[Bug]: Git file paths lose leading and trailing spaces during decoding

[Defmon3]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

packages/contracts or packages/shared

Steps to reproduce

Git action inputs and working-tree status results trim whitespace from file paths. A path such as " leading.txt" becomes "leading.txt", which names a different file.

Both GitRunStackedActionInput.filePaths and VcsStatusLocalResult.workingTree.files[].path use a string schema that trims its input.

Related: issue #5501 reports a Files panel failure involving ProjectEntry.path; this report concerns the separate Git action and working-tree status schemas.

This is a schema-level reproduction; no filesystem setup is required.

1. Decode this input with Schema.decodeUnknownSync(GitRunStackedActionInput):

   {
     "actionId": "action-1",
     "cwd": "/repo",
     "action": "commit",
     "filePaths": [" leading.txt", "trailing.txt "]
   }

2. Inspect the decoded filePaths.

3. The same transformation occurs when those paths are decoded in a valid VcsStatusLocalResult working-tree file list.

Expected behavior

File paths retain their exact characters. Empty paths remain invalid.

Actual behavior

Input:   [" leading.txt", "trailing.txt "]
Decoded: ["leading.txt", "trailing.txt"]

The decoded value identifies a different path when a filename has leading or trailing spaces. Such filenames are legal on macOS and Linux, so their working-tree status results can carry paths affected by this trimming. A complete staging or commit failure was not tested.

Impact

Minor bug or occasional failure

Version or commit

Upstream commit 9ea9c3d5d2c444133e3ddff40eecf38737951589.

Environment

Focused automated tests on Windows with Node 24.13.1 and Vitest 4.1.11. These tests decode strings; they do not create Windows files with trailing spaces.

Logs or stack traces

Both preservation assertions report:

AssertionError: expected [ 'leading.txt', 'trailing.txt' ] to deeply equal [ ' leading.txt', 'trailing.txt ' ]

Two preservation assertions fail against upstream: one for action inputs and one for status results. Two empty-path rejection assertions pass.

A local fix uses non-empty strings without trimming for these path fields. All four assertions pass with that fix.

Screenshots, recordings, or supporting files

None attached.

Workaround

No workaround was verified.

[juliusmarminge]

Triage

Confirmed on current main (9ea9c3d5d). This is a real schema bug, not a duplicate of #5501.

GitRunStackedActionInput.filePaths and VcsStatusLocalResult.workingTree.files[].path are TrimmedNonEmptyString, which runs value.trim() on both decode and encode (packages/contracts/src/baseSchemas.ts). The reported payload:

{
  "actionId": "action-1",
  "cwd": "/repo",
  "action": "commit",
  "filePaths": [" leading.txt", "trailing.txt "]
}

decodes to ["leading.txt", "trailing.txt"]. Those are different files. Empty strings remain invalid after a non-trim non-empty check, which matches the expected behavior.

Why this is not #5501

#5501 is ProjectEntry.path and the Files panel (Duplicate path after two on-disk names collapse). That thread and PRs #7354 / #6064 are about dropping unrepresentable workspace entries so the tree does not crash. This issue is the Git action input and working-tree status contracts, and the fix is the opposite: keep the exact path.

Related, still not a wash

Review-diff contracts already preserve unusual names (ReviewDiffPreviewInput.file.path is Schema.NonEmptyString; ReviewDiffFileStat.path is Schema.String). packages/contracts/src/pullRequest.ts has an explicit untrimmed FilePath for the same reason. Server tests even create " leading.txt" for review diffs.

#8310 (open) is complementary: porcelain/numstat parsing of spaces, renames, and quoting. parsePorcelainPath / parseNumstatEntries still trim today, so a full working-tree status fix needs that layer too. The schema bug stands on its own — a client that already has the exact path still loses it when GitRunStackedActionInput is decoded. Selected-file commits send those paths through prepareCommitContext as git --literal-pathspecs add -A -- <paths>.

packages/contracts/src/git.test.ts has no preservation coverage for these two fields.

Suggested fix

In packages/contracts/src/git.ts, use a non-empty string without trim for:

• GitRunStackedActionInput.filePaths
• VcsStatusLocalResult.workingTree.files[].path

Leave cwd / action ids / branch names on TrimmedNonEmptyString. Add decode tests that keep " leading.txt" / "trailing.txt " and still reject "". That is the local fix the reporter already verified.

Severity: minor / occasional (legal but uncommon names on macOS/Linux). Accepting.