Commit Graph

832 Commits

Author SHA1 Message Date
Johannes Schindelin
ab8aa22c99 mingw (git_terminal_prompt): do fall back to CONIN$/CONOUT$ method
To support Git Bash running in a MinTTY, we use a dirty trick to access
the MSYS2 pseudo terminal: we execute a Bash snippet that accesses
/dev/tty.

The idea was to fall back to writing to/reading from CONOUT$/CONIN$ if
that Bash call failed because Bash was not found.

However, we should fall back even in other error conditions, because we
have not successfully read the user input. Let's make it so.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:41:00 +01:00
Karsten Blees
f5bc316f98 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>
2020-03-10 20:41:00 +01:00
Karsten Blees
6b8b286d96 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>
2020-03-10 20:41:00 +01:00
Karsten Blees
0d198a5a6a 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>
2020-03-10 20:40:59 +01:00
Karsten Blees
7e6d86ae98 mingw: 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, added support for
chdir(), etc]

Thanks-to: Martin W. Kirst <maki@bitkings.de>
Thanks-to: Doug Kelly <dougk.ff7@gmail.com>
Original-test-by: Andrey Rogozhnikov <rogozhnikov.andrey@gmail.com>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:59 +01:00
Johannes Schindelin
14679c2c7d fscache: implement an FSCache-aware is_mount_point()
When FSCache is active, we can cache the reparse tag and use it directly
to determine whether a path refers to an NTFS junction, without any
additional, costly I/O.

Note: this change only makes a difference with the next commit, which
will make use of the FSCache in `git clean` (contingent on
`core.fscache` set, of course).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:59 +01:00
Johannes Schindelin
8718ff15df fscache: remember the reparse tag for each entry
We will use this in the next commit to implement an FSCache-aware
version of is_mount_point().

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:58 +01:00
Ben Peart
7b9a02cd28 fscache: teach fscache to use NtQueryDirectoryFile
Using FindFirstFileExW() requires the OS to allocate a 64K buffer for each
directory and then free it when we call FindClose().  Update fscache to call
the underlying kernel API NtQueryDirectoryFile so that we can do the buffer
management ourselves.  That allows us to allocate a single buffer for the
lifetime of the cache and reuse it for each directory.

This change improves performance of 'git status' by 18% in a repo with ~200K
files and 30k folders.

Documentation for NtQueryDirectoryFile can be found at:

https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntifs/nf-ntifs-ntquerydirectoryfile
https://docs.microsoft.com/en-us/windows/desktop/FileIO/file-attribute-constants
https://docs.microsoft.com/en-us/windows/desktop/fileio/reparse-point-tags

To determine if the specified directory is a symbolic link, inspect the
FileAttributes member to see if the FILE_ATTRIBUTE_REPARSE_POINT flag is
set. If so, EaSize will contain the reparse tag (this is a so far
undocumented feature, but confirmed by the NTFS developers). To
determine if the reparse point is a symbolic link (and not some other
form of reparse point), test whether the tag value equals the value
IO_REPARSE_TAG_SYMLINK.

The NtQueryDirectoryFile() call works best (and on Windows 8.1 and
earlier, it works *only*) with buffer sizes up to 64kB. Which is 32k
wide characters, so let's use that as our buffer size.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:58 +01:00
Ben Peart
30d4a3f693 fscache: make fscache_enable() thread safe
The recent change to make fscache thread specific relied on fscache_enable()
being called first from the primary thread before being called in parallel
from worker threads.  Make that more robust and protect it with a critical
section to avoid any issues.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ben Peart <benpeart@microsoft.com>
2020-03-10 20:40:58 +01:00
Ben Peart
06f40f3798 fscache: teach fscache to use mempool
Now that the fscache is single threaded, take advantage of the mem_pool as
the allocator to significantly reduce the cost of allocations and frees.

With the reduced cost of free, in future patches, we can start freeing the
fscache at the end of commands instead of just leaking it.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:57 +01:00
Ben Peart
c2f433ca5c fscache: update fscache to be thread specific instead of global
The threading model for fscache has been to have a single, global cache.
This puts requirements on it to be thread safe so that callers like
preload-index can call it from multiple threads.  This was implemented
with a single mutex and completion events which introduces contention
between the calling threads.

Simplify the threading model by making fscache thread specific.  This allows
us to remove the global mutex and synchronization events entirely and instead
associate a fscache with every thread that requests one. This works well with
the current multi-threading which divides the cache entries into blocks with
a separate thread processing each block.

At the end of each worker thread, if there is a fscache on the primary
thread, merge the cached results from the worker into the primary thread
cache. This enables us to reuse the cache later especially when scanning for
untracked files.

In testing, this reduced the time spent in preload_index() by about 25% and
also reduced the CPU utilization significantly.  On a repo with ~200K files,
it reduced overall status times by ~12%.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
2020-03-10 20:40:57 +01:00
Ben Peart
d3eae90598 fscache: fscache takes an initial size
Update enable_fscache() to take an optional initial size parameter which is
used to initialize the hashmap so that it can avoid having to rehash as
additional entries are added.

Add a separate disable_fscache() macro to make the code clearer and easier
to read.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:57 +01:00
Ben Peart
760c5c083f fscache: add fscache hit statistics
Track fscache hits and misses for lstat and opendir requests.  Reporting of
statistics is done when the cache is disabled for the last time and freed
and is only reported if GIT_TRACE_FSCACHE is set.

Sample output is:

11:33:11.836428 compat/win32/fscache.c:433 fscache: lstat 3775, opendir 263, total requests/misses 4052/269

Signed-off-by: Ben Peart <benpeart@microsoft.com>
2020-03-10 20:40:56 +01:00
Ben Peart
0c3b146bff fscache: add GIT_TEST_FSCACHE support
Add support to fscache to enable running the entire test suite with the
fscache enabled.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
2020-03-10 20:40:56 +01:00
Ben Peart
f62364bbb2 fscache: use FindFirstFileExW to avoid retrieving the short name
Use FindFirstFileExW with FindExInfoBasic to avoid forcing NTFS to look up
the short name.  Also switch to a larger (64K vs 4K) buffer using
FIND_FIRST_EX_LARGE_FETCH to minimize round trips to the kernel.

In a repo with ~200K files, this drops warm cache status times from 3.19
seconds to 2.67 seconds for a 16% savings.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
2020-03-10 20:40:55 +01:00
Takuto Ikuta
586ff150ef checkout.c: enable fscache for checkout again
This is retry of #1419.

I added flush_fscache macro to flush cached stats after disk writing
with tests for regression reported in #1438 and #1442.

git checkout checks each file path in sorted order, so cache flushing does not
make performance worse unless we have large number of modified files in
a directory containing many files.

Using chromium repository, I tested `git checkout .` performance when I
delete 10 files in different directories.
With this patch:
TotalSeconds: 4.307272
TotalSeconds: 4.4863595
TotalSeconds: 4.2975562
Avg: 4.36372923333333

Without this patch:
TotalSeconds: 20.9705431
TotalSeconds: 22.4867685
TotalSeconds: 18.8968292
Avg: 20.7847136

I confirmed this patch passed all tests in t/ with core_fscache=1.

Signed-off-by: Takuto Ikuta <tikuta@chromium.org>
2020-03-10 20:40:55 +01:00
Jeff Hostetler
5ce134f725 fscache: make fscache_enabled() public
Make fscache_enabled() function public rather than static.
Remove unneeded fscache_is_enabled() function.
Change is_fscache_enabled() macro to call fscache_enabled().

is_fscache_enabled() now takes a pathname so that the answer
is more precise and mean "is fscache enabled for this pathname",
since fscache only stores repo-relative paths and not absolute
paths, we can avoid attempting lookups for absolute paths.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2020-03-10 20:40:54 +01:00
Jeff Hostetler
d87701f564 dir.c: make add_excludes aware of fscache during status
Teach read_directory_recursive() and add_excludes() to
be aware of optional fscache and avoid trying to open()
and fstat() non-existant ".gitignore" files in every
directory in the worktree.

The current code in add_excludes() calls open() and then
fstat() for a ".gitignore" file in each directory present
in the worktree.  Change that when fscache is enabled to
call lstat() first and if present, call open().

This seems backwards because both lstat needs to do more
work than fstat.  But when fscache is enabled, fscache will
already know if the .gitignore file exists and can completely
avoid the IO calls.  This works because of the lstat diversion
to mingw_lstat when fscache is enabled.

This reduced status times on a 350K file enlistment of the
Windows repo on a NVMe SSD by 0.25 seconds.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2020-03-10 20:40:54 +01:00
Jeff Hostetler
f42b5587fb 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>
2020-03-10 20:40:53 +01:00
Jeff Hostetler
ba88b03701 fscache: add key for GIT_TRACE_FSCACHE
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:53 +01:00
Karsten Blees
5e68745767 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>
2020-03-10 20:40:53 +01:00
Karsten Blees
017ecc167c mingw: add a cache below mingw's lstat and dirent implementations
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>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:53 +01:00
Karsten Blees
ea537d7bdd add infrastructure for read-only file system level caches
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>
2020-03-10 20:40:53 +01:00
Karsten Blees
de9ac0e943 Win32: make the lstat implementation pluggable
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>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:52 +01:00
Karsten Blees
aef1a967df mingw: make the dirent implementation pluggable
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 (similar to vtable pointers in
Object-Oriented Programming). 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.

Make the fixed-size `dirent.d_name` buffer a flex array, as `d_name` may
be implementation specific (e.g. a caching implementation may allocate a
`struct dirent` with _just_ the size needed to hold the `d_name` in
question).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:52 +01:00
Karsten Blees
f3646f8363 Win32: dirent.c: Move opendir down
Move opendir down in preparation for the next patch.

Signed-off-by: Karsten Blees <blees@dcon.de>
2020-03-10 20:40:52 +01:00
Karsten Blees
7ad3cbc7a2 Win32: make FILETIME conversion functions public
We will use them in the upcoming "FSCache" patches (to accelerate
sequential lstat() calls).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:40:52 +01:00
Johannes Schindelin
8c641d9034 Merge pull request #2506 from dscho/issue-2283
Allow running Git directly from `C:\Program Files\Git\mingw64\bin\git.exe`
2020-03-10 20:39:54 +01:00
Johannes Schindelin
169e90e3a8 Merge pull request #2504 from dscho/access-repo-via-junction
Handle `git add <file>` where <file> traverses an NTFS junction
2020-03-10 20:39:53 +01:00
Johannes Schindelin
7515ece24c Merge pull request #2501 from jeffhostetler/clink-debug-curl
clink.pl: fix MSVC compile script to handle libcurl-d.lib
2020-03-10 20:39:52 +01:00
Johannes Schindelin
1fa83e7b9c Merge pull request #2488 from bmueller84/master
mingw: fix fatal error working on mapped network drives on Windows
2020-03-10 20:39:52 +01:00
Johannes Schindelin
d72334097f Merge pull request #2473 from dscho/com0-is-not-a-reserved-name
Do not mistake `COM0` for a reserved file name
2020-03-10 20:39:51 +01:00
Johannes Schindelin
fc20dc5197 Merge pull request #2449 from dscho/mingw-getcwd-and-symlinks
Do resolve symlinks in `getcwd()`
2020-03-10 20:39:50 +01:00
Johannes Schindelin
f1748d8094 Merge pull request #2405 from dscho/mingw-setsockopt
Make sure `errno` is set when socket operations fail
2020-03-10 20:39:50 +01:00
Johannes Schindelin
1e8111e6ef Merge pull request #2351 from PhilipOakley/vcpkg-tip
Vcpkg Install: detect lack of working Git, and note possible vcpkg time outs
2020-03-10 20:39:47 +01:00
Johannes Schindelin
189f632a74 Merge branch 'work-around-isilon'
It would appear that least the Isilon network filesystem (and possibly
other network filesystems, too), report non-standard error values when
trying to access a non-existing directory.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:46 +01:00
Johannes Schindelin
65eaffa758 Merge branch 'dont-clean-junctions'
This topic branch teaches `git clean` to respect NTFS junctions and Unix
bind mounts: it will now stop at those boundaries.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:45 +01:00
Johannes Schindelin
eeef7cdeef Merge branch 'msys2-strace'
Debugging support on MSYS2.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:45 +01:00
Johannes Schindelin
7347079abf Merge branch 'fsync-object-files-always'
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:42 +01:00
Johannes Schindelin
df8b670860 mingw: implement a platform-specific strbuf_realpath()
There is a Win32 API function to resolve symbolic links, and we can use
that instead of resolving them manually. Even better, this function also
resolves NTFS junction points (which are somewhat similar to bind
mounts).

This fixes https://github.com/git-for-windows/git/issues/2481.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:38 +01:00
Johannes Schindelin
307d2e3e36 mingw: allow git.exe to be used instead of the "Git wrapper"
Git for Windows wants to add `git.exe` to the users' `PATH`, without
cluttering the latter with unnecessary executables such as `wish.exe`.
To that end, it invented the concept of its "Git wrapper", i.e. a tiny
executable located in `C:\Program Files\Git\cmd\git.exe` (originally a
CMD script) whose sole purpose is to set up a couple of environment
variables and then spawn the _actual_ `git.exe` (which nowadays lives in
`C:\Program Files\Git\mingw64\bin\git.exe` for 64-bit, and the obvious
equivalent for 32-bit installations).

Currently, the following environment variables are set unless already
initialized:

- `MSYSTEM`, to make sure that the MSYS2 Bash and the MSYS2 Perl
  interpreter behave as expected, and

- `PLINK_PROTOCOL`, to force PuTTY's `plink.exe` to use the SSH
  protocol instead of Telnet,

- `PATH`, to make sure that the `bin` folder in the user's home
  directory, as well as the `/mingw64/bin` and the `/usr/bin`
  directories are included. The trick here is that the `/mingw64/bin/`
  and `/usr/bin/` directories are relative to the top-level installation
  directory of Git for Windows (which the included Bash interprets as
  `/`, i.e. as the MSYS pseudo root directory).

Using the absence of `MSYSTEM` as a tell-tale, we can detect in
`git.exe` whether these environment variables have been initialized
properly. Therefore we can call `C:\Program Files\Git\mingw64\bin\git`
in-place after this change, without having to call Git through the Git
wrapper.

Obviously, above-mentioned directories must be _prepended_ to the `PATH`
variable, otherwise we risk picking up executables from unrelated Git
installations. We do that by constructing the new `PATH` value from
scratch, appending `$HOME/bin` (if `HOME` is set), then the MSYS2 system
directories, and then appending the original `PATH`.

Side note: this modification of the `PATH` variable is independent of
the modification necessary to reach the executables and scripts in
`/mingw64/libexec/git-core/`, i.e. the `GIT_EXEC_PATH`. That
modification is still performed by Git, elsewhere, long after making the
changes described above.

While we _still_ cannot simply hard-link `mingw64\bin\git.exe` to `cmd`
(because the former depends on a couple of `.dll` files that are only in
`mingw64\bin`, i.e. calling `...\cmd\git.exe` would fail to load due to
missing dependencies), at least we can now avoid that extra process of
running the Git wrapper (which then has to wait for the spawned
`git.exe` to finish) by calling `...\mingw64\bin\git.exe` directly, via
its absolute path.

Testing this is in Git's test suite tricky: we set up a "new" MSYS
pseudo-root and copy the `git.exe` file into the appropriate location,
then verify that `MSYSTEM` is set properly, and also that the `PATH` is
modified so that scripts can be found in `$HOME/bin`, `/mingw64/bin/`
and `/usr/bin/`.

This addresses https://github.com/git-for-windows/git/issues/2283

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:38 +01:00
Johannes Schindelin
d4fa4f939c 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>
2020-03-10 20:39:38 +01:00
Jeff Hostetler
10ec0b37e8 clink.pl: fix MSVC compile script to handle libcurl-d.lib
Update clink.pl to link with either libcurl.lib or libcurl-d.lib
depending on whether DEBUG=1 is set.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:37 +01:00
Bjoern Mueller
5681c207ff mingw: fix fatal error working on mapped network drives on Windows
In 1e64d18 (mingw: do resolve symlinks in `getcwd()`) a problem was
introduced that causes git for Windows to stop working with certain
mapped network drives (in particular, drives that are mapped to
locations with long path names). Error message was "fatal: Unable to
read current working directory: No such file or directory". Present
change fixes this issue as discussed in
https://github.com/git-for-windows/git/issues/2480

Signed-off-by: Bjoern Mueller <bjoernm@gmx.de>
2020-03-10 20:39:37 +01:00
Johannes Schindelin
f984c86ec4 mingw: do not treat COM0 as a reserved file name
In 4dc42c6c18 (mingw: refuse paths containing reserved names,
2019-12-21), we started disallowing file names that are reserved, e.g.
`NUL`, `CONOUT$`, etc.

This included `COM<n>` where `<n>` is a digit. Unfortunately, this
includes `COM0` but only `COM1`, ..., `COM9` are reserved, according to
the official documentation, `COM0` is mentioned in the "NT Namespaces"
section but it is explicitly _omitted_ from the list of reserved names:
https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions

Tests corroborate this: it is totally possible to write a file called
`com0.c` on Windows 10, but not `com1.c`.

So let's tighten the code to disallow only the reserved `COM<n>` file
names, but to allow `COM0` again.

This fixes https://github.com/git-for-windows/git/issues/2470.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:37 +01:00
Johannes Schindelin
d75a1b93f3 mingw: do resolve symlinks in getcwd()
As pointed out in https://github.com/git-for-windows/git/issues/1676,
the `git rev-parse --is-inside-work-tree` command currently fails when
the current directory's path contains symbolic links.

The underlying reason for this bug is that `getcwd()` is supposed to
resolve symbolic links, but our `mingw_getcwd()` implementation did not.

We do have all the building blocks for that, though: the
`GetFinalPathByHandleW()` function will resolve symbolic links. However,
we only called that function if `GetLongPathNameW()` failed, for
historical reasons: the latter function was supported for a long time,
but the former API function was introduced only with Windows Vista, and
we used to support also Windows XP. With that support having been
dropped, we are free to call the symbolic link-resolving function right
away.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:37 +01:00
Johannes Schindelin
fabf4d6399 mingw: make sure errno is set correctly when socket operations fail
The winsock2 library provides functions that work on different data
types than file descriptors, therefore we wrap them.

But that is not the only difference: they also do not set `errno` but
expect the callers to enquire about errors via `WSAGetLastError()`.

Let's translate that into appropriate `errno` values whenever the socket
operations fail so that Git's code base does not have to change its
expectations.

This closes https://github.com/git-for-windows/git/issues/2404

Helped-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:36 +01:00
Philip Oakley
ddb800cbab vcpkg_install: add comment regarding slow network connections
The vcpkg downloads may not succeed. Warn careful readers of the time out.

A simple retry will usually resolve the issue.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:36 +01:00
Nathan Sanders
5696478461 mingw: cope with the Isilon network file system
On certain network filesystems (currently encounterd with Isilon, but in
theory more network storage solutions could be causing the same issue),
when the directory in question is missing, `raceproof_create_file()`
fails with an `ERROR_INVALID_PARAMETER` instead of an
`ERROR_PATH_NOT_FOUND`.

Since it is highly unlikely that we produce such an error by mistake
(the parameters we pass are fairly benign), we can be relatively certain
that the directory is missing in this instance. So let's just translate
that error automagically.

This fixes https://github.com/git-for-windows/git/issues/1345.

Signed-off-by: Nathan Sanders <spekbukkem@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:35 +01:00
Johannes Schindelin
61949dc333 clean: remove mount points when possible
Windows' equivalent to "bind mounts", NTFS junction points, can be
unlinked without affecting the mount target. This is clearly what users
expect to happen when they call `git clean -dfx` in a worktree that
contains NTFS junction points: the junction should be removed, and the
target directory of said junction should be left alone (unless it is
inside the worktree).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2020-03-10 20:39:35 +01:00