[Tyrie Vella (tyrielv)]

Problem and Context

gvfs.prefetch-use-idx enables the pack-index object existence checker for blob prefetch. BlobPrefetcher read this setting with GitProcess.GetFromLocalConfig and parsed it with bool.TryParse. This causes two problems:

• A value in the global or system git config has no effect. Only the repository's local config can enable the setting. Tools that roll out gvfs.* settings through the user's global git config cannot enable this feature.
• Valid git boolean values, such as yes, on, and 1, are rejected. The setting then silently falls back to the default (false).

Other gvfs.* feature settings, such as gvfs.prefetch-offload, gvfs.trust-pack-indexes, gvfs.show-hydration-status, and gvfs.mount-progress, read the merged config chain through LibGit2Repo.GetConfigBoolOrDefault. Nothing in the pack-index checker depends on the config scope. The checker gets its object roots from the enlistment.

The default stays false, so behavior does not change for users who do not set the key.

Changes

• Read gvfs.prefetch-use-idx with LibGit2Repo.GetConfigBoolOrDefault against the enlistment's working directory backing root. This is the same helper that PrefetchVerb uses for gvfs.prefetch-offload. The helper reads local, global, and system config, applies git boolean parsing, and returns the default with a warning if the value is invalid or the read fails.
• Add functional tests to PrefetchVerbTests that set gvfs.prefetch-use-idx=yes only in a temporary global config and run gvfs prefetch --files. The tests point HOME (used by libgit2) and GIT_CONFIG_GLOBAL (used by git.exe) at the temporary config. The temporary config includes the original global config files. One test asserts that the prefetch log reports the pack-index object existence checker. The other test also sets the key to false in the local config and asserts that the local value takes precedence. The tests restore the local config and delete the temporary config when they complete.

Known gaps

libgit2 finds the global config through HOME/USERPROFILE and ignores GIT_CONFIG_GLOBAL. If GIT_CONFIG_GLOBAL points at another file, git.exe and GVFS can read different global values for this setting. This limit applies to every gvfs.* setting that GVFS reads through libgit2, and this change does not alter it.

[Keith Klein (KeithIsSleeping)]

[KeithBot]: ✅ No issues found · iteration 1 (7612b28)

Validation

• ✅ GVFS.UnitTests full suite, source+base
• ✅ Prefetch + libgit2 config fixtures
• ✅ Config matrix vs git oracle, 3 probes
• ✅ GVFS.FunctionalTests compile
• ✅ GVFS.CommandLine.Tests 94/94
• ✅ CI run on head: 34/34 jobs green

Approving.

_{🤖 KeithBot · claude-opus-5.5, gpt-6.1-sol, gemini-4-argon · reply on a thread to dispute}