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A single Read can return a partial sector on .NET 6+, which silently corrupted most files extracted from compressed (PFSC) packages; the rest of the sector kept stale data from the previous one.
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PFSCReader.ReadSectordecompresses a sector with a singleDeflateStream.Read(output, 0, BlockSz). Since .NET 6,DeflateStream.Readreturns as soon as some output is available, so it can return less than a full 64 KiB sector. The rest ofoutputthen keeps whatever the previous sector left there, and files extracted from compressed (PFSC) packages are silently corrupted.In practice this hit most files of real fake packages (e.g. 147 of 204 files of one game's base package differed from an independent zlib decode).
Fix: loop until the sector is full; zero any remainder if the stream ends early.
Test:
PfscReaderTests.PfscReader_DecompressesMixedBlocksExactlybuilds a PFSC image with mixed raw/zlib blocks and compares the decoded data. It fails on master (first mismatch at byte 36173) and passes with the fix.Possibly related: #18 (bad sectors while reading compressed images).