Windows paths are typically limited to MAX_PATH = 260 characters, even
though the underlying NTFS file system supports paths up to 32,767 chars.
This limitation is also evident in Windows Explorer, cmd.exe and many
other applications (including IDEs).
Particularly annoying is that most Windows APIs return bogus error codes
if a relative path only barely exceeds MAX_PATH in conjunction with the
current directory, e.g. ERROR_PATH_NOT_FOUND / ENOENT instead of the
infinitely more helpful ERROR_FILENAME_EXCED_RANGE / ENAMETOOLONG.
Many Windows wide char APIs support longer than MAX_PATH paths through the
file namespace prefix ('\\?\' or '\\?\UNC\') followed by an absolute path.
Notable exceptions include functions dealing with executables and the
current directory (CreateProcess, LoadLibrary, Get/SetCurrentDirectory) as
well as the entire shell API (ShellExecute, SHGetSpecialFolderPath...).
Introduce a handle_long_path function to check the length of a specified
path properly (and fail with ENAMETOOLONG), and to optionally expand long
paths using the '\\?\' file namespace prefix. Short paths will not be
modified, so we don't need to worry about device names (NUL, CON, AUX).
Contrary to MSDN docs, the GetFullPathNameW function doesn't seem to be
limited to MAX_PATH (at least not on Win7), so we can use it to do the
heavy lifting of the conversion (translate '/' to '\', eliminate '.' and
'..', and make an absolute path).
Add long path error checking to xutftowcs_path for APIs with hard MAX_PATH
limit.
Add a new MAX_LONG_PATH constant and xutftowcs_long_path function for APIs
that support long paths.
While improved error checking is always active, long paths support must be
explicitly enabled via 'core.longpaths' option. This is to prevent end
users to shoot themselves in the foot by checking out files that Windows
Explorer, cmd/bash or their favorite IDE cannot handle.
Test suite:
Test the case is when the full pathname length of a dir is close
to 260 (MAX_PATH).
Bug report and an original reproducer by Andrey Rogozhnikov:
https://github.com/msysgit/git/pull/122#issuecomment-43604199
Note that the test cannot rely on the presence of short names, as they
are not enabled by default except on the system drive.
[jes: adjusted test number to avoid conflicts, reinstated && chain,
adjusted test to work without short names]
Thanks-to: Martin W. Kirst <maki@bitkings.de>
Thanks-to: Doug Kelly <dougk.ff7@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>
Original-test-by: Andrey Rogozhnikov <rogozhnikov.andrey@gmail.com>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Windows paths are typically limited to MAX_PATH = 260 characters, even
though the underlying NTFS file system supports paths up to 32,767 chars.
This limitation is also evident in Windows Explorer, cmd.exe and many
other applications (including IDEs).
Particularly annoying is that most Windows APIs return bogus error codes
if a relative path only barely exceeds MAX_PATH in conjunction with the
current directory, e.g. ERROR_PATH_NOT_FOUND / ENOENT instead of the
infinitely more helpful ERROR_FILENAME_EXCED_RANGE / ENAMETOOLONG.
Many Windows wide char APIs support longer than MAX_PATH paths through the
file namespace prefix ('\\?\' or '\\?\UNC\') followed by an absolute path.
Notable exceptions include functions dealing with executables and the
current directory (CreateProcess, LoadLibrary, Get/SetCurrentDirectory) as
well as the entire shell API (ShellExecute, SHGetSpecialFolderPath...).
Introduce a handle_long_path function to check the length of a specified
path properly (and fail with ENAMETOOLONG), and to optionally expand long
paths using the '\\?\' file namespace prefix. Short paths will not be
modified, so we don't need to worry about device names (NUL, CON, AUX).
Contrary to MSDN docs, the GetFullPathNameW function doesn't seem to be
limited to MAX_PATH (at least not on Win7), so we can use it to do the
heavy lifting of the conversion (translate '/' to '\', eliminate '.' and
'..', and make an absolute path).
Add long path error checking to xutftowcs_path for APIs with hard MAX_PATH
limit.
Add a new MAX_LONG_PATH constant and xutftowcs_long_path function for APIs
that support long paths.
While improved error checking is always active, long paths support must be
explicitly enabled via 'core.longpaths' option. This is to prevent end
users to shoot themselves in the foot by checking out files that Windows
Explorer, cmd/bash or their favorite IDE cannot handle.
Test suite:
Test the case is when the full pathname length of a dir is close
to 260 (MAX_PATH).
Bug report and an original reproducer by Andrey Rogozhnikov:
https://github.com/msysgit/git/pull/122#issuecomment-43604199
[jes: adjusted test number to avoid conflicts]
Thanks-to: Martin W. Kirst <maki@bitkings.de>
Thanks-to: Doug Kelly <dougk.ff7@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>
Original-test-by: Andrey Rogozhnikov <rogozhnikov.andrey@gmail.com>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
[jes: adusted test number to avoid conflicts, fixed non-portable use of
the 'export' statement]
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
If multiple threads access a directory that is not yet in the cache, the
directory will be loaded by each thread. Only one of the results is added
to the cache, all others are leaked. This wastes performance and memory.
On cache miss, add a future object to the cache to indicate that the
directory is currently being loaded. Subsequent threads register themselves
with the future object and wait. When the first thread has loaded the
directory, it replaces the future object with the result and notifies
waiting threads.
Signed-off-by: Karsten Blees <blees@dcon.de>
Checking the work tree status is quite slow on Windows, due to slow lstat
emulation (git calls lstat once for each file in the index). Windows
operating system APIs seem to be much better at scanning the status
of entire directories than checking single files.
Add an lstat implementation that uses a cache for lstat data. Cache misses
read the entire parent directory and add it to the cache. Subsequent lstat
calls for the same directory are served directly from the cache.
Also implement opendir / readdir / closedir so that they create and use
directory listings in the cache.
The cache doesn't track file system changes and doesn't plug into any
modifying file APIs, so it has to be explicitly enabled for git functions
that don't modify the working copy.
Note: in an earlier version of this patch, the cache was always active and
tracked file system changes via ReadDirectoryChangesW. However, this was
much more complex and had negative impact on the performance of modifying
git commands such as 'git checkout'.
Signed-off-by: Karsten Blees <blees@dcon.de>
Add a macro to mark code sections that only read from the file system,
along with a config option and documentation.
This facilitates implementation of relatively simple file system level
caches without the need to synchronize with the file system.
Enable read-only sections for 'git status' and preload_index.
Signed-off-by: Karsten Blees <blees@dcon.de>
Emulating the POSIX lstat API on Windows via GetFileAttributes[Ex] is quite
slow. Windows operating system APIs seem to be much better at scanning the
status of entire directories than checking single files. A caching
implementation may improve performance by bulk-reading entire directories
or reusing data obtained via opendir / readdir.
Make the lstat implementation pluggable so that it can be switched at
runtime, e.g. based on a config option.
Signed-off-by: Karsten Blees <blees@dcon.de>
Emulating the POSIX dirent API on Windows via FindFirstFile/FindNextFile is
pretty staightforward, however, most of the information provided in the
WIN32_FIND_DATA structure is thrown away in the process. A more
sophisticated implementation may cache this data, e.g. for later reuse in
calls to lstat.
Make the dirent implementation pluggable so that it can be switched at
runtime, e.g. based on a config option.
Define a base DIR structure with pointers to readdir/closedir that match
the opendir implementation (i.e. similar to vtable pointers in OOP).
Define readdir/closedir so that they call the function pointers in the DIR
structure. This allows to choose the opendir implementation on a
call-by-call basis.
Move the fixed sized dirent.d_name buffer to the dirent-specific DIR
structure, as d_name may be implementation specific (e.g. a caching
implementation may just set d_name to point into the cache instead of
copying the entire file name string).
Signed-off-by: Karsten Blees <blees@dcon.de>
Git for Windows ships with its own Perl interpreter, and insists on
using it, so it will most likely wreak havoc if PERL5LIB is set before
launching Git.
Let's just unset that environment variables when spawning processes.
To make this feature extensible (and overrideable), there is a new
config setting `core.unsetenvvars` that allows specifying a
comma-separated list of names to unset before spawning processes.
Reported by Gabriel Fuhrmann.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the Git for Windows project, we have ample precendent for config
settings that apply to Windows, and to Windows only.
Let's formalize this concept by introducing a platform_core_config()
function that can be #define'd in a platform-specific manner.
This will allow us to contain platform-specific code better, as the
corresponding variables no longer need to be exported so that they can
be defined in environment.c and be set in config.c
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the convention elsewhere (and prepares for the case where we may
need to pass callback data).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Fix a regression in 88f6ffc1c2 ("add -p: only bind search key if
there's more than one hunk", 2018-02-13) which is present in
2.17.0-rc*, but not 2.16.0.
In Perl, regex variables like $1 always refer to the last regex
match. When the aforementioned change added a new regex match between
the old match and the corresponding code that was expecting $1, the $1
variable would always be undef, since the newly inserted regex match
doesn't have any captures.
As a result the "/" feature to search for a string in a hunk by regex
completely broke, on git.git:
$ perl -pi -e 's/Git/Tig/g' README.md
$ ./git --exec-path=$PWD add -p
[..]
Stage this hunk [y,n,q,a,d,j,J,g,/,s,e,?]? s
Split into 4 hunks.
[...]
Stage this hunk [y,n,q,a,d,j,J,g,/,s,e,?]? /Many
Use of uninitialized value $1 in string eq at /home/avar/g/git/git-add--interactive line 1568, <STDIN> line 1.
search for regex? Many
I.e. the initial "/regex" command wouldn't work, and would always emit
a warning and ask again for a regex, now it works as intended again.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack gained partial clone support (v2.17.0-rc0~132^2~12,
2017-12-08), it was guarded by the uploadpack.allowFilter config item
to allow server operators to control when they start supporting it.
That config item didn't go far enough, though: it controls whether the
'filter' capability is advertised, but if a (custom) client ignores
the capability advertisement and passes a filter specification anyway,
the server would handle that despite allowFilter being false.
This is particularly significant if a security bug is discovered in
this new experimental partial clone code. Installations without
uploadpack.allowFilter ought not to be affected since they don't
intend to support partial clone, but they would be swept up into being
vulnerable.
Simplify and limit the attack surface by making uploadpack.allowFilter
disable the feature, not just the advertisement of it.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Hotfix for recently graduated topic that give help to completion
scripts from the Git subcommands that are being completed
* nd/parseopt-completion:
t9902: disable test on the list of merge-strategies under GETTEXT_POISON
completion: clear cached --options when sourcing the completion script
This fixes a regression introduced in 2e612731b5 (submodule: port
submodule subcommand 'deinit' from shell to C, 2018-01-15), when
handling pathspecs that do not exist gracefully. This restores the
historic behavior of reporting the pathspec as unknown and returning
instead of reporting a bug.
Reported-by: Peter Oberndorfer <kumbayo84@arcor.de>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 1ada5020b3 ("stash: use stash_push for no verb form", 2017-02-28),
when the pathspec argument was introduced in 'git stash', that was also
documented. However I forgot to remove an extra square bracket after
the '--message' argument, even though the square bracket should have
been after the pathspec argument (where it was also added).
Remove the extra square bracket after the '--message' argument, to show
that the pathspec argument should be used with the 'push' verb.
While the pathspec argument can be used without the push verb, that's a
special case described later in the man page, and removing the first extra
square bracket instead of the second one makes the synopis easier to
understand.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code to learn the list of merge strategies from the output of
"git merge -s help" forces C locale, so that it can notice the
message shown to indicate where the list starts in the output.
However, GETTEXT_POISON build corrupts its output even when run in
the C locale, and we cannot expect this test to succeed.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Whitespace errors are easy to create but hard to check manually. Add
two git commands that detect these whitespace errors to the commit
cleanup section of CONTRIBUTING.md.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Git documentation refers to $HOME and $XDG_CONFIG_HOME often, but does not specify how or where these values come from on Windows where neither is set by default. The new documentation reflects the behavior of setup_windows_environment() in compat/mingw.c.
Signed-off-by: Alejandro Barreto <alejandro.barreto@ni.com>
When working in the root directory of a file share (this is only
possible in Git Bash and Powershell, but not in CMD), the current
directory is reported without a trailing slash.
This is different from Unix and standard Windows directories: both / and
C:\ are reported with a trailing slash as current directories.
If a Git worktree is located there, Git is not quite prepared for that:
while it does manage to find the .git directory/file, it returns as
length of the top-level directory's path *one more* than the length of
the current directory, and setup_git_directory_gently() would then
return an undefined string as prefix.
In practice, this undefined string usually points to NUL bytes, and does
not cause much harm. Under rare circumstances that are really involved
to reproduce (and not reliably so), the reported prefix could be a
suffix string of Git's exec path, though.
A careful analysis determined that this bug is unlikely to be
exploitable, therefore we mark this as a regular bug fix.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Getting started contributing to Git can be difficult on a Windows machine.
CONTRIBUTING.md contains a guide to getting started, including detailed
steps for setting up build tools, running tests, and submitting patches
to upstream.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
The current CONTRIBUTING.md file is actually a code of conduct. This is
a valuable document, but is misnamed. A following patch will replace
CONTRIBUTING.md with a guide to contributing to Git using a Windows machine.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
