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Pull request overview
This PR fixes a crash that occurs when undefined color variables are referenced in the document preamble. When a variable like backcolor is undefined, it produces an abnormal value that gets incorrectly interpreted as a pattern and causes a segmentation fault during rendering.
Changes:
- Added defensive validation in
make_brush()to reject invalid composite trees before treating them as patterns - Added structure and URL validation in
get_pattern_data()to safely handle invalid patterns with fallback to default values - Added test file and documentation for the fix
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| src/Graphics/Renderer/brush.cpp | Added validation checks to prevent crashes from invalid pattern structures |
| devel/201_72.md | Documentation explaining the fix and testing instructions |
| TeXmacs/tests/tmu/201_72.tmu | Test case with undefined color variable to verify the fix |
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MoonL79
approved these changes
Feb 5, 2026
da-liii
reviewed
Feb 5, 2026
| // 防御性处理：非法复合树（例如未定义变量展开后的 UNINIT） | ||
| // 不能当作 pattern 继续解包，否则后续访问 pattern[1]/pattern[2] 可能崩溃。 | ||
| if (N (p) != 4 || !is_atomic (p[0])) return tm_new<no_brush_rep> (); | ||
| if (as_string (p[0]) == "" || as_string (p[0]) == "{}") |
da-liii
reviewed
Feb 5, 2026
| } | ||
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| static brush_rep* | ||
| make_brush (tree p, int a) { |
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如何测试
Ctrl+Shift+p进入导言区backcolor后回车应该不会导致软件闪退问题2026/2/4
What
src/Graphics/Renderer/brush.cpp的make_brush(tree p, int a)中增加非法 pattern 输入校验，遇到异常复合树时回退为no_brush。src/Graphics/Renderer/brush.cpp的get_pattern_data(...)中增加结构和 URL 健壮性检查，非法输入回退到安全默认值，避免继续解包。Why
关联issue #2745
<value|backcolor>在变量未定义时会产生异常值，该值进入颜色渲染链路后被误当作 pattern 解包。MuPDF 路径中会继续读取非法 pattern 图像信息（日志可见
bad image size for '{}'），最终触发 SIGSEGV。