Commit Graph

660 Commits

Author SHA1 Message Date
Johannes Schindelin
3f11ed2ebd 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>
2017-10-23 11:56:18 +02:00
Johannes Schindelin
ae80238073 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>
2017-10-23 11:56:06 +02:00
Johannes Schindelin
bab8dffaa5 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>
2017-10-23 11:56:05 +02:00
Johannes Schindelin
4e9ce9015e 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>
2017-10-23 11:17:43 +02:00
Jeff Hostetler
3fea15253a 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>
2017-10-23 11:17:43 +02:00
Johannes Schindelin
11bd4c8d99 msvc: use libiconv
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 11:17:42 +02:00
Johannes Schindelin
0f50e7a6c4 msvc: respect the quiet-by-default output
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 11:17:42 +02:00
Jeff Hostetler
f14ef1e4cc 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>
2017-10-23 11:17:41 +02:00
Johannes Schindelin
5bc5231a4f msvc: fix detect_msys_tty()
The ntstatus.h header is only available in MINGW.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2017-10-23 11:17:41 +02:00
Jeff Hostetler
8dd4a94eee msvc: define ftello()
It is just called different in MSVC's headers.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2017-10-23 11:17:41 +02:00
Jeff Hostetler
92d08295b1 msvc: do not re-declare the timespec struct
VS2015's headers already declare that struct.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
2017-10-23 11:17:41 +02:00
Johannes Schindelin
aff7e370a7 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>
2017-10-23 11:17:40 +02:00
Jeff Hostetler
a519ef3430 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>
2017-10-23 11:17:40 +02:00
Jeff Hostetler
ed5cfb0279 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>
2017-10-23 11:17:40 +02:00
Jeff Hostetler
450df3a22f 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>
2017-10-23 11:17:40 +02:00
Philip Oakley
cf2b0cda0a 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>
2017-10-23 11:17:40 +02:00
Philip Oakley
fa9b480d54 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>
2017-10-23 11:17:40 +02:00
Philip Oakley
f20a8bf300 msvc: include sigset_t definition
On MSVC (VS2008) sigset_t is not defined.

Signed-off-by: Philip Oakley <philipoakley@iee.org>
2017-10-23 11:17:39 +02:00
Jeff Hostetler
63ee8c04e3 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>
2017-10-23 11:17:39 +02:00
Jeff Hostetler
dda43c426e 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>
2017-10-23 11:17:39 +02:00
Johannes Schindelin
83b97d5d1e Merge branch 'redirect-std-handles'
This topic branch introduces a highly-experimental feature allowing to
override stdin/stdout/stderr by setting environment variables e.g. to
named pipes, solving a problem in highly multi-threaded applications
where inheritable handles could cause blocked Git operations.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 11:17:38 +02:00
Karsten Blees
57b3091e3f 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>
2017-10-23 11:17:31 +02:00
Karsten Blees
17b51789a2 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>
2017-10-23 11:17:30 +02:00
lchiocca
b1900829e4 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>
2017-10-23 11:17:29 +02:00
Johannes Schindelin
1317f3fb88 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>
2017-10-23 11:17:29 +02:00
Karsten Blees
b80b533e73 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>
2017-10-23 11:17:29 +02:00
Karsten Blees
c4f9569922 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>
2017-10-23 11:17:29 +02:00
Karsten Blees
fa8371fe8f 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>
2017-10-23 11:17:28 +02:00
Karsten Blees
ac1c93027c 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>
2017-10-23 11:17:28 +02:00
Karsten Blees
bced650349 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>
2017-10-23 11:17:28 +02:00
Karsten Blees
f36ad20f18 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>
2017-10-23 11:17:28 +02:00
Karsten Blees
9e32dff08d Win32: add symlink-specific error codes
Signed-off-by: Karsten Blees <blees@dcon.de>
2017-10-23 11:17:28 +02:00
Karsten Blees
8c3f3bfc90 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>
2017-10-23 11:17:27 +02:00
Karsten Blees
e52b82c72a 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>
2017-10-23 11:17:27 +02:00
Karsten Blees
58e205b523 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>
2017-10-23 11:17:27 +02:00
Johannes Schindelin
ed3cdb0026 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>
2017-10-23 11:17:27 +02:00
Karsten Blees
874a1a53fd 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>
2017-10-23 11:00:50 +02:00
Karsten Blees
59786ef19a 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>
2017-10-23 11:00:50 +02:00
Karsten Blees
5d092057e4 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>
2017-10-23 11:00:50 +02:00
Karsten Blees
54229d53d2 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>
2017-10-23 11:00:50 +02:00
Johannes Schindelin
01046c1fb8 mingw: simplify loading the CreadHardLinkW() 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>
2017-10-23 11:00:49 +02:00
Johannes Schindelin
c04228b3f7 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>
2017-10-23 11:00:49 +02:00
Johannes Schindelin
55af72f88c Merge 'default-ident' into HEAD 2017-10-23 11:00:48 +02:00
Johannes Schindelin
82d16f599e mingw: use domain information for default email
When a user is registered in a Windows domain, it is really easy to
obtain the email address. So let's do that.

Suggested by Lutz Roeder.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 11:00:46 +02:00
Johannes Schindelin
e84d57af3b getpwuid(mingw): provide a better default for the user name
We do have the excellent GetUserInfoEx() function to obtain more
detailed information of the current user (if the user is part of a
Windows domain); Let's use it.

Suggested by Lutz Roeder.

To avoid the cost of loading Secur32.dll (even lazily, loading DLLs
takes a non-neglibile amount of time), we use the established technique
to load DLLs only when, and if, needed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 11:00:44 +02:00
Johannes Schindelin
b7066fbb8c getpwuid(mingw): initialize the structure only once
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 10:59:59 +02:00
Johannes Schindelin
afd47af753 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>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 10:59:56 +02:00
Johannes Schindelin
cb5d2f0ce1 mingw: load system libraries the recommended way
When we access IPv6-related functions, we load the corresponding system
library using the `LoadLibrary()` function, which is not the recommended
way to load system libraries.

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

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2017-10-23 10:55:51 +02:00
Karsten Blees
69d86d4152 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>
2017-10-23 10:55:51 +02:00
Karsten Blees
a99e803969 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>
2017-10-23 10:55:51 +02:00