With this topic branch, the PERL5LIB variable is unset to avoid external
settings from interfering with Git's own Perl interpreter.
This branch also cleans up some of our Windows-only config setting code
(and this will need to be rearranged in the next merging rebase so that
the cleanup comes first, and fscache and longPaths support build on
top).
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
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>
Coverity is a tool to analyze code statically, trying to find common (or
not so common) problems before they occur in production.
Coverity offers its services to Open Source software, and just like
upstream Git, Git for Windows applied and was granted the use.
While Coverity reports a lot of false positives due to Git's (ab-)use of
the FLEX_ARRAY feature (where it declares a 0-byte or 1-byte array at the
end of a struct, and then allocates a variable-length data structure
holding a variable-length string at the end, so that the struct as well as
the string can be released with a single free()), there were a few issues
reported that are true positives, and not all of them were resource leaks
in builtins (for which it is considered kind of okay to not release memory
just before exit() is called anyway).
This topic branch tries to address a couple of those issues.
Note: there are a couple more issues left, either because they are tricky
to resolve (in some cases, the custody of occasionally-allocated memory is
very unclear) or because it is unclear whether they are false positives
(due to the hard-to-reason-about nature of the code). It's a start,
though.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This topic branch allows us to specify absolute paths without the drive
prefix e.g. when cloning.
Example:
C:\Users\me> git clone https://github.com/git/git \upstream-git
This will clone into a new directory C:\upstream-git, in line with how
Windows interprets absolute paths.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
There is really no reason why we would need to hold onto the allocated
string longer than necessary.
Reported by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The buffer allocated by shorten_unambiguous_ref() needs to be released.
Discovered by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When the `name_rev()` function is asked to dereference the tip name, it
allocates memory. But when it turns out that another tip already
described the commit better than the current one, we forgot to release
the memory.
Pointed out by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The `guess_ref()` returns an allocated buffer of which `make_linked_ref()`
does not take custody (`alloc_ref()` makes a copy), therefore we need to
release the buffer afterwards.
Noticed via Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We free()d the `log` buffer when dwim_log() returned 1, but not when it
returned a larger value (which meant that it still allocated the buffer
but we simply ignored it).
While in the vicinity, make sure that the `reflogs` structure as well as
the `branch` variable are released properly, too.
Identified by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The setup_explicit_git_dir() function does not take custody of the string
passed as first parameter; we have to release it if we turned the value of
git_dir into an absolute path.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Coverity reported a memory leak in this function. However, it can only
be called once, as setup_git_directory() changes global state and hence
is not reentrant.
Mark the variable as static to indicate that this is a singleton.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This function did a whole lot of unnecessary work, such as reading in
four files just to figure out that, oh, hey, we do not need to look at
them after all because the HEAD is not detached.
Simplify the entire function to return early when possible, to read in
the files only when necessary, and to release the allocated memory
always (there was a leak, reported via Coverity, where we failed to
release the allocated strings if the HEAD is not detached).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This change addresses part of the NEEDSWORK comment above the code,
therefore the comment needs to be adjusted, too.
Discovered via Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
While POSIX states that it is okay to pass EOF to isspace() (and it seems
to be implied that EOF should *not* be treated as whitespace), and also to
pass EOF to ungetc() (which seems to be intended to fail without buffering
the character), it is much better to handle these cases explicitly. Not
only does it reduce head-scratching (and helps static analysis avoid
reporting false positives), it also lets us handle files containing
nothing but whitespace by erroring out.
Reported via Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This change plugs a couple of memory leaks and makes sure that the file
descriptor is closed in run_dir_diff().
Spotted by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When we fail to read, or parse, the file, we still want to close the file
descriptor and release the strbuf.
Reported via Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In case of errors, we really want the file descriptor to be closed.
Discovered by a Coverity scan.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
It would appear that we allocate (and forget to release) memory if the
patch ID is not even defined.
Reported by the Coverity tool.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When we could not convert the UTF-8 sequence into Unicode for writing to
the Console, we should not try to write an insanely-long sequence of
invalid wide characters (mistaking the negative return value for an
unsigned length).
Reported by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
To initialize the foreground color attributes of "plain text", our ANSI
emulation tries to infer them from the currently attached console while
running the is_console() function. This function first tries to detect any
console attached to stdout, then it is called with stderr.
If neither stdout nor stderr has any console attached, it does not
actually matter what we use for "plain text" attributes, as we never need
to output any text to any console in that case.
However, after working on stdout and stderr, is_console() is called with
stdin, and it still tries to initialize the "plain text" attributes if
they had not been initialized earlier. In this case, we cannot detect any
attributes, and we used an uninitialized value for them.
Naturally, Coverity complained about this use case because it could not
reason about the code deeply enough to figure out that we do not even use
those attributes in that case.
Let's just initialize the value to 0 in that case, both to avoid future
Coverity reports, and to help catch future regressions in case anybody
changes the order of the is_console() calls (which would make the text
black on black).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the (admittedly, concocted) case that PATH consists only of path
delimiters, we would leak the duplicated string.
Reported by Coverity.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
