Commit Graph

41 Commits

Author SHA1 Message Date
Seija Kijin
592bcab61b compat/winansi: check for errors of CreateThread() correctly
The return value for failed thread creation is NULL,
not INVALID_HANDLE_VALUE, unlike other Windows API functions.

Signed-off-by: Seija Kijin <doremylover123@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-01 14:36:19 -08:00
Neeraj Singh
19d3f228c8 wrapper: make inclusion of Windows csprng header tightly scoped
Including NTSecAPI.h in git-compat-util.h causes build errors in any
other file that includes winternl.h. NTSecAPI.h was included in order to
get access to the RtlGenRandom cryptographically secure PRNG. This
change scopes the inclusion of ntsecapi.h to wrapper.c, which is the only
place that it's actually needed.

The build breakage is due to the definition of UNICODE_STRING in
NtSecApi.h:
    #ifndef _NTDEF_
    typedef LSA_UNICODE_STRING UNICODE_STRING, *PUNICODE_STRING;
    typedef LSA_STRING STRING, *PSTRING ;
    #endif

LsaLookup.h:
    typedef struct _LSA_UNICODE_STRING {
        USHORT Length;
        USHORT MaximumLength;
    #ifdef MIDL_PASS
        [size_is(MaximumLength/2), length_is(Length/2)]
    #endif // MIDL_PASS
        PWSTR  Buffer;
    } LSA_UNICODE_STRING, *PLSA_UNICODE_STRING;

winternl.h also defines UNICODE_STRING:
    typedef struct _UNICODE_STRING {
        USHORT Length;
        USHORT MaximumLength;
        PWSTR  Buffer;
    } UNICODE_STRING;
    typedef UNICODE_STRING *PUNICODE_STRING;

Both definitions have equivalent layouts. Apparently these internal
Windows headers aren't designed to be included together. This is
an oversight in the headers and does not represent an incompatibility
between the APIs.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00
Junio C Hamano
d073bdc6a0 Merge branch 'bc/csprng-mktemps'
Pick a better random number generator and use it when we prepare
temporary filenames.

* bc/csprng-mktemps:
  wrapper: use a CSPRNG to generate random file names
  wrapper: add a helper to generate numbers from a CSPRNG
2022-02-11 16:55:57 -08:00
brian m. carlson
05cd988dce wrapper: add a helper to generate numbers from a CSPRNG
There are many situations in which having access to a cryptographically
secure pseudorandom number generator (CSPRNG) is helpful.  In the
future, we'll encounter one of these when dealing with temporary files.
To make this possible, let's add a function which reads from a system
CSPRNG and returns some bytes.

We know that all systems will have such an interface.  A CSPRNG is
required for a secure TLS or SSH implementation and a Git implementation
which provided neither would be of little practical use.  In addition,
POSIX is set to standardize getentropy(2) in the next version, so in the
(potentially distant) future we can rely on that.

For systems which lack one of the other interfaces, we provide the
ability to use OpenSSL's CSPRNG.  OpenSSL is highly portable and
functions on practically every known OS, and we know it will have access
to some source of cryptographically secure randomness.  We also provide
support for the arc4random in libbsd for folks who would prefer to use
that.

Because this is a security sensitive interface, we take some
precautions.  We either succeed by filling the buffer completely as we
requested, or we fail.  We don't return partial data because the caller
will almost never find that to be a useful behavior.

Specify a makefile knob which users can use to specify one or more
suitable CSPRNGs, and turn the multiple string options into a set of
defines, since we cannot match on strings in the preprocessor.  We allow
multiple options to make the job of handling this in autoconf easier.

The order of options is important here.  On systems with arc4random,
which is most of the BSDs, we use that, since, except on MirBSD and
macOS, it uses ChaCha20, which is extremely fast, and sits entirely in
userspace, avoiding a system call.  We then prefer getrandom over
getentropy, because the former has been available longer on Linux, and
then OpenSSL. Finally, if none of those are available, we use
/dev/urandom, because most Unix-like operating systems provide that API.
We prefer options that don't involve device files when possible because
those work in some restricted environments where device files may not be
available.

Set the configuration variables appropriately for Linux and the BSDs,
including macOS, as well as Windows and NonStop.  We specifically only
consider versions which receive publicly available security support
here.  For the same reason, we don't specify getrandom(2) on Linux,
because CentOS 7 doesn't support it in glibc (although its kernel does)
and we don't want to resort to making syscalls.

Finally, add a test helper to allow this to be tested by hand and in
tests.  We don't add any tests, since invoking the CSPRNG is not likely
to produce interesting, reproducible results.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-17 14:17:48 -08:00
Matthias Aßhauer
4a9b204920 lazyload: use correct calling conventions
Christoph Reiter reported on the Git for Windows issue tracker[1], that
mingw_strftime() imports strftime() from ucrtbase.dll with the wrong
calling convention. It should be __cdecl instead of WINAPI, which we
always use in DECLARE_PROC_ADDR().

The MSYS2 project encountered cmake sefaults on x86 Windows caused by
the same issue in the cmake source. [2] There are no known git crashes
that where caused by this, yet, but we should try to prevent them.

We import two other non-WINAPI functions via DECLARE_PROC_ADDR(), too.

* NtSetSystemInformation() (NTAPI)
* GetUserNameExW()         (SEC_ENTRY)

NTAPI, SEC_ENTRY and WINAPI are all ususally defined as __stdcall,
but there are circumstances where they're defined differently.

Teach DECLARE_PROC_ADDR() about calling conventions and be explicit
about when we want to use which calling convention.

Import winnt.h for the definition of NTAPI and sspi.h for SEC_ENTRY
near their respective only users.

[1] https://github.com/git-for-windows/git/issues/3560
[2] https://github.com/msys2/MINGW-packages/issues/10152

Reported-By: Christoph Reiter <reiter.christoph@gmail.com>
Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-09 10:34:53 -08:00
Johannes Schindelin
c5a03b1e29 mingw: work around incorrect standard handles
For some reason, when being called via TortoiseGit the standard handles,
or at least what is returned by _get_osfhandle(0) for standard input,
can take on the value (HANDLE)-2 (which is not a legal value, according
to the documentation).

Even if this value is not documented anywhere, CreateProcess() seems to
work fine without complaints if hStdInput set to this value.

In contrast, the upcoming code to restrict which file handles get
inherited by spawned processes would result in `ERROR_INVALID_PARAMETER`
when including such handle values in the list.

To help this, special-case the value (HANDLE)-2 returned by
_get_osfhandle() and replace it with INVALID_HANDLE_VALUE, which will
hopefully let the handle inheritance restriction work even when called
from TortoiseGit.

This fixes https://github.com/git-for-windows/git/issues/1481

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-23 11:17:01 +09:00
Johannes Schindelin
41616ef618 winansi: use FLEX_ARRAY to avoid compiler warning
MSVC would complain thusly:

    C4200: nonstandard extension used: zero-sized array in struct/union

Let's just use the `FLEX_ARRAY` constant that we introduced for exactly
this type of scenario.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-06 09:07:44 +09:00
Junio C Hamano
0a2ff7c6b5 Merge branch 'js/mingw-use-utf8'
Windows update.

* js/mingw-use-utf8:
  mingw: fix possible buffer overrun when calling `GetUserNameW()`
  mingw: use Unicode functions explicitly
  mingw: get pw_name in UTF-8 format
2019-07-11 15:16:49 -07:00
Junio C Hamano
88b1075759 Merge branch 'jh/msvc'
Support to build with MSVC has been updated.

* jh/msvc:
  msvc: ignore .dll and incremental compile output
  msvc: avoid debug assertion windows in Debug Mode
  msvc: do not pretend to support all signals
  msvc: add pragmas for common warnings
  msvc: add a compile-time flag to allow detailed heap debugging
  msvc: support building Git using MS Visual C++
  msvc: update Makefile to allow for spaces in the compiler path
  msvc: fix detect_msys_tty()
  msvc: define ftello()
  msvc: do not re-declare the timespec struct
  msvc: mark a variable as non-const
  msvc: define O_ACCMODE
  msvc: include sigset_t definition
  msvc: fix dependencies of compat/msvc.c
  mingw: replace mingw_startup() hack
  obstack: fix compiler warning
  cache-tree/blame: avoid reusing the DEBUG constant
  t0001 (mingw): do not expect a specific order of stdout/stderr
  Mark .bat files as requiring CR/LF endings
  mingw: fix a typo in the msysGit-specific section
2019-07-09 15:25:45 -07:00
Johannes Schindelin
94238859b9 mingw: use Unicode functions explicitly
Many Win32 API functions actually exist in two variants: one with
the `A` suffix that takes ANSI parameters (`char *` or `const char *`)
and one with the `W` suffix that takes Unicode parameters (`wchar_t *`
or `const wchar_t *`).

The ANSI variant assumes that the strings are encoded according to
whatever is the current locale. This is not what Git wants to use on
Windows: we assume that `char *` variables point to strings encoded in
UTF-8.

There is a pseudo UTF-8 locale on Windows, but it does not work
as one might expect. In addition, if we overrode the user's locale, that
would modify the behavior of programs spawned by Git (such as editors,
difftools, etc), therefore we cannot use that pseudo locale.

Further, it is actually highly encouraged to use the Unicode versions
instead of the ANSI versions, so let's do precisely that.

Note: when calling the Win32 API functions _without_ any suffix, it
depends whether the `UNICODE` constant is defined before the relevant
headers are #include'd. Without that constant, the ANSI variants are
used. Let's be explicit and avoid that ambiguity.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-27 12:56:15 -07:00
Jeff Hostetler
5f3ff78081 msvc: fix detect_msys_tty()
The ntstatus.h header is only available in MINGW.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-20 14:03:05 -07:00
Johannes Schindelin
4fa42df972 winansi: simplify loading the GetCurrentConsoleFontEx() function
We introduced helper macros to simplify loading functions dynamically.
Might just as well use them.

This also side-steps a compiler warning when building with GCC v8.x: it
would complain about casting between incompatible function pointers.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-13 09:34:16 -07:00
Johannes Schindelin
ff8978d533 mingw: fix isatty() after dup2()
Since a9b8a09c3c (mingw: replace isatty() hack, 2016-12-22), we handle
isatty() by special-casing the stdin/stdout/stderr file descriptors,
caching the return value. However, we missed the case where dup2()
overrides the respective file descriptor.

That poses a problem e.g. where the `show` builtin asks for a pager very
early, the `setup_pager()` function sets the pager depending on the
return value of `isatty()` and then redirects stdout. Subsequently,
`cmd_log_init_finish()` calls `setup_pager()` *again*. What should
happen now is that `isatty()` reports that stdout is *not* a TTY and
consequently stdout should be left alone.

Let's override dup2() to handle this appropriately.

This fixes https://github.com/git-for-windows/git/issues/1077

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-31 12:48:59 +09:00
Johannes Schindelin
b6b066adf9 winansi: avoid buffer overrun
When we could not convert the UTF-8 sequence into Unicode for writing to
the Console, we should not try to write an insanely-long sequence of
invalid wide characters (mistaking the negative return value for an
unsigned length).

Reported by Coverity.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 12:18:19 +09:00
Johannes Schindelin
3057da5ad5 winansi: avoid use of uninitialized value
To initialize the foreground color attributes of "plain text", our ANSI
emulation tries to infer them from the currently attached console while
running the is_console() function. This function first tries to detect any
console attached to stdout, then it is called with stderr.

If neither stdout nor stderr has any console attached, it does not
actually matter what we use for "plain text" attributes, as we never need
to output any text to any console in that case.

However, after working on stdout and stderr, is_console() is called with
stdin, and it still tries to initialize the "plain text" attributes if
they had not been initialized earlier. In this case, we cannot detect any
attributes, and we used an uninitialized value for them.

Naturally, Coverity complained about this use case because it could not
reason about the code deeply enough to figure out that we do not even use
those attributes in that case.

Let's just initialize the value to 0 in that case, both to avoid future
Coverity reports, and to help catch future regressions in case anybody
changes the order of the is_console() calls (which would make the text
black on black).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 12:18:19 +09:00
Junio C Hamano
e048a257bf Merge branch 'js/mingw-isatty'
A hotfix for a topic already in 'master'.

* js/mingw-isatty:
  mingw: make stderr unbuffered again
2017-02-16 14:45:13 -08:00
Johannes Schindelin
a4d92d579f mingw: make stderr unbuffered again
When removing the hack for isatty(), we actually removed more than just
an isatty() hack: we removed the hack where internal data structures of
the MSVC runtime are modified in order to redirect stdout/stderr.

Instead of using that hack (that does not work with newer versions of
the runtime, anyway), we replaced it by reopening the respective file
descriptors.

What we forgot was to mark stderr as unbuffered again.

Reported by Hannes Sixt. Fixed with Jeff Hostetler's assistance.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Tested-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-14 10:54:21 -08:00
Junio C Hamano
d515fe08fc Merge branch 'js/mingw-isatty'
An update to a topic that is already in 'master'.

* js/mingw-isatty:
  mingw: follow-up to "replace isatty() hack"
2017-01-31 13:14:58 -08:00
Johannes Schindelin
1d3f065e0e mingw: follow-up to "replace isatty() hack"
The version of the "replace isatty() hack" that got merged a few
weeks ago did not actually reflect the latest iteration of the patch
series: v3 was sent out with these changes, as requested by the
reviewer Johannes Sixt:

- reworded the comment about "recycling handles"

- moved the reassignment of the `console` variable before the dup2()
  call so that it is valid at all times

- removed the "handle = INVALID_HANDLE_VALUE" assignment, as the local
  variable `handle` is not used afterwards anyway

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-18 13:31:25 -08:00
Junio C Hamano
58fcd54853 Merge branch 'js/mingw-isatty'
Update the isatty() emulation for Windows by updating the previous
hack that depended on internals of (older) MSVC runtime.

* js/mingw-isatty:
  mingw: replace isatty() hack
  mingw: fix colourization on Cygwin pseudo terminals
  mingw: adjust is_console() to work with stdin
2016-12-27 00:11:46 -08:00
Junio C Hamano
c5139e0e38 Merge branch 'mk/mingw-winansi-ttyname-termination-fix'
A potential but unlikely buffer overflow in Windows port has been
fixed.

* mk/mingw-winansi-ttyname-termination-fix:
  mingw: consider that UNICODE_STRING::Length counts bytes
2016-12-27 00:11:44 -08:00
Jeff Hostetler
a9b8a09c3c mingw: replace isatty() hack
Git for Windows has carried a patch that depended on internals
of MSVC runtime, but it does not work correctly with recent MSVC
runtime. A replacement was written originally for compiling
with VC++. The patch in this message is a backport of that
replacement, and it also fixes the previous attempt to make
isatty() tell that /dev/null is *not* an interactive terminal.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Tested-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-22 09:58:46 -08:00
Alan Davies
86924838e3 mingw: fix colourization on Cygwin pseudo terminals
Git only colours the output and uses pagination if isatty() returns 1.
MSYS2 and Cygwin emulate pseudo terminals via named pipes, meaning that
isatty() returns 0.

f7f90e0f4f (mingw: make isatty() recognize MSYS2's pseudo terminals
(/dev/pty*), 2016-04-27) fixed this for MSYS2 terminals, but not for
Cygwin.

The named pipes that Cygwin and MSYS2 use are very similar. MSYS2 PTY pipes
are called 'msys-*-pty*' and Cygwin uses 'cygwin-*-pty*'. This commit
modifies the existing check to allow both MSYS2 and Cygwin PTY pipes to be
identified as TTYs.

Note that pagination is still broken when running Git for Windows from
within Cygwin, as MSYS2's less.exe is spawned (and does not like to
interact with Cygwin's PTY).

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

Signed-off-by: Alan Davies <alan.n.davies@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-22 09:58:29 -08:00
Johannes Schindelin
fee807c5f6 mingw: adjust is_console() to work with stdin
When determining whether a handle corresponds to a *real* Win32 Console
(as opposed to, say, a character device such as /dev/null), we use the
GetConsoleOutputBufferInfo() function as a tell-tale.

However, that does not work for *input* handles associated with a
console. Let's just use the GetConsoleMode() function for input handles,
and since it does not work on output handles fall back to the previous
method for those.

This patch prepares for using is_console() instead of my previous
misguided attempt in cbb3f3c9b1 (mingw: intercept isatty() to handle
/dev/null as Git expects it, 2016-12-11) that broke everything on
Windows.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-22 09:58:20 -08:00
Max Kirillov
c46458e82f mingw: consider that UNICODE_STRING::Length counts bytes
UNICODE_STRING::Length field means size of buffer in bytes[1],
despite of buffer itself being array of wchar_t. Because of that
terminating zero is placed twice as far. Fix it.

[1] https://msdn.microsoft.com/en-us/library/windows/desktop/aa380518.aspx

Signed-off-by: Max Kirillov <max@max630.net>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-20 09:04:57 -08:00
Johannes Schindelin
cbb3f3c9b1 mingw: intercept isatty() to handle /dev/null as Git expects it
When Git's source code calls isatty(), it really asks whether the
respective file descriptor is connected to an interactive terminal.

Windows' _isatty() function, however, determines whether the file
descriptor is associated with a character device. And NUL, Windows'
equivalent of /dev/null, is a character device.

Which means that for years, Git mistakenly detected an associated
interactive terminal when being run through the test suite, which
almost always redirects stdin, stdout and stderr to /dev/null.

This bug only became obvious, and painfully so, when the new
bisect--helper entered the `pu` branch and made the automatic build & test
time out because t6030 was waiting for an answer.

For details, see

	https://msdn.microsoft.com/en-us/library/f4s0ddew.aspx

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-11 16:15:46 -08:00
Johannes Schindelin
0767172b90 mingw: let the build succeed with DEVELOPER=1
The recently introduced developer flags identified a couple of
old-style function declarations in the Windows-specific code where
the parameter list was left empty instead of specifying "void"
explicitly. Let's just fix them.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-20 12:12:12 -07:00
Karsten Blees
f7f90e0f4f 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>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-26 13:12:02 -07:00
Johannes Schindelin
7c00bc39eb mingw: avoid warnings when casting HANDLEs to int
HANDLE is defined internally as a void *, but in many cases it is
actually guaranteed to be a 32-bit integer. In these cases, GCC should
not warn about a cast of a pointer to an integer of a different type
because we know exactly what we are doing.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 14:01:52 -08:00
Johannes Schindelin
466931d9e1 compat/winansi: support compiling with MSys2
MSys2 already defines the _CONSOLE_FONT_INFOEX structure.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-14 12:21:00 -08:00
Jeff King
5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00
Karsten Blees
51822653f5 Win32: reliably detect console pipe handles
As of "Win32: Thread-safe windows console output", child processes may
print to the console even if stdout has been redirected to a file. E.g.:

 git config tar.cat.command "cat"
 git archive -o test.cat HEAD

Detecting whether stdout / stderr point to our console pipe is currently
based on the assumption that OS HANDLE values are never reused. This is
apparently not true if stdout / stderr is replaced via dup2() (as in
builtin/archive.c:17).

Instead of comparing handle values, check if the file descriptor isatty()
backed by a pipe OS handle. This is only possible by swapping the handles
in MSVCRT's internal data structures, as we do in winansi_init().

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-16 10:56:19 -07:00
Karsten Blees
fcd428f4a9 Win32: fix broken pipe detection
As of "Win32: Thread-safe windows console output", git-log no longer
terminates when the pager process dies. This is due to disabling buffering
for the replaced stdout / stderr streams. Git-log will periodically fflush
stdout (see write_or_die.c/mayble_flush_or_die()), but with no buffering,
this is a NOP that always succeeds (so we never detect the EPIPE error).

Exchange the original console handles with our console thread pipe handles
by accessing the internal MSVCRT data structures directly (which are
exposed via __pioinfo for some reason).

Implement this with minimal assumptions about the actual data structure to
make it work with different (hopefully even future) MSVCRT versions.

While messing with internal data structures is ugly, this patch solves the
problem at the source instead of adding more workarounds. We no longer need
the special winansi_isatty override, and the limitations documented in
"Win32: Thread-safe windows console output" are gone (i.e. fdopen(1/2)
returns unbuffered streams now, and isatty() for duped console file
descriptors works as expected).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:32:59 -07:00
Karsten Blees
eac14f8909 Win32: Thread-safe windows console output
Winansi.c has many static variables that are accessed and modified from
the [v][f]printf / fputs functions overridden in the file. This may cause
multi threaded git commands that print to the console to produce corrupted
output or even crash.

Additionally, winansi.c doesn't override all functions that can be used to
print to the console (e.g. fwrite, write, fputc are missing), so that ANSI
escapes don't work properly for some git commands (e.g. git-grep).

Instead of doing ANSI emulation in just a few wrapped functions on top of
the IO API, let's plug into the IO system and take advantage of the thread
safety inherent to the IO system.

Redirect stdout and stderr to a pipe if they point to the console. A
background thread reads from the pipe, handles ANSI escape sequences and
UTF-8 to UTF-16 conversion, then writes to the console.

The pipe-based stdout and stderr replacements must be set to unbuffered, as
MSVCRT doesn't support line buffering and fully buffered streams are
inappropriate for console output.

Due to the byte-oriented pipe, ANSI escape sequences and multi-byte UTF-8
sequences can no longer be expected to arrive in one piece. Replace the
string-based ansi_emulate() with a simple stateful parser (this also fixes
colored diff hunk headers, which were broken as of commit 2efcc977).

Override isatty to return true for the pipes redirecting to the console.

Exec/spawn obtain the original console handle to pass to the next process
via winansi_get_osfhandle().

All other overrides are gone, the default stdio implementations work as
expected with the piped stdout/stderr descriptors.

Global variables are either initialized on startup (single threaded) or
exclusively modified by the background thread. Threads communicate through
the pipe, no further synchronization is necessary.

The background thread is terminated by disonnecting the pipe after flushing
the stdio and pipe buffers. This doesn't work for anonymous pipes (created
via CreatePipe), as DisconnectNamedPipe only works on the read end, which
discards remaining data. Thus we have to setup the pipe manually, with the
write end beeing the server (opened with CreateNamedPipe) and the read end
the client (opened with CreateFile).

Limitations: doesn't track reopened or duped file descriptors, i.e.:
- fdopen(1/2) returns fully buffered streams
- dup(1/2), dup2(1/2) returns normal pipe descriptors (i.e. isatty() =
  false, winansi_get_osfhandle won't return the original console handle)

Currently, only the git-format-patch command uses xfdopen(xdup(1)) (see
"realstdout" in builtin/log.c), but works well with these limitations.

Many thanks to Atsushi Nakagawa <atnak@chejz.com> for suggesting and
reviewing the thread-exit-mechanism.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:32:59 -07:00
Karsten Blees
1edeb9abf5 Win32: warn if the console font doesn't support Unicode
Unicode console output won't display correctly with default settings
because the default console font ("Terminal") only supports the system's
OEM charset. Unfortunately, this is a user specific setting, so it cannot
be easily fixed by e.g. some registry tricks in the setup program.

This change prints a warning on exit if console output contained non-ascii
characters and the console font is supposedly not a TrueType font (which
usually have decent Unicode support).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:32:50 -07:00
Karsten Blees
143e615270 Win32: detect console streams more reliably
GetStdHandle(STD_OUTPUT_HANDLE) doesn't work for stderr if stdout is
redirected. Use _get_osfhandle of the FILE* instead.

_isatty() is true for all character devices (including parallel and serial
ports). Check return value of GetConsoleScreenBufferInfo instead to
reliably detect console handles (also don't initialize internal state from
an uninitialized CONSOLE_SCREEN_BUFFER_INFO structure if the function
fails).

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:32:44 -07:00
Karsten Blees
617ce965aa Win32: support Unicode console output
WriteConsoleW seems to be the only way to reliably print unicode to the
console (without weird code page conversions).

Also redirects vfprintf to the winansi.c version.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-10 13:32:37 -07:00
Marius Storm-Olsen
435bdf8c7f Make usage of windows.h lean and mean
Centralize the include of windows.h in git-compat-util.h, turn on
WIN32_LEAN_AND_MEAN to avoid including plenty of other header files
which is not needed in Git. Also ensure we load winsock2.h first,
so we don't load the older winsock definitions at a later stage,
since they contain duplicate definitions.

When moving windows.h into git-compat-util.h, we need to protect
the definition of struct pollfd in mingw.h, since this file is used
by both MinGW and MSVC, and the latter defines this struct in
winsock2.h.

We need to keep the windows.h include in compat/win32.h, since its
shared by both MinGW and Cygwin, and we're not touching Cygwin in
this commit. The include in git-compat-util.h is protected with an
ifdef WIN32, which is not the case when compiling for Cygwin.

Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18 20:00:42 -07:00
Johannes Schindelin
492f70913e Work around a regression in Windows 7, causing erase_in_line() to crash sometimes
The function FillConsoleOutputCharacterA() was pretty content in XP to take a NULL
pointer if we did not want to store the number of written columns.  In Windows 7,
it crashes, but only when called from within Git Bash, not from within cmd.exe.
Go figure.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-01 00:08:54 -07:00
Johannes Schindelin
1897713fbd winansi: support ESC [ K (erase in line)
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-10 23:23:02 -07:00
Peter Harris
c09df8a74e Add ANSI control code emulation for the Windows console
This adds only the minimum necessary to keep git pull/merge's diffstat from
wrapping. Notably absent is support for the K (erase) operation, and support
for POSIX write.

Signed-off-by: Peter Harris <git@peter.is-a-geek.org>
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-19 11:17:43 -07:00