lore-revision: Compare all 4 tag bytes when detecting Unreal packages - #173
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eyupcanakman wants to merge 1 commit into
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lore-revision: Compare all 4 tag bytes when detecting Unreal packages#173eyupcanakman wants to merge 1 commit into
eyupcanakman wants to merge 1 commit into
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`infer_is_upackage_by_slice` compared `buffer[..3]`, a 3-element slice, against a 4-element `Vec<u8>`. Slice equality checks length first, so neither comparison could ever be true, and the function returned `false` for every input in both byte orders. The `buffer.len() >= 4` guard directly above them already assumes 4 bytes. Compare `buffer[..4]` in both branches and add one test per byte order. Fixes EpicGames#172 Signed-off-by: Eyüp Can Akman <eyupcanakman@gmail.com>
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What
Compare all four bytes of the Unreal package tag in
infer_is_upackage_by_slice.Why
Both branches attempted to compare
buffer[..3](3 bytes) with a 4-byteVec<u8>. Since slice equality fails on length mismatches, the function unconditionally returned false for both byte orders, even though the precedingbuffer.len() >= 4guard was expecting 4 bytes.Its only caller,
infer_is_diffable_by_slice, still classified packages as non-diffable, because both tag orders start with an invalid UTF-8 lead byte and the check below rejects them anyway. This restores the intended check rather than changing how any file is classified today.Fixes #172.
How
buffer[..4]in both branches.Testing
Ran the nightly fmt check and clippy for
lore-revisionwith warnings denied.cargo test -p lore-revisionpasses 272 tests. Both new tests fail whenbuffer[..3]is restored.AI tools used: Claude Code (Opus 5), for the investigation and the change itself.