[Tyrie Vella (tyrielv)]

Problem and Context

The command hook takes the global GVFS lock for every worktree subcommand, including the read-only worktree list command. During that lock, GVFS rejects new ordinary-file placeholders with FileNotFound. An unrelated process can therefore fail to open a tracked file that exists in the projection.

Several other Git commands also take this lock even though they do not change index membership or tracked working-tree content. Long commands can extend the period in which unrelated first opens fail.

Like blame, default annotate reads working-tree files. This change does not serialize those reads with concurrent worktree mutations. The exclusion also lets default annotate create its own file placeholders.

Changes

• Exempt worktree list, including porcelain and NUL-delimited output. Keep locks for mutating and unknown worktree subcommands.
• Add audited exclusions for annotate, check-ref-format, cherry, count-objects, ls-remote, range-diff, shortlog, show-branch, verify-commit, verify-pack, and verify-tag.
• Keep conservative locks for describe, whose --dirty and --broken modes can write the index. Preserve the existing lock classification for index mutators and arbitrary-command dispatchers.
• Move the existing hook policy into a partial source file that the unit project also compiles. Add unit tests for both hook phases, command spellings, worktree options, and retained lock cases.
• Add a deterministic functional test that pauses the post-command chain before GVFS can release an acquired lock, and opens an unmaterialized file from another process during that pause.
• Add functional tests for read-only commands under lock contention and default-mode annotate on an unmaterialized file. The contention tests assert lock readiness before they run each command and release the test lock holder before each test returns.
• Add functional tests that verify status and for-each-repo still wait for the lock, with controlled alias configuration in the dispatcher test.

The placeholder rejection policy and alias detection remain unchanged. This change does not introduce deferred file opens.

Validation

CI run 39628260944 tested head 64f6ad82.

Targeted functional tests passed for first opens during paused worktree list, default annotate, read-only lock bypass, and retained status/for-each-repo waits. With the worktree list exemption temporarily removed, the same direct-read regression failed with FileNotFoundException.

The pipeline does not collect coverage, so no changed-line coverage report is available for this head. The evidence establishes tested behavior, not measured coverage of every changed line.

[Nathan Baird (ShiningMassXAcc)]

The new read-only-command cases pass in CI, but no changed-line coverage report is published. Please link a report if available, or record this limitation alongside the targeted lock/no-lock test evidence in the PR validation notes. This is nonblocking.

[Tyrie Vella (tyrielv)]

Note

🤖 Machine-drafted reply — reviewed and approved by Tyrie Vella.

Nathan Baird (@ShiningMassXAcc), added a Validation section with the targeted lock/no-lock test evidence and the explicit changed-line coverage limitation.

The pipeline does not currently collect coverage. I will investigate configuring it separately, including the NativeAOT limitation for functional coverage.