Commit Graph

702 Commits

Author SHA1 Message Date
Johannes Schindelin
646cf4170d Merge 'misc-vs-fixes' into HEAD 2018-10-12 22:59:56 +02:00
Philip Oakley
13334ac8a3 msvc: add pragmas for common warnings
MSVC can be overzealous about some warnings. Disable them.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
2018-10-12 22:57:52 +02:00
Johannes Schindelin
5e55fafd63 msvc: avoid debug assertion windows in Debug Mode
For regular debugging, it is pretty helpful when a debug assertion in a
running application triggers a window that offers to start the debugger.

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:49 +02:00
Jeff Hostetler
2ddba3c461 MSVC Build: Support VS2017 command line compiler tools
Teach the top-level git Makefile to use whatever VS compiler
tool chain is installed on the system.

When building git from the command line in a git-sdk BASH
window with MAKE, the shell environment has environment
variables for GCC tools, but not MSVC tools.  MSVC bindings
are only avaliable from the various "VcVarsAll.bat" scripts
run by the "Developer Command Prompt" shortcuts.

Add compat/vcbuild/find_vs_env.bat to the Makefile.  It
uses the various "VcVarsAll.bat" scripts in a background
Developer Command Prompt process to compute the proper
environment variables and publish them for use by the Makefile.

[jes: fixed typos, used %SystemRoot% instead of C:\WINDOWS]

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:48 +02:00
Johannes Schindelin
e678cad82b compat/vcbuild: possibly reuse Git for Windows' SDK's NuGet
In Git for Windows' SDK, there is already a script to package Git for
Windows as a NuGet package, downloading nuget.exe if needed.

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:48 +02:00
Jeff Hostetler
00644b7d27 vs2015: remove todo list item from README_vs2015.txt
Remove todo list item for vs2015 build notes regarding
the third party DLLs.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:48 +02:00
Johannes Schindelin
f75e781673 terminal.c: guard the inclusion of inttypes.h
We do have a lovely Makefile option to state that that header file is
not available. Let's use it everywhere...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:48 +02:00
Johannes Schindelin
94d099fb44 obstack: fix compiler warning
MS Visual C suggests that the construct

	condition ? (int) i : (ptrdiff_t) d

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:48 +02:00
Johannes Schindelin
13bd9a9246 msvc: use libiconv
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:47 +02:00
Johannes Schindelin
cdfba1608e msvc: respect the quiet-by-default output
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
7d4a1822fa msvc: release mode PDBs and library DLLs
Install required third-party DLLs next to EXEs.

Build and install release mode PDBs for git
executables allowing detailed stack traces
in the event of crash.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
11da2c1449 msvc: fix detect_msys_tty()
The ntstatus.h header is only available in MINGW.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
094dee4013 msvc: define ftello()
It is just called different in MSVC's headers.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
44cbfbfe87 msvc: do not re-declare the timespec struct
VS2015's headers already declare that struct.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
c12dcb4049 msvc: provide a main() wrapper similar to mingw_main()
The MINGW version of the main() wrapper gets away with declaring symbols
that were intentionally not exported. However, some of these symbols do
not actually exist in MSVC's UCRT.

So let's add an MSVC version of the main() wrapper that uses wmain() and
imports the UNICODE argv and environment. While at it, we pass our UTF-8
version of ARGV to the real main -- rather than overwriting __argv as is
done in the MINGW Version.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:47 +02:00
Jeff Hostetler
03baabb106 msvc: do not pretend to support all signals
This special-cases various signals that are not supported on Windows,
such as SIGPIPE. These cause the UCRT to throw asserts (at least in
debug mode).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:46 +02:00
Jeff Hostetler
7af2b1b527 msvc: mark a variable as non-const
VS2015 complains when using a const pointer in memcpy()/free().

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:46 +02:00
Jeff Hostetler
e7a90dbb4a msvc: convert environment from/to UTF-16 on the fly
This adds MSVC versions of getenv() and friends. These take UTF-8
arguments and return UTF-8 values, but use the UNICODE versions
of the CRT routines.  This avoids the need to write to __environ
(which is only visible if you statically link to the CRT).  This
also avoids the CP_ACP conversions performed inside the CRT.
It also avoids various memory leaks and problems.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:46 +02:00
Philip Oakley
bbec929606 msvc: fix the declaration of the _REPARSE_DATA_BUFFER structure
GCC and MSVC disagree about using the GCC extension _ANONYMOUS_UNION.
Simply skip that offending keyword when compiling with MSVC.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:46 +02:00
Philip Oakley
9eff0f5632 msvc: define O_ACCMODE
This constant is not defined in MSVC's headers.

In UCRT's fcntl.h, _O_RDONLY, _O_WRONLY and _O_RDWR are defined as 0, 1
and 2, respectively. Yes, that means that UCRT breaks with the tradition
that O_RDWR == O_RDONLY | O_WRONLY.

It is a perfectly legal way to define those constants, though, therefore
we need to take care of defining O_ACCMODE accordingly.

This is particularly important in order to keep our "open() can set
errno to EISDIR" emulation working: it tests that (flags & O_ACCMODE) is
not identical to O_RDONLY before going on to test specifically whether
the file for which open() reported EACCES is, in fact, a directory.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:46 +02:00
Philip Oakley
cb7df43f0e msvc: include sigset_t definition
On MSVC (VS2008) sigset_t is not defined.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
2018-10-12 22:57:46 +02:00
Jeff Hostetler
5e43aa7845 msvc: update compile helper for VS2015
Support -Z flags ("specify PDB options"), only include -l args on link
commands, and force PDBs to be created.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:46 +02:00
Jeff Hostetler
f9cdfd4e6f msvc: add NuGet scripts for building with VS2015
This commit contains a GNU Makefile and NuGet configuration scripts to
download and install the various third-party libraries that we will need
to build/link with when using VS2015 to build Git.

The file "compat/vcbuild/README_VS2015.txt" contains instructions for
using this.

In this commit, "compat/vcbuild/Makefile" contains hard-coded version
numbers of the packages we require.  These are set to the current
versions as of the time of this commit.  We use "nuget restore" to
install them explicitly using a "package.config".  A future improvement
would try to use some of the automatic package management functions and
eliminate the need to specify exact versions.  I tried, but could not
get this to work.  NuGet was happy dowload "minimum requirements" rather
than "lastest" for dependencies -- and only look at one package at a
time.  For example, both curl and openssl depend upon zlib and have
different minimums.  It was unclear which version of zlib would be
installed and seemed to be dependent on the order of the top-level
packages.  So, I'm skipping that for now.

We need to be very precise when specifying NuGet package versions: while
nuget.exe auto-completes a version, say, 1.0.2 to 1.0.2.0, we will want
to parse packages.config ourselves, to generate the Visual Studio
solution, and there we need the exact version number to be able to
generate the exact path to the correct .targets file.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2018-10-12 22:57:46 +02:00
Karsten Blees
0add81f3cc Win32: implement nanosecond-precision file times
We no longer use any of MSVCRT's stat-functions, so there's no need to
stick to a CRT-compatible 'struct stat' either.

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

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:37 +02:00
Karsten Blees
53ffa01603 Win32: replace MSVCRT's fstat() with a Win32-based implementation
fstat() is the only stat-related CRT function for which we don't have a
full replacement yet (and thus the only reason to stick with MSVCRT's
'struct stat' definition).

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:37 +02:00
Johannes Schindelin
8a8209a1de mingw: try to create symlinks without elevated permissions
With Windows 10 Build 14972 in Developer Mode, a new flag is supported
by CreateSymbolicLink() to create symbolic links even when running
outside of an elevated session (which was previously required).

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

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

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:37 +02:00
Johannes Schindelin
c2d7566a7e mingw: keep trailing slashes for _wchdir() and readlink()
This is needed so that `_wchdir()` can be used with drive root
directories, e.g. C:\ (`_wchdir("C:")` fails to switch the directory
to the root directory).

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

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:37 +02:00
Johannes Schindelin
405ecd45df 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>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:37 +02:00
Karsten Blees
4a6e4ccf41 Win32: implement basic symlink() functionality (file symlinks only)
Implement symlink() that always creates file symlinks. Fails with ENOSYS
if symlinks are disabled or unsupported.

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:37 +02:00
Karsten Blees
1d07962142 Win32: implement readlink()
Implement readlink() by reading NTFS reparse points. Works for symlinks
and directory junctions. If symlinks are disabled, fail with ENOSYS.

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:36 +02:00
Karsten Blees
0b8460c2fb Win32: mingw_chdir: change to symlink-resolved directory
If symlinks are enabled, resolve all symlinks when changing directories,
as required by POSIX.

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

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:36 +02:00
Karsten Blees
4d43a6d4ee 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
60758dc9d2 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
dd82e315b9 Win32: add symlink-specific error codes
Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:36 +02:00
Karsten Blees
249af54b09 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
93621e4e1b 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
1aeb005ee0 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
dd06a24b4b 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
844f58398b 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>
2018-10-12 22:57:36 +02:00
Karsten Blees
1191c5af51 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>
2018-10-12 22:57:35 +02:00
Karsten Blees
0181eb0c78 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>
2018-10-12 22:57:35 +02:00
Karsten Blees
9b03244a38 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>
2018-10-12 22:57:35 +02:00
Johannes Schindelin
e8ee532ae7 mingw: ensure valid CTYPE
A change between versions 2.4.1 and 2.6.0 of the MSYS2 runtime modified
how Cygwin's runtime (and hence Git for Windows' MSYS2 runtime
derivative) handles locales: d16a56306d (Consolidate wctomb/mbtowc calls
for POSIX-1.2008, 2016-07-20).

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

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:34 +02:00
Johannes Schindelin
6464c17deb winansi: simplify loading the GetCurrentConsoleFontEx() function
We introduced helper macros to simplify loading functions dynamically.
Might just as well use them.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:34 +02:00
Karsten Blees
e2e6a1c0f5 compat/terminal.c: only use the Windows console if bash 'read -r' fails
Accessing the Windows console through the special CONIN$ / CONOUT$ devices
doesn't work properly for non-ASCII usernames an passwords.

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

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

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

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:33 +02:00
Karsten Blees
8ae8d2514a mingw: Support git_terminal_prompt with more terminals
The `git_terminal_prompt()` function expects the terminal window to be
attached to a Win32 Console. However, this is not the case with terminal
windows other than `cmd.exe`'s, e.g. with MSys2's own `mintty`.

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

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

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

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

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

Helped-by: nalla <nalla@hamal.uberspace.de>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2018-10-12 22:57:33 +02:00
Karsten Blees
af9092d480 mingw: initialize HOME on startup
HOME initialization was historically duplicated in many different places,
including /etc/profile, launch scripts such as git-bash.vbs and gitk.cmd,
and (although slightly broken) in the git-wrapper.

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

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

Signed-off-by: Karsten Blees <blees@dcon.de>
2018-10-12 22:57:33 +02:00
Johannes Schindelin
567d08556e 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>
2018-10-12 22:57:33 +02:00
Johannes Schindelin
cb0c1d8185 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>
2018-10-12 22:57:33 +02:00
Johannes Schindelin
5cfc43d381 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>
2018-10-12 22:57:33 +02:00