Commit Graph

1052 Commits

Author SHA1 Message Date
Junio C Hamano
d723492127 Merge branch 'pw/add-p-single-key'
Finishing touches to C rewrite of "git add -i" in single-key
interactive mode.

* pw/add-p-single-key:
  terminal: restore settings on SIGTSTP
  terminal: work around macos poll() bug
  terminal: don't assume stdin is /dev/tty
  terminal: use flags for save_term()
2022-03-30 18:01:11 -07:00
Junio C Hamano
eb804cd405 Merge branch 'ns/core-fsyncmethod'
Replace core.fsyncObjectFiles with two new configuration variables,
core.fsync and core.fsyncMethod.

* ns/core-fsyncmethod:
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
2022-03-25 16:38:24 -07:00
Jeff Hostetler
65723b305a compat/fsmonitor/fsm-listen-darwin: implement FSEvent listener on MacOS
Implement file system event listener on MacOS using FSEvent,
CoreFoundation, and CoreServices.

Co-authored-by: Kevin Willford <Kevin.Willford@microsoft.com>
Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:16 -07:00
Jeff Hostetler
5ff01b1f1e compat/fsmonitor/fsm-listen-darwin: add MacOS header files for FSEvent
Include MacOS system declarations to allow us to use FSEvent and
CoreFoundation APIs.  We need different versions of the declarations
for GCC vs. clang because of compiler and header file conflicts.

While it is quite possible to #include Apple's CoreServices.h when
compiling C source code with clang, trying to build it with GCC
currently fails with this error:

In file included
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/Security.framework/Headers/AuthSession.h:32,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/Security.framework/Headers/Security.h:42,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/CoreServices.framework/Frameworks/...
   ...OSServices.framework/Headers/CSIdentity.h:43,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/CoreServices.framework/Frameworks/...
   ...OSServices.framework/Headers/OSServices.h:29,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/CoreServices.framework/Frameworks/...
   ...LaunchServices.framework/Headers/IconsCore.h:23,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/CoreServices.framework/Frameworks/...
   ...LaunchServices.framework/Headers/LaunchServices.h:23,
   from /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
   ...Library/Frameworks/CoreServices.framework/Headers/CoreServices.h:45,

     /Library/Developer/CommandLineTools/SDKs/MacOSX10.14.sdk/System/...
     ...Library/Frameworks/Security.framework/Headers/Authorization.h:193:7:
     error: variably modified 'bytes' at file scope
       193 | char bytes[kAuthorizationExternalFormLength];
           |      ^~~~~

The underlying reason is that GCC (rightfully) objects that an `enum`
value such as `kAuthorizationExternalFormLength` is not a constant
(because it is not, the preprocessor has no knowledge of it, only the
actual C compiler does) and can therefore not be used to define the size
of a C array.

This is a known problem and tracked in GCC's bug tracker:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93082

In the meantime, let's not block things and go the slightly ugly route
of declaring/defining the FSEvents constants, data structures and
functions that we need, so that we can avoid above-mentioned issue.

Let's do this _only_ for GCC, though, so that the CI/PR builds (which
build both with clang and with GCC) can guarantee that we _are_ using
the correct data types.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:16 -07:00
Jeff Hostetler
1448edfb51 compat/fsmonitor/fsm-listen-win32: implement FSMonitor backend on Windows
Teach the win32 backend to register a watch on the working tree
root directory (recursively).  Also watch the <gitdir> if it is
not inside the working tree.  And to collect path change notifications
into batches and publish.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:16 -07:00
Jeff Hostetler
f67df2556f compat/fsmonitor/fsm-listen-darwin: stub in backend for Darwin
Stub in empty implementation of fsmonitor--daemon
backend for Darwin (aka MacOS).

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Jeff Hostetler
62c7367133 compat/fsmonitor/fsm-listen-win32: stub in backend for Windows
Stub in empty filesystem listener backend for fsmonitor--daemon on Windows.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-25 16:04:15 -07:00
Johannes Schindelin
1f480d5127 Sync with 2.34.2
* maint-2.34:
  Git 2.34.2
  Git 2.33.2
  Git 2.32.1
  Git 2.31.2
  GIT-VERSION-GEN: bump to v2.33.1
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:42 +01:00
Johannes Schindelin
93fbff09eb Sync with 2.33.2
* maint-2.33:
  Git 2.33.2
  Git 2.32.1
  Git 2.31.2
  GIT-VERSION-GEN: bump to v2.33.1
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:36 +01:00
Johannes Schindelin
303b876f76 Sync with 2.32.1
* maint-2.32:
  Git 2.32.1
  Git 2.31.2
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:32 +01:00
Johannes Schindelin
201b0c7af6 Sync with 2.31.2
* maint-2.31:
  Git 2.31.2
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:31:28 +01:00
Johannes Schindelin
6a2381a3e5 Sync with 2.30.3
* maint-2.30:
  Git 2.30.3
  setup_git_directory(): add an owner check for the top-level directory
  Add a function to determine whether a path is owned by the current user
2022-03-24 00:24:29 +01:00
Junio C Hamano
214919b4f6 Merge branch 'pw/single-key-interactive'
The single-key interactive operation used by "git add -p" has been
made more robust.

* pw/single-key-interactive:
  add -p: disable stdin buffering when interactive.singlekey is set
  terminal: set VMIN and VTIME in non-canonical mode
  terminal: pop signal handler when terminal is restored
  terminal: always reset terminal when reading without echo
2022-03-21 15:14:24 -07:00
Johannes Schindelin
bdc77d1d68 Add a function to determine whether a path is owned by the current user
This function will be used in the next commit to prevent
`setup_git_directory()` from discovering a repository in a directory
that is owned by someone other than the current user.

Note: We cannot simply use `st.st_uid` on Windows just like we do on
Linux and other Unix-like platforms: according to
https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/stat-functions
this field is always zero on Windows (because Windows' idea of a user ID
does not fit into a single numerical value). Therefore, we have to do
something a little involved to replicate the same functionality there.

Also note: On Windows, a user's home directory is not actually owned by
said user, but by the administrator. For all practical purposes, it is
under the user's control, though, therefore we pretend that it is owned
by the user.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2022-03-21 13:16:26 +01:00
Carlo Marcelo Arenas Belón
6e7ad1e4c2 mingw: avoid fallback for {local,gm}time_r()
mingw-w64's pthread_unistd.h had a bug that mistakenly (because there is
no support for the *lockfile() functions required[1]) defined
_POSIX_THREAD_SAFE_FUNCTIONS and that was being worked around since
3ecd153a3b (compat/mingw: support MSys2-based MinGW build, 2016-01-14).

The bug was fixed in winphtreads, but as a side effect, leaves the
reentrant functions from time.h no longer visible and therefore breaks
the build.

Since the intention all along was to avoid using the fallback functions,
formalize the use of POSIX by setting the corresponding feature flag and
compile out the implementation for the fallback functions.

[1] https://unix.org/whitepapers/reentrant.html

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-17 12:52:12 +01:00
Phillip Wood
0f584debc7 terminal: restore settings on SIGTSTP
If the user suspends git while it is waiting for a keypress reset the
terminal before stopping and restore the settings when git resumes. If
the user tries to resume in the background print an error
message (taking care to use async safe functions) before stopping
again. Ideally we would reprint the prompt for the user when git
resumes but this patch just restarts the read().

The signal handler is established with sigaction() rather than using
sigchain_push() as this allows us to control the signal mask when the
handler is invoked and ensure SA_RESTART is used to restart the
read() when resuming.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:44 -07:00
Phillip Wood
6606d99bae terminal: work around macos poll() bug
On macos the builtin "add -p" does not handle keys that generate
escape sequences because poll() does not work with terminals
there. Switch to using select() on non-windows platforms to work
around this.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:44 -07:00
Phillip Wood
e4938ce3cc terminal: don't assume stdin is /dev/tty
read_key_without_echo() reads from stdin but uses /dev/tty when it
disables echo. This is unfortunate as there no guarantee that stdin is
the same device as /dev/tty. The perl version of "add -p" uses stdin
when it sets the terminal mode, this commit does the same for the
builtin version. There is still a difference between the perl and
builtin versions though - the perl version will ignore any errors when
setting the terminal mode[1] and will still read single bytes when
stdin is not a terminal. The builtin version displays a warning if
setting the terminal mode fails and switches to reading a line at a
time.

[1] b061c913bb/ReadKey.xs (L1090)

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:43 -07:00
Phillip Wood
02af15dec5 terminal: use flags for save_term()
The next commit will add another flag in addition to the existing
full_duplex so change the function signature to take a flags
argument. Also alter the functions that call save_term() so that they
can pass flags down to it.

The choice to use an enum for tho bitwise flags is because gdb will
display the symbolic names of all the flags that are set rather than
the integer value.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-16 12:24:43 -07:00
Neeraj Singh
abf38abec2 core.fsyncmethod: add writeout-only mode
This commit introduces the `core.fsyncMethod` configuration
knob, which can currently be set to `fsync` or `writeout-only`.

The new writeout-only mode attempts to tell the operating system to
flush its in-memory page cache to the storage hardware without issuing a
CACHE_FLUSH command to the storage controller.

Writeout-only fsync is significantly faster than a vanilla fsync on
common hardware, since data is written to a disk-side cache rather than
all the way to a durable medium. Later changes in this patch series will
take advantage of this primitive to implement batching of hardware
flushes.

When git_fsync is called with FSYNC_WRITEOUT_ONLY, it may fail and the
caller is expected to do an ordinary fsync as needed.

On Apple platforms, the fsync system call does not issue a CACHE_FLUSH
directive to the storage controller. This change updates fsync to do
fcntl(F_FULLFSYNC) to make fsync actually durable. We maintain parity
with existing behavior on Apple platforms by setting the default value
of the new core.fsyncMethod option.

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
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
32f3ac26e0 Merge branch 'pw/single-key-interactive' into pw/add-p-single-key
* pw/single-key-interactive:
  add -p: disable stdin buffering when interactive.singlekey is set
  terminal: set VMIN and VTIME in non-canonical mode
  terminal: pop signal handler when terminal is restored
  terminal: always reset terminal when reading without echo
2022-03-09 15:32:56 -08:00
Tao Klerks
090a3085bc t/helper/test-chmtime: update mingw to support chmtime on directories
The mingw_utime implementation in mingw.c does not support
directories. This means that "test-tool chmtime" fails on Windows when
targeting directories. This has previously been noted and sidestepped
temporarily by Jeff Hostetler, in "t/helper/test-chmtime: skip
directories on Windows" in the "Builtin FSMonitor Part 2" work, but
not yet fixed.

It would make sense to backdate file and folder changes in untracked
cache tests, to avoid needing to insert explicit delays/pauses in the
tests.

Add support for directory date manipulation in mingw_utime by
replacing the file-oriented _wopen() call with the
directory-supporting CreateFileW() windows API explicitly.

Signed-off-by: Tao Klerks <tao@klerks.biz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 22:55:07 -08:00
Phillip Wood
2c6860211f terminal: set VMIN and VTIME in non-canonical mode
If VMIN and VTIME are both set to zero then the terminal performs
non-blocking reads which means that read_key_without_echo() returns
EOF if there is no key press pending. This results in the user being
unable to select anything when running "git add -p".  Fix this by
explicitly setting VMIN and VTIME when enabling non-canonical mode.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Phillip Wood
f7da756566 terminal: pop signal handler when terminal is restored
When disable_bits() changes the terminal attributes it uses
sigchain_push_common() to restore the terminal if a signal is received
before restore_term() is called. However there is no corresponding
call to sigchain_pop_common() when the settings are restored so the
signal handler is left on the sigchain stack. This leaves the stack
unbalanced so code such as

sigchain_push_common(my_handler);
...
read_key_without_echo(...);
...
sigchain_pop_common();

pops the handler pushed by disable_bits() rather than the one it
intended to. Additionally "git add -p" changes the terminal settings
every time it reads a key press so the stack can grow significantly.

In order to fix this save_term() now sets up the signal handler so
restore_term() can unconditionally call sigchain_pop_common(). There
are no callers of save_term() outside of terminal.c as the only
external caller was removed by e3f7e01b50 ("Revert "editor: save and
reset terminal after calling EDITOR"", 2021-11-22). Any future callers
of save_term() should benefit from having the signal handler set up
for them.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Phillip Wood
24d7ce383a terminal: always reset terminal when reading without echo
Break out of the loop to ensure restore_term() is called before
returning.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-23 13:30:06 -08:00
Junio C Hamano
00e38ba6d8 Merge branch 'ab/auto-detect-zlib-compress2'
The build procedure has been taught to notice older version of zlib
and enable our replacement uncompress2() automatically.

* ab/auto-detect-zlib-compress2:
  compat: auto-detect if zlib has uncompress2()
2022-02-16 15:14:30 -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
Junio C Hamano
66775d2109 Merge branch 'jc/qsort-s-alignment-fix'
Fix a hand-rolled alloca() imitation that may have violated
alignment requirement of data being sorted in compatibility
implementation of qsort_s() and stable qsort().

* jc/qsort-s-alignment-fix:
  stable-qsort: avoid using potentially unaligned access
  compat/qsort_s.c: avoid using potentially unaligned access
2022-02-05 09:42:31 -08:00
Ævar Arnfjörð Bjarmason
07564773c2 compat: auto-detect if zlib has uncompress2()
We have a copy of uncompress2() implementation in compat/ so that we
can build with an older version of zlib that lack the function, and
the build procedure selects if it is used via the NO_UNCOMPRESS2
$(MAKE) variable.  This is yet another "annoying" knob the porters
need to tweak on platforms that are not common enough to have the
default set in the config.mak.uname file.

Attempt to instead ask the system header <zlib.h> to decide if we
need the compatibility implementation.  This is a deviation from the
way we have been handling the "compatiblity" features so far, and if
it can be done cleanly enough, it could work as a model for features
that need compatibility definition we discover in the future.  With
that goal in mind, avoid expedient but ugly hacks, like shoving the
code that is conditionally compiled into an unrelated .c file, which
may not work in future cases---instead, take an approach that uses a
file that is independently compiled and stands on its own.

Compile and link compat/zlib-uncompress2.c file unconditionally, but
conditionally hide the implementation behind #if/#endif when zlib
version is 1.2.9 or newer, and unconditionally archive the resulting
object file in the libgit.a to be picked up by the linker.

There are a few things to note in the shape of the code base after
this change:

 - We no longer use NO_UNCOMPRESS2 knob; if the system header
   <zlib.h> claims a version that is more cent than the library
   actually is, this would break, but it is easy to add it back when
   we find such a system.

 - The object file compat/zlib-uncompress2.o is always compiled and
   archived in libgit.a, just like a few other compat/ object files
   already are.

 - The inclusion of <zlib.h> is done in <git-compat-util.h>; we used
   to do so from <cache.h> which includes <git-compat-util.h> as the
   first thing it does, so from the *.c codes, there is no practical
   change.

 - Until objects in libgit.a that is already used gains a reference
   to the function, the reftable code will be the only one that
   wants it, so libgit.a on the linker command line needs to appear
   once more at the end to satisify the mutual dependency.

 - Beat found a trick used by OpenSSL to avoid making the
   conditionally-compiled object truly empty (apparently because
   they had to deal with compilers that do not want to see an
   effectively empty input file).  Our compat/zlib-uncompress2.c
   file borrows the same trick for portabilty.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-26 09:05:55 -08:00
Johannes Schindelin
e2724c1ed1 getcwd(mingw): handle the case when there is no cwd
A recent upstream topic introduced checks for certain Git commands that
prevent them from deleting the current working directory, introducing
also a regression test that ensures that commands such as `git version`
_can_ run without a current working directory.

While technically not possible on Windows via the regular Win32 API, we
do run the regression tests in an MSYS2 Bash which uses a POSIX
emulation layer (the MSYS2/Cygwin runtime) where a really evil hack
_does_ allow to delete a directory even if it is the current working
directory.

Therefore, Git needs to be prepared for a missing working directory,
even on Windows.

This issue was not noticed in upstream Git because there was no caller
that tried to discover a Git directory with a deleted current working
directory in the test suite. But in the microsoft/git fork, we do want
to run `pre-command`/`post-command` hooks for every command, even for
`git version`, which means that we make precisely such a call. The bug
is not in that `pre-command`/`post-command` feature, though, but in
`mingw_getcwd()` and needs to be addressed there.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-19 11:27:31 -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
Junio C Hamano
a4510f8106 Merge branch 'ma/windows-dynload-fix'
Fix calling dynamically loaded functions on Windows.

* ma/windows-dynload-fix:
  lazyload: use correct calling conventions
2022-01-12 15:11:41 -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
Junio C Hamano
9bfa5fbae2 compat/qsort_s.c: avoid using potentially unaligned access
The compatibility definition for qsort_s() uses "char buffer[1024]"
on the stack to avoid making malloc() calls for small temporary
space, which essentially hand-rolls alloca().

But the elements of the array being sorted may have alignment needs
more strict than what an array of bytes may have. &buf[0] may be
word aligned, but using the address as if it stores the first
element of an array of a struct, whose first member may need to be
aligned on double-word boundary, would be a no-no.

We could use xalloca() from git-compat-util.h, or alloca() directly
on platforms with HAVE_ALLOCA_H, but let's try using unconditionally
xmalloc() before we know the performance characteristics of the
callers.

It may not make much of an argument to inspect the current callers
and say "it shouldn't matter to any of them", but anyway:

 * The one in object-name.c is used to sort potential matches to a
   given ambiguous object name prefix in the error path;

 * The one in pack-write.c is done once per a pack .idx file being
   written to create the reverse index, so (1) the cost of malloc()
   overhead is dwarfed by the cost of the packing operation, and (2)
   the number of entries being sorted is the number of objects in a
   pack;

 * The one in ref-filter.c is used by "branch --list", "tag --list",
   and "for-each-ref", only once per operation.  We sort an array of
   pointers with entries, each corresponding to a ref that is shown.

 * The one in string-list.c is used by sort_string_list(), which is
   way too generic to assume any access patterns, so it may or may
   not matter, but I do not care too much ;-)

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-07 14:20:58 -08:00
Junio C Hamano
a4bbd13be3 Merge branch 'hn/reftable'
The "reftable" backend for the refs API, without integrating into
the refs subsystem, has been added.

* hn/reftable:
  Add "test-tool dump-reftable" command.
  reftable: add dump utility
  reftable: implement stack, a mutable database of reftable files.
  reftable: implement refname validation
  reftable: add merged table view
  reftable: add a heap-based priority queue for reftable records
  reftable: reftable file level tests
  reftable: read reftable files
  reftable: generic interface to tables
  reftable: write reftable files
  reftable: a generic binary tree implementation
  reftable: reading/writing blocks
  Provide zlib's uncompress2 from compat/zlib-compat.c
  reftable: (de)serialization for the polymorphic record type.
  reftable: add blocksource, an abstraction for random access reads
  reftable: utility functions
  reftable: add error related functionality
  reftable: add LICENSE
  hash.h: provide constants for the hash IDs
2021-12-15 09:39:45 -08:00
Junio C Hamano
25be7ec4bf Merge branch 'cb/mingw-gmtime-r'
Build fix on Windows.

* cb/mingw-gmtime-r:
  mingw: avoid fallback for {local,gm}time_r()
2021-12-10 14:35:15 -08:00
Junio C Hamano
0ae87432aa Merge branch 'jc/unsetenv-returns-an-int'
The compatibility implementation for unsetenv(3) were written to
mimic ancient, non-POSIX, variant seen in an old glibc; it has been
changed to return an integer to match the more modern era.

* jc/unsetenv-returns-an-int:
  unsetenv(3) returns int, not void
2021-11-29 15:41:48 -08:00
Carlo Marcelo Arenas Belón
9e12400da8 mingw: avoid fallback for {local,gm}time_r()
mingw-w64's pthread_unistd.h had a bug that mistakenly (because there is
no support for the *lockfile() functions required[1]) defined
_POSIX_THREAD_SAFE_FUNCTIONS and that was being worked around since
3ecd153a3b (compat/mingw: support MSys2-based MinGW build, 2016-01-14).

The bug was fixed in winphtreads, but as a side effect, leaves the
reentrant functions from time.h no longer visible and therefore breaks
the build.

Since the intention all along was to avoid using the fallback functions,
formalize the use of POSIX by setting the corresponding feature flag and
compile out the implementation for the fallback functions.

[1] https://unix.org/whitepapers/reentrant.html

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-27 23:49:20 -08:00
Johannes Schindelin
974ef7ced2 simple-ipc: work around issues with Cygwin's Unix socket emulation
Cygwin emulates Unix sockets by writing files with custom contents and
then marking them as system files.

The tricky problem is that while the file is written and its `system`
bit is set, it is still identified as a file. This caused test failures
when Git is too fast looking for the Unix sockets and then complains
that there is a plain file in the way.

Let's work around this by adding a delayed retry loop, specifically for
Cygwin.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Tested-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-10 09:12:19 -08:00
Junio C Hamano
a38989bd5b unsetenv(3) returns int, not void
This compatilibity implementation has been returning a wrong type,
ever since 731043fd (Add compat/unsetenv.c ., 2006-01-25) added to
the system, yet nobody noticed it in the past 16 years, presumably
because no code checks failures in their unsetenv() calls.  Sigh.

For now, make it always succeed.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-29 15:00:58 -07:00
Junio C Hamano
853ec9aa9b Merge branch 'cm/save-restore-terminal'
An editor session launched during a Git operation (e.g. during 'git
commit') can leave the terminal in a funny state.  The code path
has updated to save the terminal state before, and restore it
after, it spawns an editor.

* cm/save-restore-terminal:
  editor: save and reset terminal after calling EDITOR
  terminal: teach git how to save/restore its terminal settings
2021-10-18 15:47:57 -07:00
Junio C Hamano
af303ee392 Merge branch 'jh/builtin-fsmonitor-part1'
Built-in fsmonitor (part 1).

* jh/builtin-fsmonitor-part1:
  t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command
  run-command: create start_bg_command
  simple-ipc/ipc-win32: add Windows ACL to named pipe
  simple-ipc/ipc-win32: add trace2 debugging
  simple-ipc: move definition of ipc_active_state outside of ifdef
  simple-ipc: preparations for supporting binary messages.
  trace2: add trace2_child_ready() to report on background children
2021-10-13 15:15:58 -07:00
Junio C Hamano
a5e61a4225 Merge branch 'ab/config-based-hooks-1'
Mostly preliminary clean-up in the hook API.

* ab/config-based-hooks-1:
  hook-list.h: add a generated list of hooks, like config-list.h
  hook.c users: use "hook_exists()" instead of "find_hook()"
  hook.c: add a hook_exists() wrapper and use it in bugreport.c
  hook.[ch]: move find_hook() from run-command.c to hook.c
  Makefile: remove an out-of-date comment
  Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
  Makefile: stop hardcoding {command,config}-list.h
  Makefile: mark "check" target as .PHONY
2021-10-13 15:15:57 -07:00
Junio C Hamano
ae9e6ef35e Merge branch 'rs/git-mmap-uses-malloc' into maint
mmap() imitation used to call xmalloc() that dies upon malloc()
failure, which has been corrected to just return an error to the
caller to be handled.

* rs/git-mmap-uses-malloc:
  compat: let git_mmap use malloc(3) directly
2021-10-12 13:51:40 -07:00
Han-Wen Nienhuys
a322920d0b Provide zlib's uncompress2 from compat/zlib-compat.c
This will be needed for reading reflog blocks in reftable.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-08 10:45:48 -07:00
Carlo Marcelo Arenas Belón
e22b245ea5 terminal: teach git how to save/restore its terminal settings
Currently, git will share its console with all its children (unless
they create their own), and is therefore possible that any of them
that might change the settings for it could affect its operations once
completed.

Refactor the platform specific functionality to save the terminal
settings and expand it to also do so for the output handler.

This will allow for the state of the terminal to be saved and
restored around a child that might misbehave (ex vi) which will
be implemented next.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-06 08:53:00 -07:00
Carlo Marcelo Arenas Belón
2d84c4ed57 lazyload.h: use an even more generic function pointer than FARPROC
gcc will helpfully raise a -Wcast-function-type warning when casting
between functions that might have incompatible return types
(ex: GetUserNameExW returns bool which is only half the size of the
return type from FARPROC which is long long), so create a new type that
could be used as a completely generic function pointer and cast through
it instead.

Additionaly remove the -Wno-incompatible-pointer-types temporary
flag added in 27e0c3c (win32: allow building with pedantic mode
enabled, 2021-09-03), as it will be no longer needed.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 13:13:58 -07:00
Johannes Sixt
d2c470f9bc lazyload.h: fix warnings about mismatching function pointer types
Here, GCC warns about every use of the INIT_PROC_ADDR macro, for example:

In file included from compat/mingw.c:8:
compat/mingw.c: In function 'mingw_strftime':
compat/win32/lazyload.h:38:12: warning: assignment to
   'size_t (*)(char *, size_t,  const char *, const struct tm *)'
   {aka 'long long unsigned int (*)(char *, long long unsigned int,
      const char *, const struct tm *)'} from incompatible pointer type
   'FARPROC' {aka 'long long int (*)()'} [-Wincompatible-pointer-types]
   38 |  (function = get_proc_addr(&proc_addr_##function))
      |            ^
compat/mingw.c:1014:6: note: in expansion of macro 'INIT_PROC_ADDR'
 1014 |  if (INIT_PROC_ADDR(strftime))
      |      ^~~~~~~~~~~~~~

(message wrapped for convenience). Insert a cast to keep the compiler
happy. A cast is fine in these cases because they are generic function
pointer values that have been looked up in a DLL.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 09:31:59 -07:00
Ævar Arnfjörð Bjarmason
7c3c0a99cc Makefile: stop hardcoding {command,config}-list.h
Change various places that hardcode the names of these two files to
refer to either $(GENERATED_H), or to a new generated-hdrs
target. That target is consistent with the *-objs targets I recently
added in 029bac01a8 (Makefile: add {program,xdiff,test,git,fuzz}-objs
& objects targets, 2021-02-23).

A subsequent commit will add a new generated hook-list.h. By doing
this refactoring we'll only need to add the new file to the
GENERATED_H variable, not EXCEPT_HDRS, the vcbuild/README etc.

Hardcoding command-list.h there seems to have been a case of
copy/paste programming in 976aaedca0 (msvc: add a Makefile target to
pre-generate the Visual Studio solution, 2019-07-29). The
config-list.h was added later in 709df95b78 (help: move
list_config_help to builtin/help, 2020-04-16).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-23 15:06:47 -07:00
Junio C Hamano
403192acb6 Merge branch 'cb/pedantic-build-for-developers'
Update the build procedure to use the "-pedantic" build when
DEVELOPER makefile macro is in effect.

* cb/pedantic-build-for-developers:
  developer: enable pedantic by default
  win32: allow building with pedantic mode enabled
  gettext: remove optional non-standard parens in N_() definition
2021-09-20 15:20:41 -07:00
Junio C Hamano
76f5fdc203 Merge branch 'ab/tr2-leaks-and-fixes'
The tracing of process ancestry information has been enhanced.

* ab/tr2-leaks-and-fixes:
  tr2: log N parent process names on Linux
  tr2: do compiler enum check in trace2_collect_process_info()
  tr2: leave the parent list empty upon failure & don't leak memory
  tr2: stop leaking "thread_name" memory
  tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux
  tr2: remove NEEDSWORK comment for "non-procfs" implementations
2021-09-20 15:20:40 -07:00
Jeff Hostetler
8750249053 simple-ipc/ipc-win32: add Windows ACL to named pipe
Set an ACL on the named pipe to allow the well-known group EVERYONE
to read and write to the IPC server's named pipe.  In the event that
the daemon was started with elevation, allow non-elevated clients
to communicate with the daemon.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-20 08:57:58 -07:00
Jeff Hostetler
9bd51d4975 simple-ipc/ipc-win32: add trace2 debugging
Create "ipc-debug" category events to log unexpected errors
when creating Simple-IPC connections.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-20 08:57:58 -07:00
Jeff Hostetler
a3e2033e04 simple-ipc: preparations for supporting binary messages.
Add `command_len` argument to the Simple IPC API.

In my original Simple IPC API, I assumed that the request would always
be a null-terminated string of text characters.  The `command`
argument was just a `const char *`.

I found a caller that would like to pass a binary command to the
daemon, so I am amending the Simple IPC API to receive `const char
*command, size_t command_len` arguments.

I considered changing the `command` argument to be a `void *`, but the
IPC layer simply passes it to the pkt-line layer which takes a `const
char *`, so to avoid confusion I left it as is.

Note, the response side has always been a `struct strbuf` which
includes the buffer and length, so we already support returning a
binary answer.  (Yes, it feels a little weird returning a binary
buffer in a `strbuf`, but it works.)

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-20 08:57:58 -07:00
Junio C Hamano
ce7ae09bd4 Merge branch 'rs/git-mmap-uses-malloc'
mmap() imitation used to call xmalloc() that dies upon malloc()
failure, which has been corrected to just return an error to the
caller to be handled.

* rs/git-mmap-uses-malloc:
  compat: let git_mmap use malloc(3) directly
2021-09-08 13:30:27 -07:00
Ævar Arnfjörð Bjarmason
2d3491b117 tr2: log N parent process names on Linux
In 2f732bf15e (tr2: log parent process name, 2021-07-21) we started
logging parent process names, but only logged all parents on Windows.
on Linux only the name of the immediate parent process was logged.

Extend the functionality added there to also log full parent chain on
Linux.

This requires us to lookup "/proc/<getppid()>/stat" instead of
"/proc/<getppid()>/comm". The "comm" file just contains the name of the
process, but the "stat" file has both that information, and the parent
PID of that process, see procfs(5). We parse out the parent PID of our
own parent, and recursively walk the chain of "/proc/*/stat" files all
the way up the chain. A parent PID of 0 indicates the end of the
chain.

It's possible given the semantics of Linux's PID files that we end up
getting an entirely nonsensical chain of processes. It could happen if
e.g. we have a chain of processes like:

    1 (init) => 321 (bash) => 123 (git)

Let's assume that "bash" was started a while ago, and that as shown
the OS has already cycled back to using a lower PID for us than our
parent process. In the time it takes us to start up and get to
trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP) our parent
process might exit, and be replaced by an entirely different process!

We'd racily look up our own getppid(), but in the meantime our parent
would exit, and Linux would have cycled all the way back to starting
an entirely unrelated process as PID 321.

If that happens we'll just silently log incorrect data in our ancestry
chain. Luckily we don't need to worry about this except in this
specific cycling scenario, as Linux does not have PID
randomization. It appears it once did through a third-party feature,
but that it was removed around 2006[1]. For anyone worried about this
edge case raising PID_MAX via "/proc/sys/kernel/pid_max" will mitigate
it, but not eliminate it.

One thing we don't need to worry about is getting into an infinite
loop when walking "/proc/*/stat". See 353d3d77f4 (trace2: collect
Windows-specific process information, 2019-02-22) for the related
Windows code that needs to deal with that, and [2] for an explanation
of that edge case.

Aside from potential race conditions it's also a bit painful to
correctly parse the process name out of "/proc/*/stat". A simpler
approach is to use fscanf(), see [3] for an implementation of that,
but as noted in the comment being added here it would fail in the face
of some weird process names, so we need our own parse_proc_stat() to
parse it out.

With this patch the "ancestry" chain for a trace2 event might look
like this:

    $ GIT_TRACE2_EVENT=/dev/stdout ~/g/git/git version | grep ancestry | jq -r .ancestry
    [
      "bash",
      "screen",
      "systemd"
    ]

And in the case of naughty process names like the following. This uses
perl's ability to use prctl(PR_SET_NAME, ...). See
Perl/perl5@7636ea95c5 (Set the legacy process name with prctl() on
assignment to $0 on Linux, 2010-04-15)[4]:

    $ perl -e '$0 = "(naughty\nname)"; system "GIT_TRACE2_EVENT=/dev/stdout ~/g/git/git version"' | grep ancestry | jq -r .ancestry
    [
      "sh",
      "(naughty\nname)",
      "bash",
      "screen",
      "systemd"
    ]

1. https://grsecurity.net/news#grsec2110
2. https://lore.kernel.org/git/48a62d5e-28e2-7103-a5bb-5db7e197a4b9@jeffhostetler.com/
3. https://lore.kernel.org/git/87o8agp29o.fsf@evledraar.gmail.com/
4. 7636ea95c5

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 11:08:00 -07:00
Ævar Arnfjörð Bjarmason
326460a870 tr2: do compiler enum check in trace2_collect_process_info()
Change code added in 2f732bf15e (tr2: log parent process name,
2021-07-21) to use a switch statement without a "default" branch to
have the compiler error if this code ever drifts out of sync with the
members of the "enum trace2_process_info_reason".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 11:07:59 -07:00
Ævar Arnfjörð Bjarmason
6eccfc3adf tr2: leave the parent list empty upon failure & don't leak memory
In a subsequent commit I'll be replacing most of this code to log N
parents, but let's first fix bugs introduced in the recent
2f732bf15e (tr2: log parent process name, 2021-07-21).

It was using the strbuf_read_file() in the wrong way, its return value
is either a length or a negative value on error. If we didn't have a
procfs, or otherwise couldn't access it we'd end up pushing an empty
string to the trace2 ancestry array.

It was also using the strvec_push() API the wrong way. That API always
does an xstrdup(), so by detaching the strbuf here we'd leak
memory. Let's instead pass in our pointer for strvec_push() to
xstrdup(), and then free our own strbuf. I do have some WIP changes to
make strvec_push_nodup() non-static, which makes this and some other
callsites nicer, but let's just follow the prevailing pattern of using
strvec_push() for now.

We'll also need to free that "procfs_path" strbuf whether or not
strbuf_read_file() succeeds, which was another source of memory leaks
in 2f732bf15e, i.e. we'd leak that memory as well if we weren't on a
system where we could read the file from procfs.

Let's move all the freeing of the memory to the end of the
function. If we're still at STRBUF_INIT with "name" due to not having
taken the branch where the strbuf_read_file() succeeds freeing it is
redundant. So we could move it into the body of the "if", but just
handling freeing the same way for all branches of the function makes
it more readable.

In combination with the preceding commit this makes all of
t[0-9]*trace2*.sh pass under SANITIZE=leak on Linux.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 11:07:59 -07:00
Ævar Arnfjörð Bjarmason
f2cc8881d7 tr2: clarify TRACE2_PROCESS_INFO_EXIT comment under Linux
Rewrite a comment added in 2f732bf15e (tr2: log parent process name,
2021-07-21) to describe what we might do under
TRACE2_PROCESS_INFO_EXIT in the future, instead of vaguely referring
to "something extra".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 11:07:59 -07:00
Ævar Arnfjörð Bjarmason
7d9c80f626 tr2: remove NEEDSWORK comment for "non-procfs" implementations
I'm fairly sure that there is no way on Linux to inspect the process
tree without using procfs, any tool such as ps(1), top(1) etc. that
shows this sort of information ultimately looks the information up in
procfs.

So let's remove this comment added in 2f732bf15e (tr2: log parent
process name, 2021-07-21), it's setting us up for an impossible task.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 11:07:59 -07:00
Carlo Marcelo Arenas Belón
27e0c3c6cf win32: allow building with pedantic mode enabled
In preparation to building with pedantic mode enabled, change a couple
of places where the current mingw gcc compiler provided with the SDK
reports issues.

A full fix for the incompatible use of (void *) to store function
pointers has been punted, with the minimal change to instead use a
generic function pointer (FARPROC), and therefore the (hopefully)
temporary need to disable incompatible pointer warnings.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-03 11:40:30 -07:00
Junio C Hamano
6f64eeab60 Merge branch 'es/trace2-log-parent-process-name'
trace2 logs learned to show parent process name to see in what
context Git was invoked.

* es/trace2-log-parent-process-name:
  tr2: log parent process name
  tr2: make process info collection platform-generic
2021-08-24 15:32:40 -07:00
René Scharfe
95b4ff3931 compat: let git_mmap use malloc(3) directly
xmalloc() dies on error, allows zero-sized allocations and enforces
GIT_ALLOC_LIMIT for testing.  Our mmap replacement doesn't need any of
that.  Let's cut out the wrapper, reject zero-sized requests as required
by POSIX and use malloc(3) directly.  Allocation errors were needlessly
handled by git_mmap() before; this code becomes reachable now.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-24 14:43:45 -07:00
Thomas Bétous
3e7d4888e5 mingw: align symlinks-related rmdir() behavior with Linux
When performing a rebase, rmdir() is called on the folder .git/logs. On
Unix rmdir() exits without deleting anything in case .git/logs is a
symbolic link but the equivalent functions on Windows (_rmdir, _wrmdir
and RemoveDirectoryW) do not behave the same and remove the folder if it
is symlinked even if it is not empty.

This creates issues when folders in .git/ are symlinks which is
especially the case when git-repo[1] is used: It replaces `.git/logs/`
with a symlink.

One such issue is that the _target_ of that symlink is removed e.g.
during a `git rebase`, where `delete_reflog("REBASE_HEAD")` will not
only try to remove `.git/logs/REBASE_HEAD` but then recursively try to
remove the parent directories until an error occurs, a technique that
obviously relies on `rmdir()` refusing to remove a symlink.

This was reported in https://github.com/git-for-windows/git/issues/2967.

This commit updates mingw_rmdir() so that its behavior is the same as
Linux rmdir() in case of symbolic links.

To verify that Git does not regress on the reported issue, this patch
adds a regression test for the `git rebase` symptom, even if the same
`rmdir()` behavior is quite likely to cause potential problems in other
Git commands as well.

[1]: git-repo is a python tool built on top of Git which helps manage
many Git repositories. It stores all the .git/ folders in a central
place by taking advantage of symbolic links.
More information: https://gerrit.googlesource.com/git-repo/

Signed-off-by: Thomas Bétous <tomspycell@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-02 15:10:58 -07:00
Emily Shaffer
2f732bf15e tr2: log parent process name
It can be useful to tell who invoked Git - was it invoked manually by a
user via CLI or script? By an IDE?  In some cases - like 'repo' tool -
we can influence the source code and set the GIT_TRACE2_PARENT_SID
environment variable from the caller process. In 'repo''s case, that
parent SID is manipulated to include the string "repo", which means we
can positively identify when Git was invoked by 'repo' tool. However,
identifying parents that way requires both that we know which tools
invoke Git and that we have the ability to modify the source code of
those tools. It cannot scale to keep up with the various IDEs and
wrappers which use Git, most of which we don't know about. Learning
which tools and wrappers invoke Git, and how, would give us insight to
decide where to improve Git's usability and performance.

Unfortunately, there's no cross-platform reliable way to gather the name
of the parent process. If procfs is present, we can use that; otherwise
we will need to discover the name another way. However, the process ID
should be sufficient to look up the process name on most platforms, so
that code may be shareable.

Git for Windows gathers similar information and logs it as a "data_json"
event. However, since "data_json" has a variable format, it is difficult
to parse effectively in some languages; instead, let's pursue a
dedicated "cmd_ancestry" event to record information about the ancestry
of the current process and a consistent, parseable way.

Git for Windows also gathers information about more than one generation
of parent. In Linux further ancestry info can be gathered with procfs,
but it's unwieldy to do so. In the interest of later moving Git for
Windows ancestry logging to the 'cmd_ancestry' event, and in the
interest of later adding more ancestry to the Linux implementation - or
of adding this functionality to other platforms which have an easier
time walking the process tree - let's make 'cmd_ancestry' accept an
array of parentage.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 13:35:20 -07:00
Emily Shaffer
b7e6a41622 tr2: make process info collection platform-generic
To pave the way for non-Windows platforms to define
trace2_collect_process_info(), reorganize the stub-or-definition schema
to something which doesn't directly reference Windows.

Platforms which want to collect parent process information in the
future should:

 1. Add an implementation to compat/ (e.g. compat/somearch/procinfo.c)
 2. Add that object to COMPAT_OBJS to config.mak.uname
    (e.g. COMPAT_OBJS += compat/somearch/procinfo.o)
 3. Define HAVE_PLATFORM_PROCINFO in config.mak.uname

In the Windows case, this definition lives in
compat/win32/trace2_win32_process_info.c, which is already conditionally
added to COMPAT_OBJS; so let's add HAVE_PLATFORM_PROCINFO to hint to the
build that compat/stub/procinfo.c should not be used.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-22 13:35:20 -07:00
Junio C Hamano
6aae0e2ad2 Merge branch 'jh/simple-ipc-sans-pthread'
The "simple-ipc" did not compile without pthreads support, but the
build procedure was not properly account for it.

* jh/simple-ipc-sans-pthread:
  simple-ipc: correct ifdefs when NO_PTHREADS is defined
2021-05-22 18:29:01 +09:00
Jeff Hostetler
6aac70a870 simple-ipc: correct ifdefs when NO_PTHREADS is defined
Simple IPC always requires threads (in addition to various
platform-specific IPC support).  Fix the ifdefs in the Makefile
to define SUPPORTS_SIMPLE_IPC when appropriate.

Previously, the Unix version of the code would only verify that
Unix domain sockets were available.

This problem was reported here:
https://lore.kernel.org/git/YKN5lXs4AoK%2FJFTO@coredump.intra.peff.net/T/#m08be8f1942ea8a2c36cfee0e51cdf06489fdeafc

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-21 07:55:00 +09:00
Junio C Hamano
4090b6973b Merge branch 'js/access-nul-emulation-on-windows'
Portability fix.

* js/access-nul-emulation-on-windows:
  msvc: avoid calling `access("NUL", flags)`
2021-04-20 17:23:37 -07:00
Johannes Schindelin
9160068ac6 msvc: avoid calling access("NUL", flags)
Apparently this is not supported with Microsoft's Universal C Runtime.
So let's not actually do that.

Instead, just return success because we _know_ that we expect the `NUL`
device to be present.

Side note: it is possible to turn off the "Null device driver" and
thereby disable `NUL`. Too many things are broken if this driver is
disabled, therefore it is not worth bothering to try to detect its
presence when `access()` is called.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-16 12:05:32 -07:00
Junio C Hamano
4c6ac2da2c Merge branch 'tb/precompose-prefix-simplify'
Streamline the codepath to fix the UTF-8 encoding issues in the
argv[] and the prefix on macOS.

* tb/precompose-prefix-simplify:
  macOS: precompose startup_info->prefix
  precompose_utf8: make precompose_string_if_needed() public
2021-04-13 15:28:51 -07:00
Torsten Bögershausen
5020774aef precompose_utf8: make precompose_string_if_needed() public
commit 5c327502 (MacOS: precompose_argv_prefix(), 2021-02-03) uses
the function precompose_string_if_needed() internally.  It is only
used from precompose_argv_prefix() and therefore static in
compat/precompose_utf8.c

Expose this function, it will be used in the next commit.

While there, allow passing a NULL pointer, which will return NULL.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-05 17:30:04 -07:00
Junio C Hamano
861794b60d Merge branch 'jh/simple-ipc'
A simple IPC interface gets introduced to build services like
fsmonitor on top.

* jh/simple-ipc:
  t0052: add simple-ipc tests and t/helper/test-simple-ipc tool
  simple-ipc: add Unix domain socket implementation
  unix-stream-server: create unix domain socket under lock
  unix-socket: disallow chdir() when creating unix domain sockets
  unix-socket: add backlog size option to unix_stream_listen()
  unix-socket: eliminate static unix_stream_socket() helper function
  simple-ipc: add win32 implementation
  simple-ipc: design documentation for new IPC mechanism
  pkt-line: add options argument to read_packetized_to_strbuf()
  pkt-line: add PACKET_READ_GENTLE_ON_READ_ERROR option
  pkt-line: do not issue flush packets in write_packetized_*()
  pkt-line: eliminate the need for static buffer in packet_write_gently()
2021-04-02 14:43:14 -07:00
Jeff Hostetler
7cd5dbcaba simple-ipc: add Unix domain socket implementation
Create Unix domain socket based implementation of "simple-ipc".

A set of `ipc_client` routines implement a client library to connect
to an `ipc_server` over a Unix domain socket, send a simple request,
and receive a single response.  Clients use blocking IO on the socket.

A set of `ipc_server` routines implement a thread pool to listen for
and concurrently service client connections.

The server creates a new Unix domain socket at a known location.  If a
socket already exists with that name, the server tries to determine if
another server is already listening on the socket or if the socket is
dead.  If socket is busy, the server exits with an error rather than
stealing the socket.  If the socket is dead, the server creates a new
one and starts up.

If while running, the server detects that its socket has been stolen
by another server, it automatically exits.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-22 11:52:54 -07:00
Jeff Hostetler
59c7b88198 simple-ipc: add win32 implementation
Create Windows implementation of "simple-ipc" using named pipes.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-15 14:32:50 -07:00
Junio C Hamano
56a57652ef Sync with Git 2.30.2 for CVE-2021-21300
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-08 16:09:07 -08:00
Junio C Hamano
921846fa22 Merge branch 'jk/open-returns-eintr'
Work around platforms whose open() is reported to return EINTR (it
shouldn't, as we do our signals with SA_RESTART).

* jk/open-returns-eintr:
  config.mak.uname: enable OPEN_RETURNS_EINTR for macOS Big Sur
  Makefile: add OPEN_RETURNS_EINTR knob
2021-03-04 15:34:45 -08:00
Jeff King
2b08101204 Makefile: add OPEN_RETURNS_EINTR knob
On some platforms, open() reportedly returns EINTR when opening regular
files and we receive a signal (usually SIGALRM from our progress meter).
This shouldn't happen, as open() should be a restartable syscall, and we
specify SA_RESTART when setting up the alarm handler. So it may actually
be a kernel or libc bug for this to happen. But it has been reported on
at least one version of Linux (on a network filesystem):

  https://lore.kernel.org/git/c8061cce-71e4-17bd-a56a-a5fed93804da@neanderfunk.de/

as well as on macOS starting with Big Sur even on a regular filesystem.

We can work around it by retrying open() calls that get EINTR, just as
we do for read(), etc. Since we don't ever _want_ to interrupt an open()
call, we can get away with just redefining open, rather than insisting
all callsites use xopen().

We actually do have an xopen() wrapper already (and it even does this
retry, though there's no indication of it being an observed problem back
then; it seems simply to have been lifted from xread(), etc). But it is
used hardly anywhere, and isn't suitable for general use because it will
die() on error. In theory we could combine the two, but it's awkward to
do so because of the variable-args interface of open().

This patch adds a Makefile knob for enabling the workaround. It's not
enabled by default for any platforms in config.mak.uname yet, as we
don't have enough data to decide how common this is (I have not been
able to reproduce on either Linux or Big Sur myself). It may be worth
enabling preemptively anyway, since the cost is pretty low (if we don't
see an EINTR, it's just an extra conditional).

However, note that we must not enable this on Windows. It doesn't do
anything there, and the macro overrides the existing mingw_open()
redirection. I've added a preemptive #undef here in the mingw header
(which is processed first) to just quietly disable it (we could also
make it an #error, but there is little point in being so aggressive).

Reported-by: Aleksey Kliger <alklig@microsoft.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-26 14:15:51 -08:00
Johannes Schindelin
e4e68081bb Sync with 2.29.3
* maint-2.29:
  Git 2.29.3
  Git 2.28.1
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:51:12 +01:00
Johannes Schindelin
d7bdabe52f Sync with 2.28.1
* maint-2.28:
  Git 2.28.1
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:50:14 +01:00
Johannes Schindelin
3f01e56686 Sync with 2.27.1
* maint-2.27:
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:50:09 +01:00
Johannes Schindelin
2d1142a3e8 Sync with 2.26.3
* maint-2.26:
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:50:04 +01:00
Johannes Schindelin
8f80393c14 Sync with 2.25.5
* maint-2.25:
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:59 +01:00
Johannes Schindelin
97d1dcb1ef Sync with 2.24.4
* maint-2.24:
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:55 +01:00
Johannes Schindelin
92ac04b8ee Sync with 2.23.4
* maint-2.23:
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:50 +01:00
Johannes Schindelin
4bd06fd490 Sync with 2.22.5
* maint-2.22:
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:45 +01:00
Johannes Schindelin
bcf08f33d8 Sync with 2.21.4
* maint-2.21:
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:41 +01:00
Johannes Schindelin
b1726b1a38 Sync with 2.20.5
* maint-2.20:
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:35 +01:00
Johannes Schindelin
804963848e Sync with 2.19.6
* maint-2.19:
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:17 +01:00
Johannes Schindelin
fb049fd85b Sync with 2.18.5
* maint-2.18:
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:47:47 +01:00
Johannes Schindelin
9b77cec89b Sync with 2.17.6
* maint-2.17:
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:47:42 +01:00
Matheus Tavares
684dd4c2b4 checkout: fix bug that makes checkout follow symlinks in leading path
Before checking out a file, we have to confirm that all of its leading
components are real existing directories. And to reduce the number of
lstat() calls in this process, we cache the last leading path known to
contain only directories. However, when a path collision occurs (e.g.
when checking out case-sensitive files in case-insensitive file
systems), a cached path might have its file type changed on disk,
leaving the cache on an invalid state. Normally, this doesn't bring
any bad consequences as we usually check out files in index order, and
therefore, by the time the cached path becomes outdated, we no longer
need it anyway (because all files in that directory would have already
been written).

But, there are some users of the checkout machinery that do not always
follow the index order. In particular: checkout-index writes the paths
in the same order that they appear on the CLI (or stdin); and the
delayed checkout feature -- used when a long-running filter process
replies with "status=delayed" -- postpones the checkout of some entries,
thus modifying the checkout order.

When we have to check out an out-of-order entry and the lstat() cache is
invalid (due to a previous path collision), checkout_entry() may end up
using the invalid data and thrusting that the leading components are
real directories when, in reality, they are not. In the best case
scenario, where the directory was replaced by a regular file, the user
will get an error: "fatal: unable to create file 'foo/bar': Not a
directory". But if the directory was replaced by a symlink, checkout
could actually end up following the symlink and writing the file at a
wrong place, even outside the repository. Since delayed checkout is
affected by this bug, it could be used by an attacker to write
arbitrary files during the clone of a maliciously crafted repository.

Some candidate solutions considered were to disable the lstat() cache
during unordered checkouts or sort the entries before passing them to
the checkout machinery. But both ideas include some performance penalty
and they don't future-proof the code against new unordered use cases.

Instead, we now manually reset the lstat cache whenever we successfully
remove a directory. Note: We are not even checking whether the directory
was the same as the lstat cache points to because we might face a
scenario where the paths refer to the same location but differ due to
case folding, precomposed UTF-8 issues, or the presence of `..`
components in the path. Two regression tests, with case-collisions and
utf8-collisions, are also added for both checkout-index and delayed
checkout.

Note: to make the previously mentioned clone attack unfeasible, it would
be sufficient to reset the lstat cache only after the remove_subtree()
call inside checkout_entry(). This is the place where we would remove a
directory whose path collides with the path of another entry that we are
currently trying to check out (possibly a symlink). However, in the
interest of a thorough fix that does not leave Git open to
similar-but-not-identical attack vectors, we decided to intercept
all `rmdir()` calls in one fell swoop.

This addresses CVE-2021-21300.

Co-authored-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
2021-02-12 15:47:02 +01:00
Torsten Bögershausen
5c327502db MacOS: precompose_argv_prefix()
The following sequence leads to a "BUG" assertion running under MacOS:

  DIR=git-test-restore-p
  Adiarnfd=$(printf 'A\314\210')
  DIRNAME=xx${Adiarnfd}yy
  mkdir $DIR &&
  cd $DIR &&
  git init &&
  mkdir $DIRNAME &&
  cd $DIRNAME &&
  echo "Initial" >file &&
  git add file &&
  echo "One more line" >>file &&
  echo y | git restore -p .

 Initialized empty Git repository in /tmp/git-test-restore-p/.git/
 BUG: pathspec.c:495: error initializing pathspec_item
 Cannot close git diff-index --cached --numstat
 [snip]

The command `git restore` is run from a directory inside a Git repo.
Git needs to split the $CWD into 2 parts:
The path to the repo and "the rest", if any.
"The rest" becomes a "prefix" later used inside the pathspec code.

As an example, "/path/to/repo/dir-inside-repå" would determine
"/path/to/repo" as the root of the repo, the place where the
configuration file .git/config is found.

The rest becomes the prefix ("dir-inside-repå"), from where the
pathspec machinery expands the ".", more about this later.
If there is a decomposed form, (making the decomposing visible like this),
"dir-inside-rep°a" doesn't match "dir-inside-repå".

Git commands need to:

 (a) read the configuration variable "core.precomposeunicode"
 (b) precocompose argv[]
 (c) precompose the prefix, if there was any

The first commit,
76759c7dff "git on Mac OS and precomposed unicode"
addressed (a) and (b).

The call to precompose_argv() was added into parse-options.c,
because that seemed to be a good place when the patch was written.

Commands that don't use parse-options need to do (a) and (b) themselfs.

The commands `diff-files`, `diff-index`, `diff-tree` and `diff`
learned (a) and (b) in
commit 90a78b83e0 "diff: run arguments through precompose_argv"

Branch names (or refs in general) using decomposed code points
resulting in decomposed file names had been fixed in
commit 8e712ef6fc "Honor core.precomposeUnicode in more places"

The bug report from above shows 2 things:
- more commands need to handle precomposed unicode
- (c) should be implemented for all commands using pathspecs

Solution:
precompose_argv() now handles the prefix (if needed), and is renamed into
precompose_argv_prefix().

Inside this function the config variable core.precomposeunicode is read
into the global variable precomposed_unicode, as before.
This reading is skipped if precomposed_unicode had been read before.

The original patch for preocomposed unicode, 76759c7dff, placed
precompose_argv() into parse-options.c

Now add it into git.c::run_builtin() as well.  Existing precompose
calls in diff-files.c and others may become redundant, and if we
audit the callflows that reach these places to make sure that they
can never be reached without going through the new call added to
run_builtin(), we might be able to remove these existing ones.

But in this commit, we do not bother to do so and leave these
precompose callsites as they are.  Because precompose() is
idempotent and can be called on an already precomposed string
safely, this is safer than removing existing calls without fully
vetting the callflows.

There is certainly room for cleanups - this change intends to be a bug fix.
Cleanups needs more tests in e.g. t/t3910-mac-os-precompose.sh, and should
be done in future commits.

[1] git-bugreport-2021-01-06-1209.txt (git can't deal with special characters)
[2] https://lore.kernel.org/git/A102844A-9501-4A86-854D-E3B387D378AA@icloud.com/

Reported-by: Daniel Troger <random_n0body@icloud.com>
Helped-By: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-03 14:09:37 -08:00
Junio C Hamano
ccbde2c4f4 Merge branch 'da/vs-build-iconv-fix'
Build update.

* da/vs-build-iconv-fix:
  ci(vs-build): stop passing the iconv library location explicitly
2020-12-14 10:21:38 -08:00
Dennis Ameling
e66590348a ci(vs-build): stop passing the iconv library location explicitly
Something changed in `vcpkg` (which we use in our Visual C++ build to
provide the dependencies such as libcurl) and our `vs-build` job started
failing in CI. The reason is that we had a work-around in place to help
CMake find iconv, and this work-around is neither needed nor does it
work anymore.

For the full discussion with the vcpkg project, see this comment:
https://github.com/microsoft/vcpkg/issues/14780#issuecomment-735368280

Signed-off-by: Dennis Ameling <dennis@dennisameling.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-04 12:03:15 -08:00
Daniel Gurney
0c038fc65a compat/bswap.h: don't assume MSVC is little-endian
In 1af265f0 (compat/bswap.h: simplify MSVC endianness
detection, 2020-11-08) we attempted to simplify code by assuming MSVC
builds will be for little-endian machines, since only unusably old
versions of MSVC supported big-endian MIPS and m68k architectures.

However, it's possible that MSVC could be ported to build for a
big-endian architecture again, so the simplification wasn't as
future-proof as hoped.

So let's go back to the old way of detecting MSVC, and then checking
architecture from a list of little-endian architecture macros.

Note that MSVC does not treat ARM64 as bi-endian, so we can safely treat
it as little-endian.

Helped-by: brian m. carlson <sandals@crustytoothpaste.net>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Daniel Gurney <dgurney99@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 11:24:47 -08:00
Daniel Gurney
1af265f0a0 compat/bswap.h: simplify MSVC endianness detection
Modern MSVC or Windows versions don't support big-endian, so it's
unnecessary to consider architectures when using it.

This also makes ARM64 MSVC builds succeed.

Helped-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Daniel Gurney <dgurney99@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-09 13:01:10 -08:00
Denton Liu
fcedb379fd compat/mingw.h: drop extern from function declaration
In 554544276a (*.[ch]: remove extern from function declarations using
spatch, 2019-04-29), `extern` on function declarations were declared to
be redundant and thus removed from the codebase. An `extern` was
accidentally reintroduced in 08809c09aa (mingw: add a helper function to
attach GDB to the current process, 2020-02-13).

Remove this spurious `extern`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-07 09:55:20 -07:00
Junio C Hamano
86cca370e1 Merge branch 'jk/drop-unaligned-loads'
Compilation fix around type punning.

* jk/drop-unaligned-loads:
  Revert "fast-export: use local array to store anonymized oid"
  bswap.h: drop unaligned loads
2020-10-04 12:49:06 -07:00
Jeff King
c578e29ba0 bswap.h: drop unaligned loads
Our put_be32() routine and its variants (get_be32(), put_be64(), etc)
has two implementations: on some platforms we cast memory in place and
use nothl()/htonl(), which can cause unaligned memory access. And on
others, we pick out the individual bytes using bitshifts.

This introduces extra complexity, and sometimes causes compilers to
generate warnings about type-punning. And it's not clear there's any
performance advantage.

This split goes back to 660231aa97 (block-sha1: support for
architectures with memory alignment restrictions, 2009-08-12). The
unaligned versions were part of the original block-sha1 code in
d7c208a92e (Add new optimized C 'block-sha1' routines, 2009-08-05),
which says it is:

   Based on the mozilla SHA1 routine, but doing the input data accesses a
   word at a time and with 'htonl()' instead of loading bytes and shifting.

Back then, Linus provided timings versus the mozilla code which showed a
27% improvement:

  https://lore.kernel.org/git/alpine.LFD.2.01.0908051545000.3390@localhost.localdomain/

However, the unaligned loads were either not the useful part of that
speedup, or perhaps compilers and processors have changed since then.
Here are times for computing the sha1 of 4GB of random data, with and
without -DNO_UNALIGNED_LOADS (and BLK_SHA1=1, of course). This is with
gcc 10, -O2, and the processor is a Core i9-9880H.

  [stock]
  Benchmark #1: t/helper/test-tool sha1 <foo.rand
    Time (mean ± σ):      6.638 s ±  0.081 s    [User: 6.269 s, System: 0.368 s]
    Range (min … max):    6.550 s …  6.841 s    10 runs

  [-DNO_UNALIGNED_LOADS]
  Benchmark #1: t/helper/test-tool sha1 <foo.rand
    Time (mean ± σ):      6.418 s ±  0.015 s    [User: 6.058 s, System: 0.360 s]
    Range (min … max):    6.394 s …  6.447 s    10 runs

And here's the same test run on an AMD A8-7600, using gcc 8.

  [stock]
  Benchmark #1: t/helper/test-tool sha1 <foo.rand
    Time (mean ± σ):     11.721 s ±  0.113 s    [User: 10.761 s, System: 0.951 s]
    Range (min … max):   11.509 s … 11.861 s    10 runs

  [-DNO_UNALIGNED_LOADS]
  Benchmark #1: t/helper/test-tool sha1 <foo.rand
    Time (mean ± σ):     11.744 s ±  0.066 s    [User: 10.807 s, System: 0.928 s]
    Range (min … max):   11.637 s … 11.863 s    10 runs

So the unaligned loads don't seem to help much, and actually make things
worse. It's possible there are platforms where they provide more
benefit, but:

  - the non-x86 platforms for which we use this code are old and obscure
    (powerpc and s390).

  - the main caller that cares about performance is block-sha1. But
    these days it is rarely used anyway, in favor of sha1dc (which is
    already much slower, and nobody seems to have cared that much).

Let's just drop unaligned versions entirely in the name of simplicity.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-24 12:30:09 -07:00
Orgad Shaneh
3384a1ef78 vcbuild: fix batch file name in README
Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-03 10:19:48 -07:00
Orgad Shaneh
c2f3ef8d8f vcbuild: fix library name for expat with make MSVC=1
Signed-off-by: Orgad Shaneh <orgads@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-03 10:19:42 -07:00
Junio C Hamano
5a0482662f Merge branch 'jh/mingw-unlink'
"unlink" emulation on MinGW has been optimized.

* jh/mingw-unlink:
  mingw: improve performance of mingw_unlink()
2020-08-19 16:14:53 -07:00
Jeff Hostetler
680e0b4524 mingw: improve performance of mingw_unlink()
Update mingw_unlink() to first try to delete the file with existing
permissions before trying to force it.

Windows throws an error when trying to delete a read-only file.  The
mingw_unlink() compatibility wrapper always tries to _wchmod(666) the
file before calling _wunlink() to avoid that error.  However, since
most files in the worktree are already writable, this is usually
wasted effort.

Update mingw_unlink() to just call DeleteFileW() directly and if that
succeeds return.  If that fails, fall back into the existing code path
to update the permissions and use _wunlink() to get the existing
error code mapping.

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>
2020-08-17 11:27:16 -07:00
Jeff King
ef8d7ac42a strvec: convert more callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts remaining files from the first half of the alphabet,
to keep the diff to a manageable size.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

and then selectively staging files with "git add '[abcdefghjkl]*'".
We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Junio C Hamano
9906d5f8e9 Merge branch 'js/msvc-build-fix'
Workaround breakage in MSVC build, where "curl-config --cflags"
gives settings appropriate for GCC build.

* js/msvc-build-fix:
  msvc: fix "REG_STARTEND" issue
2020-06-17 21:54:03 -07:00
Johannes Schindelin
bb0e43d8a1 msvc: fix "REG_STARTEND" issue
In 897d68e7af (Makefile: use curl-config --cflags, 2020-03-26), we
taught the build process to use `curl-config --cflags` to make sure that
it can find cURL's headers.

In the MSVC build, this is completely bogus because we're running in a
Git for Windows SDK whose `curl-config` supports the _GCC_ build.

Let's just ignore each and every `-I<path>` option where `<path>` points
to GCC/Clang specific headers.

Reported by Jeff Hostetler in
https://github.com/microsoft/git/issues/275.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-04 15:52:21 -07:00
Junio C Hamano
7b304ab16c Merge branch 'cb/no-more-gmtime'
Code clean-up by removing a compatibility implementation of a
function we no longer use.

* cb/no-more-gmtime:
  compat: remove gmtime
2020-05-20 08:33:27 -07:00
Carlo Marcelo Arenas Belón
84b0115f0d compat: remove gmtime
ccd469450a (date.c: switch to reentrant {gm,local}time_r, 2019-11-28)
removes the only gmtime() call we had and moves to gmtime_r() which
doesn't have the same portability problems.

Remove the compat gmtime code since it is no longer needed, and confirm
by successfull running t4212 in FreeBSD 9.3 amd64 (the oldest I could
get a hold off).

Further work might be needed to ensure 32bit time_t systems (like FreeBSD
i386) will handle correctly the overflows tested in t4212, but that is
orthogonal to this change, and it doesn't change the current behaviour
as neither gmtime() or gmtime_r() will ever return NULL on those systems
because time_t is unsigned.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-14 13:52:27 -07:00
Junio C Hamano
dd094c2b75 Merge branch 'es/bugreport'
The "bugreport" tool.

* es/bugreport:
  bugreport: drop extraneous includes
  bugreport: add compiler info
  bugreport: add uname info
  bugreport: gather git version and build info
  bugreport: add tool to generate debugging info
  help: move list_config_help to builtin/help
2020-05-01 13:39:59 -07:00
Đoàn Trần Công Danh
3bc1f9e48c compat/regex: move stdlib.h up in inclusion chain
In Linux with musl libc, we have this inclusion chain:

compat/regex/regex.c:69
`-> compat/regex/regex_internal.h
   `-> /usr/include/stdlib.h
      `-> /usr/include/features.h
      `-> /usr/include/alloca.h

In that inclusion chain, `<features.h>` claims it's _BSD_SOURCE
compatible when it's NOT asked to be either
{_POSIX,_GNU,_XOPEN,_BSD}_SOURCE, or __STRICT_ANSI__.
And, `<stdlib.h>` will include `<alloca.h>` to be compatible with
software written for GNU and BSD. Thus, redefine `alloca` macro,
which was defined before at compat/regex/regex.c:66.

Considering this is only compat code, we've taken from other project,
it's not our business to decide which source should we adhere to.

Include `<stdlib.h>` early to prevent the redefinition of alloca.
This also remove a potential warning about alloca not defined on:
	#undef alloca

Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-27 11:21:16 -07:00
Junio C Hamano
a41b41ca74 Merge branch 'js/mingw-isilon-nfs'
* js/mingw-isilon-nfs:
  mingw: cope with the Isilon network file system
2020-04-22 13:42:58 -07:00
Junio C Hamano
b3eb70e0f8 Merge branch 'js/mingw-fixes'
Misc fixes for Windows.

* js/mingw-fixes:
  mingw: help debugging by optionally executing bash with strace
  mingw: do not treat `COM0` as a reserved file name
  mingw: use modern strftime implementation if possible
2020-04-22 13:42:56 -07:00
Emily Shaffer
69bcbbceb7 bugreport: add compiler info
To help pinpoint the source of a regression, it is useful to know some
info about the compiler which the user's Git client was built with. By
adding a generic get_compiler_info() in 'compat/' we can choose which
relevant information to share per compiler; to get started, let's
demonstrate the version of glibc if the user built with 'gcc'.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Helped-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-16 15:23:42 -07:00
Emily Shaffer
709df95b78 help: move list_config_help to builtin/help
Starting in 3ac68a93fd, help.o began to depend on builtin/branch.o,
builtin/clean.o, and builtin/config.o. This meant that help.o was
unusable outside of the context of the main Git executable.

To make help.o usable by other commands again, move list_config_help()
into builtin/help.c (where it makes sense to assume other builtin libraries
are present).

When command-list.h is included but a member is not used, we start to
hear a compiler warning. Since the config list is generated in a fairly
different way than the command list, and since commands and config
options are semantically different, move the config list into its own
header and move the generator into its own script and build rule.

For reasons explained in 976aaedc (msvc: add a Makefile target to
pre-generate the Visual Studio solution, 2019-07-29), some build
artifacts we consider non-source files cannot be generated in the
Visual Studio environment, and we already have some Makefile tweaks
to help Visual Studio to use generated command-list.h header file.
Do the same to a new generated file, config-list.h, introduced by
this change.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
2020-04-16 15:22:16 -07:00
Nathan Sanders
23eafd924a mingw: cope with the Isilon network file system
On certain network filesystems (currently encountered with Isilon, but
in theory more network storage solutions could be causing the same
issue), when the directory in question is missing,
`raceproof_create_file()` fails with an `ERROR_INVALID_PARAMETER`
instead of an `ERROR_PATH_NOT_FOUND`.

Since it is highly unlikely that we produce such an error by mistake
(the parameters we pass are fairly benign), we can be relatively certain
that the directory is missing in this instance. So let's just translate
that error automagically.

This fixes https://github.com/git-for-windows/git/issues/1345.

Signed-off-by: Nathan Sanders <spekbukkem@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 10:34:05 -07:00
Johannes Schindelin
3efc128cd5 mingw: help debugging 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.

Also support passing a path to a log file via GIT_STRACE_COMMANDS to
force Git to call strace.exe with the `-o <path>` argument, i.e. to log
into a file rather than print the log directly.

That comes in handy when the output would otherwise misinterpreted by a
calling process as part of Git's output.

Note: the values "1", "yes" or "true" are *not* specifying paths, but
tell Git to let strace.exe log directly to the console.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-10 10:21:07 -07:00
Johannes Schindelin
b6852e1979 mingw: do not treat COM0 as a reserved file name
In 4dc42c6c18 (mingw: refuse paths containing reserved names,
2019-12-21), we started disallowing file names that are reserved, e.g.
`NUL`, `CONOUT$`, etc.

This included `COM<n>` where `<n>` is a digit. Unfortunately, this
includes `COM0` but only `COM1`, ..., `COM9` are reserved, according to
the official documentation, `COM0` is mentioned in the "NT Namespaces"
section but it is explicitly _omitted_ from the list of reserved names:
https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions

Tests corroborate this: it is totally possible to write a file called
`com0.c` on Windows 10, but not `com1.c`.

So let's tighten the code to disallow only the reserved `COM<n>` file
names, but to allow `COM0` again.

This fixes https://github.com/git-for-windows/git/issues/2470.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-08 12:15:51 -07:00
Matthias Aßhauer
a748f3f3dc mingw: use modern strftime implementation if possible
Microsoft introduced a new "Universal C Runtime Library" (UCRT) with
Visual Studio 2015. The UCRT comes with a new strftime() implementation
that supports more date formats. We link git against the older
"Microsoft Visual C Runtime Library" (MSVCRT), so to use the UCRT
strftime() we need to load it from ucrtbase.dll using
DECLARE_PROC_ADDR()/INIT_PROC_ADDR().

Most supported Windows systems should have recieved the UCRT via Windows
update, but in some cases only MSVCRT might be available. In that case
we fall back to using that implementation.

With this change, it is possible to use e.g. the `%g` and `%V` date
format specifiers, e.g.

	git show -s --format=%cd --date=format:‘%g.%V’ HEAD

Without this change, the user would see this error message on Windows:

	fatal: invalid strftime format: '‘%g.%V’'

This fixes https://github.com/git-for-windows/git/issues/2495

Signed-off-by: Matthias Aßhauer <mha1993@live.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-08 12:15:50 -07:00
Andras Kucsma
05ac8582bc run-command: trigger PATH lookup properly on Cygwin
On Cygwin, the codepath for POSIX-like systems is taken in
run-command.c::start_command(). The prepare_cmd() helper
function is called to decide if the command needs to be looked
up in the PATH. The logic there is to do the PATH-lookup if
and only if it does not have any slash '/' in it. If this test
passes we end up attempting to run the command by appending the
string after each colon-separated component of PATH.

The Cygwin environment supports both Windows and POSIX style
paths, so both forwardslahes '/' and back slashes '\' can be
used as directory separators for any external program the user
supplies.

Examples for path strings which are being incorrectly searched
for in the PATH instead of being executed as is:

- "C:\Program Files\some-program.exe"
- "a\b\c.exe"

To handle these, the PATH lookup detection logic in prepare_cmd()
is taught to know about this Cygwin quirk, by introducing
has_dir_sep(path) helper function to abstract away the difference
between true POSIX and Cygwin systems.

Signed-off-by: Andras Kucsma <r0maikx02b@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27 11:06:17 -07:00
Junio C Hamano
32fc2c6dd6 Merge branch 'js/mingw-open-in-gdb' into maint
Dev support.

* js/mingw-open-in-gdb:
  mingw: add a helper function to attach GDB to the current process
2020-03-17 15:02:25 -07:00
Junio C Hamano
2d7247af6f Merge branch 'am/mingw-poll-fix' into maint
MinGW's poll() emulation has been improved.

* am/mingw-poll-fix:
  mingw: workaround for hangs when sending STDIN
2020-03-17 15:02:24 -07:00
Junio C Hamano
a7a2e12b6e Merge branch 'jk/clang-sanitizer-fixes' into maint
C pedantry ;-) fix.

* jk/clang-sanitizer-fixes:
  obstack: avoid computing offsets from NULL pointer
  xdiff: avoid computing non-zero offset from NULL pointer
  avoid computing zero offsets from NULL pointer
  merge-recursive: use subtraction to flip stage
  merge-recursive: silence -Wxor-used-as-pow warning
2020-03-17 15:02:21 -07:00
Junio C Hamano
1ac37deba2 Merge branch 'am/mingw-poll-fix'
MinGW's poll() emulation has been improved.

* am/mingw-poll-fix:
  mingw: workaround for hangs when sending STDIN
2020-03-09 11:21:20 -07:00
Junio C Hamano
ff41848e99 Merge branch 'rs/micro-cleanups'
Code cleanup.

* rs/micro-cleanups:
  use strpbrk(3) to search for characters from a given set
  quote: use isalnum() to check for alphanumeric characters
2020-03-02 15:07:20 -08:00
Alexandr Miloslavskiy
94f4d01932 mingw: workaround for hangs when sending STDIN
Explanation
-----------
The problem here is flawed `poll()` implementation. When it tries to
see if pipe can be written without blocking, it eventually calls
`NtQueryInformationFile()` and tests `WriteQuotaAvailable`. However,
the meaning of quota was misunderstood. The value of quota is reduced
when either some data was written to a pipe, *or* there is a pending
read on the pipe. Therefore, if there is a pending read of size >= than
the pipe's buffer size, poll() will think that pipe is not writable and
will hang forever, usually that means deadlocking both pipe users.

I have studied the problem and found that Windows pipes track two values:
`QuotaUsed` and `BytesInQueue`. The code in `poll()` apparently wants to
know `BytesInQueue` instead of quota. Unfortunately, `BytesInQueue` can
only be requested from read end of the pipe, while `poll()` receives
write end.

The git's implementation of `poll()` was copied from gnulib, which also
contains a flawed implementation up to today.

I also had a look at implementation in cygwin, which is also broken in a
subtle way. It uses this code in `pipe_data_available()`:
	fpli.WriteQuotaAvailable = (fpli.OutboundQuota - fpli.ReadDataAvailable)
However, `ReadDataAvailable` always returns 0 for the write end of the pipe,
turning the code into an obfuscated version of returning pipe's total
buffer size, which I guess will in turn have `poll()` always say that pipe
is writable. The commit that introduced the code doesn't say anything about
this change, so it could be some debugging code that slipped in.

These are the typical sizes used in git:
0x2000 - default read size in `strbuf_read()`
0x1000 - default read size in CRT, used by `strbuf_getwholeline()`
0x2000 - pipe buffer size in compat\mingw.c

As a consequence, as soon as child process uses `strbuf_read()`,
`poll()` in parent process will hang forever, deadlocking both
processes.

This results in two observable behaviors:
1) If parent process begins sending STDIN quickly (and usually that's
   the case), then first `poll()` will succeed and first block will go
   through. MAX_IO_SIZE_DEFAULT is 8MB, so if STDIN exceeds 8MB, then
   it will deadlock.
2) If parent process waits a little bit for any reason (including OS
   scheduler) and child is first to issue `strbuf_read()`, then it will
   deadlock immediately even on small STDINs.

The problem is illustrated by `git stash push`, which will currently
read the entire patch into memory and then send it to `git apply` via
STDIN. If patch exceeds 8MB, git hangs on Windows.

Possible solutions
------------------
1) Somehow obtain `BytesInQueue` instead of `QuotaUsed`
   I did a pretty thorough search and didn't find any ways to obtain
   the value from write end of the pipe.
2) Also give read end of the pipe to `poll()`
   That can be done, but it will probably invite some dirty code,
   because `poll()`
   * can accept multiple pipes at once
   * can accept things that are not pipes
   * is expected to have a well known signature.
3) Make `poll()` always reply "writable" for write end of the pipe
   Afterall it seems that cygwin (accidentally?) does that for years.
   Also, it should be noted that `pump_io_round()` writes 8MB blocks,
   completely ignoring the fact that pipe's buffer size is only 8KB,
   which means that pipe gets clogged many times during that single
   write. This may invite a deadlock, if child's STDERR/STDOUT gets
   clogged while it's trying to deal with 8MB of STDIN. Such deadlocks
   could be defeated with writing less than pipe's buffer size per
   round, and always reading everything from STDOUT/STDERR before
   starting next round. Therefore, making `poll()` always reply
   "writable" shouldn't cause any new issues or block any future
   solutions.
4) Increase the size of the pipe's buffer
   The difference between `BytesInQueue` and `QuotaUsed` is the size
   of pending reads. Therefore, if buffer is bigger than size of reads,
   `poll()` won't hang so easily. However, I found that for example
   `strbuf_read()` will get more and more hungry as it reads large inputs,
   eventually surpassing any reasonable pipe buffer size.

Chosen solution
---------------
Make `poll()` always reply "writable" for write end of the pipe.
Hopefully one day someone will find a way to implement it properly.

Reproduction
------------
printf "%8388608s" X >large_file.txt
git stash push --include-untracked -- large_file.txt

I have decided not to include this as test to avoid slowing down the
test suite. I don't expect the specific problem to come back, and
chances are that `git stash push` will be reworked to avoid sending the
entire patch via STDIN.

Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-27 14:23:29 -08:00
René Scharfe
2ce6d075fa use strpbrk(3) to search for characters from a given set
We can check if certain characters are present in a string by calling
strchr(3) on each of them, or we can pass them all to a single
strpbrk(3) call.  The latter is shorter, less repetitive and slightly
more efficient, so let's do that instead.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-24 09:30:31 -08:00
Junio C Hamano
e154451a2f Merge branch 'js/mingw-open-in-gdb'
Dev support.

* js/mingw-open-in-gdb:
  mingw: add a helper function to attach GDB to the current process
2020-02-17 13:22:18 -08:00
Junio C Hamano
54bbadaeca Merge branch 'jk/asan-build-fix' into maint
Work around test breakages caused by custom regex engine used in
libasan, when address sanitizer is used with more recent versions
of gcc and clang.

* jk/asan-build-fix:
  Makefile: use compat regex with SANITIZE=address
2020-02-14 12:42:29 -08:00
Johannes Schindelin
08809c09aa mingw: add a helper function to attach GDB to the current process
When debugging Git, the criss-cross spawning of processes can make
things quite a bit difficult, especially when a Unix shell script is
thrown in the mix that calls a `git.exe` that then segfaults.

To help debugging such things, we introduce the `open_in_gdb()` function
which can be called at a code location where the segfault happens (or as
close as one can get); This will open a new MinTTY window with a GDB
that already attached to the current process.

Inspired by Derrick Stolee.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-14 10:02:07 -08:00
Junio C Hamano
b783391018 Merge branch 'jk/clang-sanitizer-fixes'
C pedantry ;-) fix.

* jk/clang-sanitizer-fixes:
  obstack: avoid computing offsets from NULL pointer
  xdiff: avoid computing non-zero offset from NULL pointer
  avoid computing zero offsets from NULL pointer
  merge-recursive: use subtraction to flip stage
  merge-recursive: silence -Wxor-used-as-pow warning
2020-02-12 12:41:36 -08:00
Junio C Hamano
76c57fedfa Merge branch 'js/add-p-leftover-bits'
The final leg of rewriting "add -i/-p" in C.

* js/add-p-leftover-bits:
  ci: include the built-in `git add -i` in the `linux-gcc` job
  built-in add -p: handle Escape sequences more efficiently
  built-in add -p: handle Escape sequences in interactive.singlekey mode
  built-in add -p: respect the `interactive.singlekey` config setting
  terminal: add a new function to read a single keystroke
  terminal: accommodate Git for Windows' default terminal
  terminal: make the code of disable_echo() reusable
  built-in add -p: handle diff.algorithm
  built-in add -p: support interactive.diffFilter
  t3701: adjust difffilter test
2020-02-05 14:34:58 -08:00
Junio C Hamano
808dab2b58 Merge branch 'jk/asan-build-fix'
Work around test breakages caused by custom regex engine used in
libasan, when address sanitizer is used with more recent versions
of gcc and clang.

* jk/asan-build-fix:
  Makefile: use compat regex with SANITIZE=address
2020-01-30 14:17:09 -08:00
Jeff King
cf82bff73f obstack: avoid computing offsets from NULL pointer
As with the previous two commits, UBSan with clang-11 complains about
computing offsets from a NULL pointer. The failures in t4013 (and
elsewhere) look like this:

  kwset.c:102:23: runtime error: applying non-zero offset 107820859019600 to null pointer
  ...
  not ok 79 - git log -SF master # magic is (not used)

That line is not enlightening:

  ... = obstack_alloc(&kwset->obstack, sizeof (struct trie));

because obstack is implemented almost entirely in macros, and the actual
problem is five macros deep (I temporarily converted them to inline
functions to get better compiler errors, which was tedious but worked
reasonably well).

The actual problem is in these pointer-alignment macros:

  /* If B is the base of an object addressed by P, return the result of
     aligning P to the next multiple of A + 1.  B and P must be of type
     char *.  A + 1 must be a power of 2.  */

  #define __BPTR_ALIGN(B, P, A) ((B) + (((P) - (B) + (A)) & ~(A)))

  /* Similar to _BPTR_ALIGN (B, P, A), except optimize the common case
     where pointers can be converted to integers, aligned as integers,
     and converted back again.  If PTR_INT_TYPE is narrower than a
     pointer (e.g., the AS/400), play it safe and compute the alignment
     relative to B.  Otherwise, use the faster strategy of computing the
     alignment relative to 0.  */

  #define __PTR_ALIGN(B, P, A)                                                \
    __BPTR_ALIGN (sizeof (PTR_INT_TYPE) < sizeof (void *) ? (B) : (char *) 0, \
                  P, A)

If we have a sufficiently-large integer pointer type, then we do the
computation using a NULL pointer constant. That turns __BPTR_ALIGN()
into something like:

  NULL + (P - NULL + A) & ~A

and UBSan is complaining about adding the full value of P to that
initial NULL. We can fix this by doing our math as an integer type, and
then casting the result back to a pointer. The problem case only happens
when we know that the integer type is large enough, so there should be
no issue with truncation.

Another option would be just simplify out all the 0's from
__BPTR_ALIGN() for the NULL-pointer case. That probably wouldn't work
for a platform where the NULL pointer isn't all-zeroes, but Git already
wouldn't work on such a platform (due to our use of memset to set
pointers in structs to NULL). But I tried here to keep as close to the
original as possible.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-28 23:13:25 -08:00
Junio C Hamano
232378479e Sync with maint
* maint:
  msvc: accommodate for vcpkg's upgrade to OpenSSL v1.1.x
2020-01-16 15:18:46 -08:00
Jeff King
f65d07fffa Makefile: use compat regex with SANITIZE=address
Recent versions of the gcc and clang Address Sanitizer produce test
failures related to regexec(). This triggers with gcc-10 and clang-8
(but not gcc-9 nor clang-7). Running:

  make CC=gcc-10 SANITIZE=address test

results in failures in t4018, t3206, and t4062.

The cause seems to be that when built with ASan, we use a different
version of regexec() than normal. And this version doesn't understand
the REG_STARTEND flag. Here's my evidence supporting that.

The failure in t4062 is an ASan warning:

  expecting success of 4062.2 '-G matches':
  	git diff --name-only -G "^(0{64}){64}$" HEAD^ >out &&
  	test 4096-zeroes.txt = "$(cat out)"

  =================================================================
  ==672994==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fa76f672000 at pc 0x7fa7726f75b6 bp 0x7ffe41bdda70 sp 0x7ffe41bdd220
  READ of size 4097 at 0x7fa76f672000 thread T0
      #0 0x7fa7726f75b5  (/lib/x86_64-linux-gnu/libasan.so.6+0x4f5b5)
      #1 0x562ae0c9c40e in regexec_buf /home/peff/compile/git/git-compat-util.h:1117
      #2 0x562ae0c9c40e in diff_grep /home/peff/compile/git/diffcore-pickaxe.c:52
      #3 0x562ae0c9cc28 in pickaxe_match /home/peff/compile/git/diffcore-pickaxe.c:166
      [...]

In this case we're looking in a buffer which was mmap'd via
reuse_worktree_file(), and whose size is 4096 bytes. But libasan's
regex tries to look at byte 4097 anyway! If we tweak Git like this:

  diff --git a/diff.c b/diff.c
  index 8e2914c031..cfae60c120 100644
  --- a/diff.c
  +++ b/diff.c
  @@ -3880,7 +3880,7 @@ static int reuse_worktree_file(struct index_state *istate,
           */
          if (ce_uptodate(ce) ||
              (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
  -               return 1;
  +               return 0;

          return 0;
   }

to use a regular buffer (with a trailing NUL) instead of an mmap, then
the complaint goes away.

The other failures are actually diff output with an incorrect funcname
header. If I instrument xdiff to show the funcname matching like so:

  diff --git a/xdiff-interface.c b/xdiff-interface.c
  index 8509f9ea22..f6c3dc1986 100644
  --- a/xdiff-interface.c
  +++ b/xdiff-interface.c
  @@ -197,6 +197,7 @@ struct ff_regs {
   	struct ff_reg {
   		regex_t re;
   		int negate;
  +		char *printable;
   	} *array;
   };

  @@ -218,7 +219,12 @@ static long ff_regexp(const char *line, long len,

   	for (i = 0; i < regs->nr; i++) {
   		struct ff_reg *reg = regs->array + i;
  -		if (!regexec_buf(&reg->re, line, len, 2, pmatch, 0)) {
  +		int ret = regexec_buf(&reg->re, line, len, 2, pmatch, 0);
  +		warning("regexec %s:\n  regex: %s\n  buf: %.*s",
  +			ret == 0 ? "matched" : "did not match",
  +			reg->printable,
  +			(int)len, line);
  +		if (!ret) {
   			if (reg->negate)
   				return -1;
   			break;
  @@ -264,6 +270,7 @@ void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
   			expression = value;
   		if (regcomp(&reg->re, expression, cflags))
   			die("Invalid regexp to look for hunk header: %s", expression);
  +		reg->printable = xstrdup(expression);
   		free(buffer);
   		value = ep + 1;
   	}

then when compiling with ASan and gcc-10, running the diff from t4018.66
produces this:

  $ git diff -U1 cpp-skip-access-specifiers
  warning: regexec did not match:
    regex: ^[     ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])
    buf: private:
  warning: regexec matched:
    regex: ^((::[[:space:]]*)?[A-Za-z_].*)$
    buf: private:
  diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers
  index 4d4a9db..ebd6f42 100644
  --- a/cpp-skip-access-specifiers
  +++ b/cpp-skip-access-specifiers
  @@ -6,3 +6,3 @@ private:
          void DoSomething();
          int ChangeMe;
  };
          void DoSomething();
  -       int ChangeMe;
  +       int IWasChanged;
   };

That first regex should match (and is negated, so it should be telling
us _not_ to match "private:"). But it wouldn't if regexec() is looking
at the whole buffer, and not just the length-limited line we've fed to
regexec_buf(). So this is consistent again with REG_STARTEND being
ignored.

The correct output (compiling without ASan, or gcc-9 with Asan) looks
like this:

  warning: regexec matched:
    regex: ^[     ]*[A-Za-z_][A-Za-z_0-9]*:[[:space:]]*($|/[/*])
    buf: private:
  [...more lines that we end up not using...]
  warning: regexec matched:
    regex: ^((::[[:space:]]*)?[A-Za-z_].*)$
    buf: class RIGHT : public Baseclass
  diff --git a/cpp-skip-access-specifiers b/cpp-skip-access-specifiers
  index 4d4a9db..ebd6f42 100644
  --- a/cpp-skip-access-specifiers
  +++ b/cpp-skip-access-specifiers
  @@ -6,3 +6,3 @@ class RIGHT : public Baseclass
          void DoSomething();
  -       int ChangeMe;
  +       int IWasChanged;
   };

So it really does seem like libasan's regex engine is ignoring
REG_STARTEND. We should be able to work around it by compiling with
NO_REGEX, which would use our local regexec(). But to make matters even
more interesting, this isn't enough by itself.

Because ASan has support from the compiler, it doesn't seem to intercept
our call to regexec() at the dynamic library level. It actually
recognizes when we are compiling a call to regexec() and replaces it
with ASan-specific code at that point. And unlike most of our other
compat code, where we might have git_mmap() or similar, the actual
symbol name in the compiled compat/regex code is regexec(). So just
compiling with NO_REGEX isn't enough; we still end up in libasan!

We can work around that by having the preprocessor replace regexec with
git_regexec (both in the callers and in the actual implementation), and
we truly end up with a call to our custom regex code, even when
compiling with ASan. That's probably a good thing to do anyway, as it
means anybody looking at the symbols later (e.g., in a debugger) would
have a better indication of which function is which. So we'll do the
same for the other common regex functions (even though just regexec() is
enough to fix this ASan problem).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-16 14:19:39 -08:00
Johannes Schindelin
b6d4d82bd5 msvc: accommodate for vcpkg's upgrade to OpenSSL v1.1.x
With the upgrade, the library names changed from libeay32/ssleay32 to
libcrypto/libssl.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-16 12:18:23 -08:00
Johannes Schindelin
12acdf573a built-in add -p: handle Escape sequences more efficiently
When `interactive.singlekey = true`, we react immediately to keystrokes,
even to Escape sequences (e.g. when pressing a cursor key).

The problem with Escape sequences is that we do not really know when
they are done, and as a heuristic we poll standard input for half a
second to make sure that we got all of it.

While waiting half a second is not asking for a whole lot, it can become
quite annoying over time, therefore with this patch, we read the
terminal capabilities (if available) and extract known Escape sequences
from there, then stop polling immediately when we detected that the user
pressed a key that generated such a known sequence.

This recapitulates the remaining part of b5cc003253 (add -i: ignore
terminal escape sequences, 2011-05-17).

Note: We do *not* query the terminal capabilities directly. That would
either require a lot of platform-specific code, or it would require
linking to a library such as ncurses.

Linking to a library in the built-ins is something we try very hard to
avoid (we even kicked the libcurl dependency to a non-built-in remote
helper, just to shave off a tiny fraction of a second from Git's startup
time). And the platform-specific code would be a maintenance nightmare.

Even worse: in Git for Windows' case, we would need to query MSYS2
pseudo terminals, which `git.exe` simply cannot do (because it is
intentionally *not* an MSYS2 program).

To address this, we simply spawn `infocmp -L -1` and parse its output
(which works even in Git for Windows, because that helper is included in
the end-user facing installations).

This is done only once, as in the Perl version, but it is done only when
the first Escape sequence is encountered, not upon startup of `git add
-i`; This saves on startup time, yet makes reacting to the first Escape
sequence slightly more sluggish. But it allows us to keep the
terminal-related code encapsulated in the `compat/terminal.c` file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
e118f06396 built-in add -p: handle Escape sequences in interactive.singlekey mode
This recapitulates part of b5cc003253 (add -i: ignore terminal escape
sequences, 2011-05-17):

    add -i: ignore terminal escape sequences

    On the author's terminal, the up-arrow input sequence is ^[[A, and
    thus fat-fingering an up-arrow into 'git checkout -p' is quite
    dangerous: git-add--interactive.perl will ignore the ^[ and [
    characters and happily treat A as "discard everything".

    As a band-aid fix, use Term::Cap to get all terminal capabilities.
    Then use the heuristic that any capability value that starts with ^[
    (i.e., \e in perl) must be a key input sequence.  Finally, given an
    input that starts with ^[, read more characters until we have read a
    full escape sequence, then return that to the caller.  We use a
    timeout of 0.5 seconds on the subsequent reads to avoid getting stuck
    if the user actually input a lone ^[.

    Since none of the currently recognized keys start with ^[, the net
    result is that the sequence as a whole will be ignored and the help
    displayed.

Note that we leave part for later which uses "Term::Cap to get all
terminal capabilities", for several reasons:

1. it is actually not really necessary, as the timeout of 0.5 seconds
   should be plenty sufficient to catch Escape sequences,

2. it is cleaner to keep the change to special-case Escape sequences
   separate from the change that reads all terminal capabilities to
   speed things up, and

3. in practice, relying on the terminal capabilities is a bit overrated,
   as the information could be incomplete, or plain wrong. For example,
   in this developer's tmux sessions, the terminal capabilities claim
   that the "cursor up" sequence is ^[M, but the actual sequence
   produced by the "cursor up" key is ^[[A.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
a5e46e6b01 terminal: add a new function to read a single keystroke
Typically, input on the command-line is line-based. It is actually not
really easy to get single characters (or better put: keystrokes).

We provide two implementations here:

- One that handles `/dev/tty` based systems as well as native Windows.
  The former uses the `tcsetattr()` function to put the terminal into
  "raw mode", which allows us to read individual keystrokes, one by one.
  The latter uses `stty.exe` to do the same, falling back to direct
  Win32 Console access.

  Thanks to the refactoring leading up to this commit, this is a single
  function, with the platform-specific details hidden away in
  conditionally-compiled code blocks.

- A fall-back which simply punts and reads back an entire line.

Note that the function writes the keystroke into an `strbuf` rather than
a `char`, in preparation for reading Escape sequences (e.g. when the
user hit an arrow key). This is also required for UTF-8 sequences in
case the keystroke corresponds to a non-ASCII letter.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
9ea416cb51 terminal: accommodate Git for Windows' default terminal
Git for Windows' Git Bash runs in MinTTY by default, which does not have
a Win32 Console instance, but uses MSYS2 pseudo terminals instead.

This is a problem, as Git for Windows does not want to use the MSYS2
emulation layer for Git itself, and therefore has no direct way to
interact with that pseudo terminal.

As a workaround, use the `stty` utility (which is included in Git for
Windows, and which *is* an MSYS2 program, so it knows how to deal with
the pseudo terminal).

Note: If Git runs in a regular CMD or PowerShell window, there *is* a
regular Win32 Console to work with. This is not a problem for the MSYS2
`stty`: it copes with this scenario just fine.

Also note that we introduce support for more bits than would be
necessary for a mere `disable_echo()` here, in preparation for the
upcoming `enable_non_canonical()` function.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Johannes Schindelin
94ac3c31f7 terminal: make the code of disable_echo() reusable
We are about to introduce the function `enable_non_canonical()`, which
shares almost the complete code with `disable_echo()`.

Let's prepare for that, by refactoring out that shared code.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-15 12:06:17 -08:00
Junio C Hamano
13432fc6dd Merge branch 'js/mingw-reserved-filenames'
Forbid pathnames that the platform's filesystem cannot represent on
MinGW.

* js/mingw-reserved-filenames:
  mingw: refuse paths containing reserved names
  mingw: short-circuit the conversion of `/dev/null` to UTF-16
2020-01-02 12:38:30 -08:00
Johannes Schindelin
4dc42c6c18 mingw: refuse paths containing reserved names
There are a couple of reserved names that cannot be file names on
Windows, such as `AUX`, `NUL`, etc. For an almost complete list, see
https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file

If one would try to create a directory named `NUL`, it would actually
"succeed", i.e. the call would return success, but nothing would be
created.

Worse, even adding a file extension to the reserved name does not make
it a valid file name. To understand the rationale behind that behavior,
see https://devblogs.microsoft.com/oldnewthing/20031022-00/?p=42073

Let's just disallow them all.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:09:07 -08:00
Johannes Schindelin
98d9b23e90 mingw: short-circuit the conversion of /dev/null to UTF-16
In the next commit, we want to disallow accessing any path that contains
any segment that is equivalent to `NUL`. In particular, we want to
disallow accessing `NUL` (e.g. to prevent any repository from being
checked out that contains a file called `NUL`, as that is not a valid
file name on Windows).

However, there are legitimate use cases within Git itself to write to
the Null device. As Git is really a Linux project, it does not abstract
that idea, though, but instead uses `/dev/null` to describe this
intention.

So let's side-step the validation _specifically_ in the case that we
want to write to (or read from) `/dev/null`, via a dedicated short-cut
in the code that skips the call to `validate_win32_path()`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-21 16:09:06 -08:00
Junio C Hamano
4755a34c47 Merge branch 'dd/time-reentrancy'
Avoid gmtime() and localtime() and prefer their reentrant
counterparts.

* dd/time-reentrancy:
  mingw: use {gm,local}time_s as backend for {gm,local}time_r
  archive-zip.c: switch to reentrant localtime_r
  date.c: switch to reentrant {gm,local}time_r
2019-12-16 13:08:31 -08:00
Junio C Hamano
55d607d85b Merge branch 'js/mingw-inherit-only-std-handles'
Work around a issue where a FD that is left open when spawning a
child process and is kept open in the child can interfere with the
operation in the parent process on Windows.

* js/mingw-inherit-only-std-handles:
  mingw: forbid translating ERROR_SUCCESS to an errno value
  mingw: do set `errno` correctly when trying to restrict handle inheritance
  mingw: restrict file handle inheritance only on Windows 7 and later
  mingw: spawned processes need to inherit only standard handles
  mingw: work around incorrect standard handles
  mingw: demonstrate that all file handles are inherited by child processes
2019-12-10 13:11:42 -08:00
Junio C Hamano
7034cd094b Sync with Git 2.24.1 2019-12-09 22:17:55 -08:00
Johannes Schindelin
67af91c47a Sync with 2.23.1
* maint-2.23: (44 commits)
  Git 2.23.1
  Git 2.22.2
  Git 2.21.1
  mingw: sh arguments need quoting in more circumstances
  mingw: fix quoting of empty arguments for `sh`
  mingw: use MSYS2 quoting even when spawning shell scripts
  mingw: detect when MSYS2's sh is to be spawned more robustly
  t7415: drop v2.20.x-specific work-around
  Git 2.20.2
  t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
  Git 2.19.3
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  ...
2019-12-06 16:31:39 +01:00
Johannes Schindelin
7fd9fd94fb Sync with 2.22.2
* maint-2.22: (43 commits)
  Git 2.22.2
  Git 2.21.1
  mingw: sh arguments need quoting in more circumstances
  mingw: fix quoting of empty arguments for `sh`
  mingw: use MSYS2 quoting even when spawning shell scripts
  mingw: detect when MSYS2's sh is to be spawned more robustly
  t7415: drop v2.20.x-specific work-around
  Git 2.20.2
  t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
  Git 2.19.3
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  ...
2019-12-06 16:31:30 +01:00
Johannes Schindelin
5421ddd8d0 Sync with 2.21.1
* maint-2.21: (42 commits)
  Git 2.21.1
  mingw: sh arguments need quoting in more circumstances
  mingw: fix quoting of empty arguments for `sh`
  mingw: use MSYS2 quoting even when spawning shell scripts
  mingw: detect when MSYS2's sh is to be spawned more robustly
  t7415: drop v2.20.x-specific work-around
  Git 2.20.2
  t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
  Git 2.19.3
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  ...
2019-12-06 16:31:23 +01:00
Johannes Schindelin
7d8b676992 mingw: sh arguments need quoting in more circumstances
Previously, we failed to quote characters such as '*', '(' and the
likes. Let's fix this.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06 16:31:15 +01:00
Johannes Schindelin
04522edbd4 mingw: fix quoting of empty arguments for sh
When constructing command-lines to spawn processes, it is an unfortunate
but necessary decision to quote arguments differently: MSYS2 has
different dequoting rules (inherited from Cygwin) than the rest of
Windows.

To accommodate that, Git's Windows compatibility layer has two separate
quoting helpers, one for MSYS2 (which it uses exclusively when spawning
`sh`) and the other for regular Windows executables.

The MSYS2 one had an unfortunate bug where a `,` somehow slipped in,
instead of the `;`. As a consequence, empty arguments would not be
enclosed in a pair of double quotes, but the closing double quote was
skipped.

Let's fix this.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06 16:31:14 +01:00
Johannes Schindelin
49f7a76d57 mingw: use MSYS2 quoting even when spawning shell scripts
At the point where `mingw_spawn_fd()` is called, we already have a full
path to the script interpreter in that scenario, and we pass it in as
the executable to run, while the `argv` reflect what the script should
receive as command-line.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06 16:31:14 +01:00
Johannes Schindelin
e2ba3d6f6d mingw: detect when MSYS2's sh is to be spawned more robustly
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-06 16:31:14 +01:00
Johannes Schindelin
fc346cb292 Sync with 2.20.2
* maint-2.20: (36 commits)
  Git 2.20.2
  t7415: adjust test for dubiously-nested submodule gitdirs for v2.20.x
  Git 2.19.3
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  ...
2019-12-06 16:31:12 +01:00
Johannes Schindelin
d851d94151 Sync with 2.19.3
* maint-2.19: (34 commits)
  Git 2.19.3
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  ...
2019-12-06 16:30:49 +01:00
Johannes Schindelin
7c9fbda6e2 Sync with 2.18.2
* maint-2.18: (33 commits)
  Git 2.18.2
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  ...
2019-12-06 16:30:38 +01:00
Johannes Schindelin
14af7ed5a9 Sync with 2.17.3
* maint-2.17: (32 commits)
  Git 2.17.3
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  mingw: disallow backslash characters in tree objects' file names
  ...
2019-12-06 16:29:15 +01:00
Johannes Schindelin
bdfef0492c Sync with 2.16.6
* maint-2.16: (31 commits)
  Git 2.16.6
  test-drop-caches: use `has_dos_drive_prefix()`
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  mingw: disallow backslash characters in tree objects' file names
  path: safeguard `.git` against NTFS Alternate Streams Accesses
  ...
2019-12-06 16:27:36 +01:00
Johannes Schindelin
9ac92fed5b Sync with 2.15.4
* maint-2.15: (29 commits)
  Git 2.15.4
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  mingw: disallow backslash characters in tree objects' file names
  path: safeguard `.git` against NTFS Alternate Streams Accesses
  clone --recurse-submodules: prevent name squatting on Windows
  is_ntfs_dotgit(): only verify the leading segment
  ...
2019-12-06 16:27:18 +01:00
Johannes Schindelin
d3ac8c3f27 Sync with 2.14.6
* maint-2.14: (28 commits)
  Git 2.14.6
  mingw: handle `subst`-ed "DOS drives"
  mingw: refuse to access paths with trailing spaces or periods
  mingw: refuse to access paths with illegal characters
  unpack-trees: let merged_entry() pass through do_add_entry()'s errors
  quote-stress-test: offer to test quoting arguments for MSYS2 sh
  t6130/t9350: prepare for stringent Win32 path validation
  quote-stress-test: allow skipping some trials
  quote-stress-test: accept arguments to test via the command-line
  tests: add a helper to stress test argument quoting
  mingw: fix quoting of arguments
  Disallow dubiously-nested submodule git directories
  protect_ntfs: turn on NTFS protection by default
  path: also guard `.gitmodules` against NTFS Alternate Data Streams
  is_ntfs_dotgit(): speed it up
  mingw: disallow backslash characters in tree objects' file names
  path: safeguard `.git` against NTFS Alternate Streams Accesses
  clone --recurse-submodules: prevent name squatting on Windows
  is_ntfs_dotgit(): only verify the leading segment
  test-path-utils: offer to run a protectNTFS/protectHFS benchmark
  ...
2019-12-06 16:26:55 +01:00
Johannes Schindelin
2ddcccf97a Merge branch 'win32-accommodate-funny-drive-names'
While the only permitted drive letters for physical drives on Windows
are letters of the US-English alphabet, this restriction does not apply
to virtual drives assigned via `subst <letter>: <path>`.

To prevent targeted attacks against systems where "funny" drive letters
such as `1` or `!` are assigned, let's handle them as regular drive
letters on Windows.

This fixes CVE-2019-1351.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:37:09 +01:00
Johannes Schindelin
65d30a19de Merge branch 'win32-filenames-cannot-have-trailing-spaces-or-periods'
On Windows, filenames cannot have trailing spaces or periods, when
opening such paths, they are stripped automatically. Read: you can open
the file `README` via the file name `README . . .`. This ambiguity can
be used in combination with other security bugs to cause e.g. remote
code execution during recursive clones. This patch series fixes that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:37:09 +01:00
Johannes Schindelin
f82a97eb91 mingw: handle subst-ed "DOS drives"
Over a decade ago, in 25fe217b86 (Windows: Treat Windows style path
names., 2008-03-05), Git was taught to handle absolute Windows paths,
i.e. paths that start with a drive letter and a colon.

Unbeknownst to us, while drive letters of physical drives are limited to
letters of the English alphabet, there is a way to assign virtual drive
letters to arbitrary directories, via the `subst` command, which is
_not_ limited to English letters.

It is therefore possible to have absolute Windows paths of the form
`1:\what\the\hex.txt`. Even "better": pretty much arbitrary Unicode
letters can also be used, e.g. `ä:\tschibät.sch`.

While it can be sensibly argued that users who set up such funny drive
letters really seek adverse consequences, the Windows Operating System
is known to be a platform where many users are at the mercy of
administrators who have their very own idea of what constitutes a
reasonable setup.

Therefore, let's just make sure that such funny paths are still
considered absolute paths by Git, on Windows.

In addition to Unicode characters, pretty much any character is a valid
drive letter, as far as `subst` is concerned, even `:` and `"` or even a
space character. While it is probably the opposite of smart to use them,
let's safeguard `is_dos_drive_prefix()` against all of them.

Note: `[::1]:repo` is a valid URL, but not a valid path on Windows.
As `[` is now considered a valid drive letter, we need to be very
careful to avoid misinterpreting such a string as valid local path in
`url_is_local_not_ssh()`. To do that, we use the just-introduced
function `is_valid_path()` (which will label the string as invalid file
name because of the colon characters).

This fixes CVE-2019-1351.

Reported-by: Nicolas Joly <Nicolas.Joly@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:37:07 +01:00
Johannes Schindelin
d2c84dad1c mingw: refuse to access paths with trailing spaces or periods
When creating a directory on Windows whose path ends in a space or a
period (or chains thereof), the Win32 API "helpfully" trims those. For
example, `mkdir("abc ");` will return success, but actually create a
directory called `abc` instead.

This stems back to the DOS days, when all file names had exactly 8
characters plus exactly 3 characters for the file extension, and the
only way to have shorter names was by padding with spaces.

Sadly, this "helpful" behavior is a bit inconsistent: after a successful
`mkdir("abc ");`, a `mkdir("abc /def")` will actually _fail_ (because
the directory `abc ` does not actually exist).

Even if it would work, we now have a serious problem because a Git
repository could contain directories `abc` and `abc `, and on Windows,
they would be "merged" unintentionally.

As these paths are illegal on Windows, anyway, let's disallow any
accesses to such paths on that Operating System.

For practical reasons, this behavior is still guarded by the
config setting `core.protectNTFS`: it is possible (and at least two
regression tests make use of it) to create commits without involving the
worktree. In such a scenario, it is of course possible -- even on
Windows -- to create such file names.

Among other consequences, this patch disallows submodules' paths to end
in spaces on Windows (which would formerly have confused Git enough to
try to write into incorrect paths, anyway).

While this patch does not fix a vulnerability on its own, it prevents an
attack vector that was exploited in demonstrations of a number of
recently-fixed security bugs.

The regression test added to `t/t7417-submodule-path-url.sh` reflects
that attack vector.

Note that we have to adjust the test case "prevent git~1 squatting on
Windows" in `t/t7415-submodule-names.sh` because of a very subtle issue.
It tries to clone two submodules whose names differ only in a trailing
period character, and as a consequence their git directories differ in
the same way. Previously, when Git tried to clone the second submodule,
it thought that the git directory already existed (because on Windows,
when you create a directory with the name `b.` it actually creates `b`),
but with this patch, the first submodule's clone will fail because of
the illegal name of the git directory. Therefore, when cloning the
second submodule, Git will take a different code path: a fresh clone
(without an existing git directory). Both code paths fail to clone the
second submodule, both because the the corresponding worktree directory
exists and is not empty, but the error messages are worded differently.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:37:06 +01:00
Johannes Schindelin
817ddd64c2 mingw: refuse to access paths with illegal characters
Certain characters are not admissible in file names on Windows, even if
Cygwin/MSYS2 (and therefore, Git for Windows' Bash) pretend that they
are, e.g. `:`, `<`, `>`, etc

Let's disallow those characters explicitly in Windows builds of Git.

Note: just like trailing spaces or periods, it _is_ possible on Windows
to create commits adding files with such illegal characters, as long as
the operation leaves the worktree untouched. To allow for that, we
continue to guard `is_valid_win32_path()` behind the config setting
`core.protectNTFS`, so that users _can_ continue to do that, as long as
they turn the protections off via that config setting.

Among other problems, this prevents Git from trying to write to an "NTFS
Alternate Data Stream" (which refers to metadata stored alongside a
file, under a special name: "<filename>:<stream-name>"). This fix
therefore also prevents an attack vector that was exploited in
demonstrations of a number of recently-fixed security bugs.

Further reading on illegal characters in Win32 filenames:
https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:37:06 +01:00
Johannes Schindelin
6d8684161e mingw: fix quoting of arguments
We need to be careful to follow proper quoting rules. For example, if an
argument contains spaces, we have to quote them. Double-quotes need to
be escaped. Backslashes need to be escaped, but only if they are
followed by a double-quote character.

We need to be _extra_ careful to consider the case where an argument
ends in a backslash _and_ needs to be quoted: in this case, we append a
double-quote character, i.e. the backslash now has to be escaped!

The current code, however, fails to recognize that, and therefore can
turn an argument that ends in a single backslash into a quoted argument
that now ends in an escaped double-quote character. This allows
subsequent command-line parameters to be split and part of them being
mistaken for command-line options, e.g. through a maliciously-crafted
submodule URL during a recursive clone.

Technically, we would not need to quote _all_ arguments which end in a
backslash _unless_ the argument needs to be quoted anyway. For example,
`test\` would not need to be quoted, while `test \` would need to be.

To keep the code simple, however, and therefore easier to reason about
and ensure its correctness, we now _always_ quote an argument that ends
in a backslash.

This addresses CVE-2019-1350.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:36:51 +01:00
Johannes Schindelin
3ba3720b3f mingw: forbid translating ERROR_SUCCESS to an errno value
Johannes Sixt pointed out that the `err_win_to_posix()` function
mishandles `ERROR_SUCCESS`: it maps it to `ENOSYS`.

The only purpose of this function is to map Win32 API errors to `errno`
ones, and there is actually no equivalent to `ERROR_SUCCESS`: the idea
of `errno` is that it will only be set in case of an error, and left
alone in case of success.

Therefore, as pointed out by Junio Hamano, it is a bug to call this
function when there was not even any error to map.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-02 11:05:36 -08:00
Doan Tran Cong Danh
0109d676f9 mingw: use {gm,local}time_s as backend for {gm,local}time_r
Since Windows doesn't provide gmtime_r(3) and localtime_r(3),
we're providing a compat version by using non-reentrant gmtime(3) and
localtime(3) as backend. Then, we copy the returned data into the
buffer.

By doing that, in case of failure, we will dereference a NULL pointer
returned by gmtime(3), and localtime(3), and we always return a valid
pointer instead of NULL.

Drop the memcpy(3) by using gmtime_s(), and use localtime_s() as the
backend on Windows, and make sure we will return NULL in case of
failure.

Cc: Johannes Sixt <j6t@kdbg.org>
Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Doan Tran Cong Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-01 22:26:25 -08:00
Junio C Hamano
9da3948781 Merge branch 'rs/use-copy-array-in-mingw-shell-command-preparation'
Code cleanup.

* rs/use-copy-array-in-mingw-shell-command-preparation:
  mingw: use COPY_ARRAY for copying array
2019-12-01 09:04:39 -08:00
Junio C Hamano
d3096d2ba6 Merge branch 'en/doc-typofix'
Docfix.

* en/doc-typofix:
  Fix spelling errors in no-longer-updated-from-upstream modules
  multimail: fix a few simple spelling errors
  sha1dc: fix trivial comment spelling error
  Fix spelling errors in test commands
  Fix spelling errors in messages shown to users
  Fix spelling errors in names of tests
  Fix spelling errors in comments of testcases
  Fix spelling errors in code comments
  Fix spelling errors in documentation outside of Documentation/
  Documentation: fix a bunch of typos, both old and new
2019-12-01 09:04:35 -08:00
Johannes Schindelin
4d0375ca24 mingw: do set errno correctly when trying to restrict handle inheritance
In 9a780a384d (mingw: spawned processes need to inherit only standard
handles, 2019-11-22), we taught the Windows-specific part to restrict
which file handles are passed on to the spawned processes.

Since this logic seemed to be a bit fragile across Windows versions (we
_still_ support Windows Vista in Git for Windows, for example), a
fall-back was added to try spawning the process again, this time without
restricting which file handles are to be inherited by the spawned
process.

In the common case (i.e. when the process could not be spawned for
reasons _other_ than the file handle inheritance), the fall-back attempt
would still fail, of course.

Crucially, one thing we missed in that code path was to set `errno`
appropriately.

This should have been caught by t0061.2 which expected `errno` to be
`ENOENT` after trying to start a process for a non-existing executable,
but `errno` was set to `ENOENT` prior to the `CreateProcessW()` call:
while looking for the config settings for trace2, Git tries to access
`xdg_config` and `user_config` via `access_or_die()`, and as neither of
those config files exists when running the test case (because in Git's
test suite, `HOME` points to the test directory), the `errno` has the
expected value, but for the wrong reasons.

Let's fix that by making sure that `errno` is set correctly. It even
appears that `errno` was set in the _wrong_ case previously:
`CreateProcessW()` returns non-zero upon success, but `errno` was set
only in the non-zero case.

It would be nice if we could somehow fix t0061 to make sure that this
does not regress again. One approach that seemed like it should work,
but did not, was to set `errno` to 0 in the test helper that is used by
t0061.2.

However, when `mingw_spawnvpe()` wants to see whether the file in
question is a script, it calls `parse_interpreter()`, which in turn
tries to `open()` the file. Obviously, this call fails, and sets `errno`
to `ENOENT`, deep inside the call chain started from that test helper.

Instead, we force re-set `errno` at the beginning of the function
`mingw_spawnve_fd()`, which _should_ be safe given that callers of that
function will want to look at `errno` if -1 was returned. And if that
`errno` is 0 ("No error"), regression tests like t0061.2 will kick in.

Reported-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-30 14:09:09 -08:00
Johannes Schindelin
ac33519ddf mingw: restrict file handle inheritance only on Windows 7 and later
Turns out that it don't work so well on Vista, see
https://github.com/git-for-windows/git/issues/1742 for details.

According to https://devblogs.microsoft.com/oldnewthing/?p=8873, it
*should* work on Windows Vista and later.

But apparently there are issues on Windows Vista when pipes are
involved. Given that Windows Vista is past its end of life (official
support ended on April 11th, 2017), let's not spend *too* much time on
this issue and just disable the file handle inheritance restriction on
any Windows version earlier than Windows 7.

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
9a780a384d mingw: spawned processes need to inherit only standard handles
By default, CreateProcess() does not inherit any open file handles,
unless the bInheritHandles parameter is set to TRUE. Which we do need to
set because we need to pass in stdin/stdout/stderr to talk to the child
processes. Sadly, this means that all file handles (unless marked via
O_NOINHERIT) are inherited.

This lead to problems in VFS for Git, where a long-running read-object
hook is used to hydrate missing objects, and depending on the
circumstances, might only be called *after* Git opened a file handle.

Ideally, we would not open files without O_NOINHERIT unless *really*
necessary (i.e. when we want to pass the opened file handle as standard
handle into a child process), but apparently it is all-too-easy to
introduce incorrect open() calls: this happened, and prevented updating
a file after the read-object hook was started because the hook still
held a handle on said file.

Happily, there is a solution: as described in the "Old New Thing"
https://blogs.msdn.microsoft.com/oldnewthing/20111216-00/?p=8873 there
is a way, starting with Windows Vista, that lets us define precisely
which handles should be inherited by the child process.

And since we bumped the minimum Windows version for use with Git for
Windows to Vista with v2.10.1 (i.e. a *long* time ago), we can use this
method. So let's do exactly that.

We need to make sure that the list of handles to inherit does not
contain duplicates; Otherwise CreateProcessW() would fail with
ERROR_INVALID_ARGUMENT.

While at it, stop setting errno to ENOENT unless it really is the
correct value.

Also, fall back to not limiting handle inheritance under certain error
conditions (e.g. on Windows 7, which is a lot stricter in what handles
you can specify to limit to).

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
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
René Scharfe
51bd6be32d mingw: use COPY_ARRAY for copying array
Use the macro COPY_ARRAY to copy array elements.  The result is shorter
and safer, as it infers the element type automatically and does a (very)
basic type compatibility check for its first two arguments.

Coccinelle and contrib/coccinelle/array.cocci did not generate this
conversion due to the offset of 1 at both source and destination and
because the source is a const pointer; the semantic patch cautiously
handles only pure pointers and array references of the same type.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-13 11:29:22 +09:00
Elijah Newren
03670c8b23 Fix spelling errors in no-longer-updated-from-upstream modules
We have several modules originally taken from some upstream source,
and which as far as I can tell we no longer update from the upstream
anymore.  As such, I have not submitted these spelling fixes to any
external projects but just include them directly here.

Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-10 16:00:55 +09:00
Elijah Newren
15beaaa3d1 Fix spelling errors in code comments
Reported-by: Jens Schleusener <Jens.Schleusener@fossies.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-10 16:00:54 +09:00
Junio C Hamano
f2db52c46b Merge branch 'js/mingw-needs-hiding-fix'
Fix for a (rather old) buffer-overrun bug.

* js/mingw-needs-hiding-fix:
  mingw: avoid a buffer overrun in `needs_hiding()`
2019-10-30 15:13:13 +09:00
Johannes Schindelin
60e6569a12 mingw: avoid a buffer overrun in needs_hiding()
When this function is passed a path with a trailing slash, it runs right
over the end of that path.

Let's fix this.

Co-authored-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-28 12:38:51 +09:00
Junio C Hamano
2d74d28ee0 Merge branch 'dl/compat-cleanup'
Code formatting micronit fix.

* dl/compat-cleanup:
  pthread.h: manually align parameter lists
2019-10-18 11:40:47 +09:00
Junio C Hamano
6d5291be45 Merge branch 'js/azure-pipelines-msvc'
CI updates.

* js/azure-pipelines-msvc:
  ci: also build and test with MS Visual Studio on Azure Pipelines
  ci: really use shallow clones on Azure Pipelines
  tests: let --immediate and --write-junit-xml play well together
  test-tool run-command: learn to run (parts of) the testsuite
  vcxproj: include more generated files
  vcxproj: only copy `git-remote-http.exe` once it was built
  msvc: work around a bug in GetEnvironmentVariable()
  msvc: handle DEVELOPER=1
  msvc: ignore some libraries when linking
  compat/win32/path-utils.h: add #include guards
  winansi: use FLEX_ARRAY to avoid compiler warning
  msvc: avoid using minus operator on unsigned types
  push: do not pretend to return `int` from `die_push_simple()`
2019-10-15 13:48:00 +09:00
Denton Liu
9cad1c4488 pthread.h: manually align parameter lists
In previous patches, extern was mechanically removed from function
declarations without care to formatting, causing parameter lists to be
misaligned. Manually format changed sections such that the parameter
lists are realigned.

Viewing this patch with 'git diff -w' should produce no output.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-11 14:59:35 +09:00
Junio C Hamano
772cad0afb Merge branch 'js/diff-rename-force-stable-sort'
The rename detection logic sorts a list of rename source candidates
by similarity to pick the best candidate, which means that a tie
between sources with the same similarity is broken by the original
location in the original candidate list (which is sorted by path).
Force the sorting by similarity done with a stable sort, which is
not promised by system supplied qsort(3), to ensure consistent
results across platforms.

* js/diff-rename-force-stable-sort:
  diffcore_rename(): use a stable sort
  Move git_sort(), a stable sort, into into libgit.a
2019-10-09 14:00:59 +09:00
Johannes Schindelin
61d1d92aa4 msvc: work around a bug in GetEnvironmentVariable()
The return value of that function is 0 both for variables that are
unset, as well as for variables whose values are empty. To discern those
two cases, one has to call `GetLastError()`, whose return value is
`ERROR_ENVVAR_NOT_FOUND` and `ERROR_SUCCESS`, respectively.

Except that it is not actually set to `ERROR_SUCCESS` in the latter
case, apparently, but the last error value seems to be simply unchanged.

To work around this, let's just re-set the last error value just before
inspecting the environment variable.

This fixes a problem that triggers failures in t3301-notes.sh (where we
try to override config settings by passing empty values for certain
environment variables).

This problem is hidden in the MINGW build by the fact that older
MSVC runtimes (such as the one used by MINGW builds) have a `calloc()`
that re-sets the last error value in case of success, while newer
runtimes set the error value only if `NULL` is returned by that
function.

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
Johannes Schindelin
e4347c9434 msvc: handle DEVELOPER=1
We frequently build Git using the `DEVELOPER=1` make setting as a
shortcut to enable all kinds of more stringent compiler warnings.

Those compiler warnings are relatively specific to GCC, though, so let's
try our best to translate them to the equivalent options to pass to MS
Visual C++'s `cl.exe`.

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
Johannes Schindelin
ed712ef8d5 msvc: ignore some libraries when linking
To build with MSVC, we "translate" GCC options to MSVC options, and part
of those options refer to the libraries to link into the final
executable. Currently, this part looks somewhat like this on Windows:

	-lcurl -lnghttp2 -lidn2 -lssl -lcrypto -lssl -lcrypto -lgdi32
	-lcrypt32 -lwldap32 -lz -lws2_32 -lexpat

Some of those are direct dependencies (such as curl and ssl) and others
are indirect (nghttp2 and idn2, for example, are dependencies of curl,
but need to be linked in for reasons).

We already handle the direct dependencies, e.g. `-liconv` is already
handled as adding `libiconv.lib` to the list of libraries to link
against.

Let's just ignore the remaining `-l*` options so that MSVC does not have
to warn us that it ignored e.g. the `/lnghttp2` option. We do that by
extending the clause that already "eats" the `-R*` options to also eat
the `-l*` options.

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
Johannes Schindelin
5b8f9e2417 compat/win32/path-utils.h: add #include guards
This adds the common guards that allow headers to be #include'd multiple
times.

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
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
Johannes Schindelin
97fff61012 Move git_sort(), a stable sort, into into libgit.a
The `qsort()` function is not guaranteed to be stable, i.e. it does not
promise to maintain the order of items it is told to consider equal. In
contrast, the `git_sort()` function we carry in `compat/qsort.c` _is_
stable, by virtue of implementing a merge sort algorithm.

In preparation for using a stable sort in Git's rename detection, move
the stable sort into `libgit.a` so that it is compiled in
unconditionally, and rename it to `git_stable_qsort()`.

Note: this also makes the hack obsolete that was introduced in
fe21c6b285 (mingw: reencode environment variables on the fly (UTF-16
<-> UTF-8), 2018-10-30), where we included `compat/qsort.c` directly in
`compat/mingw.c` to use the stable sort.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-02 14:44:51 +09:00
Junio C Hamano
6f21347f11 Merge branch 'ar/mingw-run-external-with-non-ascii-path'
Windows update.

* ar/mingw-run-external-with-non-ascii-path:
  mingw: fix launching of externals from Unicode paths
2019-09-30 13:19:26 +09:00
Junio C Hamano
00bb74453d Merge branch 'dl/compat-cleanup'
Code cleanup.

* dl/compat-cleanup:
  compat/*.[ch]: remove extern from function declarations using spatch
  mingw: apply array.cocci rule
2019-09-30 13:19:23 +09:00
Denton Liu
7027f508c7 compat/*.[ch]: remove extern from function declarations using spatch
In 554544276a (*.[ch]: remove extern from function declarations using
spatch, 2019-04-29), we removed externs from function declarations using
spatch but we intentionally excluded files under compat/ since some are
directly copied from an upstream and we should avoid churning them so
that manually merging future updates will be simpler.

In the last commit, we determined the files which taken from an upstream
so we can exclude them and run spatch on the remainder.

This was the Coccinelle patch used:

	@@
	type T;
	identifier f;
	@@
	- extern
	  T f(...);

and it was run with:

	$ git ls-files compat/\*\*.{c,h} |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place
	$ git checkout -- \
		compat/regex/ \
		compat/inet_ntop.c \
		compat/inet_pton.c \
		compat/nedmalloc/ \
		compat/obstack.{c,h} \
		compat/poll/

Coccinelle has some trouble dealing with `__attribute__` and varargs so
we ran the following to ensure that no remaining changes were left
behind:

	$ git ls-files compat/\*\*.{c,h} |
		xargs sed -i'' -e 's/^\(\s*\)extern \([^(]*([^*]\)/\1\2/'
	$ git checkout -- \
		compat/regex/ \
		compat/inet_ntop.c \
		compat/inet_pton.c \
		compat/nedmalloc/ \
		compat/obstack.{c,h} \
		compat/poll/

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-05 11:05:45 -07:00
Denton Liu
552fc5016f mingw: apply array.cocci rule
After running Coccinelle on all sources inside compat/ that were created
by us[1], it was found that compat/mingw.c violated an array.cocci rule
in two places and, thus, a patch was generated. Apply this patch so that
all compat/ sources created by us follows all cocci rules.

[1]: Do not run Coccinelle on files that are taken from some upstream
because in case we need to pull updates from them, we would like to have
diverged as little as possible in order to make merging updates simpler.

The following sources were determined to have been taken from some
upstream:

* compat/regex/
* compat/inet_ntop.c
* compat/inet_pton.c
* compat/nedmalloc/
* compat/obstack.{c,h}
* compat/poll/

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-05 11:05:03 -07:00
Adam Roben
4e1a641ee3 mingw: 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 85faec9d3a (Win32: Unicode file name support (except dirent),
2012-03-15).

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
`lookup_prog()` was changed to use `_waccess()` directly so that we only
convert the path to UTF-16 once.

To make things work correctly, we have to maintain UTF-8 and UTF-16
versions in tandem in `lookup_prog()`.

Signed-off-by: Adam Roben <adam@roben.org>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-26 10:06:03 -07:00
Junio C Hamano
4336fdb2ef Merge branch 'rs/nedalloc-fixlets'
Compilation fix.

* rs/nedalloc-fixlets:
  nedmalloc: avoid compiler warning about unused value
  nedmalloc: do assignments only after the declaration section
2019-08-22 12:34:11 -07:00
René Scharfe
70597e8386 nedmalloc: avoid compiler warning about unused value
Cast the evaluated value of the macro INITIAL_LOCK to void to instruct
the compiler that we're not interested in said value nor the following
warning:

In file included from compat/nedmalloc/nedmalloc.c:63:
compat/nedmalloc/malloc.c.h: In function ‘init_user_mstate’:
compat/nedmalloc/malloc.c.h:1706:62: error: right-hand operand of comma expression has no effect [-Werror=unused-value]
 1706 | #define INITIAL_LOCK(sl)      (memset(sl, 0, sizeof(MLOCK_T)), 0)
      |                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
compat/nedmalloc/malloc.c.h:5020:3: note: in expansion of macro ‘INITIAL_LOCK’
 5020 |   INITIAL_LOCK(&m->mutex);
      |   ^~~~~~~~~~~~

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-07 11:54:55 -07:00
René Scharfe
c9b9c09dae nedmalloc: do assignments only after the declaration section
Avoid the following compiler warning:

In file included from compat/nedmalloc/nedmalloc.c:63:
compat/nedmalloc/malloc.c.h: In function ‘pthread_release_lock’:
compat/nedmalloc/malloc.c.h:1759:5: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
 1759 |     volatile unsigned int* lp = &sl->l;
      |     ^~~~~~~~

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-07 11:54:45 -07:00