Commit Graph

600 Commits

Author SHA1 Message Date
Johannes Schindelin
5f1dbffc6f 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>
2016-08-29 17:44:59 +02:00
Johannes Schindelin
4c539f8ff4 Merge 'mingw-getcwd' into HEAD 2016-08-29 17:44:56 +02:00
Johannes Schindelin
36d0fb58a5 Merge pull request #156 from kblees/kb/symlinks
Symlink support
2016-08-29 17:44:55 +02:00
Johannes Schindelin
81fdf656f6 Merge 'fix-externals' into HEAD 2016-08-29 17:44:51 +02:00
Johannes Schindelin
4a571f815d 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>
2016-08-29 17:43:42 +02:00
Anton Serbulov
47c871b654 mingw: fix getcwd when the parent directory cannot be queried
`GetLongPathName()` function may fail when it is unable to query
the parent directory of a path component to determine the long name
for that component. It happens, because of it uses `FindFirstFile()`
function for each next short part of path. The `FindFirstFile()`
requires `List Directory` and `Synchronize` desired access for a calling
process.

In case of lacking such permission for some part of path,
the `GetLongPathName()` returns 0 as result and `GetLastError()`
returns ERROR_ACCESS_DENIED.

`GetFinalPathNameByHandle()` function can help in such cases, because
it requires `Read Attributes` and `Synchronize` desired access to the
target path only.

The `GetFinalPathNameByHandle()` function was introduced on
`Windows Server 2008/Windows Vista`. So we need to load it dynamically.

`CreateFile()` parameters:
    `lpFileName` = path to the current directory
    `dwDesiredAccess` = 0 (it means `Read Attributes` and `Synchronize`)
    `dwShareMode` = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE
                    (it prevents `Sharing Violation`)
    `lpSecurityAttributes` = NULL (default security attributes)
    `dwCreationDisposition` = OPEN_EXISTING
                              (required to obtain a directory handle)
    `dwFlagsAndAttributes` = FILE_FLAG_BACKUP_SEMANTICS
                             (required to obtain a directory handle)
    `hTemplateFile` = NULL (when opening an existing file or directory,
                            `CreateFile` ignores this parameter)

The string that is returned by `GetFinalPathNameByHandle()` function
uses the \\?\ syntax. To skip the prefix and convert backslashes
to slashes, the `normalize_ntpath()` mingw function will be used.

Note: `GetFinalPathNameByHandle()` function returns a final path.
It is the path that is returned when a path is fully resolved.
For example, for a symbolic link named "C:\tmp\mydir" that points to
"D:\yourdir", the final path would be "D:\yourdir".

Signed-off-by: Anton Serbulov <aserbulov@plesk.com>
2016-08-29 17:43:34 +02:00
Johannes Schindelin
0617d470d7 mingw: ensure getcwd() reports the correct case
When switching the current working directory, say, in PowerShell, it is
quite possible to use a different capitalization than the one that is
recorded on disk. While doing the same in `cmd.exe` adjusts the
capitalization magically, that does not happen in PowerShell so that
`getcwd()` returns the current directory in a different way than is
recorded on disk.

Typically this creates no problems except when you call

	git log .

in a subdirectory called, say, "GIT/" but you switched to "Git/" and
your `getcwd()` reports the latter, then Git won't understand that you
wanted to see the history as per the `GIT/` subdirectory but it thinks you
wanted to see the history of some directory that may have existed in the
past (but actually never did).

So let's be extra careful to adjust the capitalization of the current
directory before working with it.

Reported by a few PowerShell power users ;-)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:43:33 +02:00
lchiocca
534c7ae954 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>
2016-08-29 17:43:30 +02:00
Johannes Schindelin
8cf92591a1 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>
2016-08-29 17:43:29 +02:00
Karsten Blees
1cb1687fa0 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>
2016-08-29 17:43:28 +02:00
Karsten Blees
240d62f670 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>
2016-08-29 17:43:27 +02:00
Karsten Blees
af854da102 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>
2016-08-29 17:43:26 +02:00
Karsten Blees
6db70e4758 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>
2016-08-29 17:43:25 +02:00
Karsten Blees
7387832fec Win32: mingw_rename: support renaming symlinks
MSVCRT's _wrename() cannot rename symlinks over existing files: it returns
success without doing anything. Newer MSVCR*.dll versions probably do not
have this problem: according to CRT sources, they just call MoveFileEx()
with the MOVEFILE_COPY_ALLOWED flag.

Get rid of _wrename() and call MoveFileEx() with proper error handling.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:24 +02:00
Karsten Blees
09173f677b Win32: mingw_unlink: support symlinks to directories
_wunlink() / DeleteFileW() refuses to delete symlinks to directories. If
_wunlink() fails with ERROR_ACCESS_DENIED, try _wrmdir() as well.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:23 +02:00
Karsten Blees
156ffbcced Win32: add symlink-specific error codes
Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:22 +02:00
Karsten Blees
c87c2afaa7 Win32: change default of 'core.symlinks' to false
Symlinks on Windows don't work the same way as on Unix systems. E.g. there
are different types of symlinks for directories and files, creating
symlinks requires administrative privileges etc.

By default, disable symlink support on Windows. I.e. users explicitly have
to enable it with 'git config [--system|--global] core.symlinks true'.

The test suite ignores system / global config files. Allow testing *with*
symlink support by checking if native symlinks are enabled in MSys2 (via
'MSYS=winsymlinks:nativestrict').

Reminder: This would need to be changed if / when we find a way to run the
test suite in a non-MSys-based shell (e.g. dash).

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:21 +02:00
Karsten Blees
80e9fff1c6 Win32: factor out retry logic
The retry pattern is duplicated in three places. It also seems to be too
hard to use: mingw_unlink() and mingw_rmdir() duplicate the code to retry,
and both of them do so incompletely. They also do not restore errno if the
user answers 'no'.

Introduce a retry_ask_yes_no() helper function that handles retry with
small delay, asking the user, and restoring errno.

mingw_unlink: include _wchmod in the retry loop (which may fail if the
file is locked exclusively).

mingw_rmdir: include special error handling in the retry loop.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:20 +02:00
Karsten Blees
3b3cd657fa Win32: simplify loading of DLL functions
Dynamic loading of DLL functions is duplicated in several places.

Add a set of macros to simplify the process.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:19 +02:00
Karsten Blees
b62c4dcabc Win32: lstat(): return adequate stat.st_size for symlinks
Git typically doesn't trust the stat.st_size member of symlinks (e.g. see
strbuf_readlink()). However, some functions take shortcuts if st_size is 0
(e.g. diff_populate_filespec()).

In mingw_lstat() and fscache_lstat(), make sure to return an adequate size.

The extra overhead of opening and reading the reparse point to calculate
the exact size is not necessary, as git doesn't rely on the value anyway.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:18 +02:00
Karsten Blees
3632fa6537 Win32: teach fscache and dirent about symlinks
Move S_IFLNK detection to file_attr_to_st_mode() and reuse it in fscache.

Implement DT_LNK detection in dirent.c and the fscache readdir version.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:17 +02:00
Karsten Blees
106a1f6de1 Win32: let mingw_lstat() error early upon problems with reparse points
When obtaining lstat information for reparse points, we need to call
FindFirstFile() in addition to GetFileInformationEx() to obtain the type
of the reparse point (symlink, mount point etc.). However, currently there
is no error handling whatsoever if FindFirstFile() fails.

Call FindFirstFile() before modifying the stat *buf output parameter and
error out if the call fails.

Note: The FindFirstFile() return value includes all the data that we get
from GetFileAttributesEx(), so we could replace GetFileAttributesEx() with
FindFirstFile(). We don't do that because GetFileAttributesEx() is about
twice as fast for single files. I.e. we only pay the extra cost of calling
FindFirstFile() in the rare case that we encounter a reparse point.

Note: The indentation of the remaining reparse point code will be fixed in
the next patch.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:16 +02:00
Karsten Blees
4f28e68afb Win32: remove separate do_lstat() function
With the new mingw_stat() implementation, do_lstat() is only called from
mingw_lstat() (with follow == 0). Remove the extra function and the old
mingw_stat()-specific (follow == 1) logic.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:16 +02:00
Karsten Blees
feefcf075f Win32: implement stat() with symlink support
With respect to symlinks, the current stat() implementation is almost the
same as lstat(): except for the file type (st_mode & S_IFMT), it returns
information about the link rather than the target.

Implement stat by opening the file with as little permissions as possible
and calling GetFileInformationByHandle on it. This way, all link resoltion
is handled by the Windows file system layer.

If symlinks are disabled, use lstat() as before, but fail with ELOOP if a
symlink would have to be resolved.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:15 +02:00
Karsten Blees
b1d6106dcc Win32: don't call GetFileAttributes twice in mingw_lstat()
GetFileAttributes cannot handle paths with trailing dir separator. The
current [l]stat implementation calls GetFileAttributes twice if the path
has trailing slashes (first with the original path passed to [l]stat, and
and a second time with a path copy with trailing '/' removed).

With Unicode conversion, we get the length of the path for free and also
have a (wide char) buffer that can be modified.

Remove trailing directory separators before calling the Win32 API.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:43:14 +02:00
Adam Roben
c411fb483d Make non-.exe externals work again
7ebac8cb94 made launching of .exe
externals work when installed in Unicode paths. But it broke launching
of non-.exe externals, no matter where they were installed. We now
correctly maintain the UTF-8 and UTF-16 paths in tandem in lookup_prog.

This fixes t5526, among others.

Signed-off-by: Adam Roben <adam@roben.org>
2016-08-29 17:43:01 +02:00
Adam Roben
9a4dd13d09 Fix launching of externals from Unicode paths
If Git were installed in a path containing non-ASCII characters,
commands such as git-am and git-submodule, which are implemented as
externals, would fail to launch with the following error:

> fatal: 'am' appears to be a git command, but we were not
> able to execute it. Maybe git-am is broken?

This was due to lookup_prog not being Unicode-aware. It was somehow
missed in 2ee5a1a14a.

Note that the only problem in this function was calling
GetFileAttributes instead of GetFileAttributesW. The calls to access()
were fine because access() is a macro which resolves to mingw_access,
which already handles Unicode correctly. But I changed lookup_prog to
use _waccess directly so that we only convert the path to UTF-16 once.

Signed-off-by: Adam Roben <adam@roben.org>
2016-08-29 17:43:00 +02:00
Evgeny Pashkin
7f4d58cf0c Fixed wrong path delimiter in exe finding
On Windows XP3 in git bash
git clone git@github.com:octocat/Spoon-Knife.git
cd Spoon-Knife
git gui
menu Remote\Fetch from\origin
error: cannot spawn git: No such file or directory
error: could not run rev-list

if u run
git fetch --all
it worked normal in git bash or gitgui tools

In second version CreateProcess get 'C:\Git\libexec\git-core/git.exe' in
first version - C:/Git/libexec/git-core/git.exe and not executes (unix
slashes)

after fixing C:\Git\libexec\git-core\git.exe or
C:/Git/libexec/git-core\git.exe it works normal

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:59 +02:00
Karsten Blees
92b4b58526 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>
2016-08-29 17:42:41 +02:00
Karsten Blees
4e02ed56de 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>
2016-08-29 17:42:40 +02:00
Karsten Blees
e0b903cc8a 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>
2016-08-29 17:42:38 +02:00
Johannes Schindelin
e915369c02 mingw: HOT FIX: work around environment issues -- again
This developer should really, really have known better. The fact that we
are changing the environment in ways for which the MSVCRT is not
prepared for is bad enough. But then this developer followed the request
to re-enable nedmalloc -- despite the prediction that it would cause an
access violation, predicting it in the same message as the request to
re-enable nedmalloc, no less!

To paper over the issue until the time when this developer finds the
time to re-design the Unicode environment handling from scratch, let's
hope that cURL is the only library we are using that *may* set an
environment variable using MSVCRT's putenv() after we fscked the
environment up.

Note: this commit can serve as no source of pride to anyone, certainly
not yours truly. It is necessary as a quick and pragmatic stop gap,
though, to prevent worse problems.

Note: cURL manages to set the variable CHARSET when nedmalloc is *not*
enabled, without causing an access violation. In that case, it sets it
successfully to the value "cp" + GetACP() (hence it is our choice, too,
cURL may need it, Git does not):

	https://github.com/bagder/curl/blob/aa5808b5/lib/easy.c#L157-L162

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:37 +02:00
Johannes Schindelin
ec987eee27 mingw: be *very* wary about outside environment changes
The environment is modified in most surprising circumstances, and not
all of them are under Git's control. For example, calling
curl_global_init() on Windows will ensure that the CHARSET variable is
set, adding one if necessary.

While the previous commit worked around crashes triggered by such
outside changes of the environment by relaxing the requirement that the
environment be terminated by a NULL pointer, the other assumption made
by `mingw_getenv()` and `mingw_putenv()` is that the environment is
sorted, for efficient lookup via binary search.

Let's make real sure that our environment is intact before querying or
modifying it, and reinitialize our idea of the environment if necessary.

With this commit, before working on the environment we look briefly for
indicators that the environment was modified outside of our control, and
to ensure that it is terminated with a NULL pointer and sorted again in
that case.

Note: the indicators are maybe not sufficient. For example, when a
variable is removed, it will not be noticed. It might also be a problem
if outside changes to the environment result in a modified `environ`
pointer: it is unclear whether such a modification could result in a
problem when `mingw_putenv()` needs to `realloc()` the environment
buffer.

For the moment, however, the current fix works well enough, so let's
only face the potential problems when (and if!) they occur.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:33 +02:00
Johannes Schindelin
e278dde0e9 mingw: be more defensive when making the environment block
Outside of our Windows-specific code, the end of the environment can be
marked also by a pointer to a NUL character, not only by a NULL pointer
as our code assumed so far.

That led to a buffer overrun in `make_environment_block()` when running
`git-remote-https` in `mintty` (because `curl_global_init()` added the
`CHARSET` environment variable *outside* of `mingw_putenv()`, ending the
environment in a pointer to an empty string).

Side note for future debugging on Windows: when running programs in
`mintty`, the standard input/output/error is not connected to a Win32
Console, but instead is pipe()d. That means that even stderr may not be
written completely before a crash, but has to be fflush()ed explicitly.
For example, when debugging crashes, the developer should insert an
`fflush(stderr);` at the end of the `error()` function defined in
usage.c.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:32 +02:00
Johannes Schindelin
53da223fc2 UTF-8 environment: be a little bit more defensive
It is unlikely that we have an empty environment, ever, but *if* we do,
when `environ_size - 1` is passed to `bsearchenv()` it is misinterpreted
as a real large integer.

To make the code truly defensive, refuse to do anything at all if the
size is negative (which should not happen, of course).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:31 +02:00
Alan Davies
b8d2fa1456 winansi.c: Fix colourization on Cygwin pseudo terminals.
Git only colours the output and uses pagination if isatty() returns 1.
MSys and Cygwin emulate pseudo terminals via named pipes, meaning that
isatty() returns 0.

Commit 3adef8de55 fixed this for MSys
terminals, but not Cygwin.

The named pipes that Cygwin and Msys use are very similar.  MSys PTY pipes
are called 'msys-*-pty*' and Cygwin uses 'cygwin-*-pty*'.  This commit
modifies the existing check to allow both MSys and Cygwin PTY pipes to be
identified as TTYs.

Note that Pagination is still broken on Cygwin.  less.exe is spawned (as
seen in Process Explorer and using GIT_TRACE=1), but the output is not
being piped into it.

This partially fixes https://github.com/git-for-windows/git/issues/267

Signed-off-by: Alan Davies <alan.n.davies@gmail.com>
2016-08-29 17:42:29 +02:00
Cesar Eduardo Barros
a12f8628ac mingw: Embed a manifest to trick UAC into Doing The Right Thing
On Windows >= Vista, not having an application manifest with a
requestedExecutionLevel can cause several kinds of confusing behavior.

The first and more obvious behavior is "Installer Detection", where
Windows sometimes decides (by looking at things like the file name and
even sequences of bytes within the executable) that an executable is an
installer and should run elevated (causing the well-known popup dialog
to appear). In Git's context, subcommands such as "git patch-id" or "git
update-index" fall prey to this behavior.

The second and more confusing behavior is "File Virtualization". It
means that when files are written without having write permission, it
does not fail (as expected), but they are instead redirected to
somewhere else. When the files are read, the original contents are
returned, though, not the ones that were just written somewhere else.
Even more confusing, not all write accesses are redirected; Trying to
write to write-protected .exe files, for example, will fail instead of
redirecting.

In addition to being unwanted behavior, File Virtualization causes
dramatic slowdowns in Git (see for instance
http://code.google.com/p/msysgit/issues/detail?id=320).

There are two ways to prevent those two behaviors: Either you embed an
application manifest within all your executables, or you add an external
manifest (a file with the same name followed by .manifest) to all your
executables. Since Git's builtins are hardlinked (or copied), it is
simpler and more robust to embed a manifest.

A recent enough MSVC compiler should already embed a working internal
manifest, but for MinGW you have to do so by hand.

Very lightly tested on Wine, where like on Windows XP it should not make
any difference.

References:
  - New UAC Technologies for Windows Vista
    http://msdn.microsoft.com/en-us/library/bb756960.aspx
  - Create and Embed an Application Manifest (UAC)
    http://msdn.microsoft.com/en-us/library/bb756929.aspx

[js: simplified the embedding dramatically by reusing Git for Windows'
existing Windows resource file, removed the optional (and dubious)
processorArchitecture attribute of the manifest's assemblyIdentity
section.]

Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:28 +02:00
Johannes Schindelin
073898e0c8 Error out when mingw_startup() *and* NO_UNSETENV are active
The unsetenv code has no idea to update our environ_size, therefore
causing segmentation faults when environment variables are removed
without compat/mingw.c's knowing (MinGW's optimized lookup would try
to strcmp() against NULL in such a case).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:26 +02:00
Johannes Schindelin
db8d9aeedf Help debugging with MSys2 by optionally executing bash with strace
MSys2's strace facility is very useful for debugging... With this patch,
the bash will be executed through strace if the environment variable
GIT_STRACE_COMMANDS is set, which comes in real handy when investigating
issues in the test suite.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-08-29 17:42:25 +02:00
Karsten Blees
7fa3fa7afc 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>
2016-08-29 17:42:05 +02:00
Karsten Blees
a418a706c4 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>
2016-08-29 17:42:04 +02:00
Johannes Schindelin
25dea26f07 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>
2016-08-29 17:42:03 +02:00
Karsten Blees
3a663a0d9d 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>
2016-08-29 17:41:59 +02:00
Karsten Blees
a6cd831b1b Win32: 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>
2016-08-29 17:41:58 +02:00
Karsten Blees
5b468ba8af 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>
2016-08-29 17:41:56 +02:00
Karsten Blees
28cc85b372 Win32: 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 (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>
2016-08-29 17:41:55 +02:00
Karsten Blees
509b307131 Win32: dirent.c: Move opendir down
Move opendir down in preparation for the next patch.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:41:54 +02:00
Karsten Blees
829d006b6d Win32: make FILETIME conversion functions public
Signed-off-by: Karsten Blees <blees@dcon.de>
2016-08-29 17:41:53 +02:00
Junio C Hamano
3dc01702df Merge branch 'bw/mingw-avoid-inheriting-fd-to-lockfile'
The tempfile (hence its user lockfile) API lets the caller to open
a file descriptor to a temporary file, write into it and then
finalize it by first closing the filehandle and then either
removing or renaming the temporary file.  When the process spawns a
subprocess after obtaining the file descriptor, and if the
subprocess has not exited when the attempt to remove or rename is
made, the last step fails on Windows, because the subprocess has
the file descriptor still open.  Open tempfile with O_CLOEXEC flag
to avoid this (on Windows, this is mapped to O_NOINHERIT).

* bw/mingw-avoid-inheriting-fd-to-lockfile:
  mingw: ensure temporary file handles are not inherited by child processes
  t6026-merge-attr: child processes must not inherit index.lock handles
2016-08-25 13:55:07 -07:00
Junio C Hamano
13e11ff707 Merge branch 'js/no-html-bypass-on-windows'
On Windows, help.browser configuration variable used to be ignored,
which has been corrected.

* js/no-html-bypass-on-windows:
  Revert "display HTML in default browser using Windows' shell API"
2016-08-25 13:55:06 -07:00