#1025: .ai editing data keeps sublayers with global colours and pattern fills

The editing-data reader stopped on `Xk`/`XK` (global process colours) and
on `p`/`P` (pattern fills), so the file fell back to its PDF part, which has
only the top-level layers.

- `Xk`/`XK` read like `Xx`: a global swatch (not a spot ink), linked at its tint.
- `%AI3_BeginPattern` sections are read by a reader of their own into
  pattern swatches (tile from `(name) llx lly urx ury`, art in pattern space);
  `p`/`P` fill or stroke with them, placed by the operator's matrix. A pattern
  it can't read whole still makes a fill with it unreadable, as before.
- Tests on synthetic editing data; fuzz tokens and fixture extended.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/file-format-parity.md

@@ -35,14 +35,14 @@ private editing data. VectorCraft:
 - **Known failures in users' files:** layer structure flattened or multiplied (#951: 109 layers instead of
   14; #868: round trip with Illustrator 2018 loses layers and groups), guides and non-printing construction
   lines lost (#779), some files 4× slower to open since the editing data is read whole (#758), live effects,
-  brushes, symbols and pattern fills come in as their drawn look (#637), legacy `.ai` without the prolog not
-  read.
+  brushes and symbols come in as their drawn look (#637; pattern fills are read since #1025), legacy `.ai`
+  without the prolog not read.
 - Estimate: **~65%** for real exchange with Illustrator users (open: ~75%; save: PDF-compatible only).
   Closing the open-side issues: 10–20 h with users' files.
 
 ### Illustrator's private editing data
 
-the app's own editing copy of a file (an EPS after its `%%EOF`, a `.ai`'s `AIPrivateData` streams, Zstandard or zlib, the EPS's in ASCII85) is not documented as a whole. VectorCraft reads its structure: layers and sublayers (names, order, visibility, lock, printing, preview, dimming, colour), groups as they were nested, compound paths, clipping groups and layer clipping, object names, hidden and locked objects, fills and strokes (grey, CMYK, RGB, named and spot colours), linear and radial gradients, opacity, blend modes, isolation and knockout, embedded images with their alpha channel, guides, and every artboard where it is. An object with several fills or strokes, effects or a brush comes in as its drawn look (a group named after it). Type is made from the file's text document, whole and editable, shown or not: point type, area type (a story in several frames as threaded type) and type on a path, with its characters, fonts, size, leading, tracking, scaling, baseline shift, fill and stroke (grey, RGB or CMYK), alignment, indents and paragraph spacing; the page's drawing of it (often in pieces) is left out. Where the text document can't say (a frame of another kind, or a document that doesn't agree with the page), type that shows comes from the page into its text object's place (no group around it), and hidden type is left out with a note. Kerning, underline and the other character and paragraph options aren't read yet. A `.ai` saved without PDF compatibility (a placeholder page) opens from its editing data alone, its point type, area type and type on a path made from the text document. Symbols, pattern fills, placed files and anything else it doesn't read make the file come in as its page (on a layer that doesn't show, they are left out of that layer), with a warning saying what. The layers' art is also compared with the page (by lightness, so colours written as their CMYK equivalents compare alike, and by whether a pixel is inked at all); the page is used when they differ by more than 5%, where one draws an object the other doesn't (away from type, whose lines may be laid out afresh), and when an EPS whose page is its art's box has art printed outside it (#735). `textAs: "outlines"` opens a `.ai` whose type shows from its PDF part, which has the outlines; `editingData: false` opens any of them as its page or PDF part only, for print pipelines (#735). A file whose import left something out (hidden text, art or layers) is never written over by an export or Save As to its own path unless `acknowledgeLoss: true` (`convert --replace-lossy`), so the original keeps what the document lacks. Where a `.ai` can't be read that way (or its layers are turned off in the import options), we read its PDF-compatible part, so Illustrator-only live objects arrive as appearance, and plain groups arrive ungrouped: that part draws each object on its own and marks only layers, clipping groups and groups with opacity, blending or a mask (those come back). Art outside the artboards isn't in that part at all (Illustrator's PDF part leaves it out), so it doesn't open; the import says so in a note (#472). That part also has no paragraphs: area type is written line by line, and comes back as area type only where its font is installed and lays the lines out with the same breaks, else as a point type object per line (#508). Art off the page that a PDF does draw opens on the pasteboard.
+the app's own editing copy of a file (an EPS after its `%%EOF`, a `.ai`'s `AIPrivateData` streams, Zstandard or zlib, the EPS's in ASCII85) is not documented as a whole. VectorCraft reads its structure: layers and sublayers (names, order, visibility, lock, printing, preview, dimming, colour), groups as they were nested, compound paths, clipping groups and layer clipping, object names, hidden and locked objects, fills and strokes (grey, CMYK, RGB, named and spot colours, global process colours as global swatches at their tint), linear and radial gradients, pattern fills with their patterns as pattern swatches (#1025), opacity, blend modes, isolation and knockout, embedded images with their alpha channel, guides, and every artboard where it is. An object with several fills or strokes, effects or a brush comes in as its drawn look (a group named after it). Type is made from the file's text document, whole and editable, shown or not: point type, area type (a story in several frames as threaded type) and type on a path, with its characters, fonts, size, leading, tracking, scaling, baseline shift, fill and stroke (grey, RGB or CMYK), alignment, indents and paragraph spacing; the page's drawing of it (often in pieces) is left out. Where the text document can't say (a frame of another kind, or a document that doesn't agree with the page), type that shows comes from the page into its text object's place (no group around it), and hidden type is left out with a note. Kerning, underline and the other character and paragraph options aren't read yet. A `.ai` saved without PDF compatibility (a placeholder page) opens from its editing data alone, its point type, area type and type on a path made from the text document. Symbols, pattern fills whose pattern it can't read, placed files and anything else it doesn't read make the file come in as its page (on a layer that doesn't show, they are left out of that layer), with a warning saying what. The layers' art is also compared with the page (by lightness, so colours written as their CMYK equivalents compare alike, and by whether a pixel is inked at all); the page is used when they differ by more than 5%, where one draws an object the other doesn't (away from type, whose lines may be laid out afresh), and when an EPS whose page is its art's box has art printed outside it (#735). `textAs: "outlines"` opens a `.ai` whose type shows from its PDF part, which has the outlines; `editingData: false` opens any of them as its page or PDF part only, for print pipelines (#735). A file whose import left something out (hidden text, art or layers) is never written over by an export or Save As to its own path unless `acknowledgeLoss: true` (`convert --replace-lossy`), so the original keeps what the document lacks. Where a `.ai` can't be read that way (or its layers are turned off in the import options), we read its PDF-compatible part, so Illustrator-only live objects arrive as appearance, and plain groups arrive ungrouped: that part draws each object on its own and marks only layers, clipping groups and groups with opacity, blending or a mask (those come back). Art outside the artboards isn't in that part at all (Illustrator's PDF part leaves it out), so it doesn't open; the import says so in a note (#472). That part also has no paragraphs: area type is written line by line, and comes back as area type only where its font is installed and lays the lines out with the same breaks, else as a point type object per line (#508). Art off the page that a PDF does draw opens on the pasteboard.
 
 ## Format by format
 
@@ -78,4 +78,5 @@ the app's own editing copy of a file (an EPS after its `%%EOF`, a `.ai`'s `AIPri
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-11 | minor | `.ai` editing data: global process colours and pattern fills read, so they no longer drop sublayers (#1025) |
 | 2026-10-10 | major | First checklist; moved the `.ai` editing-data scope from the ROADMAP's "Out of scope" here; added the user-reported `.ai` failures |

docs/gaps.md

@@ -55,8 +55,8 @@ from G14 and the budget run of G15: **~170–270 h** one agent, ~50–80 h wall
 
 - **Missing:** faithful layer and group structure from the editing data in real files (#951: 109 layers instead
   of 14; #868: round trip with Illustrator 2018 loses layers and groups), guides and non-printing construction
-  lines (#779), open speed on large files (#758), legacy `.ai` without the prolog, live effects, brushes, symbols
-  and pattern fills as live objects (#637). Writing Illustrator's own editing data is out of scope
+  lines (#779), open speed on large files (#758), legacy `.ai` without the prolog, live effects, brushes and
+  symbols as live objects (#637; pattern fills and global colours are read since #1025). Writing Illustrator's own editing data is out of scope
   (undocumented); Save As `.ai` stays PDF-compatible.
 - **Evidence:** the issues above; 28 of the 350 issues are about `.ai`/EPS (about 22 people, the most common single
   format theme), 20 fixed, and the 8 open ones are about structure (layers, guides, speed, live objects), not missing
@@ -200,6 +200,7 @@ from G14 and the budget run of G15: **~170–270 h** one agent, ~50–80 h wall
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-11 | minor | G9: `.ai` pattern fills and global colours read from the editing data (#1025) |
 | 2026-10-10 | minor | G3: initial Revolve landed (#846), 45–75 h left |
 | 2026-10-10 | minor | G9 evidence counted from the tracker (28 `.ai`/EPS issues, 20 fixed); impact narrowed to handing files back |
 | 2026-10-10 | minor | Alpha blockers checked against the core-workflow gate: none |