2 XZ Utils User-Visible Changes
3 =============================
7 * LZMA2 decompressor now correctly accepts LZMA2 streams with no
8 uncompressed data. Previously it considered them corrupt. The
9 bug can affect applications that use raw LZMA2 streams. It is
10 very unlikely to affect .xz files because no compressor creates
11 .xz files with empty LZMA2 streams. (Empty .xz files are a
12 different thing than empty LZMA2 streams.)
14 * "xz --suffix=.foo filename.foo" now refuses to compress the
15 file due to it already having the suffix .foo. It was already
16 documented on the man page, but the code lacked the test.
18 * "xzgrep -l foo bar.xz" works now.
20 * Polish translation was added.
25 * xz --force now (de)compresses files that have setuid, setgid,
26 or sticky bit set and files that have multiple hard links.
27 The man page had it documented this way already, but the code
30 * gzip and bzip2 support in xzdiff was fixed.
34 * Minor fix to Czech translation
39 Only the most important changes compared to 4.999.9beta are listed
40 here. One change is especially important:
42 * The memory usage limit is now disabled by default. Some scripts
43 written before this change may have used --memory=max on xz command
44 line or in XZ_OPT. THESE USES OF --memory=max SHOULD BE REMOVED
45 NOW, because they interfere with user's ability to set the memory
46 usage limit himself. If user-specified limit causes problems to
47 your script, blame the user.
49 Other significant changes:
51 * Added support for XZ_DEFAULTS environment variable. This variable
52 allows users to set default options for xz, e.g. default memory
53 usage limit or default compression level. Scripts that use xz
54 must never set or unset XZ_DEFAULTS. Scripts should use XZ_OPT
55 instead if they need a way to pass options to xz via an
58 * The compression settings associated with the preset levels
59 -0 ... -9 have been changed. --extreme was changed a little too.
60 It is now less likely to make compression worse, but with some
61 files the new --extreme may compress slightly worse than the old
64 * If a preset level (-0 ... -9) is specified after a custom filter
65 chain options have been used (e.g. --lzma2), the custom filter
66 chain will be forgotten. Earlier the preset options were
67 completely ignored after custom filter chain options had been
70 * xz will create sparse files when decompressing if the uncompressed
71 data contains long sequences of binary zeros. This is done even
72 when writing to standard output that is connected to a regular
73 file and certain additional conditions are met to make it safe.
75 * Support for "xz --list" was added. Combine with --verbose or
76 --verbose --verbose (-vv) for detailed output.
78 * I had hoped that liblzma API would have been stable after
79 4.999.9beta, but there have been a couple of changes in the
80 advanced features, which don't affect most applications:
82 - Index handling code was revised. If you were using the old
83 API, you will get a compiler error (so it's easy to notice).
85 - A subtle but important change was made to the Block handling
86 API. lzma_block.version has to be initialized even for
87 lzma_block_header_decode(). Code that doesn't do it will work
88 for now, but might break in the future, which makes this API
91 * The major soname has been bumped to 5.0.0. liblzma API and ABI
92 are now stable, so the need to recompile programs linking against
93 liblzma shouldn't arise soon.