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A negation under an excluded directory takes effect; git says it cannot #25
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The mechanism, measured rather than reasoned about. I asked the library why, with
MatchDetail,
and askedgitwithcheck-ignore -v, on the same three trees. Only the first line changes:rules path git this library .vscode+!.vscode/extensions.json.vscode/extensions.jsonignored ( .vscode)not ignored ( !.vscode/extensions.json).vscode/+ same negationsame ignored ( .vscode/)not ignored ( !.vscode/extensions.json).vscode/*+ same negationsame not ignored ( !.vscode/extensions.json)not ignored ( !.vscode/extensions.json)The library answers the same thing three times; git answers two different things. That is the whole
bug:Matchpicks the last pattern that matches the full path, so it never learns that an ancestor
was excluded. git decides per directory and stops descending into one it has excluded, which is why
.vscode/*— one segment deep, excluding the contents and not the directory — is the idiom that
actually works.Worth separating from #26, because the fix points the other way. #26 is the implicit
**reaching
down from a negation; here nothing reaches down far enough — a negation needs to be dropped when
an excluded ancestor sits above it. Patching one won't touch the other.Repro, three lines:
mkdir -p t/.vscode && cd t && git init -q printf '.vscode\n!.vscode/extensions.json\n' > .gitignore touch .vscode/extensions.json && git check-ignore -v .vscode/extensions.json
git names
.gitignore:1:.vscode; the library says not ignored.- added a commit that references this issue
on Sep 12, 2026
gitignore(5): "It is not possible to re-include a file if a parent directory of that file is
excluded." The library re-includes it.
.vscodeexcludes the directory, so git never walks into it and the!line has no effect at all— not on the directory, not on anything under it.
matchwalks the pattern list backwards andreturns on the first hit, so the later negation wins instead of never being reached.
Note the exclusion has no trailing slash and still excludes the directory;
!.vscode/ext/behavesthe same way, so it isn't about dir-only patterns.
Found by an outside bench (33 repos' real rule files, 8,953 nested-
.gitignorequeries,git check-ignoreas the oracle), where it accounts for 4 divergences — ollama'sapp/ui/app/.gitignorehas
!.vscode/extensions.jsonunder a root.vscode. Separate from #23 and from the negationinheritance in the issue I'm filing next; this one survives removing the
literalSuffixfast-reject entirely.