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681 Commits

Author SHA1 Message Date
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
Carlo Marcelo Arenas Belón
6fc527a8d0 wrapper: remove xunsetenv()
Remove the unused wrapper function.

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-29 14:59:29 -07:00
Junio C Hamano
d8d33378ed Merge branch 'ab/repo-settings-cleanup'
Code cleanup.

* ab/repo-settings-cleanup:
  repository.h: don't use a mix of int and bitfields
  repo-settings.c: simplify the setup
  read-cache & fetch-negotiator: check "enum" values in switch()
  environment.c: remove test-specific "ignore_untracked..." variable
  wrapper.c: add x{un,}setenv(), and use xsetenv() in environment.c
2021-10-06 13:40:11 -07:00
Junio C Hamano
c2e799012b Merge branch 'cb/unix-sockets-with-windows'
Adjust credential-cache helper to Windows.

* cb/unix-sockets-with-windows:
  git-compat-util: include declaration for unix sockets in windows
  credential-cache: check for windows specific errors
  t0301: fixes for windows compatibility
2021-09-23 13:44:48 -07:00
Ævar Arnfjörð Bjarmason
3540c71ea5 wrapper.c: add x{un,}setenv(), and use xsetenv() in environment.c
Add fatal wrappers for setenv() and unsetenv(). In d7ac12b25d3 (Add
set_git_dir() function, 2007-08-01) we started checking its return
value, and since 48988c4d0c3 (set_git_dir: die when setenv() fails,
2018-03-30) we've had set_git_dir_1() die if we couldn't set it.

Let's provide a wrapper for both, this will be useful in many other
places, a subsequent patch will make another use of xsetenv().

The checking of the return value here is over-eager according to
setenv(3) and POSIX. It's documented as returning just -1 or 0, so
perhaps we should be checking -1 explicitly.

Let's just instead die on any non-zero, if our C library is so broken
as to return something else than -1 on error (and perhaps not set
errno?) the worst we'll do is die with a nonsensical errno value, but
we'll want to die in either case.

Let's make these return "void" instead of "int". As far as I can tell
there's no other x*() wrappers that needed to make the decision of
deviating from the signature in the C library, but since their return
value is only used to indicate errors (so we'd die here), we can catch
unreachable code such as

    if (xsetenv(...) < 0)
        [...];

I think it would be OK skip the NULL check of the "name" here for the
calls to die_errno(). Almost all of our setenv() callers are taking a
constant string hardcoded in the source as the first argument, and for
the rest we can probably assume they've done the NULL check
themselves. Even if they didn't, modern C libraries are forgiving
about it (e.g. glibc formatting it as "(null)"), on those that aren't,
well, we were about to die anyway. But let's include the check anyway
for good measure.

1. https://pubs.opengroup.org/onlinepubs/009604499/functions/setenv.html

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-22 13:15:00 -07:00
Carlo Marcelo Arenas Belón
bb390b1f49 git-compat-util: include declaration for unix sockets in windows
Available since Windows 10 release 1803 and Windows Server 2019.

NO_UNIX_SOCKETS is still the default for Windows builds, as they need
to keep backward compatibility with releases up to Windows 7, but allow
including the header otherwise.

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-14 09:30:54 -07:00
Ævar Arnfjörð Bjarmason
153fb49e60 gettext: remove optional non-standard parens in N_() definition
Remove the USE_PARENS_AROUND_GETTEXT_N compile-time option which was
meant to catch an inadvertent mistake which is too obscure to
maintain this facility.

The backstory of how USE_PARENS_AROUND_GETTEXT_N came about is: When I
added the N_() macro in 65784830366 (i18n: add no-op _() and N_()
wrappers, 2011-02-22) it was defined as:

    #define N_(msgid) (msgid)

This is non-standard C, as was noticed and fixed in 642f85faab2 (i18n:
avoid parenthesized string as array initializer, 2011-04-07).
I.e. this needed to be defined as:

    #define N_(msgid) msgid

Then in e62cd35a3e8 (i18n: log: mark parseopt strings for translation,
2012-08-20) when "builtin_log_usage" was marked for translation the
string concatenation for passing to usage() added in 1c370ea4e51
(Show usage string for 'git log -h', 'git show -h' and 'git diff -h',
2009-08-06) was faithfully preserved:

-       "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
-       "   or: git show [options] <object>...",
+       N_("git log [<options>] [<since>..<until>] [[--] <path>...]\n")
+       N_("   or: git show [options] <object>..."),

This was then fixed to be the expected array of usage strings in
e66dc0cc4b1 (log.c: fix translation markings, 2015-01-06) rather than
a string with multiple "\n"-delimited usage strings, and finally in
290c8e7a3fe (gettext.h: add parentheses around N_ expansion if
supported, 2015-01-11) USE_PARENS_AROUND_GETTEXT_N was added to ensure
this mistake didn't happen again.

I think that even if this was a N_()-specific issue this
USE_PARENS_AROUND_GETTEXT_N facility wouldn't be worth it, the issue
would be too rare to worry about.

But I also think that 290c8e7a3fe which introduced
USE_PARENS_AROUND_GETTEXT_N misattributed the problem. The issue
wasn't with the N_() macro added in e62cd35a3e8, but that before the
N_() macro existed in the codebase the initial migration to
parse_options() in 1c370ea4e51 continued passsing in a "\n"-delimited
string, when the new API it was migrating to supported and expected
the passing of an array.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
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
a93c6fd677 Merge branch 'ew/mmap-failures'
Error message update.

* ew/mmap-failures:
  xmmap: inform Linux users of tuning knobs on ENOMEM
2021-07-16 17:42:47 -07:00
Junio C Hamano
a515f26eac Merge branch 'ar/typofix'
Typofixes.

* ar/typofix:
  *: fix typos which duplicate a word
2021-07-08 13:14:59 -07:00
Eric Wong
dc05929411 xmmap: inform Linux users of tuning knobs on ENOMEM
Linux users may benefit from additional information on how to
avoid ENOMEM from mmap despite the system having enough RAM to
accomodate them.  We can't reliably unmap pack windows to work
around the issue since malloc and other library routines may
mmap without our knowledge.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-29 23:14:25 -07:00
Andrei Rybak
abcb66c614 *: fix typos which duplicate a word
Fix typos in documentation, code comments, and RelNotes which repeat
various words.  In trivial cases, just delete the duplicated word and
rewrap text, if needed.  Reword the affected sentence in
Documentation/RelNotes/1.8.4.txt for it to make sense.

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-06-14 10:16:06 +09:00
Junio C Hamano
d6e35a2644 Merge branch 'jn/size-t-casted-to-off-t-fix'
Rewrite code that triggers undefined behaiour warning.

* jn/size-t-casted-to-off-t-fix:
  xsize_t: avoid implementation defined behavior when len < 0
2021-06-10 12:04:23 +09:00
Jonathan Nieder
aafa5df0df xsize_t: avoid implementation defined behavior when len < 0
The xsize_t helper aims to safely convert an off_t to a size_t,
erroring out when a file offset is too large to fit into a memory
address.  It does this by using two casts:

	size_t size = (size_t) len;
	if (len != (off_t) size)
		... error out ...

On a platform with sizeof(size_t) < sizeof(off_t), this check is safe
and correct.  The first cast truncates to a size_t by finding the
remainder modulo SIZE_MAX+1 (see C99 section 6.3.1.3 Signed and
unsigned integers) and the second promotes to an off_t, meaning the
result is true if and only if len is representable as a size_t.

On other platforms, this two-casts strategy still works well (always
succeeds) for len >= 0.  But for len < 0, when the first cast succeeds
and produces SIZE_MAX + 1 + len, the resulting value is too large to
be represented as an off_t, so the second cast produces implementation
defined behavior.  In practice, it is likely to produce a result of
true despite len not being representable as size_t.

Simplify by replacing with a more straightforward check: compare len
to the relevant bounds and then cast it.  (To avoid a -Wsign-compare
warning, after checking that len >= 0, we explicitly convert to a
sufficiently-large unsigned type before comparing to SIZE_MAX.)

In practice, this is not likely to come up since typical callers use
nonnegative len.  Still, it's helpful to handle this case to make the
behavior easy to reason about.

Historical note: the original bounds-checking in 46be82dfd0 (xsize_t:
check whether we lose bits, 2010-07-28) did not produce this
implementation-defined behavior, though it still did not handle
negative offsets.  It was not until 73560c793a (git-compat-util.h:
xsize_t() - avoid -Wsign-compare warnings, 2017-09-21) introduced the
double cast that the implementation-defined behavior was triggered.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-19 15:00:30 +09:00
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
204333b015 Merge branch 'jk/open-dotgitx-with-nofollow'
It does not make sense to make ".gitattributes", ".gitignore" and
".mailmap" symlinks, as they are supposed to be usable from the
object store (think: bare repositories where HEAD:.mailmap etc. are
used).  When these files are symbolic links, we used to read the
contents of the files pointed by them by mistake, which has been
corrected.

* jk/open-dotgitx-with-nofollow:
  mailmap: do not respect symlinks for in-tree .mailmap
  exclude: do not respect symlinks for in-tree .gitignore
  attr: do not respect symlinks for in-tree .gitattributes
  exclude: add flags parameter to add_patterns()
  attr: convert "macro_ok" into a flags field
  add open_nofollow() helper
2021-03-22 14:00:22 -07:00
René Scharfe
f1121499e6 git-compat-util.h: drop trailing semicolon from macro definition
Make CALLOC_ARRAY usable like a function by requiring callers to supply
the trailing semicolon, which all of the current ones already do.  With
the extra semicolon e.g. the following code wouldn't compile because it
disconnects the "else" from the "if":

	if (condition)
		CALLOC_ARRAY(ptr, n);
	else
		whatever();

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-13 15:56:13 -08:00
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
Jeff King
00611d8440 add open_nofollow() helper
Some callers of open() would like to use O_NOFOLLOW, but it is not
available on all platforms. Let's abstract this into a helper function
so we can provide system-specific implementations.

Some light web-searching reveals that we might be able to get something
similar on Windows using FILE_FLAG_OPEN_REPARSE_POINT. I didn't dig into
this further.

For other systems without O_NOFOLLOW or any equivalent, we have two
options for fallback:

  - we can just open anyway, following symlinks; this may have security
    implications (e.g., following untrusted in-tree symlinks)

  - we can determine whether the path is a symlink with lstat().

    This is slower (two syscalls instead of one), but that may be
    acceptable for infrequent uses like looking up .gitattributes files
    (especially because we can get away with a single syscall for the
    common case of ENOENT).

    It's also racy, but should be sufficient for our needs (we are
    worried about in-tree symlinks that we ourselves would have
    previously created). We could make it non-racy at the cost of making
    it even slower, by doing an fstat() on the opened descriptor and
    comparing the dev/ino fields to the original lstat().

This patch implements the lstat() option in its slightly-faster racy
form.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16 09:41:32 -08:00
Junio C Hamano
8b25dee615 Merge branch 'tb/precompose-prefix-too'
When commands are started from a subdirectory, they may have to
compare the path to the subdirectory (called prefix and found out
from $(pwd)) with the tracked paths.  On macOS, $(pwd) and
readdir() yield decomposed path, while the tracked paths are
usually normalized to the precomposed form, causing mismatch.  This
has been fixed by taking the same approach used to normalize the
command line arguments.

* tb/precompose-prefix-too:
  MacOS: precompose_argv_prefix()
2021-02-12 14:21:04 -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
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,
76759c7dff53 "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 90a78b83e0b8 "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 8e712ef6fc97 "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, 76759c7dff53, 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
Jeff King
765dc16888 git-compat-util: always enable variadic macros
We allow variadic macros in the code base, but only if there is fallback
code for platforms that lack it. This leads to some annoyances:

  - the code is more complicated because of the fallbacks (e.g.,
    trace_printf(), etc, is implemented twice with a set of parallel
    wrappers).

  - some constructs are just impossible and we've had to live without
    them (e.g., a cross between FLEX_ALLOC and xstrfmt)

Since this feature is present in C99, we may be able to start counting
on it being available everywhere. Let's start with a weather balloon
patch to find out.

This patch makes the absolute minimal change by always setting
HAVE_VARIADIC_MACROS. If somebody runs into a platform where it's a
problem, they can undo it by commenting out the define. Likewise, if we
have to revert this, it would be quite unlikely to cause conflicts.

Once we feel comfortable that this is the right direction, then we can
start ripping out all the spots that actually look at the flag, and
removing the dead code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-27 22:14:37 -08:00
Junio C Hamano
ecfc02df85 Merge branch 'jc/compat-util-setitimer-fix'
Fix a recent bug in a rarely used replacement code.

* jc/compat-util-setitimer-fix:
  compat-util: pretend that stub setitimer() always succeeds
2020-12-18 15:15:17 -08:00
Junio C Hamano
14639a4779 compat-util: pretend that stub setitimer() always succeeds
When 15b52a44 (compat-util: type-check parameters of no-op
replacement functions, 2020-08-06) turned a handful of no-op
C-preprocessor macros into static inline functions to give the
callers a better type checking for their parameters, it forgot
to return anything from the stubbed out setitimer() function,
even though the function was defined to return an int just like the
real thing.

Since the original C-preprocessor macro implementation was to just
turn the call to the function an empty statement, we know that the
existing callers do not check the return value from it, and it does
not matter what value we return.  But it is safer to pretend that
the call succeeded by returning 0 than making it fail by returning -1
and clobbering errno with some value.

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-15 15:31:10 -08:00
Junio C Hamano
43c1c79f1f Merge branch 'hn/sleep-millisec-decl'
Move a definition of compatibility wrapper from cache.h to
git-compat-util.h

* hn/sleep-millisec-decl:
  move sleep_millisec to git-compat-util.h
2020-11-30 14:49:44 -08:00
Han-Wen Nienhuys
a76b138daa move sleep_millisec to git-compat-util.h
The sleep function is defined in wrapper.c, so it makes more sense to be a in
system compatibility header.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-24 17:40:16 -08:00
Junio C Hamano
01194384d6 Merge branch 'jk/report-fn-typedef'
Code clean-up.

* jk/report-fn-typedef:
  usage: define a type for a reporting function
2020-11-02 13:17:42 -08:00
Jeff King
5710dcce74 usage: define a type for a reporting function
The usage, die, warning, and error routines all work with a function
pointer that takes the message to be reported. We usually just mention
the function's full type inline. But this makes the use of these
pointers hard to read, especially because C's syntax for returning a
function pointer is so awful:

  void (*get_error_routine(void))(const char *err, va_list params);

Unless you read it very carefully, this looks like a function pointer
declaration. Let's instead use a single typedef to define a reporting
function, which is the same for all four types.

Note that this also removes the "extern" from these declarations to
match the surrounding functions. They were missed in 554544276a (*.[ch]:
remove extern from function declarations using spatch, 2019-04-29)
presumably because of the unusual syntax.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-16 08:33:58 -07:00
Junio C Hamano
15b52a44e0 compat-util: type-check parameters of no-op replacement functions
When there is no need to run a specific function on certain platforms,
we often #define an empty function to swallow its parameters and
make it into a no-op, e.g.

    #define precompose_argv(c,v) /* no-op */

While this guarantees that no unneeded code is generated, it also
discards type and other checks on these parameters, e.g. a new code
written with the argv-array API (diff_args is of type "struct
argv_array" that has .argc and .argv members):

    precompose_argv(diff_args.argc, diff_args.argv);

must be updated to use "struct strvec diff_args" with .nr and .v
members, like so:

    precompose_argv(diff_args.nr, diff_args.v);

after the argv-array API has been updated to the strvec API.
However, the "no oop" C preprocessor macro is too aggressive to
discard what is unused, and did not catch such a call that was left
unconverted.

Using a "static inline" function whose body is a no-op should still
result in the same binary with decent compilers yet catch such a
reference to a missing field or passing a value of a wrong type.

While at it, I notice that precompute_str() has never been used
anywhere in the code, since it was introduced at 76759c7d (git on
Mac OS and precomposed unicode, 2012-07-08).  Instead of turning it
into a static inline, just remove it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-06 17:25:37 -07:00
Junio C Hamano
12210859da Merge branch 'bc/sha-256-part-2'
SHA-256 migration work continues.

* bc/sha-256-part-2: (44 commits)
  remote-testgit: adapt for object-format
  bundle: detect hash algorithm when reading refs
  t5300: pass --object-format to git index-pack
  t5704: send object-format capability with SHA-256
  t5703: use object-format serve option
  t5702: offer an object-format capability in the test
  t/helper: initialize the repository for test-sha1-array
  remote-curl: avoid truncating refs with ls-remote
  t1050: pass algorithm to index-pack when outside repo
  builtin/index-pack: add option to specify hash algorithm
  remote-curl: detect algorithm for dumb HTTP by size
  builtin/ls-remote: initialize repository based on fetch
  t5500: make hash independent
  serve: advertise object-format capability for protocol v2
  connect: parse v2 refs with correct hash algorithm
  connect: pass full packet reader when parsing v2 refs
  Documentation/technical: document object-format for protocol v2
  t1302: expect repo format version 1 for SHA-256
  builtin/show-index: provide options to determine hash algo
  t5302: modernize test formatting
  ...
2020-07-06 22:09:13 -07:00
brian m. carlson
14570dc67d wrapper: add function to compare strings with different NUL termination
When parsing capabilities for the pack protocol, there are times we'll
want to compare the value of a capability to a NUL-terminated string.
Since the data we're reading will be space-terminated, not
NUL-terminated, we need a function that compares the two strings, but
also checks that they're the same length.  Otherwise, if we used strncmp
to compare these strings, we might accidentally accept a parameter that
was a prefix of the expected value.

Add a function, xstrncmpz, that takes a NUL-terminated string and a
non-NUL-terminated string, plus a length, and compares them, ensuring
that they are the same length.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-27 10:07:06 -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
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
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
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
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
Hariom Verma
ebc3278665 git-compat-util.h: drop the PRIuMAX and other fallback definitions
Git's code base already seems to be using `PRIdMAX` without any such
fallback definition for quite a while (75459410edd (json_writer: new
routines to create JSON data, 2018-07-13), to be precise, and the
first Git version to include that commit was v2.19.0).  Having a
fallback definition only for `PRIuMAX` is a bit inconsistent.

We do sometimes get portability reports more than a year after the
problem was introduced.  This one should be fairly safe.  PRIuMAX is
in C99 (for that matter, SCNuMAX, PRIu32 and others also are), and
we've been picking up other C99-isms without complaint.

The PRIuMAX fallback definition was originally added in 3efb1f343a
(Check for PRIuMAX rather than NO_C99_FORMAT in fast-import.c.,
2007-02-20). But it was replacing a construct that was introduced in
an even earlier commit, 579d1fbfaf (Add NO_C99_FORMAT to support
older compilers., 2006-07-30), which talks about gcc 2.95.

That's pretty ancient at this point.

Signed-off-by: Hariom Verma <hariom18599@gmail.com>
Helped-by: Jeff King <peff@peff.net>
[jc: tweaked both message and code, taking what peff wrote]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-25 11:44:51 +09:00
Junio C Hamano
e5fca6b573 Merge branch 'bb/compat-util-comment-fix'
Code cleanup.

* bb/compat-util-comment-fix:
  git-compat-util: fix documentation syntax
2019-10-18 11:40:48 +09:00
Junio C Hamano
5efabc7ed9 Merge branch 'ew/hashmap'
Code clean-up of the hashmap API, both users and implementation.

* ew/hashmap:
  hashmap_entry: remove first member requirement from docs
  hashmap: remove type arg from hashmap_{get,put,remove}_entry
  OFFSETOF_VAR macro to simplify hashmap iterators
  hashmap: introduce hashmap_free_entries
  hashmap: hashmap_{put,remove} return hashmap_entry *
  hashmap: use *_entry APIs for iteration
  hashmap_cmp_fn takes hashmap_entry params
  hashmap_get{,_from_hash} return "struct hashmap_entry *"
  hashmap: use *_entry APIs to wrap container_of
  hashmap_get_next returns "struct hashmap_entry *"
  introduce container_of macro
  hashmap_put takes "struct hashmap_entry *"
  hashmap_remove takes "const struct hashmap_entry *"
  hashmap_get takes "const struct hashmap_entry *"
  hashmap_add takes "struct hashmap_entry *"
  hashmap_get_next takes "const struct hashmap_entry *"
  hashmap_entry_init takes "struct hashmap_entry *"
  packfile: use hashmap_entry in delta_base_cache_entry
  coccicheck: detect hashmap_entry.hash assignment
  diff: use hashmap_entry_init on moved_entry.ent
2019-10-15 13:48:02 +09:00
Beat Bolli
68b69211b2 git-compat-util: fix documentation syntax
The parameter marker for x was garbled in its introduction in 89c855ed3c
("git-compat-util.h: implement a different ARRAY_SIZE macro for for
safely deriving the size of array", 2015-04-30).

Signed-off-by: Beat Bolli <dev+git@drbeat.li>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-12 10:57:55 +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
Junio C Hamano
0b4fae553c Merge branch 'sg/name-rev-cutoff-underflow-fix'
Integer arithmetic fix.

* sg/name-rev-cutoff-underflow-fix:
  name-rev: avoid cutoff timestamp underflow
2019-10-09 14:00:58 +09:00
Eric Wong
23dee69f53 OFFSETOF_VAR macro to simplify hashmap iterators
While we cannot rely on a `__typeof__' operator being portable
to use with `offsetof'; we can calculate the pointer offset
using an existing pointer and the address of a member using
pointer arithmetic for compilers without `__typeof__'.

This allows us to simplify usage of hashmap iterator macros
by not having to specify a type when a pointer of that type
is already given.

In the future, list iterator macros (e.g. list_for_each_entry)
may also be implemented using OFFSETOF_VAR to save hackers the
trouble of using container_of/list_entry macros and without
relying on non-portable `__typeof__'.

v3: use `__typeof__' to avoid clang warnings

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
f0e63c4113 hashmap: use *_entry APIs to wrap container_of
Using `container_of' can be verbose and choosing names for
intermediate "struct hashmap_entry" pointers is a hard problem.
So introduce "*_entry" APIs inspired by similar linked-list
APIs in the Linux kernel.

Unfortunately, `__typeof__' is not portable C, so we need an
extra parameter to specify the type.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
973d5eea74 introduce container_of macro
This macro is popular within the Linux kernel for supporting
intrusive data structures such as linked lists, red-black trees,
and chained hash tables while allowing the compiler to do
type checking.

Later patches will use container_of() to remove the limitation
of "hashmap_entry" being location-dependent. This will complete
the transition to compile-time type checking for the hashmap API.

This macro already exists in our source as "list_entry" in
list.h and making "list_entry" an alias to "container_of"
as the Linux kernel has done is a possibility.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +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
fe21c6b285d (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
SZEDER Gábor
2e09c01232 name-rev: avoid cutoff timestamp underflow
When 'git name-rev' is invoked with commit-ish parameters, it tries to
save some work, and doesn't visit commits older than the committer
date of the oldest given commit minus a one day worth of slop.  Since
our 'timestamp_t' is an unsigned type, this leads to a timestamp
underflow when the committer date of the oldest given commit is within
a day of the UNIX epoch.  As a result the cutoff timestamp ends up
far-far in the future, and 'git name-rev' doesn't visit any commits,
and names each given commit as 'undefined'.

Check whether subtracting the slop from the oldest committer date
would lead to an underflow, and use no cutoff in that case.  We don't
have a TIME_MIN constant, dddbad728c (timestamp_t: a new data type for
timestamps, 2017-04-26) didn't add one, so do it now.

Note that the type of the cutoff timestamp variable used to be signed
before 5589e87fd8 (name-rev: change a "long" variable to timestamp_t,
2017-05-20).  The behavior was still the same even back then, but the
underflow didn't happen when substracting the slop from the oldest
committer date, but when comparing the signed cutoff timestamp with
unsigned committer dates in name_rev().  IOW, this underflow bug is as
old as 'git name-rev' itself.

Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-28 13:36:04 +09:00
Jeff King
9827d4c185 packfile: drop release_pack_memory()
Long ago, in 97bfeb34df (Release pack windows before reporting out of
memory., 2006-12-24), we taught xmalloc() and friends to try unmapping
pack windows when malloc() failed. It's unlikely that his helps a lot in
practice, and it has some downsides. First, the downsides:

  1. It makes xmalloc() not thread-safe. We've worked around this in
     pack-objects.c, which installs its own locking version of the
     try_to_free_routine(). But other threaded code doesn't.

  2. It makes the system as a whole harder to reason about. Functions
     which allocate heap memory under the hood may have farther-reaching
     effects than expected.

That might be worth the tradeoff if there's a benefit. But in practice,
it seems unlikely. We're generally dealing with mmap'd files, so the OS
is going to do a much better job at responding to memory pressure by
dropping individual pages (the exception is systems with NO_MMAP, but
even there the OS can probably respond just as well with swapping).

So the only thing we're really freeing is address space. On 64-bit
systems, we have plenty of that to go around. On 32-bit systems, it
could possibly help. But around the same time we made two other changes:
77ccc5bbd1 (Introduce new config option for mmap limit., 2006-12-23) and
60bb8b1453 (Fully activate the sliding window pack access., 2006-12-23).
Together that means that a 32-bit system should have no more than 256MB
total of packed-git mmaps at one time, split between a few 32MB windows.
It's unlikely we have any address space problems since then, but we
don't have any data since the features were all added at the same time.

Likewise, xmmap() will try to free memory. At first glance, it seems
like we'd need this (when we try to mmap a new window, we might need to
close an old one to save address space on a 32-bit system). But we're
saved again by core.packedGitLimit: if we're going to exceed our 256MB
limit, we'll close an existing window before we even call mmap().

So it seems unlikely that this feature is actually doing anything
useful. And while we don't have reports of it harming anything (probably
because it rarely if ever kicks in), it would be nice to simplify the
system overall. This patch drops the whole try_to_free system from
xmalloc(), as well as the manual pack memory release in xmmap().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-13 12:21:33 -07:00
Jeff Hostetler
556702f86c msvc: add a compile-time flag to allow detailed heap debugging
MS Visual C comes with a few neat features we can use to analyze the
heap consumption (i.e. leaks, max memory, etc).

With this patch, we introduce support via the build-time flag
`USE_MSVC_CRTDBG`.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-25 10:46:57 -07:00
Junio C Hamano
40bef4992e Merge branch 'cc/access-on-aix-workaround'
Workaround for standard-compliant but less-than-useful behaviour of
access(2) for the root user.

* cc/access-on-aix-workaround:
  git-compat-util: work around for access(X_OK) under root
2019-05-13 23:50:35 +09:00
Junio C Hamano
4aeeef3773 Merge branch 'dl/no-extern-in-func-decl'
Mechanically and systematically drop "extern" from function
declarlation.

* dl/no-extern-in-func-decl:
  *.[ch]: manually align parameter lists
  *.[ch]: remove extern from function declarations using sed
  *.[ch]: remove extern from function declarations using spatch
2019-05-13 23:50:32 +09:00
Junio C Hamano
70542df566 Merge branch 'ss/msvc-path-utils-fix'
An earlier update for MinGW and Cygwin accidentally broke MSVC build,
which has been fixed.

* ss/msvc-path-utils-fix:
  MSVC: include compat/win32/path-utils.h for MSVC, too, for real_path()
2019-05-09 00:37:26 +09:00
Denton Liu
ad6dad0996 *.[ch]: 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 should be 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>
2019-05-05 15:20:10 +09:00
Denton Liu
b199d7147a *.[ch]: remove extern from function declarations using sed
There has been a push to remove extern from function declarations.
Finish the job by removing all instances of "extern" for function
declarations in headers using sed.

This was done by running the following on my system with sed 4.2.2:

    $ git ls-files \*.{c,h} |
        grep -v ^compat/ |
        xargs sed -i'' -e 's/^\(\s*\)extern \([^(]*([^*]\)/\1\2/'

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Then, leftover instances of extern were found by running

    $ git grep -w -C3 extern \*.{c,h}

and manually checking the output. No other instances were found.

Note that the regex used specifically excludes function variables which
_should_ be left as extern.

Not the most elegant way to do it but it gets the job done.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:08 +09:00
Denton Liu
554544276a *.[ch]: remove extern from function declarations using spatch
There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.

This was the Coccinelle patch used:

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

and it was run with:

	$ git ls-files \*.{c,h} |
		grep -v ^compat/ |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-05 15:20:06 +09:00
Clément Chigot
400caafb2b git-compat-util: work around for access(X_OK) under root
On AIX, access(X_OK) may succeed when run as root even if the
execution isn't possible. This behavior is allowed by POSIX
which says:

  ... for a process with appropriate privileges, an implementation
  may indicate success for X_OK even if execute permission is not
  granted to any user.

It can lead hook programs to have their execution refused:

   git commit -m content
   fatal: cannot exec '.git/hooks/pre-commit': Permission denied

Add NEED_ACCESS_ROOT_HANDLER in order to use an access helper function.
It checks with stat if any executable flags is set when the current user
is root.

Signed-off-by: Clément Chigot <clement.chigot@atos.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-25 17:49:44 +09:00
Sven Strickroth
22c3634c0f MSVC: include compat/win32/path-utils.h for MSVC, too, for real_path()
A path such as 'c:/somepath/submodule/../.git/modules/submodule' wasn't
resolved correctly any more, because the *nix variant of offset_1st_component
is used instead of the Win32 specific version.

Regression was introduced in commit 1cadad6f6 when mingw_offset_1st_component
was moved from mingw.c which is included by msvc.c to a separate file. Then,
the new file "compat/win32/path-utils.h" was only included for the __CYGWIN__
and __MINGW32__ cases in git-compat-util.h, the case for _MSC_VER was missing.

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-09 20:40:07 +09:00
Jeff Hostetler
ee4512ed48 trace2: create new combined trace facility
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-22 15:27:59 -08:00
Junio C Hamano
1db999ce8d Merge branch 'nd/fileno-may-be-macro'
* nd/fileno-may-be-macro:
  git-compat-util: work around fileno(fp) that is a macro
2019-02-13 18:18:41 -08:00
Duy Nguyen
18a4f6be6b git-compat-util: work around fileno(fp) that is a macro
On various BSD's, fileno(fp) is implemented as a macro that directly
accesses the fields in the FILE * object, which breaks a function that
accepts a "void *fp" parameter and calls fileno(fp) and expect it to
work.

Work it around by adding a compile-time knob FILENO_IS_A_MACRO that
inserts a real helper function in the middle of the callchain.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-12 10:01:59 -08:00
Junio C Hamano
9f2eba2b90 Merge branch 'rb/hpe'
Portability updates for the HPE NonStop platform.

* rb/hpe:
  compat/regex/regcomp.c: define intptr_t and uintptr_t on NonStop
  git-compat-util.h: add FLOSS headers for HPE NonStop
  config.mak.uname: support for modern HPE NonStop config.
  transport-helper: drop read/write errno checks
  transport-helper: use xread instead of read
2019-01-18 13:49:54 -08:00
Junio C Hamano
f2b6aa98be Merge branch 'nd/indentation-fix'
Code cleanup.

* nd/indentation-fix:
  Indent code with TABs
2019-01-14 15:29:32 -08:00
Junio C Hamano
25d90d1cb7 Merge branch 'tb/use-common-win32-pathfuncs-on-cygwin'
Cygwin update.

* tb/use-common-win32-pathfuncs-on-cygwin:
  git clone <url> C:\cygwin\home\USER\repo' is working (again)
2019-01-14 15:29:32 -08:00
Randall S. Becker
1305ef3784 git-compat-util.h: add FLOSS headers for HPE NonStop
The HPE NonStop (a.k.a. __TANDEM) platform cannot build git without
using the FLOSS package supplied by HPE. The convenient location
for including the relevant headers is in this file.

The NSIG define is also not defined on __TANDEM, so we define it
here as 100 if it is not defined only for __TANDEM builds.

Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-03 14:16:20 -08:00
Torsten Bögershausen
1cadad6f65 git clone <url> C:\cygwin\home\USER\repo' is working (again)
A regression for cygwin users was introduced with commit 05b458c,
 "real_path: resolve symlinks by hand".

In the the commit message we read:
  The current implementation of real_path uses chdir() in order to resolve
    symlinks.  Unfortunately this isn't thread-safe as chdir() affects a
      process as a whole...

The old (and non-thread-save) OS calls chdir()/pwd() had been
replaced by a string operation.
The cygwin layer "knows" that "C:\cygwin" is an absolute path,
but the new string operation does not.

"git clone <url> C:\cygwin\home\USER\repo" fails like this:
fatal: Invalid path '/home/USER/repo/C:\cygwin\home\USER\repo'

The solution is to implement has_dos_drive_prefix(), skip_dos_drive_prefix()
is_dir_sep(), offset_1st_component() and convert_slashes() for cygwin
in the same way as it is done in 'Git for Windows' in compat/mingw.[ch]

Extract the needed code into compat/win32/path-utils.[ch] and use it
for cygwin as well.

Reported-by: Steven Penny <svnpenn@gmail.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-26 15:26:17 -08:00
Nguyễn Thái Ngọc Duy
ec36c42a63 Indent code with TABs
We indent with TABs and sometimes for fine alignment, TABs followed by
spaces, but never all spaces (unless the indentation is less than 8
columns). Indenting with spaces slips through in some places. Fix
them.

Imported code and compat/ are left alone on purpose. The former should
remain as close as upstream as possible. The latter pretty much has
separate maintainers, it's up to them to decide.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-09 12:37:32 +09:00
Junio C Hamano
7fab474656 Merge branch 'cc/delta-islands'
A few issues in the implementation of "delta-islands" feature has
been corrected.

* cc/delta-islands:
  pack-objects: fix off-by-one in delta-island tree-depth computation
  pack-objects: zero-initialize tree_depth/layer arrays
  pack-objects: fix tree_depth and layer invariants
2018-11-21 20:39:02 +09:00
Jeff King
e159b81071 pack-objects: zero-initialize tree_depth/layer arrays
Commit 108f530385 (pack-objects: move tree_depth into 'struct
packing_data', 2018-08-16) started maintaining a tree_depth array that
matches the "objects" array. We extend the array when:

  1. The objects array is extended, in which case we use realloc to
     extend the tree_depth array.

  2. A caller asks to store a tree_depth for object N, and this is the
     first such request; we create the array from scratch and store the
     value for N.

In the latter case, though, we use regular xmalloc(), and the depth
values for any objects besides N is undefined. This happens to not
trigger a bug with the current code, but the reasons are quite subtle:

 - we never ask about the depth for any object with index i < N. This is
   because we store the depth immediately for all trees and blobs. So
   any such "i" must be a non-tree, and therefore we will never need to
   care about its depth (in fact, we really only care about the depth of
   trees).

 - there are no objects at this point with index i > N, because we
   always fill in the depth for a tree immediately after its object
   entry is created (we may still allocate uninitialized depth entries,
   but they'll be initialized by packlist_alloc() when it initializes
   the entry in the "objects" array).

So it works, but only by chance. To be defensive, let's zero the array,
which matches the "unset" values which would be handed out by
oe_tree_depth() already.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21 13:50:27 +09:00
Đoàn Trần Công Danh
2648ccc231 git-compat-util: prefer poll.h to sys/poll.h
POSIX specifies that <poll.h> is the correct header for poll(2)
whereas <sys/poll.h> is only needed for some old libc.

Let's follow the POSIX way by default.

This effectively eliminates musl's warning:

    warning redirecting incorrect #include <sys/poll.h> to <poll.h>

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 16:32:24 +09:00
Johannes Schindelin
70fc5793df config: allow for platform-specific core.* config settings
In the Git for Windows project, we have ample precendent for config
settings that apply to Windows, and to Windows only.

Let's formalize this concept by introducing a platform_core_config()
function that can be #define'd in a platform-specific manner.

This will allow us to contain platform-specific code better, as the
corresponding variables no longer need to be exported so that they can
be defined in environment.c and be set in config.c

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-31 12:46:21 +09:00
Junio C Hamano
d1622fdbdd Merge branch 'cb/khash-maybe-unused-function'
Build fix.

* cb/khash-maybe-unused-function:
  khash: silence -Wunused-function for delta-islands
  commit-slabs: move MAYBE_UNUSED out
2018-10-30 15:43:48 +09:00
Junio C Hamano
16ce0b92bd Merge branch 'js/mingw-default-ident'
The logic to select the default user name and e-mail on Windows has
been improved.

* js/mingw-default-ident:
  mingw: use domain information for default email
  getpwuid(mingw): provide a better default for the user name
  getpwuid(mingw): initialize the structure only once
2018-10-26 14:22:15 +09:00
Carlo Marcelo Arenas Belón
bbd8eb3ecb commit-slabs: move MAYBE_UNUSED out
after 36da893114 ("config.mak.dev: enable -Wunused-function", 2018-10-18)
it is expected to be used to prevent -Wunused-function warnings for code
that was macro generated

Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-24 14:52:50 +09:00
Johannes Schindelin
501afcb8b0 mingw: use domain information for default email
When a user is registered in a Windows domain, it is really easy to
obtain the email address. So let's do that.

Suggested by Lutz Roeder.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-16 12:59:57 +09:00
Johannes Schindelin
2939a1f703 mingw: bump the minimum Windows version to Vista
Quite some time ago, a last plea to the XP users out there who want to
see Windows XP support in Git for Windows, asking them to get engaged
and help, vanished into the depths of the universe.

We tried for a long time to play nice with the last remaining XP users
who somehow manage to build Git from source, but a recent update of
mingw-w64 (7.0.0.5233.e0c09544 -> 7.0.0.5245.edf66197) finally dropped
the last sign of XP support, and Git for Windows' SDK is no longer able
to build core Git's `master` branch as a consequence. (Git for Windows'
`master` branch already bumped the minimum Windows version to Vista a
while ago, so it is fine.)

It is time to require Windows Vista or later to build Git from source.
This, incidentally, lets us use quite a few nice new APIs.

It also means that we no longer need the inet_pton() and inet_ntop()
emulation, which is nice.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 05:39:56 -07:00
Johannes Schindelin
3571e78aa4 mingw: set _WIN32_WINNT explicitly for Git for Windows
Previously, we only ever declared a target Windows version if compiling
with Visual C.

Which meant that we were relying on the MinGW headers to guess which
Windows version we want to target...

Let's be explicit about it, in particular because we actually want to
bump the target Windows version to Vista (which we will do in the next
commit).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 05:39:56 -07:00
Junio C Hamano
13bf260ac7 Merge branch 'js/typofixes'
Comment update.

* js/typofixes:
  remote-curl: remove spurious period
  git-compat-util.h: fix typo
2018-08-20 11:33:50 -07:00
Johannes Schindelin
c70e1b04f6 git-compat-util.h: fix typo
The words "save" and "safe" are both very wonderful words, each with
their own set of meanings. Let's not confuse them with one another save
on occasion of a pun.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-08 09:07:16 -07:00
Jeff King
c8af66ab8a automatically ban strcpy()
There are a few standard C functions (like strcpy) which are
easy to misuse. E.g.:

  char path[PATH_MAX];
  strcpy(path, arg);

may overflow the "path" buffer. Sometimes there's an earlier
constraint on the size of "arg", but even in such a case
it's hard to verify that the code is correct. If the size
really is unbounded, you're better off using a dynamic
helper like strbuf:

  struct strbuf path = STRBUF_INIT;
  strbuf_addstr(path, arg);

or if it really is bounded, then use xsnprintf to show your
expectation (and get a run-time assertion):

  char path[PATH_MAX];
  xsnprintf(path, sizeof(path), "%s", arg);

which makes further auditing easier.

We'd usually catch undesirable code like this in a review,
but there's no automated enforcement. Adding that
enforcement can help us be more consistent and save effort
(and a round-trip) during review.

This patch teaches the compiler to report an error when it
sees strcpy (and will become a model for banning a few other
functions). This has a few advantages over a separate
linting tool:

  1. We know it's run as part of a build cycle, so it's
     hard to ignore. Whereas an external linter is an extra
     step the developer needs to remember to do.

  2. Likewise, it's basically free since the compiler is
     parsing the code anyway.

  3. We know it's robust against false positives (unlike a
     grep-based linter).

The two big disadvantages are:

  1. We'll only check code that is actually compiled, so it
     may miss code that isn't triggered on your particular
     system. But since presumably people don't add new code
     without compiling it (and if they do, the banned
     function list is the least of their worries), we really
     only care about failing to clean up old code when
     adding new functions to the list. And that's easy
     enough to address with a manual audit when adding a new
     function (which is what I did for the functions here).

  2. If this ends up generating false positives, it's going
     to be harder to disable (as opposed to a separate
     linter, which may have mechanisms for overriding a
     particular case).

     But the intent is to only ban functions which are
     obviously bad, and for which we accept using an
     alternative even when this particular use isn't buggy
     (e.g., the xsnprintf alternative above).

The implementation here is simple: we'll define a macro for
the banned function which replaces it with a reference to a
descriptively named but undeclared identifier.  Replacing it
with any invalid code would work (since we just want to
break compilation).  But ideally we'd meet these goals:

 - it should be portable; ideally this would trigger
   everywhere, and does not need to be part of a DEVELOPER=1
   setup (because unlike warnings which may depend on the
   compiler or system, this is a clear indicator of
   something wrong in the code).

 - it should generate a readable error that gives the
   developer a clue what happened

 - it should avoid generating too much other cruft that
   makes it hard to see the actual error

 - it should mention the original callsite in the error

The output with this patch looks like this (using gcc 7, on
a checkout with 022d2ac1f3 reverted, which removed the final
strcpy from blame.c):

      CC builtin/blame.o
  In file included from ./git-compat-util.h:1246,
                   from ./cache.h:4,
                   from builtin/blame.c:8:
  builtin/blame.c: In function ‘cmd_blame’:
  ./banned.h:11:22: error: ‘sorry_strcpy_is_a_banned_function’ undeclared (first use in this function)
   #define BANNED(func) sorry_##func##_is_a_banned_function
                        ^~~~~~
  ./banned.h:14:21: note: in expansion of macro ‘BANNED’
   #define strcpy(x,y) BANNED(strcpy)
                       ^~~~~~
  builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’
      strcpy(repeated_meta_color, GIT_COLOR_CYAN);
      ^~~~~~
  ./banned.h:11:22: note: each undeclared identifier is reported only once for each function it appears in
   #define BANNED(func) sorry_##func##_is_a_banned_function
                        ^~~~~~
  ./banned.h:14:21: note: in expansion of macro ‘BANNED’
   #define strcpy(x,y) BANNED(strcpy)
                       ^~~~~~
  builtin/blame.c:1074:4: note: in expansion of macro ‘strcpy’
      strcpy(repeated_meta_color, GIT_COLOR_CYAN);
      ^~~~~~

This prominently shows the phrase "strcpy is a banned
function", along with the original callsite in blame.c and
the location of the ban code in banned.h. Which should be
enough to get even a developer seeing this for the first
time pointed in the right direction.

This doesn't match our ideals perfectly, but it's a pretty
good balance. A few alternatives I tried:

  1. Instead of using an undeclared variable, using an
     undeclared function. This shortens the message, because
     the "each undeclared identifier" message is not needed
     (and as you can see above, it triggers a separate
     mention of each of the expansion points).

     But it doesn't actually stop compilation unless you use
     -Werror=implicit-function-declaration in your CFLAGS.
     This is the case for DEVELOPER=1, but not for a default
     build (on the other hand, we'd eventually produce a
     link error pointing to the correct source line with the
     descriptive name).

  2. The linux kernel uses a similar mechanism in its
     BUILD_BUG_ON_MSG(), where they actually declare the
     function but do so with gcc's error attribute. But
     that's not portable to other compilers (and it also
     runs afoul of our error() macro).

     We could make a gcc-specific technique and fallback on
     other compilers, but it's probably not worth the
     complexity. It also isn't significantly shorter than
     the error message shown above.

  3. We could drop the BANNED() macro, which would shorten
     the number of lines in the error. But curiously,
     removing it (and just expanding strcpy directly to the
     bogus identifier) causes gcc _not_ to report the
     original line of code.

So this strategy seems to be an acceptable mix of
information, portability, simplicity, and robustness,
without _too_ much extra clutter. I also tested it with
clang, and it looks as good (actually, slightly less
cluttered than with gcc).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-26 10:12:09 -07:00
Junio C Hamano
50f08db594 Merge branch 'js/use-bug-macro'
Developer support update, by using BUG() macro instead of die() to
mark codepaths that should not happen more clearly.

* js/use-bug-macro:
  BUG_exit_code: fix sparse "symbol not declared" warning
  Convert remaining die*(BUG) messages
  Replace all die("BUG: ...") calls by BUG() ones
  run-command: use BUG() to report bugs, not die()
  test-tool: help verifying BUG() code paths
2018-05-30 14:04:07 +09:00
Junio C Hamano
7913f53b56 Sync with Git 2.17.1
* maint: (25 commits)
  Git 2.17.1
  Git 2.16.4
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  fsck: complain when .gitmodules is a symlink
  index-pack: check .gitmodules files with --strict
  unpack-objects: call fsck_finish() after fscking objects
  fsck: call fsck_finish() after fscking objects
  fsck: check .gitmodules content
  fsck: handle promisor objects in .gitmodules check
  fsck: detect gitmodules files
  fsck: actually fsck blob data
  fsck: simplify ".git" check
  index-pack: make fsck error message more specific
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  ...
2018-05-29 17:10:05 +09:00
Junio C Hamano
30b015bffe Merge branch 'nd/repack-keep-pack'
"git gc" in a large repository takes a lot of time as it considers
to repack all objects into one pack by default.  The command has
been taught to pretend as if the largest existing packfile is
marked with ".keep" so that it is left untouched while objects in
other packs and loose ones are repacked.

* nd/repack-keep-pack:
  pack-objects: show some progress when counting kept objects
  gc --auto: exclude base pack if not enough mem to "repack -ad"
  gc: handle a corner case in gc.bigPackThreshold
  gc: add gc.bigPackThreshold config
  gc: add --keep-largest-pack option
  repack: add --keep-pack option
  t7700: have closing quote of a test at the beginning of line
2018-05-23 14:38:14 +09:00
Junio C Hamano
68f95b26e4 Sync with Git 2.16.4
* maint-2.16:
  Git 2.16.4
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:25:26 +09:00
Junio C Hamano
023020401d Sync with Git 2.15.2
* maint-2.15:
  Git 2.15.2
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:18:06 +09:00
Junio C Hamano
9e0f06d55d Sync with Git 2.14.4
* maint-2.14:
  Git 2.14.4
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:15:14 +09:00
Junio C Hamano
7b01c71b64 Sync with Git 2.13.7
* maint-2.13:
  Git 2.13.7
  verify_path: disallow symlinks in .gitmodules
  update-index: stat updated files earlier
  verify_dotfile: mention case-insensitivity in comment
  verify_path: drop clever fallthrough
  skip_prefix: add case-insensitive variant
  is_{hfs,ntfs}_dotgitmodules: add tests
  is_ntfs_dotgit: match other .git files
  is_hfs_dotgit: match other .git files
  is_ntfs_dotgit: use a size_t for traversing string
  submodule-config: verify submodule names as paths
2018-05-22 14:10:49 +09:00
Jeff King
41a80924ae skip_prefix: add case-insensitive variant
We have the convenient skip_prefix() helper, but if you want
to do case-insensitive matching, you're stuck doing it by
hand. We could add an extra parameter to the function to
let callers ask for this, but the function is small and
somewhat performance-critical. Let's just re-implement it
for the case-insensitive version.

Signed-off-by: Jeff King <peff@peff.net>
2018-05-21 23:50:11 -04:00
Ramsay Jones
746ea4adc6 BUG_exit_code: fix sparse "symbol not declared" warning
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-10 18:23:09 +09:00
Junio C Hamano
1ac0ce4d32 Merge branch 'ls/checkout-encoding'
The new "checkout-encoding" attribute can ask Git to convert the
contents to the specified encoding when checking out to the working
tree (and the other way around when checking in).

* ls/checkout-encoding:
  convert: add round trip check based on 'core.checkRoundtripEncoding'
  convert: add tracing for 'working-tree-encoding' attribute
  convert: check for detectable errors in UTF encodings
  convert: add 'working-tree-encoding' attribute
  utf8: add function to detect a missing UTF-16/32 BOM
  utf8: add function to detect prohibited UTF-16/32 BOM
  utf8: teach same_encoding() alternative UTF encoding names
  strbuf: add a case insensitive starts_with()
  strbuf: add xstrdup_toupper()
  strbuf: remove unnecessary NUL assignment in xstrdup_tolower()
2018-05-08 15:59:22 +09:00
Johannes Schindelin
c3c3486b24 Convert remaining die*(BUG) messages
These were not caught by the previous commit, as they did not match the
regular expression.

While at it, remove the localization from one instance: we never want
BUG() messages to be translated, as they target Git developers, not the
end user (hence it would be quite unhelpful to not only burden the
translators, but then even end up with a bug report in a language that
no core Git contributor understands).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-06 19:06:14 +09:00
Nguyễn Thái Ngọc Duy
9806f5a7bf gc --auto: exclude base pack if not enough mem to "repack -ad"
pack-objects could be a big memory hog especially on large repos,
everybody knows that. The suggestion to stick a .keep file on the
giant base pack to avoid this problem is also known for a long time.

Recent patches add an option to do just this, but it has to be either
configured or activated manually. This patch lets `git gc --auto`
activate this mode automatically when it thinks `repack -ad` will use
a lot of memory and start affecting the system due to swapping or
flushing OS cache.

gc --auto decides to do this based on an estimation of pack-objects
memory usage, which is quite accurate at least for the heap part, and
whether that fits in half of system memory (the assumption here is for
desktop environment where there are many other applications running).

This mechanism only kicks in if gc.bigBasePackThreshold is not configured.
If it is, it is assumed that the user already knows what they want.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-16 13:52:29 +09:00
Lars Schneider
66b8af3e12 strbuf: add a case insensitive starts_with()
Check in a case insensitive manner if one string is a prefix of another
string.

This function is used in a subsequent commit.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-09 10:17:23 -08:00
Brandon Williams
eb78e23f22 wrapper: rename 'template' variables
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-22 10:08:05 -08:00
Christian Couder
afaef55e23 git-compat-util: introduce skip_to_optional_arg()
We often accept both a "--key" option and a "--key=<val>" option.

These options currently are parsed using something like:

if (!strcmp(arg, "--key")) {
	/* do something */
} else if (skip_prefix(arg, "--key=", &arg)) {
	/* do something with arg */
}

which is a bit cumbersome compared to just:

if (skip_to_optional_arg(arg, "--key", &arg)) {
	/* do something with arg */
}

This also introduces skip_to_optional_arg_default() for the few
cases where something different should be done when the first
argument is exactly "--key" than when it is exactly "--key=".

In general it is better for UI consistency and simplicity if
"--key" and "--key=" do the same thing though, so that using
skip_to_optional_arg() should be encouraged compared to
skip_to_optional_arg_default().

Note that these functions can be used to parse any "key=value"
string where "key" is also considered as valid, not just
command line options.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-11 16:10:12 -08:00
Junio C Hamano
14a8168e2f Merge branch 'rj/no-sign-compare'
Many codepaths have been updated to squelch -Wsign-compare
warnings.

* rj/no-sign-compare:
  ALLOC_GROW: avoid -Wsign-compare warnings
  cache.h: hex2chr() - avoid -Wsign-compare warnings
  commit-slab.h: avoid -Wsign-compare warnings
  git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings
2017-09-29 11:23:42 +09:00
Ramsay Jones
73560c793a git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings
Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-22 13:00:33 +09:00
Jonathan Tan
5de3de329a git-compat-util: make UNLEAK less error-prone
Commit 0e5bba5 ("add UNLEAK annotation for reducing leak false
positives", 2017-09-08) introduced an UNLEAK macro to be used as
"UNLEAK(var);", but its existing definitions leave semicolons that act
as empty statements, which will lead to syntax errors, e.g.

	if (condition)
		UNLEAK(var);
	else
		something_else(var);

would be broken with two statements between if (condition) and else.
Lose the excess semicolon from the end of the macro replacement text.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-20 15:00:41 +09:00
Jeff King
0e5bba53af add UNLEAK annotation for reducing leak false positives
It's a common pattern in git commands to allocate some
memory that should last for the lifetime of the program and
then not bother to free it, relying on the OS to throw it
away.

This keeps the code simple, and it's fast (we don't waste
time traversing structures or calling free at the end of the
program). But it also triggers warnings from memory-leak
checkers like valgrind or LSAN. They know that the memory
was still allocated at program exit, but they don't know
_when_ the leaked memory stopped being useful. If it was
early in the program, then it's probably a real and
important leak. But if it was used right up until program
exit, it's not an interesting leak and we'd like to suppress
it so that we can see the real leaks.

This patch introduces an UNLEAK() macro that lets us do so.
To understand its design, let's first look at some of the
alternatives.

Unfortunately the suppression systems offered by
leak-checking tools don't quite do what we want. A
leak-checker basically knows two things:

  1. Which blocks were allocated via malloc, and the
     callstack during the allocation.

  2. Which blocks were left un-freed at the end of the
     program (and which are unreachable, but more on that
     later).

Their suppressions work by mentioning the function or
callstack of a particular allocation, and marking it as OK
to leak.  So imagine you have code like this:

  int cmd_foo(...)
  {
	/* this allocates some memory */
	char *p = some_function();
	printf("%s", p);
	return 0;
  }

You can say "ignore allocations from some_function(),
they're not leaks". But that's not right. That function may
be called elsewhere, too, and we would potentially want to
know about those leaks.

So you can say "ignore the callstack when main calls
some_function".  That works, but your annotations are
brittle. In this case it's only two functions, but you can
imagine that the actual allocation is much deeper. If any of
the intermediate code changes, you have to update the
suppression.

What we _really_ want to say is that "the value assigned to
p at the end of the function is not a real leak". But
leak-checkers can't understand that; they don't know about
"p" in the first place.

However, we can do something a little bit tricky if we make
some assumptions about how leak-checkers work. They
generally don't just report all un-freed blocks. That would
report even globals which are still accessible when the
leak-check is run.  Instead they take some set of memory
(like BSS) as a root and mark it as "reachable". Then they
scan the reachable blocks for anything that looks like a
pointer to a malloc'd block, and consider that block
reachable. And then they scan those blocks, and so on,
transitively marking anything reachable from a global as
"not leaked" (or at least leaked in a different category).

So we can mark the value of "p" as reachable by putting it
into a variable with program lifetime. One way to do that is
to just mark "p" as static. But that actually affects the
run-time behavior if the function is called twice (you
aren't likely to call main() twice, but some of our cmd_*()
functions are called from other commands).

Instead, we can trick the leak-checker by putting the value
into _any_ reachable bytes. This patch keeps a global
linked-list of bytes copied from "unleaked" variables. That
list is reachable even at program exit, which confers
recursive reachability on whatever values we unleak.

In other words, you can do:

  int cmd_foo(...)
  {
	char *p = some_function();
	printf("%s", p);
	UNLEAK(p);
	return 0;
  }

to annotate "p" and suppress the leak report.

But wait, couldn't we just say "free(p)"? In this toy
example, yes. But UNLEAK()'s byte-copying strategy has
several advantages over actually freeing the memory:

  1. It's recursive across structures. In many cases our "p"
     is not just a pointer, but a complex struct whose
     fields may have been allocated by a sub-function. And
     in some cases (e.g., dir_struct) we don't even have a
     function which knows how to free all of the struct
     members.

     By marking the struct itself as reachable, that confers
     reachability on any pointers it contains (including those
     found in embedded structs, or reachable by walking
     heap blocks recursively.

  2. It works on cases where we're not sure if the value is
     allocated or not. For example:

       char *p = argc > 1 ? argv[1] : some_function();

     It's safe to use UNLEAK(p) here, because it's not
     freeing any memory. In the case that we're pointing to
     argv here, the reachability checker will just ignore
     our bytes.

  3. Likewise, it works even if the variable has _already_
     been freed. We're just copying the pointer bytes. If
     the block has been freed, the leak-checker will skip
     over those bytes as uninteresting.

  4. Because it's not actually freeing memory, you can
     UNLEAK() before we are finished accessing the variable.
     This is helpful in cases like this:

       char *p = some_function();
       return another_function(p);

     Writing this with free() requires:

       int ret;
       char *p = some_function();
       ret = another_function(p);
       free(p);
       return ret;

     But with unleak we can just write:

       char *p = some_function();
       UNLEAK(p);
       return another_function(p);

This patch adds the UNLEAK() macro and enables it
automatically when Git is compiled with SANITIZE=leak.  In
normal builds it's a noop, so we pay no runtime cost.

It also adds some UNLEAK() annotations to show off how the
feature works. On top of other recent leak fixes, these are
enough to get t0000 and t0001 to pass when compiled with
LSAN.

Note the case in commit.c which actually converts a
strbuf_release() into an UNLEAK. This code was already
non-leaky, but the free didn't do anything useful, since
we're exiting. Converting it to an annotation means that
non-leak-checking builds pay no runtime cost. The cost is
minimal enough that it's probably not worth going on a
crusade to convert these kinds of frees to UNLEAKS. I did it
here for consistency with the "sb" leak (though it would
have been equally correct to go the other way, and turn them
both into strbuf_release() calls).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-08 15:43:17 +09:00
Jonathan Tan
f0e17e86e1 pack: move release_pack_memory()
The function unuse_one_window() needs to be temporarily made global. Its
scope will be restored to static in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23 15:12:06 -07:00
Junio C Hamano
d3b7ee087e Merge branch 'rs/move-array' into maint
Code clean-up.

* rs/move-array:
  ls-files: don't try to prune an empty index
  apply: use COPY_ARRAY and MOVE_ARRAY in update_image()
  use MOVE_ARRAY
  add MOVE_ARRAY
2017-08-23 14:33:46 -07:00
Junio C Hamano
32f90258bd Merge branch 'rs/move-array'
Code clean-up.

* rs/move-array:
  ls-files: don't try to prune an empty index
  apply: use COPY_ARRAY and MOVE_ARRAY in update_image()
  use MOVE_ARRAY
  add MOVE_ARRAY
2017-08-11 13:26:57 -07:00
Junio C Hamano
33400c0e96 Merge branch 'tb/push-to-cygwin-unc-path'
On Cygwin, similar to Windows, "git push //server/share/repository"
ought to mean a repository on a network share that can be accessed
locally, but this did not work correctly due to stripping the double
slashes at the beginning.

This may need to be heavily tested before it gets unleashed to the
wild, as the change is at a fairly low-level code and would affect
not just the code to decide if the push destination is local.  There
may be unexpected fallouts in the path normalization.

* tb/push-to-cygwin-unc-path:
  cygwin: allow pushing to UNC paths
2017-07-18 12:48:09 -07:00
René Scharfe
578398071e add MOVE_ARRAY
Similar to COPY_ARRAY (introduced in 60566cbb58), add a safe and
convenient helper for moving potentially overlapping ranges of array
entries.  It infers the element size, multiplies automatically and
safely to get the size in bytes, does a basic type safety check by
comparing element sizes and unlike memmove(3) it supports NULL
pointers iff 0 elements are to be moved.

Also add a semantic patch to demonstrate the helper's intended usage.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-17 14:54:53 -07:00
Torsten Bögershausen
496f256989 cygwin: allow pushing to UNC paths
cygwin can use an UNC path like //server/share/repo

 $ cd //server/share/dir
 $ mkdir test
 $ cd test
 $ git init --bare

 However, when we try to push from a local Git repository to this repo,
 there is a problem: Git converts the leading "//" into a single "/".

 As cygwin handles an UNC path so well, Git can support them better:

 - Introduce cygwin_offset_1st_component() which keeps the leading "//",
   similar to what Git for Windows does.

 - Move CYGWIN out of the POSIX in the tests for path normalization in t0060

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-05 14:01:03 -07:00
Ævar Arnfjörð Bjarmason
481df65f4f git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL
Add a FREE_AND_NULL() wrapper marco for the common pattern of freeing
a pointer and assigning NULL to it right afterwards.

The implementation is similar to the (currently unused) XDL_PTRFREE
macro in xdiff/xmacros.h added in commit 3443546f6e ("Use a *real*
built-in diff generator", 2006-03-24). The only difference is that
free() is called unconditionally, see [1].

See [2] for a suggested alternative which does this via a function
instead of a macro. As covered in replies to that message, while it's
a viable approach, it would introduce caveats which this approach
doesn't have, so that potential change is left to a future follow-up
change.

This merely allows us to translate exactly what we're doing now to a
less verbose & idiomatic form using a macro, while guaranteeing that
we don't introduce any functional changes.

1. <alpine.DEB.2.20.1608301948310.129229@virtualbox>
   (http://public-inbox.org/git/alpine.DEB.2.20.1608301948310.129229@virtualbox/)

2. <20170610032143.GA7880@starla>
   (https://public-inbox.org/git/20170610032143.GA7880@starla/)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15 14:56:39 -07:00
Junio C Hamano
b9a7d55d93 Merge branch 'nd/fopen-errors'
We often try to open a file for reading whose existence is
optional, and silently ignore errors from open/fopen; report such
errors if they are not due to missing files.

* nd/fopen-errors:
  mingw_fopen: report ENOENT for invalid file names
  mingw: verify that paths are not mistaken for remote nicknames
  log: fix memory leak in open_next_file()
  rerere.c: move error_errno() closer to the source system call
  print errno when reporting a system call error
  wrapper.c: make warn_on_inaccessible() static
  wrapper.c: add and use fopen_or_warn()
  wrapper.c: add and use warn_on_fopen_errors()
  config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too
  config.mak.uname: set FREAD_READS_DIRECTORIES for Linux and FreeBSD
  clone: use xfopen() instead of fopen()
  use xfopen() in more places
  git_fopen: fix a sparse 'not declared' warning
2017-06-13 13:47:09 -07:00
Junio C Hamano
93dd544f54 Merge branch 'jc/noent-notdir'
Our code often opens a path to an optional file, to work on its
contents when we can successfully open it.  We can ignore a failure
to open if such an optional file does not exist, but we do want to
report a failure in opening for other reasons (e.g. we got an I/O
error, or the file is there, but we lack the permission to open).

The exact errors we need to ignore are ENOENT (obviously) and
ENOTDIR (less obvious).  Instead of repeating comparison of errno
with these two constants, introduce a helper function to do so.

* jc/noent-notdir:
  treewide: use is_missing_file_error() where ENOENT and ENOTDIR are checked
  compat-util: is_missing_file_error()
2017-06-13 13:47:07 -07:00
Junio C Hamano
e350625b68 Merge branch 'bw/forking-and-threading' into maint
The "run-command" API implementation has been made more robust
against dead-locking in a threaded environment.

* bw/forking-and-threading:
  usage.c: drop set_error_handle()
  run-command: restrict PATH search to executable files
  run-command: expose is_executable function
  run-command: block signals between fork and execve
  run-command: add note about forking and threading
  run-command: handle dup2 and close errors in child
  run-command: eliminate calls to error handling functions in child
  run-command: don't die in child when duping /dev/null
  run-command: prepare child environment before forking
  string-list: add string_list_remove function
  run-command: use the async-signal-safe execv instead of execvp
  run-command: prepare command before forking
  t0061: run_command executes scripts without a #! line
  t5550: use write_script to generate post-update hook
2017-06-13 13:27:00 -07:00
Junio C Hamano
7d5e13f652 Merge branch 'bw/forking-and-threading'
The "run-command" API implementation has been made more robust
against dead-locking in a threaded environment.

* bw/forking-and-threading:
  usage.c: drop set_error_handle()
  run-command: restrict PATH search to executable files
  run-command: expose is_executable function
  run-command: block signals between fork and execve
  run-command: add note about forking and threading
  run-command: handle dup2 and close errors in child
  run-command: eliminate calls to error handling functions in child
  run-command: don't die in child when duping /dev/null
  run-command: prepare child environment before forking
  string-list: add string_list_remove function
  run-command: use the async-signal-safe execv instead of execvp
  run-command: prepare command before forking
  t0061: run_command executes scripts without a #! line
  t5550: use write_script to generate post-update hook
2017-05-30 11:16:41 +09:00
Junio C Hamano
dc5a18b364 compat-util: is_missing_file_error()
Our code often opens a path to an optional file, to work on its
contents when we can successfully open it.  We can ignore a failure
to open if such an optional file does not exist, but we do want to
report a failure in opening for other reasons (e.g. we got an I/O
error, or the file is there, but we lack the permission to open).

The exact errors we need to ignore are ENOENT (obviously) and
ENOTDIR (less obvious).  Instead of repeating comparison of errno
with these two constants, introduce a helper function to do so.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-30 09:14:39 +09:00
Junio C Hamano
220c6a7080 Merge branch 'jk/bug-to-abort'
Introduce the BUG() macro to improve die("BUG: ...").

* jk/bug-to-abort:
  usage: add NORETURN to BUG() function definitions
  config: complain about --local outside of a git repo
  setup_git_env: convert die("BUG") to BUG()
  usage.c: add BUG() function
2017-05-29 12:34:45 +09:00
Nguyễn Thái Ngọc Duy
382fb07f7b wrapper.c: make warn_on_inaccessible() static
After the last patch, this function is not used outside anymore. Keep it
static.

Noticed-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-26 12:33:56 +09:00
Nguyễn Thái Ngọc Duy
e9d983f116 wrapper.c: add and use fopen_or_warn()
When fopen() returns NULL, it could be because the given path does not
exist, but it could also be some other errors and the caller has to
check. Add a wrapper so we don't have to repeat the same error check
everywhere.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-26 12:33:56 +09:00
Nguyễn Thái Ngọc Duy
11dc1fcb3f wrapper.c: add and use warn_on_fopen_errors()
In many places, Git warns about an inaccessible file after a fopen()
failed. To discern these cases from other cases where we want to warn
about inaccessible files, introduce a new helper specifically to test
whether fopen() failed because the current user lacks the permission to
open file in question.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-26 12:33:55 +09:00
Ramsay Jones
b0a642ac46 git_fopen: fix a sparse 'not declared' warning
If git is built with the FREAD_READS_DIRECTORIES build variable set, this
would cause sparse to issue a 'not declared, should it be static?' warning
on Linux. This is a result of the method employed by 'compat/fopen.c' to
suppress the (possible) redefinition of the (system) fopen macro, which
also removes the extern declaration of the git_fopen function.

In order to suppress the warning, introduce a new macro to suppress the
definition (or possibly the re-definition) of the fopen symbol as a macro
override. This new macro (SUPPRESS_FOPEN_REDEFINITION) is only defined in
'compat/fopen.c', just prior to the inclusion of the 'git-compat-util.h'
header file.

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-26 12:33:55 +09:00
Junio C Hamano
b15667bbdc Merge branch 'js/larger-timestamps'
Some platforms have ulong that is smaller than time_t, and our
historical use of ulong for timestamp would mean they cannot
represent some timestamp that the platform allows.  Invent a
separate and dedicated timestamp_t (so that we can distingiuish
timestamps and a vanilla ulongs, which along is already a good
move), and then declare uintmax_t is the type to be used as the
timestamp_t.

* js/larger-timestamps:
  archive-tar: fix a sparse 'constant too large' warning
  use uintmax_t for timestamps
  date.c: abort if the system time cannot handle one of our timestamps
  timestamp_t: a new data type for timestamps
  PRItime: introduce a new "printf format" for timestamps
  parse_timestamp(): specify explicitly where we parse timestamps
  t0006 & t5000: skip "far in the future" test when time_t is too limited
  t0006 & t5000: prepare for 64-bit timestamps
  ref-filter: avoid using `unsigned long` for catch-all data type
2017-05-16 11:51:59 +09:00
Junio C Hamano
d97141b0b9 Merge branch 'dt/raise-core-packed-git-limit'
The default packed-git limit value has been raised on larger
platforms to save "git fetch" from a (recoverable) failure while
"gc" is running in parallel.

* dt/raise-core-packed-git-limit:
  Increase core.packedGitLimit
2017-05-16 11:51:49 +09:00
Jeff King
e3f43ce765 usage.c: drop set_error_handle()
The set_error_handle() function was introduced by 3b331e926
(vreportf: report to arbitrary filehandles, 2015-08-11) so
that run-command could send post-fork, pre-exec errors to
the parent's original stderr.

That use went away in 79319b194 (run-command: eliminate
calls to error handling functions in child, 2017-04-19),
which pushes all of the error reporting to the parent.
This leaves no callers of set_error_handle(). As we're not
likely to add any new ones, let's drop it.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-15 13:00:25 +09:00
Jeff King
d8193743e0 usage.c: add BUG() function
There's a convention in Git's code base to write assertions
as:

  if (...some_bad_thing...)
	die("BUG: the terrible thing happened");

with the idea that users should never see a "BUG:" message
(but if they, it at least gives a clue what happened).  We
use die() here because it's convenient, but there are a few
draw-backs:

  1. Without parsing the messages, it's hard for callers to
     distinguish BUG assertions from regular errors.

     For instance, it would be nice if the test suite could
     check that we don't hit any assertions, but
     test_must_fail will pass BUG deaths as OK.

  2. It would be useful to add more debugging features to
     BUG assertions, like file/line numbers or dumping core.

  3. The die() handler can be replaced, and might not
     actually exit the whole program (e.g., it may just
     pthread_exit()). This is convenient for normal errors,
     but for an assertion failure (which is supposed to
     never happen), we're probably better off taking down
     the whole process as quickly and cleanly as possible.

We could address these by checking in die() whether the
error message starts with "BUG", and behaving appropriately.
But there's little advantage at that point to sharing the
die() code, and only downsides (e.g., we can't change the
BUG() interface independently). Moreover, converting all of
the existing BUG calls reveals that the test suite does
indeed trigger a few of them.

Instead, this patch introduces a new BUG() function, which
prints an error before dying via SIGABRT. This gives us test
suite checking and core dumps.  The function is actually a
macro (when supported) so that we can show the file/line
number.

We can convert die("BUG") invocations to BUG() in further
patches, dealing with any test fallouts individually.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-15 11:29:51 +09:00
Johannes Schindelin
28f4aee3fb use uintmax_t for timestamps
Previously, we used `unsigned long` for timestamps. This was only a good
choice on Linux, where we know implicitly that `unsigned long` is what is
used for `time_t`.

However, we want to use a different data type for timestamps for two
reasons:

- there is nothing that says that `unsigned long` should be the same data
  type as `time_t`, and indeed, on 64-bit Windows for example, it is not:
  `unsigned long` is 32-bit but `time_t` is 64-bit.

- even on 32-bit Linux, where `unsigned long` (and thereby `time_t`) is
  32-bit, we *want* to be able to encode timestamps in Git that are
  currently absurdly far in the future, *even if* the system library is
  not able to format those timestamps into date strings.

So let's just switch to the maximal integer type available, which should
be at least 64-bit for all practical purposes these days. It certainly
cannot be worse than `unsigned long`, so...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-27 13:07:40 +09:00
Johannes Schindelin
dddbad728c timestamp_t: a new data type for timestamps
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).

So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.

By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.

As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-27 13:07:39 +09:00
Junio C Hamano
5938454cbc Merge branch 'dt/xgethostname-nul-termination'
gethostname(2) may not NUL terminate the buffer if hostname does
not fit; unfortunately there is no easy way to see if our buffer
was too small, but at least this will make sure we will not end up
using garbage past the end of the buffer.

* dt/xgethostname-nul-termination:
  xgethostname: handle long hostnames
  use HOST_NAME_MAX to size buffers for gethostname(2)
2017-04-23 22:07:57 -07:00
Johannes Schindelin
cb71f8bdb5 PRItime: introduce a new "printf format" for timestamps
Currently, Git's source code treats all timestamps as if they were
unsigned longs. Therefore, it is okay to write "%lu" when printing them.

There is a substantial problem with that, though: at least on Windows,
time_t is *larger* than unsigned long, and hence we will want to switch
away from the ill-specified `unsigned long` data type.

So let's introduce the pseudo format "PRItime" (currently simply being
defined to "lu") to make it easier to change the data type used for
timestamps.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-23 20:19:15 -07:00
Johannes Schindelin
1aeb7e756c parse_timestamp(): specify explicitly where we parse timestamps
Currently, Git's source code represents all timestamps as `unsigned
long`. In preparation for using a more appropriate data type, let's
introduce a symbol `parse_timestamp` (currently being defined to
`strtoul`) where appropriate, so that we can later easily switch to,
say, use `strtoull()` instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-23 20:19:15 -07:00
David Turner
be4ca29057 Increase core.packedGitLimit
When core.packedGitLimit is exceeded, git will close packs.  If there
is a repack operation going on in parallel with a fetch, the fetch
might open a pack, and then be forced to close it due to
packedGitLimit being hit.  The repack could then delete the pack
out from under the fetch, causing the fetch to fail.

Increase core.packedGitLimit's default value to prevent
this.

On current 64-bit x86_64 machines, 48 bits of address space are
available.  It appears that 64-bit ARM machines have no standard
amount of address space (that is, it varies by manufacturer), and IA64
and POWER machines have the full 64 bits.  So 48 bits is the only
limit that we can reasonably care about.  We reserve a few bits of the
48-bit address space for the kernel's use (this is not strictly
necessary, but it's better to be safe), and use up to the remaining
45.  No git repository will be anywhere near this large any time soon,
so this should prevent the failure.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-20 22:06:00 -07:00