Commit Graph

59035 Commits

Author SHA1 Message Date
Karsten Blees
d49f92f851 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>
2016-03-29 10:24:40 +02:00
Karsten Blees
a5dd56aafc 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>
2016-03-29 10:24:40 +02:00
Karsten Blees
25d3386ddf lockfile.c: use is_dir_sep() instead of hardcoded '/' checks
Signed-off-by: Karsten Blees <blees@dcon.de>
2016-03-29 10:24:39 +02:00
Karsten Blees
47c2443811 strbuf_readlink: support link targets that exceed PATH_MAX
strbuf_readlink() refuses to read link targets that exceed PATH_MAX (even
if a sufficient size was specified by the caller).

As some platforms support longer paths, remove this restriction (similar
to strbuf_getcwd()).

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-03-29 10:24:31 +02:00
Karsten Blees
04bd9e6f17 strbuf_readlink: don't call readlink twice if hint is the exact link size
strbuf_readlink() calls readlink() twice if the hint argument specifies the
exact size of the link target (e.g. by passing stat.st_size as returned by
lstat()). This is necessary because 'readlink(..., hint) == hint' could
mean that the buffer was too small.

Use hint + 1 as buffer size to prevent this.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-03-29 10:22:54 +02:00
Thomas Braun
02f1487075 Config option to disable side-band-64k for transport
Since commit 0c499ea60f the send-pack builtin uses the side-band-64k
capability if advertised by the server.

Unfortunately this breaks pushing over the dump git protocol if used
over a network connection.

The detailed reasons for this breakage are (by courtesy of Jeff Preshing,
quoted from ttps://groups.google.com/d/msg/msysgit/at8D7J-h7mw/eaLujILGUWoJ):
----------------------------------------------------------------------------
MinGW wraps Windows sockets in CRT file descriptors in order to mimic the
functionality of POSIX sockets. This causes msvcrt.dll to treat sockets as
Installable File System (IFS) handles, calling ReadFile, WriteFile,
DuplicateHandle and CloseHandle on them. This approach works well in simple
cases on recent versions of Windows, but does not support all usage patterns.
In particular, using this approach, any attempt to read & write concurrently
on the same socket (from one or more processes) will deadlock in a scenario
where the read waits for a response from the server which is only invoked after
the write. This is what send_pack currently attempts to do in the use_sideband
codepath.
----------------------------------------------------------------------------

The new config option "sendpack.sideband" allows to override the side-band-64k
capability of the server, and thus makes the dump git protocol work.

Other transportation methods like ssh and http/https still benefit from
the sideband channel, therefore the default value of "sendpack.sideband"
is still true.

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>
2016-03-29 10:22:52 +02:00
Johannes Schindelin
29a0068952 README.md: Add a Windows-specific preamble
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:22:41 +02:00
Johannes Schindelin
1498f3bc64 Add a Code of Conduct
It is better to state clearly expectations and intentions than to assume
quietly that everybody agrees.

This Code of Conduct is the Open Code of Conduct as per
http://todogroup.org/opencodeofconduct/ (the only modifications are the
adjustments to reflect that there is no "response team" in addition to the
Git for Windows maintainer, and the addition of the link to the Open Code
of Conduct itself).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:44 +02:00
Heiko Voigt
7fed9941c4 help: correct behavior for is_executable on Windows
The previous implementation said that the filesystem information on
Windows is not reliable to determine whether a file is executable.
To find gather this information it was peeking into the first two bytes
of a file to see whether it looks executable.
Apart from the fact that on Windows executables are usually defined as
such by their extension it lead to slow opening of help file in some
situations.

When you have virus scanner running calling open on an executable file
is a potentially expensive operation. See the following measurements (in
seconds) for example.

With virus scanner running (coldcache):

$ ./a.exe /libexec/git-core/
before open (git-add.exe): 0.000000
after open (git-add.exe): 0.412873
before open (git-annotate.exe): 0.000175
after open (git-annotate.exe): 0.397925
before open (git-apply.exe): 0.000243
after open (git-apply.exe): 0.399996
before open (git-archive.exe): 0.000147
after open (git-archive.exe): 0.397783
before open (git-bisect--helper.exe): 0.000160
after open (git-bisect--helper.exe): 0.397700
before open (git-blame.exe): 0.000160
after open (git-blame.exe): 0.399136
...

With virus scanner running (hotcache):

$ ./a.exe /libexec/git-core/
before open (git-add.exe): 0.000000
after open (git-add.exe): 0.000325
before open (git-annotate.exe): 0.000229
after open (git-annotate.exe): 0.000177
before open (git-apply.exe): 0.000167
after open (git-apply.exe): 0.000150
before open (git-archive.exe): 0.000154
after open (git-archive.exe): 0.000156
before open (git-bisect--helper.exe): 0.000132
after open (git-bisect--helper.exe): 0.000180
before open (git-blame.exe): 0.000718
after open (git-blame.exe): 0.000724
...

This test did just list the given directory and open() each file in it.

With this patch I get:

$ time git help git
Launching default browser to display HTML ...

real    0m8.723s
user    0m0.000s
sys     0m0.000s

and without

$ time git help git
Launching default browser to display HTML ...

real    1m37.734s
user    0m0.000s
sys     0m0.031s

both tests with cold cache and giving the machine some time to settle
down after restart.

Signed-off-by: Heiko Voigt <heiko.voigt@mahr.de>
2016-03-29 10:21:43 +02:00
Adam Roben
8f42b8a4a1 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>
2016-03-29 10:21:42 +02:00
Adam Roben
0df142379c 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>
2016-03-29 10:21:41 +02:00
Evgeny Pashkin
53b0021449 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>
2016-03-29 10:21:40 +02:00
Johannes Schindelin
64b063e9fa Always auto-gc after calling a fast-import transport
After importing anything with fast-import, we should always let the
garbage collector do its job, since the objects are written to disk
inefficiently.

This brings down an initial import of http://selenic.com/hg from about
230 megabytes to about 14.

In the future, we may want to make this configurable on a per-remote
basis, or maybe teach fast-import about it in the first place.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:39 +02:00
Sverre Rabbelier
a000e477ed remote-helper: check helper status after import/export
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
2016-03-29 10:21:38 +02:00
Sverre Rabbelier
a3f01f8c15 transport-helper: add trailing --
[PT: ensure we add an additional element to the argv array]
2016-03-29 10:21:38 +02:00
Johannes Schindelin
bf95e241ce fast-export: do not refer to non-existing marks
When calling `git fast-export a..a b` when a and b refer to the same
commit, nothing would be exported, and an incorrect reset line would
be printed for b ('from :0').

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
2016-03-29 10:21:37 +02:00
Johannes Schindelin
c679b3b888 t3404: fix typo
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:36 +02:00
Johannes Schindelin
1810dbe235 t0302: add forgotten quotes
This was probably missed because nobody had a left-over `trash/`
directory and the `-f` flag made sure that no error message was
produced when the file was not found that *actually* wanted to
be removed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:36 +02:00
Johannes Schindelin
3cfd8ac2fa Skip t9020 with MSys2
POSIX-to-Windows path mangling would make it fail.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:35 +02:00
Johannes Schindelin
cf0428ece0 Mark t0027-auto-crlf as cheap enough for MinGW
t0027 is marked expensive, but really, for MinGW we want to run these
tests always.

Suggested by Thomas Braun.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:34 +02:00
Thomas Braun
e471b05684 t0027: Disable test on MINGW
We can't mmap 2GB of RAM on our 32bit platform, so
just disable the test.

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>
2016-03-29 10:21:34 +02:00
Thomas Braun
a2ad7f4d91 t5503: Mark flaky tests as known breakages
As non reliable tests are nasty.

Signed-off-by: Thomas Braun <thomas.braun@byte-physics.de>
2016-03-29 10:21:33 +02:00
Stepan Kasal
b2fdd3a6ef Revert "test: fix t7001 cp to use POSIX options"
This reverts commit 00764ca1, as our ancient version of "cp" has
problems about the "new" POSIX option "-P" (yields exit code 1).
2016-03-29 10:21:33 +02:00
Karsten Blees
fa97809f16 t800[12]: work around MSys limitation
MSys works very hard to convert Unix-style paths into DOS-style ones.
*Very* hard.

So hard, indeed, that

	git blame -L/hello/,/green/

is translated into something like

	git blame -LC:/msysgit/hello/,C:/msysgit/green/

As seen in msys_p2w in src\msys\msys\rt\src\winsup\cygwin\path.cc, line
3204ff:

	case '-':
	  //
	  // here we check for POSIX paths as attributes to a POSIX switch.
	  //
	...

seemingly absolute POSIX paths in single-letter options get expanded by
msys.dll unless they contain '=' or ';'.

So a quick and very dirty fix is to use '-L/;*evil/'. (Using an equal sign
works only when it is before a comma, so in the above example, /=*green/
would still be converted to a DOS-style path.)

Commit-message-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:32 +02:00
Sverre Rabbelier
842f76646a t9350: point out that refs are not updated correctly
This happens only when the corresponding commits are not exported in
the current fast-export run. This can happen either when the relevant
commit is already marked, or when the commit is explicitly marked
as UNINTERESTING with a negative ref by another argument.

This breaks fast-export basec remote helpers.

Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
2016-03-29 10:21:32 +02:00
Johannes Schindelin
54d8d117f8 Handle new t1501 test case properly with MinGW
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:31 +02:00
Johannes Schindelin
a0ef3c5a22 Windows: force-recompile git.res for differing architectures
When git.rc is compiled into git.res, the result is actually dependent
on the architecture. That is, you cannot simply link a 32-bit git.res
into a 64-bit git.exe.

Therefore, to allow 32-bit and 64-bit builds in the same directory, we
let git.res depend on GIT-PREFIX so that it gets recompiled when
compiling for a different architecture (this works because the exec path
changes based on the architecture: /mingw32/libexec/git-core for 32-bit
and /mingw64/libexec/git-core for 64-bit).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:30 +02:00
Anton Serbulov
3191a0c27b 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>
2016-03-29 10:21:29 +02:00
Johannes Schindelin
5e5dff9d05 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>
2016-03-29 10:21:29 +02:00
Johannes Schindelin
21890ed89d mingw: Suppress warning that <commit>:.gitattributes does not exist
On Windows, a file name containing a colon is illegal. We should
therefore expect the corresponding errno when `fopen()` is called for a
path of the form <commit>:.gitattributes.

This fixes https://github.com/git-for-windows/git/issues/255.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:21:28 +02:00
Karsten Blees
0a14a804c4 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>
2016-03-29 10:21:27 +02:00
Karsten Blees
537377279a 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>
2016-03-29 10:21:27 +02:00
nalla
cc5d7fa371 mingw: explicitly fflush stdout
For performance reasons `stdout` is not unbuffered by default. That leads
to problems if after printing to `stdout` a read on `stdin` is performed.

For that reason interactive commands like `git clean -i` do not function
properly anymore if the `stdout` is not flushed by `fflush(stdout)` before
trying to read from `stdin`.

In the case of `git clean -i` all reads on `stdin` were preceded by a
`fflush(stdout)` call.

Signed-off-by: nalla <nalla@hamal.uberspace.de>
2016-03-29 10:21:17 +02:00
Karsten Blees
d8d1d640e0 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>
2016-03-29 10:14:53 +02:00
Johannes Schindelin
02b607d6e4 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>
2016-03-29 10:14:52 +02:00
Karsten Blees
486600ded4 gettext: always use UTF-8 on native Windows
Git on native Windows exclusively uses UTF-8 for console output (both with
mintty and native console windows). Gettext uses setlocale() to determine
the output encoding for translated text, however, MSVCRT's setlocale()
doesn't support UTF-8. As a result, translated text is encoded in system
encoding (GetAPC()), and non-ASCII chars are mangled in console output.

Use gettext's bind_textdomain_codeset() to force the encoding to UTF-8 on
native Windows.

In this developers' setup, HAVE_LIBCHARSET_H is apparently defined, but
we *really* want to override the locale_charset() here.

Signed-off-by: Karsten Blees <blees@dcon.de>
2016-03-29 10:14:52 +02:00
Johannes Schindelin
633e2c09c6 Avoid illegal filenames when building Documentation on NTFS
A '+' is not a valid part of a filename with Windows file systems (it is
reserved because the '+' operator meant file concatenation back in the
DOS days).

Let's just not use it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:51 +02:00
Johannes Schindelin
da060bad38 git-gui (MinGW): make use of MSys2's msgfmt
When Git for Windows was still based on MSys1, we had no gettext, ergo
no msgfmt, either. Therefore, we introduced a small and simple Tcl
script to perform the same task.

However, with MSys2, we no longer need that because we have a proper
msgfmt executable. Plus, the po2msg.sh script somehow manages to hang
when run in parallel.

Two reasons to use real msgfmt.exe instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:50 +02:00
Johannes Schindelin
1876b81352 Windows: make sure that merge-octopus only outputs LF line endings
This happens to shut up t7602 on Windows which would otherwise take
the different line endings for a sign that the merge failed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:50 +02:00
Johannes Schindelin
7cbf92627a 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>
2016-03-29 10:14:49 +02:00
Johannes Schindelin
a7f0c288c0 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>
2016-03-29 10:14:48 +02:00
Johannes Schindelin
54d8cabc4b 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>
2016-03-29 10:14:48 +02:00
Johannes Schindelin
f5f2b12b77 mingw: enable stack smashing protector
As suggested privately to Brendan Forster by some unnamed person
(suggestion for the future: use the public mailing list, or even the
public GitHub issue tracker, that is a much better place to offer such
suggestions), we should make use of gcc's stack smashing protector that
helps detect stack buffer overruns early.

Rather than using -fstack-protector, we use -fstack-protector-strong
because it strikes a better balance between how much code is affected
and the performance impact.

In a local test (time git log --grep=is -p), best of 5 timings went from
23.009s to 22.997s (i.e. the performance impact was *well* lost in the
noise).

This fixes https://github.com/git-for-windows/git/issues/501

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:47 +02:00
Alan Davies
668bbe1d2d 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>
2016-03-29 10:14:47 +02:00
Karsten Blees
f392f79aeb mingw: make isatty() recognize MSYS2's pseudo terminals (/dev/pty*)
MSYS2 emulates pseudo terminals via named pipes, and isatty() returns 0
for such file descriptors. Therefore, some interactive functionality
(such as launching a pager, asking if a failed unlink should be repeated
etc.) doesn't work when run in a terminal emulator that uses MSYS2's
ptys (such as mintty).

However, MSYS2 uses special names for its pty pipes ('msys-*-pty*'),
which allows us to distinguish them from normal piped input / output.

On startup, check if stdin / stdout / stderr are connected to such pipes
using the NtQueryObject API from NTDll.dll. If the names match, adjust
the flags in MSVCRT's ioinfo structure accordingly.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:46 +02:00
Cesar Eduardo Barros
4eeedfa7c4 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>
2016-03-29 10:14:46 +02:00
Johannes Schindelin
b7c6d1829f Tests: optionally skip redirecting stdin/stdout/stderr
There is a really useful debugging technique developed by Sverre
Rabbelier that inserts "bash &&" somewhere in the test scripts, letting
the developer interact at given points with the current state.

Another debugging technique, used a lot by this here coder, is to run
certain executables via gdb by guarding a "gdb -args" call in
bin-wrappers/git.

Both techniques were disabled by 781f76b1(test-lib: redirect stdin of
tests).

Let's reinstate the ability to run an interactive shell by making the
redirection optional: setting the TEST_NO_REDIRECT environment variable
will skip the redirection.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:14:45 +02:00
Johannes Schindelin
b31dad1f0c 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>
2016-03-29 10:13:54 +02:00
Johannes Schindelin
61bc170d6e Build Python stuff with MSys2
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2016-03-29 10:13:54 +02:00
Johannes Schindelin
05b10fdc63 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>
2016-03-29 10:13:53 +02:00