method\":\"engine.execute\",\"params\":{\"command\":\"shape.rectangle\"}}\r\n").unwrap();
+    client.write_all(b"\r\n{\"id\":\"test\",\"method\":\"engine.execute\",\"params\":{\"command\":\"shape.rectangle\"}}\r\n").unwrap();
    let mut reader = BufReader::new(client);
-    assert_eq!(reply(&mut reader)["ok"], false);
    let start = Instant::now();
    let r = loop {
        if let Some(r) = pending.lock().unwrap().pop() {
@@ -73,6 +72,23 @@ fn valid_frames_keep_their_order_ids_and_parameters() {
    worker.join().unwrap().unwrap();
 }

+#[test]
+fn a_line_that_is_not_json_ends_the_connection_before_anything_after_it_runs() {
+    // What a browser sends when a web page posts to the port: the JSON line in its body never runs.
+    let (mut client, server) = pair();
+    let pending = queue();
+    let q = pending.clone();
+    let worker = std::thread::spawn(move || serve(server, q, context(), Duration::from_secs(5)));
+    let body = "{\"id\":1,\"method\":\"engine.execute\",\"params\":{\"command\":\"file.save\"}}\n";
+    let http = format!("POST / HTTP/1.1\r\nHost: 127.0.0.1\r\nContent-Type: text/plain\r\nContent-Length: {}\r\n\r\n{body}", body.len());
+    client.write_all(http.as_bytes()).unwrap();
+    let mut reader = BufReader::new(client);
+    assert_eq!(reply(&mut reader)["ok"], false);
+    assert_eq!(reader.read(&mut [0]).unwrap(), 0, "the connection is closed");
+    worker.join().unwrap().unwrap();
+    assert!(pending.lock().unwrap().is_empty(), "nothing was dispatched");
+}
+
 #[test]
 fn full_queue_rejects_before_dispatch_and_ui_queue_stays_bounded() {
    let (mut client, server) = pair();
@@ -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()
    }
@@ -194,15 +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() {
@@ -242,6 +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 +16,31 @@
 #
 # 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]
+
+[people.Nael-Nathanael]
+sync_github_name = true
+
+[people.volkovskey]
+real_name = "Andrii Volkov"
@@ -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.
@@ -11,6 +11,7 @@ use serde::{Deserialize, Serialize};
 mod blend;
 mod hsx;
 mod icc;
+mod named;
 mod profile;
 pub use blend::BlendMode;
 pub use hsx::*;
@@ -139,7 +140,13 @@ impl Color {
        Some(Self::from_rgba8(r, g, b, a))
    }

-    /// Parse a CSS colour: hex, `rgb()/rgba()`, `hsl()/hsla()` or a few common names.
+    /// What a colour field accepts: hex as [`Color::from_hex`] reads it, or a CSS colour name
+    /// (`red` → `FF0000`, `Cornflower Blue` → `6495ED`; opaque).
+    pub fn from_hex_or_name(s: &str) -> Option<Self> {
+        Self::from_hex(s).or_else(|| named::lookup(s).map(|[r, g, b]| Self::from_rgba8(r, g, b, 255)))
+    }
+
+    /// Parse a CSS colour: hex, `rgb()/rgba()`, `hsl()/hsla()`, a CSS colour name or `transparent`.
    pub fn parse_css(s: &str) -> Option<Self> {
        let t = s.trim().to_ascii_lowercase();
        if t.starts_with('#') {
@@ -166,21 +173,10 @@ impl Color {
            let alpha = parts.get(3).and_then(|a| parse_alpha(a)).unwrap_or(1.0);
            return Some(Hsl { h, s, l }.to_color().with_alpha(alpha));
        }
-        let named = match t.as_str() {
-            "black" => Color::BLACK,
-            "white" => Color::WHITE,
-            "transparent" => Color::TRANSPARENT,
-            "red" => Color::from_rgb8_const(255, 0, 0),
-            "green" => Color::from_rgb8_const(0, 128, 0),
-            "lime" => Color::from_rgb8_const(0, 255, 0),
-            "blue" => Color::from_rgb8_const(0, 0, 255),
-            "yellow" => Color::from_rgb8_const(255, 255, 0),
-            "orange" => Color::from_rgb8_const(255, 165, 0),
-            "purple" => Color::from_rgb8_const(128, 0, 128),
-            "gray" | "grey" => Color::from_rgb8_const(128, 128, 128),
-            _ => return Self::from_hex(&t),
-        };
-        Some(named)
+        if t == "transparent" {
+            return Some(Color::TRANSPARENT);
+        }
+        Self::from_hex_or_name(&t)
    }

    /// CSS `rgba(...)` / hex text for copy-as-CSS.
@@ -0,0 +1,197 @@
+//! The CSS named colours (CSS Color Module Level 4 §6.1), so a colour field takes `red` as well as
+//! `FF0000`.
+
+/// Every CSS named colour except `transparent`, sorted by name for binary search.
+const NAMED: [(&str, [u8; 3]); 148] = [
+    ("aliceblue", [240, 248, 255]),
+    ("antiquewhite", [250, 235, 215]),
+    ("aqua", [0, 255, 255]),
+    ("aquamarine", [127, 255, 212]),
+    ("azure", [240, 255, 255]),
+    ("beige", [245, 245, 220]),
+    ("bisque", [255, 228, 196]),
+    ("black", [0, 0, 0]),
+    ("blanchedalmond", [255, 235, 205]),
+    ("blue", [0, 0, 255]),
+    ("blueviolet", [138, 43, 226]),
+    ("brown", [165, 42, 42]),
+    ("burlywood", [222, 184, 135]),
+    ("cadetblue", [95, 158, 160]),
+    ("chartreuse", [127, 255, 0]),
+    ("chocolate", [210, 105, 30]),
+    ("coral", [255, 127, 80]),
+    ("cornflowerblue", [100, 149, 237]),
+    ("cornsilk", [255, 248, 220]),
+    ("crimson", [220, 20, 60]),
+    ("cyan", [0, 255, 255]),
+    ("darkblue", [0, 0, 139]),
+    ("darkcyan", [0, 139, 139]),
+    ("darkgoldenrod", [184, 134, 11]),
+    ("darkgray", [169, 169, 169]),
+    ("darkgreen", [0, 100, 0]),
+    ("darkgrey", [169, 169, 169]),
+    ("darkkhaki", [189, 183, 107]),
+    ("darkmagenta", [139, 0, 139]),
+    ("darkolivegreen", [85, 107, 47]),
+    ("darkorange", [255, 140, 0]),
+    ("darkorchid", [153, 50, 204]),
+    ("darkred", [139, 0, 0]),
+    ("darksalmon", [233, 150, 122]),
+    ("darkseagreen", [143, 188, 143]),
+    ("darkslateblue", [72, 61, 139]),
+    ("darkslategray", [47, 79, 79]),
+    ("darkslategrey", [47, 79, 79]),
+    ("darkturquoise", [0, 206, 209]),
+    ("darkviolet", [148, 0, 211]),
+    ("deeppink", [255, 20, 147]),
+    ("deepskyblue", [0, 191, 255]),
+    ("dimgray", [105, 105, 105]),
+    ("dimgrey", [105, 105, 105]),
+    ("dodgerblue", [30, 144, 255]),
+    ("firebrick", [178, 34, 34]),
+    ("floralwhite", [255, 250, 240]),
+    ("forestgreen", [34, 139, 34]),
+    ("fuchsia", [255, 0, 255]),
+    ("gainsboro", [220, 220, 220]),
+    ("ghostwhite", [248, 248, 255]),
+    ("gold", [255, 215, 0]),
+    ("goldenrod", [218, 165, 32]),
+    ("gray", [128, 128, 128]),
+    ("green", [0, 128, 0]),
+    ("greenyellow", [173, 255, 47]),
+    ("grey", [128, 128, 128]),
+    ("honeydew", [240, 255, 240]),
+    ("hotpink", [255, 105, 180]),
+    ("indianred", [205, 92, 92]),
+    ("indigo", [75, 0, 130]),
+    ("ivory", [255, 255, 240]),
+    ("khaki", [240, 230, 140]),
+    ("lavender", [230, 230, 250]),
+    ("lavenderblush", [255, 240, 245]),
+    ("lawngreen", [124, 252, 0]),
+    ("lemonchiffon", [255, 250, 205]),
+    ("lightblue", [173, 216, 230]),
+    ("lightcoral", [240, 128, 128]),
+    ("lightcyan", [224, 255, 255]),
+    ("lightgoldenrodyellow", [250, 250, 210]),
+    ("lightgray", [211, 211, 211]),
+    ("lightgreen", [144, 238, 144]),
+    ("lightgrey", [211, 211, 211]),
+    ("lightpink", [255, 182, 193]),
+    ("lightsalmon", [255, 160, 122]),
+    ("lightseagreen", [32, 178, 170]),
+    ("lightskyblue", [135, 206, 250]),
+    ("lightslategray", [119, 136, 153]),
+    ("lightslategrey", [119, 136, 153]),
+    ("lightsteelblue", [176, 196, 222]),
+    ("lightyellow", [255, 255, 224]),
+    ("lime", [0, 255, 0]),
+    ("limegreen", [50, 205, 50]),
+    ("linen", [250, 240, 230]),
+    ("magenta", [255, 0, 255]),
+    ("maroon", [128, 0, 0]),
+    ("mediumaquamarine", [102, 205, 170]),
+    ("mediumblue", [0, 0, 205]),
+    ("mediumorchid", [186, 85, 211]),
+    ("mediumpurple", [147, 112, 219]),
+    ("mediumseagreen", [60, 179, 113]),
+    ("mediumslateblue", [123, 104, 238]),
+    ("mediumspringgreen", [0, 250, 154]),
+    ("mediumturquoise", [72, 209, 204]),
+    ("mediumvioletred", [199, 21, 133]),
+    ("midnightblue", [25, 25, 112]),
+    ("mintcream", [245, 255, 250]),
+    ("mistyrose", [255, 228, 225]),
+    ("moccasin", [255, 228, 181]),
+    ("navajowhite", [255, 222, 173]),
+    ("navy", [0, 0, 128]),
+    ("oldlace", [253, 245, 230]),
+    ("olive", [128, 128, 0]),
+    ("olivedrab", [107, 142, 35]),
+    ("orange", [255, 165, 0]),
+    ("orangered", [255, 69, 0]),
+    ("orchid", [218, 112, 214]),
+    ("palegoldenrod", [238, 232, 170]),
+    ("palegreen", [152, 251, 152]),
+    ("paleturquoise", [175, 238, 238]),
+    ("palevioletred", [219, 112, 147]),
+    ("papayawhip", [255, 239, 213]),
+    ("peachpuff", [255, 218, 185]),
+    ("peru", [205, 133, 63]),
+    ("pink", [255, 192, 203]),
+    ("plum", [221, 160, 221]),
+    ("powderblue", [176, 224, 230]),
+    ("purple", [128, 0, 128]),
+    ("rebeccapurple", [102, 51, 153]),
+    ("red", [255, 0, 0]),
+    ("rosybrown", [188, 143, 143]),
+    ("royalblue", [65, 105, 225]),
+    ("saddlebrown", [139, 69, 19]),
+    ("salmon", [250, 128, 114]),
+    ("sandybrown", [244, 164, 96]),
+    ("seagreen", [46, 139, 87]),
+    ("seashell", [255, 245, 238]),
+    ("sienna", [160, 82, 45]),
+    ("silver", [192, 192, 192]),
+    ("skyblue", [135, 206, 235]),
+    ("slateblue", [106, 90, 205]),
+    ("slategray", [112, 128, 144]),
+    ("slategrey", [112, 128, 144]),
+    ("snow", [255, 250, 250]),
+    ("springgreen", [0, 255, 127]),
+    ("steelblue", [70, 130, 180]),
+    ("tan", [210, 180, 140]),
+    ("teal", [0, 128, 128]),
+    ("thistle", [216, 191, 216]),
+    ("tomato", [255, 99, 71]),
+    ("turquoise", [64, 224, 208]),
+    ("violet", [238, 130, 238]),
+    ("wheat", [245, 222, 179]),
+    ("white", [255, 255, 255]),
+    ("whitesmoke", [245, 245, 245]),
+    ("yellow", [255, 255, 0]),
+    ("yellowgreen", [154, 205, 50]),
+];
+
+/// Longest name in [`NAMED`]; anything longer can't match.
+const LONGEST: usize = 20;
+
+/// The opaque sRGB bytes of a CSS colour name. Case, spaces, `-` and `_` are ignored, so
+/// `Light Blue`, `light-blue` and `lightblue` are the same colour.
+pub fn lookup(s: &str) -> Option<[u8; 3]> {
+    let key: String = s.chars().filter(|c| !c.is_whitespace() && *c != '-' && *c != '_').take(LONGEST + 1).collect::<String>().to_ascii_lowercase();
+    if key.is_empty() || key.len() > LONGEST {
+        return None;
+    }
+    NAMED.binary_search_by(|(name, _)| name.cmp(&key.as_str())).ok().and_then(|i| NAMED.get(i)).map(|(_, rgb)| *rgb)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn table_is_sorted_and_unique() {
+        assert!(NAMED.windows(2).all(|w| w[0].0 < w[1].0));
+        assert_eq!(NAMED.iter().map(|(n, _)| n.len()).max(), Some(LONGEST));
+    }
+
+    #[test]
+    fn every_name_is_found() {
+        for (name, rgb) in NAMED {
+            assert_eq!(lookup(name), Some(rgb), "{name}");
+        }
+    }
+
+    #[test]
+    fn lookup_normalises() {
+        assert_eq!(lookup("Red"), Some([255, 0, 0]));
+        assert_eq!(lookup("  CORNFLOWER blue "), Some([100, 149, 237]));
+        assert_eq!(lookup("light-goldenrod_yellow"), Some([250, 250, 210]));
+        assert_eq!(lookup(""), None);
+        assert_eq!(lookup("transparent"), None);
+        assert_eq!(lookup("reddish"), None);
+        assert_eq!(lookup("rédé"), None);
+        assert_eq!(lookup(&"a".repeat(10_000)), None);
+    }
+}
@@ -17,6 +17,23 @@ fn css_parsing() {
    assert_eq!(Color::parse_css("rgba(0 0 255 / 50%)").unwrap().to_rgba8(), [0, 0, 255, 128]);
    assert_eq!(Color::parse_css("hsl(120, 100%, 50%)").unwrap().to_hex(), "00FF00");
    assert_eq!(Color::parse_css("white").unwrap(), Color::WHITE);
+    assert_eq!(Color::parse_css("RebeccaPurple").unwrap().to_hex(), "663399");
+    assert_eq!(Color::parse_css("transparent").unwrap(), Color::TRANSPARENT);
+}
+
+#[test]
+fn colour_fields_take_names() {
+    assert_eq!(Color::from_hex_or_name("red").unwrap().to_css_hex(), "#FF0000");
+    assert_eq!(Color::from_hex_or_name(" Cornflower Blue ").unwrap().to_hex(), "6495ED");
+    assert_eq!(Color::from_hex_or_name("darkblue").unwrap().to_rgba8(), [0, 0, 139, 255]);
+    // Hex wins: every digit string still reads as hex.
+    assert_eq!(Color::from_hex_or_name("abc").unwrap().to_hex(), "AABBCC");
+    assert_eq!(Color::from_hex_or_name("#0D99FF").unwrap().to_hex(), "0D99FF");
+    // Names are opaque; `transparent` is not a field colour.
+    assert!(Color::from_hex_or_name("transparent").is_none());
+    for junk in ["", "#", "redd", "re d d", "12345", "\u{0}", "🟥", &"x".repeat(100_000)] {
+        assert!(Color::from_hex_or_name(junk).is_none(), "{junk:?}");
+    }
 }

 #[test]
@@ -781,6 +781,23 @@ impl Document {
        self.paste_nodes(&src_nodes, &map, id, parent, index)
    }

+    /// Deep-copy each of `ids`' subtrees to the end of `parent`, in order, returning the new root
+    /// ids. One id map covers every copy, so references between the copied subtrees (a navigation
+    /// from one copied frame to another) point at the copies.
+    pub fn duplicate_all_into(&mut self, ids: &[NodeId], parent: NodeId) -> DocResult<Vec<NodeId>> {
+        let mut map = BTreeMap::new();
+        let mut trees = Vec::with_capacity(ids.len());
+        for &id in ids {
+            let src_nodes: Vec<Node> = self.subtree(id).into_iter().filter_map(|i| self.node(i).cloned()).collect();
+            for n in &src_nodes {
+                let nid = self.alloc_id();
+                map.insert(n.id, nid);
+            }
+            trees.push((id, src_nodes));
+        }
+        trees.into_iter().map(|(id, src_nodes)| self.paste_nodes(&src_nodes, &map, id, parent, None)).collect()
+    }
+
    /// Insert copies of `nodes` (a subtree rooted at `root`, from this or another document) with ids
    /// remapped by `map`. Interactions, instance references and pattern sources pointing inside the
    /// subtree are remapped too.
@@ -903,15 +920,22 @@ 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> {
@@ -143,7 +143,7 @@ impl Expr {
            return "…".into();
        }
        match self {
-            Expr::Value(VariableValue::Alias(id)) => vars.get(id).map_or_else(|| "(missing variable)".into(), |v| v.name.clone()),
+            Expr::Value(VariableValue::Alias(id)) => vars.get(id).map_or_else(|| "(missing variable)".into(), |v| var_ref(vars, v)),
            Expr::Value(VariableValue::String(s)) => quote(s),
            // Exact numbers and `#` colours, so the text reads back as the same expression.
            Expr::Value(VariableValue::Number(n)) => format!("{n}"),
@@ -178,6 +178,18 @@ impl Expr {
    }
 }

+/// A variable as written in an expression: its bare name when that reads back as this variable,
+/// otherwise `{name}` (or `{id}` when even the braced name wouldn't), so names like `1`, `2x` or
+/// `"q"` don't read back as literals or errors.
+fn var_ref(vars: &Variables, v: &crate::Variable) -> String {
+    let this = Expr::var(v.id.clone());
+    if Expr::parse(&v.name, vars).is_ok_and(|e| e == this) {
+        return v.name.clone();
+    }
+    let braced = !v.name.contains('}') && v.name.trim() == v.name && vars.get(&v.name).is_some_and(|x| x.id == v.id);
+    if braced { format!("{{{}}}", v.name) } else { format!("{{{}}}", v.id) }
+}
+
 /// A collection or mode name as written inside `mode(…)` or `[…]`: as it is, or quoted when it has
 /// spaces at its ends, quotes or brackets.
 fn name_arg(name: &str) -> String {
@@ -176,3 +176,22 @@ fn hostile_text_is_bounded() {
        }
    }
 }
+
+#[test]
+fn names_that_look_like_literals_read_back_as_variables() {
+    for name in ["count", "count total", "2x", "1", "-3", ".5", "(x)", "#ff", "\"q\"", "not", "true"] {
+        let mut v = vars();
+        if let Some(var) = v.variables.iter_mut().find(|x| x.id == "n") {
+            var.name = name.into();
+        }
+        for e in [Expr::var("n"), Expr::op(ExprOp::Add, vec![Expr::var("n"), n(1.0)]), Expr::InMode { variable: "n".into(), mode: "dark".into() }] {
+            let shown = e.display(&v);
+            assert_eq!(Expr::parse(&shown, &v), Ok(e.clone()), "{name:?} shown as {shown:?}");
+        }
+    }
+    // Plain names stay bare, and literals still read as literals.
+    let v = vars();
+    assert_eq!(Expr::var("n").display(&v), "n-name");
+    assert_eq!(parse("1"), n(1.0));
+    assert_eq!(parse("\"q\""), Expr::Value(VariableValue::String("q".into())));
+}
@@ -168,6 +168,27 @@ fn text_runs_restyle_and_replace() {
    assert_eq!(t.characters, "");
 }

+/// A run that reaches past the text (a file can carry one: nothing clamps `runs` on load)
+/// must not overflow the arithmetic that shifts the runs along, and must not leave the
+/// text unwritable.
+#[test]
+fn text_runs_past_the_text_never_overflow() {
+    let style = || TextStyle { font_style: "Bold".into(), ..Default::default() };
+    for end in [usize::MAX, usize::MAX - 1, 1_000_000] {
+        let mut t = TextData::new("hi");
+        t.runs = vec![StyleRun { start: 0, end, style: style() }];
+        // Typing at the caret, and replacing a selection: both shift `end`.
+        t.replace_range(0, 0, "x");
+        assert_eq!(t.characters, "xhi", "end {end}");
+        t.replace_range(0, 3, "yo");
+        assert_eq!(t.characters, "yo", "end {end}");
+        // The text is still writable and the runs are back inside it.
+        t.replace_range(0, 0, "!");
+        assert_eq!(t.characters, "!yo", "end {end}");
+        assert!(t.runs.iter().all(|r| r.start < r.end && r.end <= t.char_count()), "end {end}: {:?}", t.runs);
+    }
+}
+
 #[test]
 fn text_case() {
    assert_eq!(TextCase::Title.apply("hello big world"), "Hello Big World");
@@ -335,6 +356,16 @@ 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;
@@ -371,3 +402,65 @@ fn custom_easings() {
    assert_eq!(back, Easing::CustomSpring { mass: 2.0, stiffness: 50.0, damping: 5.0 });
    assert_eq!(serde_json::from_value::<Easing>(serde_json::json!("easeInOut")).unwrap(), Easing::EaseInOut);
 }
+
+#[test]
+fn text_style_updates_merge_equal_runs() {
+    let def = TextStyle { font_size: 14.0, ..Default::default() };
+    let mut t = TextData::new("abcd");
+    t.link_text_style(0, 2, &def, "S");
+    t.link_text_style(2, 4, &def, "S");
+    t.restyle(2, 4, |s| s.font_size = 24.0);
+    assert_eq!(t.runs.len(), 2);
+    t.update_text_style("S", &TextStyle { font_size: 24.0, ..def.clone() });
+    let spans = t.spans();
+    assert_eq!(spans.len(), 1);
+    assert_eq!((spans[0].0, spans[0].1), (0, 4));
+    assert_eq!(spans[0].2.font_size, 24.0);
+    assert_eq!(spans[0].2.style_id.as_deref(), Some("S"));
+
+    // Remapping two links to one id merges the runs.
+    let mut t = TextData::new("ab");
+    t.link_text_style(0, 1, &def, "A");
+    t.link_text_style(1, 2, &def, "B");
+    t.map_text_styles(|_| Some("C".into()));
+    assert_eq!(t.spans().len(), 1);
+    assert_eq!(t.style_at(1).style_id.as_deref(), Some("C"));
+
+    // Different values stay separate.
+    let mut t = TextData::new("ab");
+    t.link_text_style(0, 1, &def, "A");
+    t.link_text_style(1, 2, &TextStyle { font_size: 30.0, ..Default::default() }, "B");
+    t.map_text_styles(|_| Some("C".into()));
+    let spans = t.spans();
+    assert_eq!(spans.len(), 2);
+    assert_eq!((spans[0].2.font_size, spans[1].2.font_size), (14.0, 30.0));
+
+    // Unlinking a run equal to the base drops it.
+    let mut t = TextData::new("ab");
+    let base = t.style.clone();
+    t.link_text_style(0, 1, &base, "S");
+    t.map_text_styles(|_| None);
+    assert!(t.runs.is_empty());
+}
+
+#[test]
+fn text_style_empty_range_links_and_unlinks_all() {
+    let def = TextStyle { font_style: "Bold".into(), ..Default::default() };
+    let mut t = TextData::new("abcd");
+    t.link_text_style(2, 2, &def, "S");
+    assert!((0..4).all(|i| t.style_at(i).style_id.as_deref() == Some("S") && t.style_at(i).font_style == "Bold"));
+    t.unlink_text_style(2, 2);
+    assert!((0..4).all(|i| t.style_at(i).style_id.is_none() && t.style_at(i).font_style == "Bold"));
+    // Partial ranges stay partial.
+    t.link_text_style(0, 4, &def, "S");
+    t.unlink_text_style(1, 3);
+    assert_eq!(t.style_at(0).style_id.as_deref(), Some("S"));
+    assert!(t.style_at(1).style_id.is_none() && t.style_at(2).style_id.is_none());
+    assert_eq!(t.style_at(3).style_id.as_deref(), Some("S"));
+    // Empty text changes the base style.
+    let mut e = TextData::new("");
+    e.link_text_style(0, 0, &def, "S");
+    assert_eq!(e.style.style_id.as_deref(), Some("S"));
+    e.unlink_text_style(0, 0);
+    assert!(e.style.style_id.is_none());
+}
@@ -562,7 +562,7 @@ impl TextData {
        }
    }

-    /// Drop empty/out-of-range runs and runs equal to the base style.
+    /// Drop empty/out-of-range runs and runs equal to the base style, and merge touching equal runs.
    pub fn normalize(&mut self) {
        let n = self.char_count();
        let base = self.style.clone();
@@ -571,6 +571,14 @@ impl TextData {
            r.end = r.end.min(n);
        }
        self.runs.sort_by_key(|r| r.start);
+        let mut merged: Vec<StyleRun> = Vec::with_capacity(self.runs.len());
+        for r in std::mem::take(&mut self.runs) {
+            match merged.last_mut() {
+                Some(prev) if prev.end == r.start && prev.style == r.style => prev.end = r.end,
+                _ => merged.push(r),
+            }
+        }
+        self.runs = merged;
    }

    /// Replace chars `start..end` with `text`, shifting runs (inserted text takes the style at `start`).
@@ -602,7 +610,9 @@ impl TextData {
                if p <= start {
                    p
                } else if p >= end {
-                    p - removed + inserted
+                    // Runs of a file that reach past the text (nothing clamps them on load)
+                    // would otherwise overflow here; `normalize` below drops what is left.
+                    p.saturating_sub(removed).saturating_add(inserted)
                } else {
                    start + inserted
                }
@@ -675,11 +685,13 @@ impl TextData {
    /// Link chars `start..end` (all of them when the range is empty or the whole text) to text
    /// style `id`, defined as `def`.
    pub fn link_text_style(&mut self, start: usize, end: usize, def: &TextStyle, id: &str) {
+        let (start, end) = if start == end { (0, self.char_count()) } else { (start, end) };
        self.restyle(start, end, |s| s.take_text_style(def, id));
    }

    /// Unlink chars `start..end` (all when empty or whole) from their text styles; values stay.
    pub fn unlink_text_style(&mut self, start: usize, end: usize) {
+        let (start, end) = if start == end { (0, self.char_count()) } else { (start, end) };
        self.restyle(start, end, |s| s.style_id = None);
    }

@@ -136,8 +136,8 @@ impl VectorNetwork {
        }
        let k = key(&face.loops);
        match (self.regions.iter().position(|r| key(&r.loops) == k), want) {
-            (Some(i), None | Some(false)) => {
-                self.regions.remove(i);
+            (Some(_), None | Some(false)) => {
+                self.regions.retain(|r| key(&r.loops) != k);
                Some(false)
            }
            (Some(_), Some(true)) => Some(true),
@@ -525,4 +525,21 @@ mod tests {
        let _ = j.paint(Point::new(f64::NAN, 5.0));
        assert!(interior_point(&BezPath::new()).is_none());
    }
+
+    #[test]
+    fn the_bucket_unfills_a_face_with_duplicate_regions_in_one_click() {
+        let c = Point::new(50.0, 50.0);
+        let mut n = square(0.0, 0.0, 100.0);
+        n.regions.push(n.regions[0].clone());
+        assert_eq!(n.paint(c), Some(false));
+        assert!(!n.fill_contains(c));
+        assert_eq!(n.region_at(c), None);
+        assert_eq!(n.paint(c), Some(true));
+        assert!(n.fill_contains(c));
+
+        let mut e = square(0.0, 0.0, 100.0);
+        e.regions.push(e.regions[0].clone());
+        assert_eq!(e.paint_to(c, Some(false)), Some(false));
+        assert!(!e.fill_contains(c));
+    }
 }
@@ -18,8 +18,9 @@ impl VectorNetwork {
    /// second; a segment that doesn't touch the point reached so far (a malformed loop) is taken
    /// as stored. Missing segments are skipped.
    pub fn loop_walk(&self, lp: &[usize]) -> Vec<(usize, bool)> {
-        let Some(first) = lp.first().and_then(|i| self.segments.get(*i)) else { return Vec::new() };
-        let forward_first = match lp.get(1).and_then(|i| self.segments.get(*i)) {
+        let mut existing = lp.iter().filter_map(|i| self.segments.get(*i));
+        let Some(first) = existing.next() else { return Vec::new() };
+        let forward_first = match existing.next() {
            Some(second) => first.b == second.a || first.b == second.b,
            None => true,
        };
@@ -102,10 +103,18 @@ impl VectorNetwork {
        (0..self.regions.len()).rev().find(|r| self.region_contains(*r, p))
    }

-    /// Every point on region `r`'s loops (holes' too), each once, sorted.
+    /// Every point on region `r`'s loops (holes' too), each once, sorted (segments or points that
+    /// don't exist are left out).
    pub fn region_points(&self, r: usize) -> Vec<usize> {
        let Some(region) = self.regions.get(r) else { return Vec::new() };
-        let mut out: Vec<usize> = region.loops.iter().flatten().filter_map(|i| self.segments.get(*i)).flat_map(|s| [s.a, s.b]).collect();
+        let mut out: Vec<usize> = region
+            .loops
+            .iter()
+            .flatten()
+            .filter_map(|i| self.segments.get(*i))
+            .flat_map(|s| [s.a, s.b])
+            .filter(|v| *v < self.vertices.len())
+            .collect();
        out.sort_unstable();
        out.dedup();
        out
@@ -148,6 +148,28 @@ fn a_loop_that_does_not_close_is_closed_implicitly() {
    assert_eq!(n.region_at(p(300.0, 100.0)), None);
 }

+#[test]
+fn missing_segments_are_skipped_wherever_they_sit_in_a_loop() {
+    use figcraft_geom::Shape;
+    let mut n = VectorNetwork::default();
+    square(&mut n, 0.0, 0.0, 200.0);
+    n.regions = vec![region(vec![vec![0, 1, 2]], WindingRule::NonZero)];
+    let control = n.region_path(0).unwrap();
+    let control_walk = n.loop_walk(&[0, 1, 2]);
+    for lp in [vec![99, 0, 1, 2], vec![0, 99, 1, 2], vec![99, 98, 0, 1, 2]] {
+        n.regions = vec![region(vec![lp.clone()], WindingRule::NonZero)];
+        assert_eq!(n.loop_walk(&lp), control_walk, "{lp:?}");
+        assert_eq!(n.region_at(p(100.0, 100.0)), Some(0), "{lp:?}");
+        assert!(n.region_contains(0, p(100.0, 100.0)), "{lp:?}");
+        let path = n.region_path(0).unwrap();
+        assert_eq!(path.elements().len(), control.elements().len(), "{lp:?}");
+        assert!((path.area().abs() - control.area().abs()).abs() < 1e-6, "{lp:?}");
+    }
+    n.regions = vec![region(vec![vec![99]], WindingRule::NonZero)];
+    assert!(n.region_path(0).is_none());
+    assert!(!n.region_contains(0, p(100.0, 100.0)));
+}
+
 #[test]
 fn a_regions_points_are_listed_once() {
    let mut n = nested();
@@ -186,6 +208,19 @@ fn empty_and_damaged_networks_have_no_regions_and_never_panic() {
    }
 }

+#[test]
+fn region_points_leave_out_segment_ends_that_do_not_exist() {
+    let mut n = VectorNetwork::default();
+    let ring = square(&mut n, 0.0, 0.0, 100.0);
+    n.regions = vec![region(vec![ring], WindingRule::NonZero)];
+    assert_eq!(n.region_points(0), vec![0, 1, 2, 3]);
+    n.segments[3] = Segment::line(3, 9);
+    assert_eq!(n.region_points(0), vec![0, 1, 2, 3]);
+    assert!(n.region_path(0).is_some());
+    n.regions = vec![region(vec![vec![99]], WindingRule::NonZero)];
+    assert!(n.region_points(0).is_empty());
+}
+
 #[test]
 fn the_topology_key_ignores_moved_points_but_not_new_segments() {
    let mut n = nested();
@@ -74,6 +74,27 @@ fn along_the_flow_skips_hidden_and_absolute_siblings() {
    assert_eq!(kids(&s, col), vec![c1, c0], "Right does nothing in a lone column");
 }

+#[test]
+fn single_item_wrapped_lines_move_and_drop_by_line() {
+    let mut s = Session::new();
+    // Full-width items: one per row.
+    let row = al(&mut s, None, "horizontal", 160.0, 200.0);
+    set(&mut s, row, json!({"wrap": true}));
+    let k: Vec<NodeId> = (0..2).map(|_| rect(&mut s, row, 160.0, 20.0)).collect();
+    assert_eq!(s.doc().unwrap().world_bounds(k[1]).unwrap().y0, 30.0, "second row");
+    let slot = crate::drop::auto_layout_slot(s.doc().unwrap(), row, figcraft_geom::Point::new(10.0, 35.0), &[]);
+    assert_eq!(slot, Some((1, Some([-2.0, 30.0, -2.0, 50.0]))));
+    arrow(&mut s, &[k[1]], 0, -1);
+    assert_eq!(kids(&s, row), vec![k[1], k[0]]);
+
+    // Full-height items in a vertical wrap: one per column.
+    let col = al(&mut s, None, "vertical", 200.0, 160.0);
+    set(&mut s, col, json!({"wrap": true}));
+    let c: Vec<NodeId> = (0..3).map(|_| rect(&mut s, col, 20.0, 160.0)).collect();
+    arrow(&mut s, &[c[2]], -1, 0);
+    assert_eq!(kids(&s, col), vec![c[0], c[2], c[1]]);
+}
+
 #[test]
 fn wrapped_rows_move_up_and_down_a_row() {
    let mut s = Session::new();
@@ -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()
@@ -216,7 +216,7 @@ pub fn create(s: &mut Session, p: &Value) -> Result<Value> {
        }
    }
    if let NodeKind::Text(td) = &mut kind {
-        td.characters = string(p, "text").or_else(|| string(p, "characters")).unwrap_or_default();
+        td.characters = super::props::normalize_line_endings(&string(p, "text").or_else(|| string(p, "characters")).unwrap_or_default());
        if w > 0.0 {
            td.auto_resize = TextAutoResize::Height;
        }
@@ -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 {
@@ -944,21 +988,37 @@ 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() {
        return Err(bad("edit.findReplace", "`find` is empty"));
    }
-    let replace = string(p, "replace");
+    // Line breaks stored as the editor stores them (CRLF, CR, U+2028 and U+2029 become LF).
+    let replace = string(p, "replace").map(|r| super::props::normalize_line_endings(&r));
    let names = boolean(p, "layerNames").unwrap_or(false);
    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 +1026,27 @@ 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();
                }
            }
        }
@@ -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")]
@@ -696,10 +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> {
@@ -724,9 +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()}))
 }
@@ -765,12 +824,21 @@ pub fn export_bytes(doc: &Document, ids: &[NodeId], format: ExportFormat, scale:
 }

 /// The page area exporting `ids` with `setting` covers: what they paint (a clipping frame's own
-/// area), or their boxes with "include bounding box" and for slices.
+/// area), or their boxes with "include bounding box" and for slices. Hidden layers paint nothing,
+/// so they take no room next to visible ones (a hidden-only export keeps its own area).
 pub fn export_area(doc: &Document, ids: &[NodeId], setting: &ExportSetting) -> Option<figcraft_geom::Rect> {
+    let any_visible = ids.iter().any(|i| doc.node(*i).is_some_and(|n| n.visible));
    ids.iter()
        .filter_map(|i| {
-            let slice = doc.node(*i).is_some_and(|n| matches!(n.kind, NodeKind::Slice));
-            if setting.include_bounding_box || slice { doc.world_bounds(*i) } else { figcraft_render::export_bounds(doc, *i) }
+            let node = doc.node(*i);
+            let slice = node.is_some_and(|n| matches!(n.kind, NodeKind::Slice));
+            if setting.include_bounding_box || slice {
+                doc.world_bounds(*i)
+            } else if any_visible && node.is_some_and(|n| !n.visible) {
+                None
+            } else {
+                figcraft_render::export_bounds(doc, *i)
+            }
        })
        .reduce(|a, b| a.union(b))
 }
@@ -1327,3 +1395,126 @@ 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);
+    }
+}
@@ -1,5 +1,6 @@
 //! Pages.

+use figcraft_doc::proto::Flow;
 use figcraft_doc::*;
 use serde_json::{Value, json};

@@ -23,10 +24,24 @@ fn settle(s: &mut Session, cmd: &str) -> crate::Result<()> {
    Ok(())
 }

+/// The page a command targets: the explicit `id` (which must be a page) or the open page.
+fn page_target(s: &Session, cmd: &str, p: &Value) -> crate::Result<NodeId> {
+    let Some(target) = id(p, "id") else { return s.page() };
+    if !s.doc()?.pages.contains(&target) {
+        return Err(bad(cmd, format!("{target} is not a page")));
+    }
+    Ok(target)
+}
+
 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 +62,7 @@ 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"))?
                }
            };
@@ -66,13 +81,13 @@ pub fn specs() -> Vec<CommandSpec> {
        }),
        spec!("page.rename", "Rename page", "{id?, name} (an empty page named with a leading hyphen becomes a divider)", true, |s, p| {
            let name = req_string("page.rename", p, "name")?;
-            let id = id(p, "id").unwrap_or(s.page()?);
+            let id = page_target(s, "page.rename", p)?;
            s.doc_mut()?.get_mut(id)?.name = name;
            settle(s, "page.rename")?;
            ok()
        }),
        spec!("page.delete", "Delete page", "{id?}", true, |s, p| {
-            let id = id(p, "id").unwrap_or(s.page()?);
+            let id = page_target(s, "page.delete", p)?;
            s.doc_mut()?.remove(id)?;
            settle(s, "page.delete")?;
            ok()
@@ -82,13 +97,25 @@ pub fn specs() -> Vec<CommandSpec> {
            let doc = s.doc_mut()?;
            let name = format!("Copy of {}", doc.get(src)?.name);
            let np = doc.add_page(&name);
-            if let NodeKind::Page { background, .. } = doc.get(src)?.kind.clone()
-                && let NodeKind::Page { background: b, .. } = &mut doc.get_mut(np)?.kind
+            // One copy with one id map, so navigation between the copied frames points at the copies;
+            // then each layer and its copy (also those in sections), so flows can follow their start frames.
+            let children = doc.get(src)?.children.clone();
+            let copied = doc.duplicate_all_into(&children, np)?;
+            let mut copies = Vec::new();
+            for (c, copy) in children.iter().zip(&copied) {
+                copies.extend(doc.subtree(*c).into_iter().zip(doc.subtree(*copy)));
+            }
+            // The copy keeps the page's colour, flows (pointing at the copied frames), prototype settings and guides.
+            if let NodeKind::Page { background, flows, prototype, guides } = doc.get(src)?.kind.clone()
+                && let NodeKind::Page { background: b, flows: f, prototype: pr, guides: g } = &mut doc.get_mut(np)?.kind
            {
                *b = background;
-            }
-            for c in doc.get(src)?.children.clone() {
-                doc.duplicate_into(c, np, None)?;
+                *f = flows
+                    .into_iter()
+                    .filter_map(|fl| copies.iter().find(|(old, _)| *old == fl.start).map(|(_, new)| Flow { start: *new, ..fl }))
+                    .collect();
+                *pr = prototype;
+                *g = guides;
            }
            // Keep the new page right after the source.
            if let Some(si) = doc.pages.iter().position(|x| *x == src) {
@@ -102,6 +129,9 @@ 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);
@@ -109,7 +139,7 @@ pub fn specs() -> Vec<CommandSpec> {
        }),
        spec!("page.setBackground", "Page background", "{id?, color}", true, |s, p| {
            let c = color(p, "color").ok_or_else(|| bad("page.setBackground", "`color` required"))?;
-            let id = id(p, "id").unwrap_or(s.page()?);
+            let id = page_target(s, "page.setBackground", p)?;
            if let NodeKind::Page { background, .. } = &mut s.doc_mut()?.get_mut(id)?.kind {
                *background = c;
            }
@@ -155,8 +185,11 @@ pub fn specs() -> Vec<CommandSpec> {
            }
            guides.remove(k);
            let ds = s.ds_mut()?;
-            if ds.guide == Some((owner, k)) {
-                ds.guide = None;
+            match ds.guide {
+                Some((o, i)) if o == owner && i == k => ds.guide = None,
+                // A later guide of the same owner moves up one place; keep the selection on it.
+                Some((o, i)) if o == owner && i > k => ds.guide = Some((o, i - 1)),
+                _ => {}
            }
            ok()
        }),
@@ -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), \
@@ -30,6 +30,11 @@ fontVariations / variationSettings ({axis: number}, e.g. {\"wght\": 550, \"wdth\
 arcInner, booleanOperation (a boolean group's operation, or an operand's own; null: the group's), operandOperation (a layer in a boolean \
 group: how it combines with the operands below it; null: the group's), constrainProportions, description, interactions, overflow, pluginData {k: v}";

+/// CRLF, bare CR, U+2028 and U+2029 become LF, the only line ending text layout understands (editor insertion does the same).
+pub(crate) fn normalize_line_endings(s: &str) -> String {
+    s.replace("\r\n", "\n").replace(['\r', '\u{2028}', '\u{2029}'], "\n")
+}
+
 /// camelCase object keys → snake_case (accept the inspect/camel forms for serde-backed values).
 pub fn snake(v: &Value) -> Value {
    match v {
@@ -599,7 +604,7 @@ pub fn apply(cmd: &str, doc: &mut Document, id: NodeId, props: &Map<String, Valu
                let n = doc.get_mut(id)?;
                let t = text_mut(cmd, n)?;
                let len = t.char_count();
-                t.replace_range(0, len, &s);
+                t.replace_range(0, len, &normalize_line_endings(&s));
                n.overrides.insert("characters".into());
            }
            "fontFamily"
@@ -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);
@@ -112,6 +112,9 @@ pub fn specs() -> Vec<CommandSpec> {
        spec!("variable.createCollection", "Create variable collection", "{name, modes? [names]}", true, |s, p| {
            let name = req_string("variable.createCollection", p, "name")?;
            let doc = s.doc_mut()?;
+            if doc.variables.collections.iter().any(|c| c.name == name) {
+                return Err(bad("variable.createCollection", format!("a collection named `{name}` already exists")));
+            }
            let id = doc.new_collection_id();
            let modes: Vec<String> = match get(p, "modes") {
                Some(Value::Array(a)) => a.iter().filter_map(|m| m.as_str().map(str::to_string)).collect(),
@@ -87,7 +87,7 @@ fn update(s: &mut Session, p: &Value) -> Result<Value> {
        }
        None => None,
    };
-    let scopes = match get(p, "scopes") {
+    let scopes = match p.get("scopes") {
        None => None,
        Some(Value::Null) => Some(None),
        Some(Value::Array(a)) => {
@@ -138,8 +138,16 @@ fn page_step(s: &mut Session, dir: i64) -> Result<Value> {
    let pages = &ds.doc.pages;
    let i = pages.iter().position(|p| *p == ds.page).unwrap_or(0) as i64;
    let n = pages.len() as i64;
-    let next = (i + dir).clamp(0, n - 1) as usize;
-    let Some(pg) = pages.get(next).copied() else { return ok() };
+    // Dividers never open: step over them, and stay put when only dividers lie ahead.
+    let mut next = i + dir;
+    let pg = loop {
+        let page = usize::try_from(next).ok().and_then(|k| pages.get(k).copied());
+        match page {
+            Some(p) if !ds.doc.is_divider(p) => break p,
+            Some(_) if dir != 0 && next >= 0 && next < n => next += dir,
+            _ => break ds.page,
+        }
+    };
    let ds = s.ds_mut()?;
    ds.page = pg;
    ds.selection.clear();
@@ -334,6 +342,7 @@ 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 +378,24 @@ 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")),
@@ -113,8 +113,58 @@ pub(crate) fn num(v: f64) -> String {
 }

 /// `code` with every pixel length (`12px`) in rem of `root` pixels (`0.75rem`); names that end
-/// in "px" are left alone.
+/// in "px", markup lines (layer text), string literals and comments are left alone.
 pub fn px_to_rem(code: &str, root: f64) -> String {
+    let mut out = String::with_capacity(code.len());
+    let mut in_comment = false;
+    for line in code.split_inclusive('\n') {
+        if !in_comment && line.trim_start().starts_with('<') {
+            out.push_str(line);
+            continue;
+        }
+        // Lengths outside strings and comments convert; `plain` is where that stretch starts.
+        let mut plain = 0;
+        let mut chars = line.char_indices().peekable();
+        while let Some((i, c)) = chars.next() {
+            if in_comment {
+                if c == '*' && chars.peek().is_some_and(|(_, n)| *n == '/') {
+                    chars.next();
+                    out.push_str(line.get(plain..i + 2).unwrap_or(""));
+                    plain = i + 2;
+                    in_comment = false;
+                }
+            } else if c == '/' && chars.peek().is_some_and(|(_, n)| *n == '*') {
+                chars.next();
+                out.push_str(&lengths_to_rem(line.get(plain..i).unwrap_or(""), root));
+                plain = i;
+                in_comment = true;
+            } else if c == '"' {
+                out.push_str(&lengths_to_rem(line.get(plain..i).unwrap_or(""), root));
+                let mut end = line.len();
+                while let Some((j, s)) = chars.next() {
+                    if s == '\\' {
+                        chars.next();
+                    } else if s == '"' {
+                        end = j + 1;
+                        break;
+                    }
+                }
+                out.push_str(line.get(i..end).unwrap_or(""));
+                plain = end;
+            }
+        }
+        let rest = line.get(plain..).unwrap_or("");
+        if in_comment {
+            out.push_str(rest);
+        } else {
+            out.push_str(&lengths_to_rem(rest, root));
+        }
+    }
+    out
+}
+
+/// `code` with every pixel length in rem of `root` pixels; names that end in "px" are left alone.
+fn lengths_to_rem(code: &str, root: f64) -> String {
    let ident = |c: char| c.is_alphanumeric() || c == '_';
    let mut out = String::with_capacity(code.len());
    let mut rest = code;
@@ -615,10 +615,10 @@ pub fn definition(doc: &Document, c: &Component, lang: CodeLang) -> String {
    }
 }

-/// `data-*` attribute names for variant parameters.
-fn data_attr(p: &Param) -> String {
+/// `data-*` attribute names for variant parameters, unique among them (in order).
+fn data_attrs(variants: &[&Param]) -> Vec<String> {
    let mut used = Vec::new();
-    format!("data-{}", class_name(&p.prop, &mut used))
+    variants.iter().map(|p| format!("data-{}", class_name(&p.prop, &mut used))).collect()
 }

 /// `c`'s markup in React or Leptos (two levels in) and its stylesheet (variables as custom
@@ -628,6 +628,7 @@ fn web(doc: &Document, c: &Component, lang: CodeLang) -> (String, String, String
    let root_name = c.set.and_then(|s| doc.node(s)).or_else(|| doc.node(c.comp)).map(|n| n.name.clone()).unwrap_or_default();
    let root_class = class_name(&root_name, &mut Vec::new());
    let variants: Vec<&Param> = c.params.iter().filter(|p| matches!(p.kind, ParamKind::Variant(_))).collect();
+    let attr_names = data_attrs(&variants);
    let pass = |root: NodeId| {
        let vctx = Ctx { doc, root, comp: Some(c), base: 2 };
        let mut m = Markup::new(&vctx, lang);
@@ -639,9 +640,10 @@ fn web(doc: &Document, c: &Component, lang: CodeLang) -> (String, String, String
    m.root_class = Some(root_class.clone());
    m.root_attrs = variants
        .iter()
-        .map(|p| match lang {
-            CodeLang::Leptos => format!(" {}={{{}.as_str()}}", data_attr(p), rust_ident(&p.ident)),
-            _ => format!(" {}={{{}}}", data_attr(p), p.ident),
+        .zip(&attr_names)
+        .map(|(p, attr)| match lang {
+            CodeLang::Leptos => format!(" {attr}={{{}.as_str()}}", rust_ident(&p.ident)),
+            _ => format!(" {attr}={{{}}}", p.ident),
        })
        .collect();
    m.node(c.comp, None, 2, "");
@@ -653,7 +655,8 @@ fn web(doc: &Document, c: &Component, lang: CodeLang) -> (String, String, String
        let pairs = variant_props(&vn.name);
        let attrs: String = variants
            .iter()
-            .filter_map(|p| pairs.get(&p.prop).map(|val| format!("[{}=\"{}\"]", data_attr(p), val.replace(['"', '\\'], ""))))
+            .zip(&attr_names)
+            .filter_map(|(p, attr)| pairs.get(&p.prop).map(|val| format!("[{attr}=\"{}\"]", val.replace(['"', '\\'], ""))))
            .collect();
        for (path, _, decls) in pass(v) {
            let Some((_, class, base)) = m.rules.iter().find(|(p, _, _)| *p == path) else { continue };
@@ -314,3 +314,32 @@ fn bound_variables_become_custom_properties() {
    let react = code(&mut s, c, "react");
    assert!(react.contains(":root {\n  --colors-brand-500: #3366FF;\n}"), "{react}");
 }
+
+#[test]
+fn case_colliding_variant_properties_get_distinct_data_attributes() {
+    let mut s = Session::new();
+    let mut variants = Vec::new();
+    for (k, (first, second, fill)) in [("Small", "Big", "#0000FF"), ("Large", "Small", "#FF0000")].iter().enumerate() {
+        let name = format!("Size={first}, size={second}");
+        let f = idv(&ex(
+            &mut s,
+            "frame.create",
+            json!({"x": k as f64 * 150.0, "y": 0, "width": 100, "height": 40, "name": name, "props": {"fill": fill}}),
+        ));
+        variants.push(idv(&ex(&mut s, "component.create", json!({"ids": [f]}))));
+    }
+    let set = idv(&ex(&mut s, "component.combineVariants", json!({"ids": variants})));
+    ex(&mut s, "node.set", json!({"id": set, "props": {"name": "Chip"}}));
+    for lang in ["react", "leptos"] {
+        let v = component_code(&mut s, set, lang);
+        let def = v["definition"].as_str().unwrap_or_default();
+        let root = def.lines().find(|l| l.trim_start().starts_with("<div ")).unwrap_or_default();
+        let attrs: Vec<&str> =
+            root.split_whitespace().filter_map(|w| w.strip_prefix("data-")).map(|w| w.split('=').next().unwrap_or_default()).collect();
+        assert_eq!(attrs.len(), 2, "{lang}: {root}");
+        assert_ne!(attrs[0], attrs[1], "{lang}: distinct attributes in {root}");
+        let sel = format!(".chip[data-{}=\"Large\"][data-{}=\"Small\"]", attrs[0], attrs[1]);
+        assert!(def.contains(&sel), "{lang}: {sel} in:\n{def}");
+        assert!(def.contains("#FF0000"), "{lang}:\n{def}");
+    }
+}
@@ -472,11 +472,11 @@ fn apply_prop(doc: &Document, n: &mut Node, field: &str, val: &Value) {
            }
        }
        "characters" => {
-            if let (NodeKind::Text(t), Some(sv)) = (&mut n.kind, val.as_str())
+            if let (NodeKind::Text(t), Some(sv)) = (&mut n.kind, val.as_str().map(crate::cmd::props::normalize_line_endings))
                && t.characters != sv
            {
                let len = t.char_count();
-                t.replace_range(0, len, sv);
+                t.replace_range(0, len, &sv);
            }
        }
        "mainComponent" => {
@@ -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}})));
@@ -216,6 +219,24 @@ fn an_edit_an_instance_refuses_shows_not_allowed_and_is_undone() {
    assert_eq!(s.doc().unwrap().world_bounds(inner).unwrap(), before, "the move was undone");
 }

+#[test]
+fn a_pen_click_that_wobbles_a_pixel_is_still_a_click() {
+    let mut s = Session::new();
+    s.set_tool(ToolId::Pen);
+    // A real click: the mouse moves a pixel or two between press and release.
+    s.pointer(&ev(PointerKind::Down, (100.0, 100.0), NONE)).unwrap();
+    s.pointer(&ev(PointerKind::Move, (102.0, 101.0), NONE)).unwrap();
+    s.pointer(&ev(PointerKind::Up, (102.0, 101.0), NONE)).unwrap();
+    let out = s.tool.pen.as_ref().and_then(|p| p.points.first()).map(|(_, _, o)| *o);
+    assert_eq!(out.map(|o| o.hypot()), Some(0.0), "no handle pulled out");
+    assert!(s.tool.overlay.pen_handles.is_empty());
+    // Past the slop it is a drag: the handle follows the pointer from where it was pressed.
+    s.pointer(&ev(PointerKind::Down, (200.0, 100.0), NONE)).unwrap();
+    s.pointer(&ev(PointerKind::Move, (204.0, 100.0), NONE)).unwrap();
+    let out = s.tool.pen.as_ref().and_then(|p| p.points.last()).map(|(_, _, o)| (o.x, o.y));
+    assert_eq!(out, Some((4.0, 0.0)));
+}
+
 #[test]
 fn the_pen_shows_what_a_click_would_do() {
    // The Pen tool drawing a new path: three points, then over each of them.
@@ -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());
 }
@@ -93,3 +93,29 @@ fn only_the_focused_frame_is_hit_and_escape_leaves() {
    click(&mut s, 350.0, 100.0);
    assert_eq!(s.selection(), vec![b], "everything is hit again");
 }
+
+#[test]
+fn nested_frames_stay_out_of_the_ready_list_and_its_navigation() {
+    let mut s = Session::new();
+    let screen = frame(&mut s, 0.0, "Screen");
+    let card = idv(&ex(&mut s, "frame.create", json!({"parent": screen, "width": 100, "height": 50, "name": "Card"})));
+    // A status a nested frame already stores (an older file, or set through node.set) is ignored.
+    ex(&mut s, "node.set", json!({"id": card, "props": {"devStatus": "readyForDev"}}));
+    assert_eq!(ex(&mut s, "inspect.readyForDev", json!({"status": "any"}))["items"], json!([]));
+    assert!(s.execute("dev.focus", &json!({"direction": "next"})).is_err(), "nothing is ready");
+    ex(&mut s, "node.set", json!({"id": screen, "props": {"devStatus": "readyForDev"}}));
+    let ids = |v: serde_json::Value| -> Vec<serde_json::Value> {
+        v["items"].as_array().map(|a| a.iter().map(|i| i["id"].clone()).collect()).unwrap_or_default()
+    };
+    assert_eq!(ids(ex(&mut s, "inspect.readyForDev", json!({}))), vec![json!(screen)]);
+    ex(&mut s, "dev.focus", json!({"id": screen}));
+    for direction in ["next", "previous"] {
+        let v = ex(&mut s, "dev.focus", json!({"direction": direction}));
+        assert_eq!((v["id"].clone(), v["count"].clone()), (json!(screen), json!(1)), "{direction} wraps to the only ready frame");
+    }
+    // A frame directly inside a section still counts.
+    let sec = idv(&ex(&mut s, "node.create", json!({"type": "section", "x": 1000, "y": 0, "width": 400, "height": 300})));
+    let in_sec = idv(&ex(&mut s, "frame.create", json!({"parent": sec, "width": 100, "height": 100, "name": "In section"})));
+    ex(&mut s, "node.set", json!({"ids": [sec, in_sec], "props": {"devStatus": "readyForDev"}}));
+    assert_eq!(ids(ex(&mut s, "inspect.readyForDev", json!({}))), vec![json!(screen), json!(sec), json!(in_sec)]);
+}
@@ -231,7 +231,7 @@ pub fn has_status(doc: &Document, id: NodeId) -> bool {
 }

 /// The layers with handoff status `status` (`None`: any status) on `page` (`None`: every page),
-/// in page and layer order (bounded).
+/// in page and layer order (bounded). Only layers that can carry a status are listed.
 pub fn dev_items(doc: &Document, status: Option<DevStatus>, page: Option<NodeId>) -> Vec<DevItem> {
    let mut out = Vec::new();
    let mut visited = 0usize;
@@ -243,7 +243,7 @@ pub fn dev_items(doc: &Document, status: Option<DevStatus>, page: Option<NodeId>
                return out;
            }
            let Some(n) = doc.node(id) else { continue };
-            if !n.dev_status.is_none() && status.is_none_or(|s| s == n.dev_status) {
+            if !n.dev_status.is_none() && status.is_none_or(|s| s == n.dev_status) && has_status(doc, id) {
                out.push(DevItem { id, name: n.name.clone(), page: pg, status: n.dev_status });
            }
            stack.extend(n.children.iter().rev().copied());
@@ -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)] {
@@ -61,12 +61,15 @@ pub fn flip(r: figcraft_geom::Rect, vertical: bool) -> figcraft_geom::Rect {

 /// The visual rows (columns when `vertical`) of a wrapping layout's placed children `kids`, each
 /// child as (its index in `kids`, its page bounds [`flip`]ped so the flow runs along x). Children
-/// wrap in flow order, so a new row starts where a child sits before the one before.
+/// wrap in flow order, so a new row starts where a child sits before the one before, or where it
+/// does not follow the one before along the flow but sits past it across (one child per line).
 pub fn wrap_rows(doc: &Document, kids: &[NodeId], vertical: bool) -> Vec<Vec<(usize, figcraft_geom::Rect)>> {
    let mut rows: Vec<Vec<(usize, figcraft_geom::Rect)>> = Vec::new();
    for (i, b) in kids.iter().enumerate().filter_map(|(i, c)| doc.world_bounds(*c).map(|b| (i, flip(b, vertical)))) {
        match rows.last_mut() {
-            Some(row) if row.last().is_some_and(|(_, prev)| b.x0 >= prev.x0 - 0.5) => row.push((i, b)),
+            Some(row) if row.last().is_some_and(|(_, prev)| b.x0 >= prev.x0 - 0.5 && !(b.x0 < prev.x1 - 0.5 && b.y0 >= prev.y1 - 0.5)) => {
+                row.push((i, b))
+            }
            _ => rows.push(vec![(i, b)]),
        }
    }
@@ -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());
+}
@@ -77,3 +77,43 @@ fn leptos_wraps_the_markup_in_a_component_with_text_as_string_literals() {
    let out = s.execute("inspect.code", &json!({"id": card, "language": "leptos", "unit": "rem"})).unwrap();
    assert!(out["code"].as_str().unwrap().contains("width: 12.5rem;"), "{}", out["code"]);
 }
+
+fn web_code(s: &mut Session, id: figcraft_doc::NodeId, language: &str, unit: &str) -> String {
+    let out = s.execute("inspect.code", &json!({"id": id, "language": language, "unit": unit})).unwrap();
+    out["code"].as_str().unwrap().to_string()
+}
+
+#[test]
+fn rem_preserves_text_in_web_markup() {
+    let mut s = Session::new();
+    let frame = id(s.execute("frame.create", &json!({"width": 200, "height": 100, "name": "Card"})).unwrap());
+    s.execute("text.create", &json!({"text": "Tile 24px", "parent": frame, "name": "Label"})).unwrap();
+    let mut changed = Vec::new();
+    for language in ["html", "react", "leptos"] {
+        let px = web_code(&mut s, frame, language, "px");
+        let rem = web_code(&mut s, frame, language, "rem");
+        assert!(px.contains("Tile 24px"), "{language}: px control: {px}");
+        assert!(rem.contains("width: 12.5rem;"), "{language}: width: {rem}");
+        assert!(rem.contains("font-size: 0.75rem;"), "{language}: font: {rem}");
+        if !rem.contains("Tile 24px") {
+            changed.push(language);
+        }
+    }
+    assert!(changed.is_empty(), "text rewritten in {changed:?}");
+}
+
+#[test]
+fn rem_preserves_text_property_default() {
+    let mut s = Session::new();
+    let frame = id(s.execute("frame.create", &json!({"width": 100, "height": 40, "name": "Chip"})).unwrap());
+    let label = id(s.execute("text.create", &json!({"text": "24px", "parent": frame, "name": "Label"})).unwrap());
+    let component = id(s.execute("component.create", &json!({"ids": [frame]})).unwrap());
+    s.execute("component.addProperty", &json!({"id": component, "name": "Label", "type": "text", "default": "24px", "layer": label})).unwrap();
+    for unit in ["px", "rem"] {
+        let code = web_code(&mut s, component, "react", unit);
+        assert!(code.contains("label = \"24px\""), "{unit}: changed default: {code}");
+        if unit == "rem" {
+            assert!(code.contains("width: 6.25rem;"), "rem still converts lengths: {code}");
+        }
+    }
+}
@@ -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>,
@@ -611,11 +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(),
@@ -663,8 +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.
@@ -721,7 +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 }
    }
@@ -837,10 +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;
@@ -1071,9 +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
@@ -1082,6 +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();

@@ -1099,8 +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;
@@ -1167,8 +1236,8 @@ pub fn changed_nodes(doc: &Document, before: &Document) -> Vec<NodeId> {
 pub fn normalize(doc: &mut Document, before: &Document) {
    // Only what was touched since the last normalisation (edited, added or removed).
    let mut touched: BTreeSet<NodeId> = doc.take_dirty();
-    // A variable edit changes no layer directly, but bound layers must follow it.
-    if touched.is_empty() && doc.variables == before.variables {
+    // A variable or style edit changes no layer directly, but bound and linked layers must follow it.
+    if touched.is_empty() && doc.variables == before.variables && doc.styles == before.styles {
        return;
    }
    let m = measure::TextMeasure;
@@ -1393,6 +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;
@@ -1441,6 +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;
@@ -1467,6 +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;
@@ -1477,12 +1552,18 @@ 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;
 #[cfg(test)]
+mod library_range_styles_tests;
+#[cfg(test)]
 mod library_variables_tests;
 #[cfg(test)]
+mod line_endings_tests;
+#[cfg(test)]
 mod live_access_tests;
 #[cfg(test)]
 mod live_docs_tests;
@@ -1509,6 +1590,10 @@ mod open_issues_tests;
 #[cfg(test)]
 mod outline_options_tests;
 #[cfg(test)]
+mod page_copy_navigation_tests;
+#[cfg(test)]
+mod page_target_tests;
+#[cfg(test)]
 mod paint_reorder_tests;
 #[cfg(test)]
 mod paint_tests;
@@ -1517,6 +1602,8 @@ 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;
@@ -134,9 +134,12 @@ pub fn closure(doc: &Document, roots: &[NodeId]) -> Vec<NodeId> {
    out
 }

-/// The style ids a layer links to (fill, stroke, effect, grid, text).
+/// The style ids a layer links to (fill, stroke, effect, grid, text, and text styles on
+/// character ranges).
 pub(crate) fn style_links(n: &Node) -> impl Iterator<Item = &String> {
-    [&n.styles.fill, &n.styles.stroke, &n.styles.effect, &n.styles.grid, &n.styles.text].into_iter().flatten()
+    let chars =
+        n.kind.text().into_iter().flat_map(|t| std::iter::once(&t.style).chain(t.runs.iter().map(|r| &r.style))).filter_map(|s| s.style_id.as_ref());
+    [&n.styles.fill, &n.styles.stroke, &n.styles.effect, &n.styles.grid, &n.styles.text].into_iter().flatten().chain(chars)
 }

 /// Style ids the layers under `roots` link to.
@@ -582,11 +585,15 @@ fn local_key(lid: &str, key: &str, taken: impl Fn(&str) -> bool) -> String {
 }

 /// Copy library styles `keys` into `doc` as linked remote styles (with `update`, copies older than
-/// the library's are refreshed). Returns library style id → local id.
+/// the library's are refreshed). The variables a written copy binds are imported too and its
+/// bindings point at their copies (never at this file's variables of the same ids). Returns library
+/// style id → local id.
 pub fn import_styles(doc: &mut Document, lib: &PublishedLibrary, keys: &BTreeSet<String>, update: bool) -> BTreeMap<String, String> {
    let lid = lib.manifest.id.clone();
    let mut out = BTreeMap::new();
    let mut hashes = BTreeSet::new();
+    // Local ids of the copies written now, with the library style they copy.
+    let mut written: Vec<(String, &Style)> = Vec::new();
    for key in keys {
        let Some(style) = lib.doc.styles.iter().find(|s| s.id == *key) else { continue };
        let version = lib.manifest.style(key).map_or(lib.manifest.version, |s| s.version);
@@ -598,6 +605,7 @@ pub fn import_styles(doc: &mut Document, lib: &PublishedLibrary, keys: &BTreeSet
                {
                    *slot = Style { id: r.local.clone(), ..style.clone() };
                    set_record(&mut doc.libraries_mut().styles, ImportedStyle { version, ..r.clone() });
+                    written.push((r.local.clone(), style));
                }
                r.local
            }
@@ -605,6 +613,7 @@ pub fn import_styles(doc: &mut Document, lib: &PublishedLibrary, keys: &BTreeSet
                let local = local_key(&lid, key, |l| doc.styles.iter().any(|s| s.id == l));
                doc.styles.push(Style { id: local.clone(), ..style.clone() });
                set_record(&mut doc.libraries_mut().styles, ImportedStyle { library: lid.clone(), key: key.clone(), local: local.clone(), version });
+                written.push((local.clone(), style));
                local
            }
        };
@@ -613,6 +622,17 @@ pub fn import_styles(doc: &mut Document, lib: &PublishedLibrary, keys: &BTreeSet
        }
        out.insert(key.clone(), local);
    }
+    let bound: BTreeSet<VariableId> = written.iter().flat_map(|(_, s)| s.bound.values().cloned()).collect();
+    if !bound.is_empty() {
+        let vars = import_variables(doc, lib, &bound, &BTreeSet::new(), update);
+        for (local, _) in &written {
+            if let Some(slot) = doc.styles.iter_mut().find(|s| s.id == *local) {
+                // Bindings to variables the library lacks are dropped (the published value stays).
+                slot.bound =
+                    std::mem::take(&mut slot.bound).into_iter().filter_map(|(f, v)| vars.variables.get(&v).map(|l| (f, l.clone()))).collect();
+            }
+        }
+    }
    copy_images(doc, &lib.doc, &hashes);
    out
 }
@@ -0,0 +1,66 @@
+//! Text styles linked on character ranges travel with components (publish and place).
+
+use crate::Session;
+use figcraft_doc::NodeId;
+use serde_json::{Value, json};
+
+fn run(s: &mut Session, command: &str, params: Value) -> Value {
+    s.execute(command, &params).unwrap_or_else(|e| panic!("{command}: {e}"))
+}
+
+fn node(value: Value) -> NodeId {
+    NodeId(value["id"].as_u64().unwrap())
+}
+
+/// A component with "Hello" (chars 0..2 linked to a range style) and "World" (whole-layer style).
+fn fixture() -> (Session, NodeId, String, String) {
+    let mut s = Session::new();
+    let frame = node(run(&mut s, "frame.create", json!({"name":"Card", "width":100, "height":40})));
+    let text = node(run(&mut s, "text.create", json!({"parent":frame, "text":"Hello"})));
+    let range = run(&mut s, "style.create", json!({"type":"text", "name":"Emphasis", "value":{"fontSize":32}}))["id"].as_str().unwrap().to_owned();
+    run(&mut s, "style.apply", json!({"id":text, "style":range, "start":0, "end":2}));
+    let whole_text = node(run(&mut s, "text.create", json!({"parent":frame, "text":"World"})));
+    let whole = run(&mut s, "style.create", json!({"type":"text", "name":"Whole", "value":{"fontSize":24}}))["id"].as_str().unwrap().to_owned();
+    run(&mut s, "style.apply", json!({"id":whole_text, "style":whole}));
+    let component = node(run(&mut s, "component.create", json!({"ids":[frame]})));
+    let source = s.doc().unwrap().node(text).unwrap();
+    let chars = source.kind.text().unwrap();
+    assert!(source.styles.text.is_none());
+    assert_eq!(chars.style_at(0).style_id.as_deref(), Some(range.as_str()));
+    assert_eq!(chars.style_at(2).style_id, None);
+    (s, component, range, whole)
+}
+
+#[test]
+fn component_publish_keeps_range_text_style() {
+    let (mut s, component, range, whole) = fixture();
+    run(&mut s, "library.publish", json!({"include":[component]}));
+    let snapshot = &s.doc().unwrap().published.as_ref().unwrap().doc;
+    assert!(snapshot.style(&whole).is_some());
+    assert!(snapshot.style(&range).is_some(), "character-range style missing from snapshot");
+}
+
+#[test]
+fn component_place_imports_range_text_style() {
+    let (mut source, component, range, whole) = fixture();
+    let publication = run(&mut source, "library.publish", json!({}));
+    let library = source.doc().unwrap().published.as_ref().unwrap().clone();
+    assert!(library.doc.style(&range).is_some());
+    let mut target = Session::new();
+    let path = "figcraft://library.test/range-styles";
+    target.libraries.insert(path, Ok(library));
+    run(&mut target, "library.add", json!({"path":path}));
+    let instance = node(run(&mut target, "library.place", json!({"library":publication["id"], "component":component})));
+    let doc = target.doc().unwrap();
+    let children = &doc.node(instance).unwrap().children;
+    let ranged = doc.node(children[0]).unwrap().kind.text().unwrap();
+    let full = doc.node(children[1]).unwrap().kind.text().unwrap();
+    let whole_record = doc.libraries.styles.iter().find(|r| r.key == whole).unwrap();
+    assert_eq!(full.style_at(0).style_id.as_deref(), Some(whole_record.local.as_str()));
+    assert_eq!(ranged.style_at(0).font_size, 32.0);
+    assert!(ranged.style_at(2).style_id.is_none());
+    let record = doc.libraries.styles.iter().find(|r| r.key == range);
+    assert!(record.is_some(), "character-range style missing after placement");
+    assert_eq!(ranged.style_at(0).style_id.as_deref(), record.map(|r| r.local.as_str()));
+    assert!(doc.style(ranged.style_at(0).style_id.as_deref().unwrap()).is_some());
+}
@@ -314,3 +314,33 @@ fn library_variable_commands_fail_cleanly() {
    }
    assert!(s.doc().unwrap().libraries.is_empty());
 }
+
+#[test]
+fn library_style_bindings_ignore_unrelated_local_variables() {
+    let d = dir("style-bound");
+    let path = path_str(&d.join("lib.figcraft"));
+    let mut lib = Session::new();
+    ex(&mut lib, "variable.createCollection", json!({"name": "Tokens"}));
+    let var = ex(&mut lib, "variable.create", json!({"collection": "Tokens", "name": "Brand", "type": "color", "value": "#0000ff"}))["id"].clone();
+    let style = ex(&mut lib, "style.create", json!({"type": "paint", "name": "Brand", "value": "#0000ff"}))["id"].clone();
+    ex(&mut lib, "style.bind", json!({"style": style, "field": "fill", "variable": var}));
+    let lid = publish_to(&mut lib, &path);
+
+    let mut s = Session::new();
+    ex(&mut s, "variable.createCollection", json!({"name": "Local"}));
+    let local = ex(&mut s, "variable.create", json!({"collection": "Local", "name": "Unrelated", "type": "color", "value": "#ff0000"}))["id"].clone();
+    assert_eq!(local, var, "the ids must collide for this test");
+    let r = idv(&ex(&mut s, "shape.rectangle", json!({"width": 40, "height": 40})));
+    ex(&mut s, "library.add", json!({"path": path}));
+    ex(&mut s, "library.applyStyle", json!({"library": lid, "style": "Brand", "id": r}));
+    assert_eq!(fill(&s, r), "0000FF");
+    healthy(&s);
+
+    // An updated style follows the library's variable, not the local one.
+    ex(&mut lib, "variable.set", json!({"variable": "Brand", "value": "#00ffff"}));
+    republish(&mut lib);
+    ex(&mut s, "library.acceptUpdates", json!({}));
+    assert_eq!(fill(&s, r), "00FFFF");
+    healthy(&s);
+    let _ = std::fs::remove_dir_all(&d);
+}
@@ -0,0 +1,56 @@
+//! Text set by a command stores every line ending as LF, like editor insertion does, so layout
+//! sees two lines and no stray glyph for CRLF, bare CR, U+2028 or U+2029.
+
+use serde_json::json;
+
+use crate::Session;
+use crate::components::tests::{card, chars, copy_of, ex, idv};
+use crate::params::id_of;
+
+const INPUTS: [&str; 5] = ["a\nb", "a\r\nb", "a\rb", "a\u{2028}b", "a\u{2029}b"];
+
+#[test]
+fn text_set_normalizes_line_endings() {
+    let mut s = Session::new();
+    let created = s.execute("text.create", &json!({"text": "", "x": 0, "y": 0})).unwrap();
+    let id = id_of(&created["id"]).unwrap();
+    for input in INPUTS {
+        s.execute("text.set", &json!({"id": id, "characters": input})).unwrap();
+        let t = s.doc().unwrap().node(id).unwrap().kind.text().unwrap().clone();
+        assert_eq!(t.characters, "a\nb", "text.set {input:?}");
+    }
+}
+
+#[test]
+fn text_create_normalizes_line_endings() {
+    let mut s = Session::new();
+    for input in INPUTS {
+        let created = s.execute("text.create", &json!({"text": input, "x": 0, "y": 0})).unwrap();
+        let id = id_of(&created["id"]).unwrap();
+        let t = s.doc().unwrap().node(id).unwrap().kind.text().unwrap().clone();
+        assert_eq!(t.characters, "a\nb", "text.create {input:?}");
+    }
+}
+
+#[test]
+fn find_replace_normalizes_line_endings() {
+    for input in INPUTS {
+        let mut s = Session::new();
+        let id = idv(&ex(&mut s, "text.create", json!({"text": "x", "x": 0, "y": 0})));
+        ex(&mut s, "edit.findReplace", json!({"find": "x", "replace": input}));
+        assert_eq!(chars(&s, id), "a\nb", "edit.findReplace {input:?}");
+    }
+}
+
+#[test]
+fn text_property_values_normalize_line_endings() {
+    let mut s = Session::new();
+    let (c, _bg, title, _dot) = card(&mut s);
+    ex(&mut s, "component.addProperty", json!({"id": c, "name": "Title", "type": "text", "layer": title}));
+    let i = idv(&ex(&mut s, "instance.create", json!({"component": c, "x": 300, "y": 0})));
+    let copy = copy_of(&s, i, title);
+    for input in INPUTS {
+        ex(&mut s, "instance.setProperties", json!({"ids": [i], "properties": {"Title": input}}));
+        assert_eq!(chars(&s, copy), "a\nb", "instance.setProperties {input:?}");
+    }
+}
@@ -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();
@@ -0,0 +1,48 @@
+//! Duplicating a page copies its prototype connections: navigation between two frames that are both
+//! on the page leads between the copies, while a destination outside the copied contents is kept.
+
+use figcraft_doc::NodeId;
+use serde_json::{Value, json};
+
+use crate::Session;
+use crate::params::id_of;
+
+fn ex(s: &mut Session, cmd: &str, p: Value) -> Value {
+    s.execute(cmd, &p).unwrap_or_else(|e| panic!("{cmd}: {e}"))
+}
+
+fn frame(s: &mut Session, x: f64) -> NodeId {
+    id_of(&ex(s, "frame.create", json!({"x": x, "y": 0, "width": 100, "height": 100}))["id"]).unwrap()
+}
+
+fn dest(s: &Session, id: NodeId) -> NodeId {
+    s.doc().unwrap().node(id).unwrap().interactions[0].actions[0].dest().unwrap()
+}
+
+#[test]
+fn page_copy_navigation_uses_the_copied_destination() {
+    let mut s = Session::new();
+    let first = frame(&mut s, 0.0);
+    let second = frame(&mut s, 200.0);
+    ex(&mut s, "proto.interaction.add", json!({"id": first, "action": {"type": "navigate", "dest": second}}));
+    let copy = id_of(&ex(&mut s, "page.duplicate", json!({}))["id"]).unwrap();
+    let children = s.doc().unwrap().node(copy).unwrap().children.clone();
+    assert_eq!(children.len(), 2);
+    assert_eq!(dest(&s, children[0]), children[1]);
+    let visited = Default::default();
+    assert_eq!(crate::proto_run::navigate_target(s.doc().unwrap(), dest(&s, children[0]), &visited), Some(children[1]));
+    assert_eq!(dest(&s, first), second, "the original keeps its destination");
+}
+
+#[test]
+fn frame_copy_keeps_an_outside_destination() {
+    let mut s = Session::new();
+    let first = frame(&mut s, 0.0);
+    let second = frame(&mut s, 200.0);
+    ex(&mut s, "proto.interaction.add", json!({"id": first, "action": {"type": "navigate", "dest": second}}));
+    ex(&mut s, "select.set", json!({"ids": [first]}));
+    ex(&mut s, "edit.duplicate", json!({}));
+    let copy = s.selection()[0];
+    assert_ne!(copy, first);
+    assert_eq!(dest(&s, copy), second);
+}
@@ -0,0 +1,63 @@
+//! Page commands act on pages: a layer id (a rectangle, a frame) is refused before anything about
+//! the layer changes, as `page.select` already does.
+
+use figcraft_doc::{NodeId, NodeKind};
+use serde_json::{Value, json};
+
+use crate::Session;
+
+fn ex(s: &mut Session, cmd: &str, p: Value) -> Value {
+    s.execute(cmd, &p).unwrap_or_else(|e| panic!("{cmd}: {e}"))
+}
+
+fn id_of(v: &Value) -> NodeId {
+    NodeId(v["id"].as_u64().unwrap())
+}
+
+fn name(s: &Session, id: NodeId) -> String {
+    s.doc().unwrap().get(id).unwrap().name.clone()
+}
+
+#[test]
+fn page_commands_reject_a_rectangle() {
+    let mut s = Session::new();
+    let page = s.page().unwrap();
+    let r = id_of(&ex(&mut s, "shape.rectangle", json!({"x": 0, "y": 0, "width": 10, "height": 10})));
+    let before = name(&s, r);
+    assert!(s.execute("page.select", &json!({"id": r})).is_err());
+    assert!(s.execute("page.rename", &json!({"id": r, "name": "Not a page"})).is_err(), "rename refuses a layer");
+    assert_eq!(name(&s, r), before, "the layer keeps its name");
+    assert!(s.execute("page.setBackground", &json!({"id": r, "color": "#123456"})).is_err(), "background refuses a layer");
+    assert!(s.execute("page.delete", &json!({"id": r})).is_err(), "delete refuses a layer");
+    assert!(s.doc().unwrap().contains(r), "the layer is still there");
+    assert!(s.doc().unwrap().contains(page));
+}
+
+#[test]
+fn page_delete_keeps_a_frame_and_its_child() {
+    let mut s = Session::new();
+    let f = id_of(&ex(&mut s, "frame.create", json!({"x": 0, "y": 0, "width": 100, "height": 100})));
+    let c = id_of(&ex(&mut s, "shape.rectangle", json!({"x": 5, "y": 5, "width": 10, "height": 10, "parent": f})));
+    assert_eq!(s.doc().unwrap().get(c).unwrap().parent, Some(f));
+    assert!(s.execute("page.delete", &json!({"id": f})).is_err());
+    assert!(s.doc().unwrap().contains(f) && s.doc().unwrap().contains(c), "the frame and its child remain");
+    assert!(s.execute("page.rename", &json!({"id": f, "name": "Not a page"})).is_err());
+    assert_ne!(name(&s, f), "Not a page");
+}
+
+#[test]
+fn page_commands_still_work_on_pages() {
+    let mut s = Session::new();
+    let first = s.page().unwrap();
+    let second = id_of(&ex(&mut s, "page.add", json!({})));
+    ex(&mut s, "page.rename", json!({"id": second, "name": "Flows"}));
+    assert_eq!(name(&s, second), "Flows");
+    ex(&mut s, "page.setBackground", json!({"id": second, "color": "#123456"}));
+    match s.doc().unwrap().get(second).unwrap().kind {
+        NodeKind::Page { background, .. } => assert_eq!(background.to_css_hex().to_uppercase(), "#123456"),
+        _ => panic!("not a page"),
+    }
+    ex(&mut s, "page.delete", json!({"id": second}));
+    assert!(!s.doc().unwrap().contains(second));
+    assert!(s.execute("page.delete", &json!({"id": first})).is_err(), "the last ordinary page stays");
+}
@@ -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 +414,36 @@ 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");
+}
+
+#[test]
+fn page_navigation_skips_dividers() {
+    // A trailing divider: Next page stays on the ordinary page.
+    let mut s = Session::new();
+    let first = s.page().unwrap();
+    let div = id(&ex(&mut s, "page.add", json!({"name": "-"})));
+    assert!(s.execute("page.select", &json!({"id": div})).is_err(), "a divider isn't a page to open");
+    let r = ex(&mut s, "view.nextPage", json!({}));
+    assert_eq!(s.page().unwrap(), first, "Next page doesn't open a trailing divider");
+    assert_eq!(id_of(&r["page"]), Some(first), "the result names the current page");
+    // A middle divider: Previous page crosses it, Next page crosses it back.
+    let later = id(&ex(&mut s, "page.add", json!({"name": "Later"})));
+    assert_eq!(s.page().unwrap(), later);
+    let r = ex(&mut s, "view.prevPage", json!({}));
+    assert_eq!(s.page().unwrap(), first, "Previous page crosses a divider");
+    assert_eq!(id_of(&r["page"]), Some(first));
+    ex(&mut s, "view.nextPage", json!({}));
+    assert_eq!(s.page().unwrap(), later, "Next page crosses a divider");
+    ex(&mut s, "view.nextPage", json!({}));
+    assert_eq!(s.page().unwrap(), later, "Next page stops on the last page");
+}
@@ -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());
+}
@@ -322,7 +322,7 @@ fn apply(s: &mut Session, cmd: &str, p: &Value, merge: bool) -> Result<Value> {
    let whole_shape =
        touched.len() == 1 && a.regions.iter().enumerate().all(|(i, r)| pick.contains(&i) || !r.sources.iter().any(|x| touched.contains(x)));
    if merge && whole_shape {
-        return Ok(json!({"id": null, "changed": [], "removed": [], "regions": pick}));
+        return Ok(json!({"id": null, "changed": [], "removed": [], "outlines": [], "regions": pick}));
    }
    let doc = s.doc_mut()?;
    let created = if merge {
@@ -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) {
@@ -66,7 +66,8 @@ pub fn large_document(layers: usize) -> DocResult<(Document, NodeId)> {
            made += 4;
        }
        // A card group (5 layers).
-        if budget(made) >= 5 {
+        // The card and the instances leave one layer for the grid, which starts with a rectangle.
+        if budget(made) > 5 {
            let card = doc.create(screen, NodeKind::Group, "Card", 12.0, 52.0, 160.0, 64.0)?;
            // Children are in the group's space; normalising fits the group around them.
            let cbg = doc.create(card, NodeKind::Rectangle, "Card background", 0.0, 0.0, 160.0, 64.0)?;
@@ -78,7 +79,7 @@ pub fn large_document(layers: usize) -> DocResult<(Document, NodeId)> {
        }
        // Three button instances (3 layers each).
        for k in 0..3 {
-            if budget(made) < 3 {
+            if budget(made) < 3 + 1 {
                break;
            }
            crate::components::create_instance(&mut doc, button, screen, 12.0 + k as f64 * 108.0, SCREEN_H - 44.0)?;
@@ -89,12 +90,14 @@ pub fn large_document(layers: usize) -> DocResult<(Document, NodeId)> {
        for k in 0..rest {
            let (gx, gy) = (184.0 + (k % 8) as f64 * 21.0, 52.0 + (k / 8) as f64 * 34.0);
            let hue = ((s * PER_SCREEN + k) % 360) as f32 / 360.0;
-            let id = match k % 5 {
+            // The grid starts with a rectangle so even the smallest workload has one.
+            let kind = (k + 2) % 5;
+            let id = match kind {
                0 => doc.create(screen, text(&format!("Item {k}")), "Text", gx, gy, 20.0, 14.0)?,
                1 | 3 => doc.create(screen, ellipse(), "Ellipse", gx, gy, 18.0, 18.0)?,
                _ => doc.create(screen, NodeKind::Rectangle, "Rectangle", gx, gy, 18.0, 18.0)?,
            };
-            if k % 5 != 0 {
+            if kind != 0 {
                fill(&mut doc, id, Color::new(hue, 0.5, 1.0 - hue, 1.0));
                if let Some(n) = doc.node_mut(id) {
                    n.corners.radii = [3.0; 4];
@@ -124,4 +127,16 @@ mod tests {
            assert!(doc.page_content_bounds(page).is_some());
        }
    }
+
+    #[test]
+    fn small_documents_hold_the_benchmark_targets() {
+        for n in [10, 11, 12, 13, 14, 15] {
+            let (doc, page) = super::large_document(n).unwrap();
+            let nodes: Vec<_> = doc.subtree(page).into_iter().filter_map(|id| doc.node(id)).collect();
+            let has = |f: &dyn Fn(&figcraft_doc::Node) -> bool| nodes.iter().any(|node| f(node));
+            assert!(has(&|x| matches!(x.kind, figcraft_doc::NodeKind::Rectangle) && x.name == "Rectangle"), "{n}: no rectangle");
+            assert!(has(&|x| x.name == "Title"), "{n}: no title");
+            assert!(has(&|x| matches!(x.kind, figcraft_doc::NodeKind::Component { .. })), "{n}: no component");
+        }
+    }
 }
@@ -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()));
+}