Commit Graph

705 Commits

Author SHA1 Message Date
Johannes Schindelin
e20a052a5a mingw: when path_lookup() failed, try BusyBox
BusyBox comes with a ton of applets ("applet" being the identical
concept to Git's "builtins"). And similar to Git's builtins, the applets
can be called via `busybox <command>`, or the BusyBox executable can be
copied/hard-linked to the command name.

The similarities do not end here. Just as with Git's builtins, it is
problematic that BusyBox' hard-linked applets cannot easily be put into
a .zip file: .zip archives have no concept of hard-links and therefore
would store identical copies (and also extract identical copies,
"inflating" the archive unnecessarily).

To counteract that issue, MinGit already ships without hard-linked
copies of the builtins, and the plan is to do the same with BusyBox'
applets: simply ship busybox.exe as single executable, without
hard-linked applets.

To accommodate that, Git is being taught by this commit a very special
trick, exploiting the fact that it is possible to call an executable
with a command-line whose argv[0] is different from the executable's
name: when `sh` is to be spawned, and no `sh` is found in the PATH, but
busybox.exe is, use that executable (with unchanged argv).

Likewise, if any executable to be spawned is not on the PATH, but
busybox.exe is found, parse the output of `busybox.exe --help` to find
out what applets are included, and if the command matches an included
applet name, use busybox.exe to execute it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
b0541befc2 mingw: explicitly specify with which cmd to prefix the cmdline
The main idea of this patch is that even if we have to look up the
absolute path of the script, if only the basename was specified as
argv[0], then we should use that basename on the command line, too, not
the absolute path.

This patch will also help with the upcoming patch where we automatically
substitute "sh ..." by "busybox sh ..." if "sh" is not in the PATH but
"busybox" is: we will do that by substituting the actual executable, but
still keep prepending "sh" to the command line.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
b7e75e05f0 t5580: test cloning without file://, test fetching via UNC paths
It gets a bit silly to add the commands to the name of the test script,
so let's just rename it while we're testing more UNC stuff.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
98121f5bf8 mingw: special-case arguments to sh
The MSYS2 runtime does its best to emulate the command-line wildcard
expansion and de-quoting which would be performed by the calling Unix
shell on Unix systems.

Those Unix shell quoting rules differ from the quoting rules applying to
Windows' cmd and Powershell, making it a little awkward to quote
command-line parameters properly when spawning other processes.

In particular, git.exe passes arguments to subprocesses that are *not*
intended to be interpreted as wildcards, and if they contain
backslashes, those are not to be interpreted as escape characters, e.g.
when passing Windows paths.

Note: this is only a problem when calling MSYS2 executables, not when
calling MINGW executables such as git.exe. However, we do call MSYS2
executables frequently, most notably when setting the use_shell flag in
the child_process structure.

There is no elegant way to determine whether the .exe file to be
executed is an MSYS2 program or a MINGW one. But since the use case of
passing a command line through the shell is so prevalent, we need to
work around this issue at least when executing sh.exe.

Let's introduce an ugly, hard-coded test whether argv[0] is "sh", and
whether it refers to the MSYS2 Bash, to determine whether we need to
quote the arguments differently than usual.

That still does not fix the issue completely, but at least it is
something.

Incidentally, this also fixes the problem where `git clone \\server\repo`
failed due to incorrect handling of the backslashes when handing the path
to the git-upload-pack process.

We need to take care to quote not only whitespace, but also curly
brackets. As aliases frequently go through the MSYS2 Bash, and
as aliases frequently get parameters such as HEAD@{yesterday}, let's
make sure that this does not regress by adding a test case for that.

Helped-by: Kim Gybels <kgybels@infogroep.be>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
864c105d58 mingw: try to create symlinks without elevated permissions
With Windows 10 Build 14972 in Developer Mode, a new flag is supported
by CreateSymbolicLink() to create symbolic links even when running
outside of an elevated session (which was previously required).

This new flag is called SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE and
has the numeric value 0x02.

Previous Windows 10 versions will not understand that flag and return an
ERROR_INVALID_PARAMETER, therefore we have to be careful to try passing
that flag only when the build number indicates that it is supported.

For more information about the new flag, see this blog post:
https://blogs.windows.com/buildingapps/2016/12/02/symlinks-windows-10/

This patch is loosely based on the patch submitted by Samuel D. Leslie
as https://github.com/git-for-windows/git/pull/1184.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
58782f0a02 mingw: kill child processes in a gentler way
The TerminateProcess() function does not actually leave the child
processes any chance to perform any cleanup operations. This is bad
insofar as Git itself expects its signal handlers to run.

A symptom is e.g. a left-behind .lock file that would not be left behind
if the same operation was run, say, on Linux.

To remedy this situation, we use an obscure trick: we inject a thread
into the process that needs to be killed and to let that thread run the
ExitProcess() function with the desired exit status. Thanks J Wyman for
describing this trick.

The advantage is that the ExitProcess() function lets the atexit
handlers run. While this is still different from what Git expects (i.e.
running a signal handler), in practice Git sets up signal handlers and
atexit handlers that call the same code to clean up after itself.

In case that the gentle method to terminate the process failed, we still
fall back to calling TerminateProcess(), but in that case we now also
make sure that processes spawned by the spawned process are terminated;
TerminateProcess() does not give the spawned process a chance to do so
itself.

Please note that this change only affects how Git for Windows tries to
terminate processes spawned by Git's own executables. Third-party
software that *calls* Git and wants to terminate it *still* need to make
sure to imitate this gentle method, otherwise this patch will not have
any effect.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
cac53eee31 Merge branch 'drive-prefix'
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>
2018-06-08 18:35:28 +02:00
Johannes Schindelin
c59bcbd31e mingw: fix isatty() after dup2()
We newly handle isatty() by special-casing the stdin/stdout/stderr file
descriptors, caching the return value. However, we missed the case where
dup2() overrides the respective file descriptor.

That poses a problem e.g. where the `show` builtin asks for a pager very
early, the `setup_pager()` function sets the pager depending on the
return value of `isatty()` and then redirects stdout. Subsequently,
`cmd_log_init_finish()` calls `setup_pager()` *again*. What should
happen now is that `isatty()` reports that stdout is *not* a TTY and
consequently stdout should be left alone.

Let's override dup2() to handle this appropriately.

This fixes https://github.com/git-for-windows/git/issues/1077

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
94ed5a1445 mingw: ensure valid CTYPE
A change between versions 2.4.1 and 2.6.0 of the MSYS2 runtime modified
how Cygwin's runtime (and hence Git for Windows' MSYS2 runtime
derivative) handles locales: d16a56306d (Consolidate wctomb/mbtowc calls
for POSIX-1.2008, 2016-07-20).

An unintended side-effect is that "cold-calling" into the POSIX
emulation will start with a locale based on the current code page,
something that Git for Windows is very ill-prepared for, as it expects
to be able to pass a command-line containing non-ASCII characters to the
shell without having those characters munged.

One symptom of this behavior: when `git clone` or `git fetch` shell out
to call `git-upload-pack` with a path that contains non-ASCII
characters, the shell tried to interpret the entire command-line
(including command-line parameters) as executable path, which obviously
must fail.

This fixes https://github.com/git-for-windows/git/issues/1036

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
f9c9fadd85 Merge pull request #994 from jeffhostetler/jeffhostetler/fscache_nfd
fscache: add not-found directory cache to fscache
2018-06-08 18:35:19 +02:00
Johannes Schindelin
97117f6842 Merge pull request #1003 from shoelzer/master
poll: Use GetTickCount64 to avoid wraparound issues
2018-06-08 18:35:08 +02:00
Johannes Schindelin
a76c21f386 Merge 'misc-vs-fixes-extra' into HEAD
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:35:02 +02:00
Johannes Schindelin
285dc629c6 Merge branch 'visual-studio'
This topic branch teaches the project generator to generate a Visual
Studio solution, ready to be opened in Visual Studio 2010 or later.

The idea, of course, is to let some automatic build job generate and
commit the project files with

	make MSVC=1 vcxproj

and then (force-)push to a special-purpose branch.

The major part of this branch thicket concerns itself not only with
generating the Visual Studio project files, but making sure that the
user can then run the test suite from a regular Git Bash (i.e. *not*
requiring a Git for Windows SDK), e.g. by running

	cd t
	prove --timer --jobs 15 ./t[0-9]*.sh

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:35:00 +02:00
Johannes Schindelin
2d86e984b7 mingw: make readlink() independent of core.symlinks
Regardless whether we think we are able to create symbolic links, we
should always read them.

This fixes https://github.com/git-for-windows/git/issues/958

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 18:29:52 +02:00
Johannes Schindelin
97c434e90a Merge branch 'spawn-with-spaces'
This change lets us spawn .bat scripts whose paths contain spaces.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:42:53 +02:00
Johannes Schindelin
ac0068fc62 Merge pull request #773 from jeffhostetler/vs2015
Build with VS2015
2018-06-08 13:42:38 +02:00
Johannes Schindelin
466e56791b Merge branch 'program-data-config'
This branch introduces support for reading the "Windows-wide" Git
configuration from `%PROGRAMDATA%\Git\config`. As these settings are
intended to be shared between *all* Git-related software, that config
file takes an even lower precedence than `$(prefix)/etc/gitconfig`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:42:33 +02:00
Johannes Schindelin
bb32d95873 Merge 'mingw-getcwd' into HEAD 2018-06-08 13:42:30 +02:00
Johannes Schindelin
d4f1873782 Merge pull request #443 from kblees/kb/nanosecond-file-times-v2.5.3
nanosecond file times for v2.5.3
2018-06-08 13:42:27 +02:00
Johannes Schindelin
d73cb206d6 Merge pull request #156 from kblees/kb/symlinks
Symlink support
2018-06-08 13:42:24 +02:00
Johannes Schindelin
b0632f5594 Merge 'fix-externals' into HEAD 2018-06-08 13:42:19 +02:00
Johannes Schindelin
14a6404718 Merge 'misc-vs-fixes' into HEAD 2018-06-08 13:41:03 +02:00
Johannes Schindelin
0f525a91c9 mingw: allow absolute paths without drive prefix
When specifying an absolute path without a drive prefix, we convert that
path internally. Let's make sure that we handle that case properly, too
;-)

This fixes the command

	git clone https://github.com/git-for-windows/git \G4W

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
cd9f3885b7 msvc: avoid debug assertion windows in Debug Mode
For regular debugging, it is pretty helpful when a debug assertion in a
running application triggers a window that offers to start the debugger.

However, when running the test suite, it is not so helpful, in
particular when the debug assertions are then suppressed anyway because
we disable the invalid parameter checking (via invalidcontinue.obj, see
the comment in config.mak.uname about that object for more information).

So let's simply disable that window in Debug Mode (it is already
disabled in Release Mode).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
bfe2ce2c85 mingw: support spawning programs containing spaces in their names
The CreateProcessW() function does not really support spaces in its
first argument, lpApplicationName. But it supports passing NULL as
lpApplicationName, which makes it figure out the application from the
(possibly quoted) first argument of lpCommandLine.

Let's use that trick (if we are certain that the first argument matches
the executable's path) to support launching programs whose path contains
spaces.

This fixes https://github.com/git-for-windows/git/issue/692

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
7a0a91e602 compat/vcbuild: possibly reuse Git for Windows' SDK's NuGet
In Git for Windows' SDK, there is already a script to package Git for
Windows as a NuGet package, downloading nuget.exe if needed.

Let's just fall back to using that executable (if it is there) if
nuget.exe was not found in the PATH.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
58b8283250 Win32: implement nanosecond-precision file times
We no longer use any of MSVCRT's stat-functions, so there's no need to
stick to a CRT-compatible 'struct stat' either.

Define and use our own POSIX-2013-compatible 'struct stat' with nanosecond-
precision file times.

Note: Due to performance issues when using git variants with different file
time resolutions, this patch does *not* yet enable nanosecond precision in
the Makefile (use 'make USE_NSEC=1').

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
lchiocca
f40d1c93c2 The stat() function should be independent of core.symlinks
The contract for the stat() and lstat() function is:
> stat():  stats the file pointed to by path and fills in buf.
> lstat(): is identical to stat(), except that if path is a symbolic link,
>          then the link itself is stat-ed, not the file that it refers to.

stat() should always return the statistics of the file or directory a
symbolic link is pointing to. The lstat() function is used to get the
stats for the symlink. Hence the check should not be there.

Signed-off-by: Loris Chiocca <loris@chiocca.ch>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
4448963c6a mingw: load system libraries the recommended way
When we access IPv6-related functions, we load the corresponding system
library using the `LoadLibrary()` function, which is not the recommended
way to load system libraries.

In practice, it does not make a difference: the `ws2_32.dll` library
containing the IPv6 functions is already loaded into memory, so
LoadLibrary() simply reuses the already-loaded library.

Still, recommended way is recommended way, so let's use that instead.

While at it, also adjust the code in contrib/ that loads system libraries.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Jeff Hostetler
baee1cf973 fscache: remember not-found directories
Teach FSCACHE to remember "not found" directories.

This is a performance optimization.

FSCACHE is a performance optimization available for Windows.  It
intercepts Posix-style lstat() calls into an in-memory directory
using FindFirst/FindNext.  It improves performance on Windows by
catching the first lstat() call in a directory, using FindFirst/
FindNext to read the list of files (and attribute data) for the
entire directory into the cache, and short-cut subsequent lstat()
calls in the same directory.  This gives a major performance
boost on Windows.

However, it does not remember "not found" directories.  When STATUS
runs and there are missing directories, the lstat() interception
fails to find the parent directory and simply return ENOENT for the
file -- it does not remember that the FindFirst on the directory
failed. Thus subsequent lstat() calls in the same directory, each
re-attempt the FindFirst.  This completely defeats any performance
gains.

This can be seen by doing a sparse-checkout on a large repo and
then doing a read-tree to reset the skip-worktree bits and then
running status.

This change reduced status times for my very large repo by 60%.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
be2a3d8c7c Win32: fix 'lstat("dir/")' with long paths
Use a suffciently large buffer to strip the trailing slash.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Jeff Hostetler
74665d181e vs2015: remove todo list item from README_vs2015.txt
Remove todo list item for vs2015 build notes regarding
the third party DLLs.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-06-08 13:38:15 +02:00
Andreas Heiduk
5c96177266 Remove support for XP specific config location
Current Git for Windows supports an additional configuration location
for system setting. On contemporary versionws of Windows this is
$PROGRAMDATA/Git/config. But XP does not know about $PRORGRAMDATA so
$ALLUSERSPROFILE/Application Data/Git/config was used.

XP itself is EOL for quite some time and Git for Windows ceased to
support it officially with version 2.10.0 (release 3 Sep 2016).

https://github.com/git-for-windows/git/wiki/FAQ#which-versions-of-windows-are-supported
https://git-for-windows.github.io/requirements.html

Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
2018-06-08 13:38:15 +02:00
Karsten Blees
27c26c5c54 Win32: replace MSVCRT's fstat() with a Win32-based implementation
fstat() is the only stat-related CRT function for which we don't have a
full replacement yet (and thus the only reason to stick with MSVCRT's
'struct stat' definition).

Fully implement fstat(), in preparation of implementing a POSIX 2013
compatible 'struct stat' with nanosecond-precision file times.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
80a5a9cb47 mingw: keep trailing slashes for _wchdir() and readlink()
This is needed so that `_wchdir()` can be used with drive root
directories, e.g. C:\ (`_wchdir("C:")` fails to switch the directory
to the root directory).

This fixes https://github.com/msysgit/git/issues/359 (in Git for Windows
2.x only, though).

Likewise, `readlink()`'s semantics require a trailing slash for symbolic
links pointing to directories. Otherwise all checked out symbolic links
pointing to directories would be marked as modified even directly after a
fresh clone.

This fixes https://github.com/git-for-windows/git/issues/210

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Jeff Hostetler
3dd2ee115d fscache: add key for GIT_TRACE_FSCACHE
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
9eee0030d5 Win32: support long paths
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>
2018-06-08 13:38:15 +02:00
Karsten Blees
52b656d41f Win32: symlink: add support for symlinks to directories
Symlinks on Windows have a flag that indicates whether the target is a file
or a directory. Symlinks of wrong type simply don't work. This even affects
core Win32 APIs (e.g. DeleteFile() refuses to delete directory symlinks).

However, CreateFile() with FILE_FLAG_BACKUP_SEMANTICS doesn't seem to care.
Check the target type by first creating a tentative file symlink, opening
it, and checking the type of the resulting handle. If it is a directory,
recreate the symlink with the directory flag set.

It is possible to create symlinks before the target exists (or in case of
symlinks to symlinks: before the target type is known). If this happens,
create a tentative file symlink and postpone the directory decision: keep
a list of phantom symlinks to be processed whenever a new directory is
created in mingw_mkdir().

Limitations: This algorithm may fail if a link target changes from file to
directory or vice versa, or if the target directory is created in another
process.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
ba29b85dcc compat/terminal.c: only use the Windows console if bash 'read -r' fails
Accessing the Windows console through the special CONIN$ / CONOUT$ devices
doesn't work properly for non-ASCII usernames an passwords.

It also doesn't work for terminal emulators that hide the native console
window (such as mintty), and 'TERM=xterm*' is not necessarily a reliable
indicator for such terminals.

The new shell_prompt() function, on the other hand, works fine for both
MSys1 and MSys2, in native console windows as well as mintty, and properly
supports Unicode. It just needs bash on the path (for 'read -s', which is
bash-specific).

On Windows, try to use the shell to read from the terminal. If that fails
with ENOENT (i.e. bash was not found), use CONIN/OUT as fallback.

Note: To test this, create a UTF-8 credential file with non-ASCII chars,
e.g. in git-bash: 'echo url=http://täst.com > cred.txt'. Then in git-cmd,
'git credential fill <cred.txt' works (shell version), while calling git
without the git-wrapper (i.e. 'mingw64\bin\git credential fill <cred.txt')
mangles non-ASCII chars in both console output and input.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
13260eb866 Win32: support long paths
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>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
ea4c77c0d1 Windows: add support for a Windows-wide configuration
Between the libgit2 and the Git for Windows project, there has been a
discussion how we could share Git configuration to avoid duplication (or
worse: skew).

Earlier, libgit2 was nice enough to just re-use Git for Windows'

	C:\Program Files (x86)\Git\etc\gitconfig

but with the upcoming Git for Windows 2.x, there would be more paths to
search, as we will have 64-bit and 32-bit versions, and the
corresponding config files will be in %PROGRAMFILES%\Git\mingw64\etc and
...\mingw32\etc, respectively.

Worse: there are portable Git for Windows versions out there which live
in totally unrelated directories, still.

Therefore we came to a consensus to use `%PROGRAMDATA%\Git\config` as the
location for shared Git settings that are of wider interest than just Git
for Windows.

On XP, there is no %PROGRAMDATA%, therefore we need to use
"%ALLUSERSPROFILE%\Application Data\Git\config" in those setups.

Of course, the configuration in `%PROGRAMDATA%\Git\config` has the
widest reach, therefore it must take the lowest precedence, i.e. Git for
Windows can still override settings in its `etc/gitconfig` file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
250564147b Merge 'default-ident' into HEAD 2018-06-08 13:39:43 +02:00
Karsten Blees
b881598ecd Win32: implement basic symlink() functionality (file symlinks only)
Implement symlink() that always creates file symlinks. Fails with ENOSYS
if symlinks are disabled or unsupported.

Note: CreateSymbolicLinkW() was introduced with symlink support in Windows
Vista. For compatibility with Windows XP, we need to load it dynamically
and fail gracefully if it isnt's available.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
83e9e70709 mingw: Support git_terminal_prompt with more terminals
The `git_terminal_prompt()` function expects the terminal window to be
attached to a Win32 Console. However, this is not the case with terminal
windows other than `cmd.exe`'s, e.g. with MSys2's own `mintty`.

Non-cmd terminals such as `mintty` still have to have a Win32 Console
to be proper console programs, but have to hide the Win32 Console to
be able to provide more flexibility (such as being resizeable not only
vertically but also horizontally). By writing to that Win32 Console,
`git_terminal_prompt()` manages only to send the prompt to nowhere and
to wait for input from a Console to which the user has no access.

This commit introduces a function specifically to support `mintty` -- or
other terminals that are compatible with MSys2's `/dev/tty` emulation. We
use the `TERM` environment variable as an indicator for that: if the value
starts with "xterm" (such as `mintty`'s "xterm_256color"), we prefer to
let `xterm_prompt()` handle the user interaction.

The most prominent user of `git_terminal_prompt()` is certainly
`git-remote-https.exe`. It is an interesting use case because both
`stdin` and `stdout` are redirected when Git calls said executable, yet
it still wants to access the terminal.

When running inside a `mintty`, the terminal is not accessible to the
`git-remote-https.exe` program, though, because it is a MinGW program
and the `mintty` terminal is not backed by a Win32 console.

To solve that problem, we simply call out to the shell -- which is an
*MSys2* program and can therefore access `/dev/tty`.

Helped-by: nalla <nalla@hamal.uberspace.de>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
4b673f2e78 terminal.c: guard the inclusion of inttypes.h
We do have a lovely Makefile option to state that that header file is
not available. Let's use it everywhere...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
3d9ea693a9 Win32: implement readlink()
Implement readlink() by reading NTFS reparse points. Works for symlinks
and directory junctions. If symlinks are disabled, fail with ENOSYS.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Johannes Schindelin
33415e1e3d obstack: fix compiler warning
MS Visual C suggests that the construct

	condition ? (int) i : (ptrdiff_t) d

is incorrect. Let's fix this by casting to ptrdiff_t also for the
positive arm of the conditional.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
bccec23042 fscache: load directories only once
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>
2018-06-08 13:38:15 +02:00
Karsten Blees
b7a1a71c0d Win32: mingw_chdir: change to symlink-resolved directory
If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.

Note: Git's real_path() function bases its link resolution algorithm on
this property of chdir(). Unfortunately, the current directory on Windows
is limited to only MAX_PATH (260) characters. Therefore using symlinks and
long paths in combination may be problematic.

Note: GetFinalPathNameByHandleW() was introduced with symlink support in
Windows Vista. Thus, for compatibility with Windows XP, we need to load it
dynamically and behave gracefully if it isnt's available.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00
Karsten Blees
6cb96e1984 mingw: initialize HOME on startup
HOME initialization was historically duplicated in many different places,
including /etc/profile, launch scripts such as git-bash.vbs and gitk.cmd,
and (although slightly broken) in the git-wrapper.

Even unrelated projects such as GitExtensions and TortoiseGit need to
implement the same logic to be able to call git directly.

Initialize HOME in git's own startup code so that we can eventually retire
all the duplicate initialization code.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-06-08 13:38:15 +02:00