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Handle bvx2 LZFSE blocks in IWA decompression #1

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Handle bvx2 LZFSE blocks in IWA decompression #1

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6 changes: 3 additions & 3 deletions Sources/WorkKit/IWorkParser.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -434,17 +434,17 @@ enum IWorkParser {
// MARK: - IWA Decompression

/// LZFSE block magics. Apple's LZFSE framing uses these little-endian 4-byte markers;
/// `bvxn` is the LZVN compressed-block header and `bvx$` closes the stream.
/// `bvxn` (LZVN) and `bvx2` (LZFSE) are compressed-block headers and `bvx$` closes the stream.
/// Creator Studio–era writers emit some IWAs (e.g. `OperationStorage.iwa`) in this framing
/// instead of the classic `0x00 | len24 | snappy-chunk` repeating structure.
private static let lzfseMagicBvxn: [UInt8] = [0x62, 0x76, 0x78, 0x6E]
private static let lzfseMagicBvx: [UInt8] = [0x62, 0x76, 0x78]

private static func decompressIWA(_ data: Data) throws -> Data {
guard data.count >= 4 else {
throw IWorkError.invalidArchiveStructure(reason: "IWA file too small to contain a header.")
}

if data.starts(with: Self.lzfseMagicBvxn) {
if data.starts(with: Self.lzfseMagicBvx) {
return try decompressLZFSE(data)
}

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