XZ Utils Release Notes
======================
5.3.2alpha (2021-10-28)
This release was made on short notice so that recent erofs-utils can
be built with LZMA support without needing a snapshot from xz.git.
Thus many pending things were not included, not even updated
translations (which would need to be updated for the new --list
strings anyway).
* All fixes from 5.2.5.
* xz:
- When copying metadata from the source file to the destination
file, don't try to set the group (GID) if it is already set
correctly. This avoids a failure on OpenBSD (and possibly on
a few other OSes) where files may get created so that their
group doesn't belong to the user, and fchown(2) can fail even
if it needs to do nothing.
- The --keep option now accepts symlinks, hardlinks, and
setuid, setgid, and sticky files. Previously this required
using --force.
- Split the long strings used in --list and --info-memory modes
to make them much easier for translators.
- If built with sandbox support and enabling the sandbox fails,
xz will now immediately exit with exit status of 1. Previously
it would only display a warning if -vv was used.
- Cap --memlimit-compress to 2000 MiB on MIPS32 because on
MIPS32 userspace processes are limited to 2 GiB of address
space.
* liblzma:
- Added lzma_microlzma_encoder() and lzma_microlzma_decoder().
The API is in lzma/container.h.
The MicroLZMA format is a raw LZMA stream (without end marker)
whose first byte (always 0x00) has been replaced with
bitwise-negation of the LZMA properties (lc/lp/pb). It was
created for use in EROFS but may be used in other contexts
as well where it is important to avoid wasting bytes for
stream headers or footers. The format is also supported by
XZ Embedded.
The MicroLZMA encoder API in liblzma can compress into a
fixed-sized output buffer so that as much data is compressed
as can be fit into the buffer while still creating a valid
MicroLZMA stream. This is needed for EROFS.
- Added fuzzing support.
- Support Intel Control-flow Enforcement Technology (CET) in
32-bit x86 assembly files.
- Visual Studio: Use non-standard _MSVC_LANG to detect C++
standard version in the lzma.h API header. It's used to
detect when "noexcept" can be used.
* Scripts:
- Fix exit status of xzdiff/xzcmp. Exit status could be 2 when
the correct value is 1.
- Fix exit status of xzgrep.
- Detect corrupt .bz2 files in xzgrep.
- Add zstd support to xzgrep and xzdiff/xzcmp.
- Fix less(1) version detection in xzless. It failed if the
version number from "less -V" contained a dot.
* Fix typos and technical issues in man pages.
* Build systems:
- Windows: Fix building of resource files when config.h isn't
used. CMake + Visual Studio can now build liblzma.dll.
- Various fixes to the CMake support. It might still need a few
more fixes even for liblzma-only builds.
5.3.1alpha (2018-04-29)
* All fixes from 5.2.4.
* Add lzma_file_info_decoder() into liblzma and use it in xz to
implement the --list feature.
* Capsicum sandbox support is enabled by default where available
(FreeBSD >= 10).
5.2.5 (2020-03-17)
* liblzma:
- Fixed several C99/C11 conformance bugs. Now the code is clean
under gcc/clang -fsanitize=undefined. Some of these changes
might have a negative effect on performance with old GCC
versions or compilers other than GCC and Clang. The configure
option --enable-unsafe-type-punning can be used to (mostly)
restore the old behavior but it shouldn't normally be used.
- Improved API documentation of lzma_properties_decode().
- Added a very minor encoder speed optimization.
* xz:
- Fixed a crash in "xz -dcfv not_an_xz_file". All four options
were required to trigger it. The crash occurred in the
progress indicator code when xz was in passthru mode where
xz works like "cat".
- Fixed an integer overflow with 32-bit off_t. It could happen
when decompressing a file that has a long run of zero bytes
which xz would try to write as a sparse file. Since the build
system enables large file support by default, off_t is
normally 64-bit even on 32-bit systems.
- Fixes for --flush-timeout:
* Fix semi-busy-waiting.
* Avoid unneeded flushes when no new input has arrived
since the previous flush was completed.
- Added a special case for 32-bit xz: If --memlimit-compress is
used to specify a limit that exceeds 4020 MiB, the limit will
be set to 4020 MiB. The values "0" and "max" aren't affected
by this and neither is decompression. This hack can be
helpful when a 32-bit xz has access to 4 GiB address space
but the specified memlimit exceeds 4 GiB. This can happen
e.g. with some scripts.
- Capsicum sandbox is now enabled by default where available
(FreeBSD >= 10). The sandbox debug messages (xz -vv) were
removed since they seemed to be more annoying than useful.
- DOS build now requires DJGPP 2.05 instead of 2.04beta.
A workaround for a locale problem with DJGPP 2.05 was added.
* xzgrep and other scripts:
- Added a configure option --enable-path-for-scripts=PREFIX.
It is disabled by default except on Solaris where the default
is /usr/xpg4/bin. See INSTALL for details.
- Added a workaround for a POSIX shell detection problem on
Solaris.
* Build systems:
- Added preliminary build instructions for z/OS. See INSTALL
section 1.2.9.
- Experimental CMake support was added. It should work to build
static liblzma on a few operating systems. It may or may not
work to build shared liblzma. On some platforms it can build
xz and xzdec too but those are only for testing. See the
comment in the beginning of CMakeLists.txt for details.
- Visual Studio project files were updated.
WindowsTargetPlatformVersion was removed from VS2017 files
and set to "10.0" in the added VS2019 files. In the future
the VS project files will be removed when CMake support is
good enough.
- New #defines in config.h: HAVE___BUILTIN_ASSUME_ALIGNED,
HAVE___BUILTIN_BSWAPXX, and TUKLIB_USE_UNSAFE_TYPE_PUNNING.
- autogen.sh has a new optional dependency on po4a and a new
option --no-po4a to skip that step. This matters only if one
wants to remake the build files. po4a is used to update the
translated man pages but as long as the man pages haven't
been modified, there's nothing to update and one can use
--no-po4a to avoid the dependency on po4a.
* Translations:
- XZ Utils translations are now handled by the Translation
Project: https://translationproject.org/domain/xz.html
- All man pages are now included in German too.
- New xz translations: Brazilian Portuguese, Finnish,
Hungarian, Chinese (simplified), Chinese (traditional),
and Danish (partial translation)
- Updated xz translations: French, German, Italian, and Polish
- Unfortunately a few new xz translations weren't included due
to technical problems like too long lines in --help output or
misaligned column headings in tables. In the future, many of
these strings will be split and e.g. the table column
alignment will be handled in software. This should make the
strings easier to translate.
5.2.4 (2018-04-29)
* liblzma:
- Allow 0 as memory usage limit instead of returning
LZMA_PROG_ERROR. Now 0 is treated as if 1 byte was specified,
which effectively is the same as 0.
- Use "noexcept" keyword instead of "throw()" in the public
headers when a C++11 (or newer standard) compiler is used.
- Added a portability fix for recent Intel C Compilers.
- Microsoft Visual Studio build files have been moved under
windows/vs2013 and windows/vs2017.
* xz:
- Fix "xz --list --robot missing_or_bad_file.xz" which would
try to print an uninitialized string and thus produce garbage
output. Since the exit status is non-zero, most uses of such
a command won't try to interpret the garbage output.
- "xz --list foo.xz" could print "Internal error (bug)" in a
corner case where a specific memory usage limit had been set.
5.2.3 (2016-12-30)
* xz:
- Always close a file before trying to delete it to avoid
problems on some operating system and file system combinations.
- Fixed copying of file timestamps on Windows.
- Added experimental (disabled by default) sandbox support using
Capsicum (FreeBSD >= 10). See --enable-sandbox in INSTALL.
* C99/C11 conformance fixes to liblzma. The issues affected at least
some builds using link-time optimizations.
* Fixed bugs in the rarely-used function lzma_index_dup().
* Use of external SHA-256 code is now disabled by default.
It can still be enabled by passing --enable-external-sha256
to configure. The reasons to disable it by default (see INSTALL
for more details):
- Some OS-specific SHA-256 implementations conflict with
OpenSSL and cause problems in programs that link against both
liblzma and libcrypto. At least FreeBSD 10 and MINIX 3.3.0
are affected.
- The internal SHA-256 is faster than the SHA-256 code in
some operating systems.
* Changed CPU core count detection to use sched_getaffinity() on
GNU/Linux and GNU/kFreeBSD.
* Fixes to the build-system and xz to make xz buildable even when
encoders, decoders, or threading have been disabled from libilzma
using configure options. These fixes added two new #defines to
config.h: HAVE_ENCODERS and HAVE_DECODERS.
5.2.2 (2015-09-29)
* Fixed bugs in QNX-specific code.
* Omitted the use of pipe2() even if it is available to avoid
portability issues with some old Linux and glibc combinations.
* Updated German translation.
* Added project files to build static and shared liblzma (not the
whole XZ Utils) with Visual Studio 2013 update 2 or later.
* Documented that threaded decompression hasn't been implemented
yet. A 5.2.0 NEWS entry describing multi-threading support had
incorrectly said "decompression" when it should have said
"compression".
5.2.1 (2015-02-26)
* Fixed a compression-ratio regression in fast mode of LZMA1 and
LZMA2. The bug is present in 5.1.4beta and 5.2.0 releases.
* Fixed a portability problem in xz that affected at least OpenBSD.
* Fixed xzdiff to be compatible with FreeBSD's mktemp which differs
from most other mktemp implementations.
* Changed CPU core count detection to use cpuset_getaffinity() on
FreeBSD.
5.2.0 (2014-12-21)
Since 5.1.4beta:
* All fixes from 5.0.8
* liblzma: Fixed lzma_stream_encoder_mt_memusage() when a preset
was used.
* xzdiff: If mktemp isn't installed, mkdir will be used as
a fallback to create a temporary directory. Installing mktemp
is still recommended.
* Updated French, German, Italian, Polish, and Vietnamese
translations.
Summary of fixes and new features added in the 5.1.x development
releases:
* liblzma:
- Added support for multi-threaded compression. See the
lzma_mt structure, lzma_stream_encoder_mt(), and
lzma_stream_encoder_mt_memusage() in <lzma/container.h>,
lzma_get_progress() in <lzma/base.h>, and lzma_cputhreads()
in <lzma/hardware.h> for details.
- Made the uses of lzma_allocator const correct.
- Added lzma_block_uncomp_encode() to create uncompressed
.xz Blocks using LZMA2 uncompressed chunks.
- Added support for LZMA_IGNORE_CHECK.
- A few speed optimizations were made.
- Added support for symbol versioning. It is enabled by default
on GNU/Linux, other GNU-based systems, and FreeBSD.
- liblzma (not the whole XZ Utils) should now be buildable
with MSVC 2013 update 2 or later using windows/config.h.
* xz:
- Fixed a race condition in the signal handling. It was
possible that e.g. the first SIGINT didn't make xz exit
if reading or writing blocked and one had bad luck. The fix
is non-trivial, so as of writing it is unknown if it will be
backported to the v5.0 branch.
- Multi-threaded compression can be enabled with the
--threads (-T) option.
[Fixed: This originally said "decompression".]
- New command line options in xz: --single-stream,
--block-size=SIZE, --block-list=SIZES,
--flush-timeout=TIMEOUT, and --ignore-check.
- xz -lvv now shows the minimum xz version that is required to
decompress the file. Currently it is 5.0.0 for all supported
.xz files except files with empty LZMA2 streams require 5.0.2.
* xzdiff and xzgrep now support .lzo files if lzop is installed.
The .tzo suffix is also recognized as a shorthand for .tar.lzo.
5.1.4beta (2014-09-14)
* All fixes from 5.0.6
* liblzma: Fixed the use of presets in threaded encoder
initialization.
* xz --block-list and --block-size can now be used together
in single-threaded mode. Previously the combination only
worked in multi-threaded mode.
* Added support for LZMA_IGNORE_CHECK to liblzma and made it
available in xz as --ignore-check.
* liblzma speed optimizations:
- Initialization of a new LZMA1 or LZMA2 encoder has been
optimized. (The speed of reinitializing an already-allocated
encoder isn't affected.) This helps when compressing many
small buffers with lzma_stream_buffer_encode() and other
similar situations where an already-allocated encoder state
isn't reused. This speed-up is visible in xz too if one
compresses many small files one at a time instead running xz
once and giving all files as command-line arguments.
- Buffer comparisons are now much faster when unaligned access
is allowed (configured with --enable-unaligned-access). This
speeds up encoding significantly. There is arch-specific code
for 32-bit and 64-bit x86 (32-bit needs SSE2 for the best
results and there's no run-time CPU detection for now).
For other archs there is only generic code which probably
isn't as optimal as arch-specific solutions could be.
- A few speed optimizations were made to the SHA-256 code.
(Note that the builtin SHA-256 code isn't used on all
operating systems.)
* liblzma can now be built with MSVC 2013 update 2 or later
using windows/config.h.
* Vietnamese translation was added.
5.1.3alpha (2013-10-26)
* All fixes from 5.0.5
* liblzma:
- Fixed a deadlock in the threaded encoder.
- Made the uses of lzma_allocator const correct.
- Added lzma_block_uncomp_encode() to create uncompressed
.xz Blocks using LZMA2 uncompressed chunks.
- Added support for native threads on Windows and the ability
to detect the number of CPU cores.
* xz:
- Fixed a race condition in the signal handling. It was
possible that e.g. the first SIGINT didn't make xz exit
if reading or writing blocked and one had bad luck. The fix
is non-trivial, so as of writing it is unknown if it will be
backported to the v5.0 branch.
- Made the progress indicator work correctly in threaded mode.
- Threaded encoder now works together with --block-list=SIZES.
- Added preliminary support for --flush-timeout=TIMEOUT.
It can be useful for (somewhat) real-time streaming. For
now the decompression side has to be done with something
else than the xz tool due to how xz does buffering, but this
should be fixed.
5.1.2alpha (2012-07-04)
* All fixes from 5.0.3 and 5.0.4
* liblzma:
- Fixed a deadlock and an invalid free() in the threaded encoder.
- Added support for symbol versioning. It is enabled by default
on GNU/Linux, other GNU-based systems, and FreeBSD.
- Use SHA-256 implementation from the operating system if one is
available in libc, libmd, or libutil. liblzma won't use e.g.
OpenSSL or libgcrypt to avoid introducing new dependencies.
- Fixed liblzma.pc for static linking.
- Fixed a few portability bugs.
* xz --decompress --single-stream now fixes the input position after
successful decompression. Now the following works:
echo foo | xz > foo.xz
echo bar | xz >> foo.xz
( xz -dc --single-stream ; xz -dc --single-stream ) < foo.xz
Note that it doesn't work if the input is not seekable
or if there is Stream Padding between the concatenated
.xz Streams.
* xz -lvv now shows the minimum xz version that is required to
decompress the file. Currently it is 5.0.0 for all supported .xz
files except files with empty LZMA2 streams require 5.0.2.
* Added an *incomplete* implementation of --block-list=SIZES to xz.
It only works correctly in single-threaded mode and when
--block-size isn't used at the same time. --block-list allows
specifying the sizes of Blocks which can be useful e.g. when
creating files for random-access reading.
5.1.1alpha (2011-04-12)
* All fixes from 5.0.2
* liblzma fixes that will also be included in 5.0.3:
- A memory leak was fixed.
- lzma_stream_buffer_encode() no longer creates an empty .xz
Block if encoding an empty buffer. Such an empty Block with
LZMA2 data would trigger a bug in 5.0.1 and older (see the
first bullet point in 5.0.2 notes). When releasing 5.0.2,
I thought that no encoder creates this kind of files but
I was wrong.
- Validate function arguments better in a few functions. Most
importantly, specifying an unsupported integrity check to
lzma_stream_buffer_encode() no longer creates a corrupt .xz
file. Probably no application tries to do that, so this
shouldn't be a big problem in practice.
- Document that lzma_block_buffer_encode(),
lzma_easy_buffer_encode(), lzma_stream_encoder(), and
lzma_stream_buffer_encode() may return LZMA_UNSUPPORTED_CHECK.
- The return values of the _memusage() functions are now
documented better.
* Support for multithreaded compression was added using the simplest
method, which splits the input data into blocks and compresses
them independently. Other methods will be added in the future.
The current method has room for improvement, e.g. it is possible
to reduce the memory usage.
* Added the options --single-stream and --block-size=SIZE to xz.
* xzdiff and xzgrep now support .lzo files if lzop is installed.
The .tzo suffix is also recognized as a shorthand for .tar.lzo.
* Support for short 8.3 filenames under DOS was added to xz. It is
experimental and may change before it gets into a stable release.
5.0.8 (2014-12-21)
* Fixed an old bug in xzgrep that affected OpenBSD and probably
a few other operating systems too.
* Updated French and German translations.
* Added support for detecting the amount of RAM on AmigaOS/AROS.
* Minor build system updates.
5.0.7 (2014-09-20)
* Fix regressions introduced in 5.0.6:
- Fix building with non-GNU make.
- Fix invalid Libs.private value in liblzma.pc which broke
static linking against liblzma if the linker flags were
taken from pkg-config.
5.0.6 (2014-09-14)
* xzgrep now exits with status 0 if at least one file matched.
* A few minor portability and build system fixes
5.0.5 (2013-06-30)
* lzmadec and liblzma's lzma_alone_decoder(): Support decompressing
.lzma files that have less common settings in the headers
(dictionary size other than 2^n or 2^n + 2^(n-1), or uncompressed
size greater than 256 GiB). The limitations existed to avoid false
positives when detecting .lzma files. The lc + lp <= 4 limitation
still remains since liblzma's LZMA decoder has that limitation.
NOTE: xz's .lzma support or liblzma's lzma_auto_decoder() are NOT
affected by this change. They still consider uncommon .lzma headers
as not being in the .lzma format. Changing this would give way too
many false positives.
* xz:
- Interaction of preset and custom filter chain options was
made less illogical. This affects only certain less typical
uses cases so few people are expected to notice this change.
Now when a custom filter chain option (e.g. --lzma2) is
specified, all preset options (-0 ... -9, -e) earlier are on
the command line are completely forgotten. Similarly, when
a preset option is specified, all custom filter chain options
earlier on the command line are completely forgotten.
Example 1: "xz -9 --lzma2=preset=5 -e" is equivalent to "xz -e"
which is equivalent to "xz -6e". Earlier -e didn't put xz back
into preset mode and thus the example command was equivalent
to "xz --lzma2=preset=5".
Example 2: "xz -9e --lzma2=preset=5 -7" is equivalent to
"xz -7". Earlier a custom filter chain option didn't make
xz forget the -e option so the example was equivalent to
"xz -7e".
- Fixes and improvements to error handling.
- Various fixes to the man page.
* xzless: Fixed to work with "less" versions 448 and later.
* xzgrep: Made -h an alias for --no-filename.
* Include the previously missing debug/translation.bash which can
be useful for translators.
* Include a build script for Mac OS X. This has been in the Git
repository since 2010 but due to a mistake in Makefile.am the
script hasn't been included in a release tarball before.
5.0.4 (2012-06-22)
* liblzma:
- Fix lzma_index_init(). It could crash if memory allocation
failed.
- Fix the possibility of an incorrect LZMA_BUF_ERROR when a BCJ
filter is used and the application only provides exactly as
much output space as is the uncompressed size of the file.
- Fix a bug in doc/examples_old/xz_pipe_decompress.c. It didn't
check if the last call to lzma_code() really returned
LZMA_STREAM_END, which made the program think that truncated
files are valid.
- New example programs in doc/examples (old programs are now in
doc/examples_old). These have more comments and more detailed
error handling.
* Fix "xz -lvv foo.xz". It could crash on some corrupted files.
* Fix output of "xz --robot -lv" and "xz --robot -lvv" which
incorrectly printed the filename also in the "foo (x/x)" format.
* Fix exit status of "xzdiff foo.xz bar.xz".
* Fix exit status of "xzgrep foo binary_file".
* Fix portability to EBCDIC systems.
* Fix a configure issue on AIX with the XL C compiler. See INSTALL
for details.
* Update French, German, Italian, and Polish translations.
5.0.3 (2011-05-21)
* liblzma fixes:
- A memory leak was fixed.
- lzma_stream_buffer_encode() no longer creates an empty .xz
Block if encoding an empty buffer. Such an empty Block with
LZMA2 data would trigger a bug in 5.0.1 and older (see the
first bullet point in 5.0.2 notes). When releasing 5.0.2,
I thought that no encoder creates this kind of files but
I was wrong.
- Validate function arguments better in a few functions. Most
importantly, specifying an unsupported integrity check to
lzma_stream_buffer_encode() no longer creates a corrupt .xz
file. Probably no application tries to do that, so this
shouldn't be a big problem in practice.
- Document that lzma_block_buffer_encode(),
lzma_easy_buffer_encode(), lzma_stream_encoder(), and
lzma_stream_buffer_encode() may return LZMA_UNSUPPORTED_CHECK.
- The return values of the _memusage() functions are now
documented better.
* Fix command name detection in xzgrep. xzegrep and xzfgrep now
correctly use egrep and fgrep instead of grep.
* French translation was added.
5.0.2 (2011-04-01)
* LZMA2 decompressor now correctly accepts LZMA2 streams with no
uncompressed data. Previously it considered them corrupt. The
bug can affect applications that use raw LZMA2 streams. It is
very unlikely to affect .xz files because no compressor creates
.xz files with empty LZMA2 streams. (Empty .xz files are a
different thing than empty LZMA2 streams.)
* "xz --suffix=.foo filename.foo" now refuses to compress the
file due to it already having the suffix .foo. It was already
documented on the man page, but the code lacked the test.
* "xzgrep -l foo bar.xz" works now.
* Polish translation was added.
5.0.1 (2011-01-29)
* xz --force now (de)compresses files that have setuid, setgid,
or sticky bit set and files that have multiple hard links.
The man page had it documented this way already, but the code
had a bug.
* gzip and bzip2 support in xzdiff was fixed.
* Portability fixes
* Minor fix to Czech translation
5.0.0 (2010-10-23)
Only the most important changes compared to 4.999.9beta are listed
here. One change is especially important:
* The memory usage limit is now disabled by default. Some scripts
written before this change may have used --memory=max on xz command
line or in XZ_OPT. THESE USES OF --memory=max SHOULD BE REMOVED
NOW, because they interfere with user's ability to set the memory
usage limit himself. If user-specified limit causes problems to
your script, blame the user.
Other significant changes:
* Added support for XZ_DEFAULTS environment variable. This variable
allows users to set default options for xz, e.g. default memory
usage limit or default compression level. Scripts that use xz
must never set or unset XZ_DEFAULTS. Scripts should use XZ_OPT
instead if they need a way to pass options to xz via an
environment variable.
* The compression settings associated with the preset levels
-0 ... -9 have been changed. --extreme was changed a little too.
It is now less likely to make compression worse, but with some
files the new --extreme may compress slightly worse than the old
--extreme.
* If a preset level (-0 ... -9) is specified after a custom filter
chain options have been used (e.g. --lzma2), the custom filter
chain will be forgotten. Earlier the preset options were
completely ignored after custom filter chain options had been
seen.
* xz will create sparse files when decompressing if the uncompressed
data contains long sequences of binary zeros. This is done even
when writing to standard output that is connected to a regular
file and certain additional conditions are met to make it safe.
* Support for "xz --list" was added. Combine with --verbose or
--verbose --verbose (-vv) for detailed output.
* I had hoped that liblzma API would have been stable after
4.999.9beta, but there have been a couple of changes in the
advanced features, which don't affect most applications:
- Index handling code was revised. If you were using the old
API, you will get a compiler error (so it's easy to notice).
- A subtle but important change was made to the Block handling
API. lzma_block.version has to be initialized even for
lzma_block_header_decode(). Code that doesn't do it will work
for now, but might break in the future, which makes this API
change easy to miss.
* The major soname has been bumped to 5.0.0. liblzma API and ABI
are now stable, so the need to recompile programs linking against
liblzma shouldn't arise soon.
