Image Trace: retain pieces returning to a junction

Squashed from #2205 onto main.

docs/roadmap.md

@@ -64,7 +64,7 @@ Checked 2026-10-10 from the code, tests and open issues; no workflow fails, so V
 | M11 | Artboards & views (selected-set deletion shared by Artboards menu, trash and Properties, retaining artboard 1 when all are selected; Artboard deletion keys keep the first of an all-selected set and protect artwork; history prunes invalid indices while preserving valid multiselection (history tests and full workspace CI pass); click-to-fit objects with the Artboard tool (#1227), artboard escape routing and document setup modal handoff done; artboard panel/tool with Move Artwork for X/Y fields and Artboard Options, Trim View, middle-button pan, print tiling and the status bar's artboard navigator with synchronized Artboard tool selection done; multiple windows, presentation polish) | 🟡 | 15–25 |
 | M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
 | M13 | Automation (Actions ✅ record/playback, persisted; variables, scripting, batch) | 🟡 MCP `add_text` exposes existing vertical point, area and path type; broader scripting and batch work remains | 18–27 |
-| M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (quick presets reveal adjustment controls; Properties reopens them; tiny fitted contours retain islands and holes; 15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; closed outlines retain their interior after straightening; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
+| M12 | Advanced color & art (CMYK/ICC, separations, Gradient Mesh, Live Paint, Image Trace, Graphs) | 🟡 Gradient Mesh, Live Paint, Image Trace (junction-returning pieces retain their positioned boundaries; quick presets reveal adjustment controls; Properties reopens them; tiny fitted contours retain islands and holes; 15 presets, the 14 documented ones each with an enhanced version; Ignore Color, Shapes, Auto Grouping and Gradients options; measured in `image-trace-quality.md`; closed outlines retain their interior after straightening; the Flat Logo mode places edges to a fraction of a pixel, restores sharp corners, snaps lines and circles, and refuses gradients), Recolor Artwork, colour management (ICC, soft proofing, separations preview), Graphs (all 9 tools, Graph Data/Type, group-selected series colours persist through regenerate/save/open) done; Graph Design and Marker designs, Transpose and Switch x/y, `|` label line breaks, the pie options, drop shadows, the legend across the top, overlapping widths, First Row/Column in Front, filled lines, kept label formatting and the Graph Data worksheet done; graph Column designs pending | 6–10 |
 | M13 | Automation (Actions ✅ record/playback, persisted; variables, scripting, batch) | 🟡 | 18–27 |
 | M14 | 1.0 polish (preferences, shortcut editor, workspaces, accessibility, packaging for all OSes) | 🟡 Numeric-field pointer selection and focus regression-tested (#1326, in part; short movements still select all); RPM runtime capabilities and glibc floor checked (#1275; real-distro install/start-up pending), Eyedropper cursor with precise-setting checks (#1269), Preferences, shortcut editor (chords with Shift and a punctuation key fire as typed; other apps' text shortcut sets imported), workspaces, a custom title bar on Windows/Linux with a Home button, content-sized dialogs, menus that scroll when longer than the window and macOS native menu dismissal done (M14.8), and native macOS save sheets with a Format menu (#866); an experimental, unsupported Windows 7 x64 portable OpenGL build (not verified by maintainers); accessibility and broader Windows/Linux packaging/QA pending | 18–28 |
 | — | Interaction fidelity pass (every tool's modifiers, Properties panel per context, isolation, nuance; width-point creation and adjoining adjustment regression-tested; dialog layout reviewed) | ⬜ (new ruler-guide Alt orientation implemented; existing-guide Escape cancellation regression-tested; broader pass remains) | 60–90 |
@@ -84,6 +84,7 @@ After placed documents (File › Place of a `.vectorcraft` file, linked), M4.14
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-15 | minor | Image Trace retains nonzero positioned boundaries when a fixed-end returning piece has fewer than two fitted cubics. Source-generated tests check survival, winding, shared-edge reversal and Noise controls; see `image-trace-quality.md`. Scores and hours unchanged. |
 | 2026-10-16 | minor | G2: Effect › Sketch › Halftone Pattern (Size, Contrast, Pattern Type Circle, Dot or Line; black ink on white paper, Size in points at any Document Raster Effects resolution); measured Photoshop filters 30/57, 27 remaining (22–38 h). |
 | 2026-10-14 | minor | Effect > Warp: style, orientation and percent controls; focused checks passed and original captures reviewed; scores and hours unchanged |
 | 2026-10-14 | minor | G11: open-path anchor Delete removes adjoining segments without bridging the gap; explicit Remove Anchors keeps its reconnect/refit behavior. Scores and hours unchanged. |