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LibCompress: Only require new LZMA2 properties after dictionary reset

This commit is contained in:
Tim Schumacher 2023-03-29 03:18:00 +02:00 committed by Andreas Kling
parent d9627503a9
commit 9ccb0fc1d8
2 changed files with 63 additions and 3 deletions

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@ -9,6 +9,65 @@
#include <AK/MemoryStream.h>
#include <LibCompress/Xz.h>
TEST_CASE(lzma2_compressed_without_settings_after_uncompressed)
{
Array<u8, 72> const compressed {
// Stream Header
0xFD, 0x37, 0x7A, 0x58, 0x5A, 0x00, // Magic
0x00, 0x00, // Stream Flags (Check: None)
0xFF, 0x12, 0xD9, 0x41, // CRC32
// Block Header
0x02, // Block Header Size [(0x02 + 1) * 4, i.e. 12 bytes]
0x00, // Block Flags (one filter, no compressed or uncompressed size present)
// Filter 0 Flags
0x21, // Filter ID (0x21 for LZMA2, encoded as a multibyte integer)
0x01, // Size of Properties (0x01, encoded as a multibyte integer)
0x00, // Filter Properties (LZMA2 encoded dictionary size byte; 0x00 = 4 KiB)
0x00, 0x00, 0x00, // Header Padding
0x37, 0x27, 0x97, 0xD6, // CRC32
// Compressed Data (LZMA2)
// LZMA chunk with dictionary reset
0xe0, // Control Byte
0x00, 0x00, // Low 16 bits of uncompressed size minus one (big-endian)
0x00, 0x05, // Compressed size minus one (big-endian)
0x31, // LZMA properties byte (lc = 1; lp = 1; pb = 1)
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
// Uncompressed chunk without dictionary reset
0x02, // Control Byte
0x00, 0x00, // 16-bit data size minus one (big-endian)
0x00,
// LZMA chunk with state reset
0xa0, // Control Byte
0x00, 0x00, // Low 16 bits of uncompressed size minus one (big-endian)
0x00, 0x05, // Compressed size minus one (big-endian)
0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
// End of LZMA2 stream
0x00,
// Index
0x00, // Index Indicator
0x01, // Number of Records (multibyte integer)
// Record 0
0x28, // Unpadded Size (multibyte integer)
0x03, // Uncompressed Size (multibyte integer)
// CRC32
0x3B, 0x4A, 0xD2, 0xE4,
// Stream Footer
0x06, 0x72, 0x9E, 0x7A, // CRC32
0x01, 0x00, 0x00, 0x00, // Backward Size
0x00, 0x00, // Stream Flags
0x59, 0x5A, // Footer Magic Bytes
};
auto stream = MUST(try_make<FixedMemoryStream>(compressed));
auto decompressor = MUST(Compress::XzDecompressor::create(move(stream)));
auto buffer = MUST(decompressor->read_until_eof(PAGE_SIZE));
EXPECT_EQ("\x00\x00\x00"sv.bytes(), buffer.span());
}
// The following tests are based on test files from the XZ utils package, which have been placed in the public domain:
// https://tukaani.org/xz/xz-5.4.1.tar.xz (subdirectory /xz-5.4.1/tests/files)
// Test descriptions have been taken from the README file in the test files directory.