Don't let append overwrite sibling results in tspath.GetCommonParents - #64493
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Jake Bailey (jakebailey) merged 2 commits intoSep 29, 2026
Merged
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Jake Bailey (jakebailey) merged 2 commits into
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Copilot review overview
🟢 Approval recommended
The focused allocation fix addresses the reported corruption and is covered by a suitable regression test.
Review effort: Balanced
Findings: None
What changed in this PR
Fixes backing-array aliasing in GetCommonParents, preventing sibling path results from overwriting one another.
Changes:
- Uses
slices.Concatto create independent result slices. - Adds a nested fan-out regression test.
| File | Description |
|---|---|
tsc/internal/tspath/path.go |
Prevents result slices from sharing mutable backing storage. |
tsc/internal/tspath/path_test.go |
Verifies all nested fan-out results are retained. |
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Jake Bailey (jakebailey)
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Sep 29, 2026
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Jake Bailey (jakebailey)
September 29, 2026 07:27
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Fixes #64492
Cause:
group.headis a subslice of an input path's components that still has spare capacity, so when a group has more than one sub-result, they overwrite each other in the shared backing array. One directory comes out twice (or as a nonexistent path), and another is dropped.