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Автор SHA1 Сообщение Дата
Junio C Hamano 3736c92558 Merge branch 'bw/recurse-submodules-relative-fix'
A few commands that recently learned the "--recurse-submodule"
option misbehaved when started from a subdirectory of the
superproject.

* bw/recurse-submodules-relative-fix:
  ls-files: fix bug when recursing with relative pathspec
  ls-files: fix typo in variable name
  grep: fix bug when recursing with relative pathspec
  setup: allow for prefix to be passed to git commands
  grep: fix help text typo
2017-03-30 14:07:15 -07:00
Brandon Williams b58a68c1c1 setup: allow for prefix to be passed to git commands
In a future patch child processes which act on submodules need a little
more context about the original command that was invoked.  This patch
teaches git to use the prefix stored in `GIT_INTERNAL_TOPLEVEL_PREFIX`
instead of the prefix that was potentally found during the git directory
setup process.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-17 11:54:50 -07:00
Johannes Schindelin 4557f1add2 rebase--helper: add a builtin helper for interactive rebases
Git's interactive rebase is still implemented as a shell script, despite
its complexity. This implies that it suffers from the portability point
of view, from lack of expressibility, and of course also from
performance. The latter issue is particularly serious on Windows, where
we pay a hefty price for relying so much on POSIX.

Unfortunately, being such a huge shell script also means that we missed
the train when it would have been relatively easy to port it to C, and
instead piled feature upon feature onto that poor script that originally
never intended to be more than a slightly pimped cherry-pick in a loop.

To open the road toward better performance (in addition to all the other
benefits of C over shell scripts), let's just start *somewhere*.

The approach taken here is to add a builtin helper that at first intends
to take care of the parts of the interactive rebase that are most
affected by the performance penalties mentioned above.

In particular, after we spent all those efforts on preparing the sequencer
to process rebase -i's git-rebase-todo scripts, we implement the `git
rebase -i --continue` functionality as a new builtin, git-rebase--helper.

Once that is in place, we can work gradually on tackling the rest of the
technical debt.

Note that the rebase--helper needs to learn about the transient
--ff/--no-ff options of git-rebase, as the corresponding flag is not
persisted to, and re-read from, the state directory.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-09 14:55:26 -08:00
Junio C Hamano 2243d229f7 Merge branch 'sb/unpack-trees-super-prefix'
"git read-tree" and its underlying unpack_trees() machinery learned
to report problematic paths prefixed with the --super-prefix option.

* sb/unpack-trees-super-prefix:
  unpack-trees: support super-prefix option
  t1001: modernize style
  t1000: modernize style
  read-tree: use OPT_BOOL instead of OPT_SET_INT
2017-02-03 11:25:18 -08:00
Junio C Hamano b7786bb4b0 Merge branch 'js/difftool-builtin'
Rewrite a scripted porcelain "git difftool" in C.

* js/difftool-builtin:
  difftool: hack around -Wzero-length-format warning
  difftool: retire the scripted version
  difftool: implement the functionality in the builtin
  difftool: add a skeleton for the upcoming builtin
2017-01-31 13:15:00 -08:00
Stefan Beller 3d415425c7 unpack-trees: support super-prefix option
In the future we want to support working tree operations within submodules,
e.g. "git checkout --recurse-submodules", which will update the submodule
to the commit as recorded in its superproject. In the submodule the
unpack-tree operation is carried out as usual, but the reporting to the
user needs to prefix any path with the superproject. The mechanism for
this is the super-prefix. (see 74866d757, git: make super-prefix option)

Add support for the super-prefix option for commands that unpack trees
by wrapping any path output in unpacking trees in the newly introduced
super_prefixed function. This new function prefixes any path with the
super-prefix if there is one.  Assuming the submodule case doesn't happen
in the majority of the cases, we'd want to have a fast behavior for no
super prefix, i.e. no reallocation/copying, but just returning path.

Another aspect of introducing the `super_prefixed` function is to consider
who owns the memory and if this is the right place where the path gets
modified. As the super prefix ought to change the output behavior only and
not the actual unpack tree part, it is fine to be that late in the line.
As we get passed in 'const char *path', we cannot change the path itself,
which means in case of a super prefix we have to copy over the path.
We need two static buffers in that function as the error messages
contain at most two paths.

For testing purposes enable it in read-tree, which has no output
of paths other than an unpack-trees.c. These are all converted in
this patch.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-25 12:33:33 -08:00
Johannes Schindelin 019678d6b1 difftool: retire the scripted version
It served its purpose, but now we have a builtin difftool. Time for the
Perl script to enjoy Florida.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-19 13:23:43 -08:00
Junio C Hamano 5918bdcf26 Merge branch 'jk/execv-dashed-external'
Typing ^C to pager, which usually does not kill it, killed Git and
took the pager down as a collateral damage in certain process-tree
structure.  This has been fixed.

* jk/execv-dashed-external:
  execv_dashed_external: wait for child on signal death
  execv_dashed_external: stop exiting with negative code
  execv_dashed_external: use child_process struct
2017-01-18 15:12:16 -08:00
Junio C Hamano 55d128ae06 Merge branch 'bw/grep-recurse-submodules'
"git grep" has been taught to optionally recurse into submodules.

* bw/grep-recurse-submodules:
  grep: search history of moved submodules
  grep: enable recurse-submodules to work on <tree> objects
  grep: optionally recurse into submodules
  grep: add submodules as a grep source type
  submodules: load gitmodules file from commit sha1
  submodules: add helper to determine if a submodule is initialized
  submodules: add helper to determine if a submodule is populated
  real_path: canonicalize directory separators in root parts
  real_path: have callers use real_pathdup and strbuf_realpath
  real_path: create real_pathdup
  real_path: convert real_path_internal to strbuf_realpath
  real_path: resolve symlinks by hand
2017-01-18 15:12:11 -08:00
Johannes Schindelin be8a90e59c difftool: add a skeleton for the upcoming builtin
This adds a builtin difftool that still falls back to the legacy Perl
version, which has been renamed to `legacy-difftool`.

The idea is that the new, experimental, builtin difftool immediately hands
off to the legacy difftool for now, unless the config variable
difftool.useBuiltin is set to true.

This feature flag will be used in the upcoming Git for Windows v2.11.0
release, to allow early testers to opt-in to use the builtin difftool and
flesh out any bugs.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-17 13:32:47 -08:00
Junio C Hamano da2b74eeec Merge branch 'sb/submodule-embed-gitdir'
A new submodule helper "git submodule embedgitdirs" to make it
easier to move embedded .git/ directory for submodules in a
superproject to .git/modules/ (and point the latter with the former
that is turned into a "gitdir:" file) has been added.

* sb/submodule-embed-gitdir:
  worktree: initialize return value for submodule_uses_worktrees
  submodule: add absorb-git-dir function
  move connect_work_tree_and_git_dir to dir.h
  worktree: check if a submodule uses worktrees
  test-lib-functions.sh: teach test_commit -C <dir>
  submodule helper: support super prefix
  submodule: use absolute path for computing relative path connecting
2017-01-10 15:24:28 -08:00
Jeff King 46df6906f3 execv_dashed_external: wait for child on signal death
When you hit ^C to interrupt a git command going to a pager,
this usually leaves the pager running. But when a dashed
external is in use, the pager ends up in a funny state and
quits (but only after eating one more character from the
terminal!). This fixes it.

Explaining the reason will require a little background.

When git runs a pager, it's important for the git process to
hang around and wait for the pager to finish, even though it
has no more data to feed it. This is because git spawns the
pager as a child, and thus the git process is the session
leader on the terminal. After it dies, the pager will finish
its current read from the terminal (eating the one
character), and then get EIO trying to read again.

When you hit ^C, that sends SIGINT to git and to the pager,
and it's a similar situation.  The pager ignores it, but the
git process needs to hang around until the pager is done. We
addressed that long ago in a3da882120 (pager: do
wait_for_pager on signal death, 2009-01-22).

But when you have a dashed external (or an alias pointing to
a builtin, which will re-exec git for the builtin), there's
an extra process in the mix. For instance, running:

  $ git -c alias.l=log l

will end up with a process tree like:

  git (parent)
    \
     git-log (child)
      \
       less (pager)

If you hit ^C, SIGINT goes to all of them. The pager ignores
it, and the child git process will end up in wait_for_pager().
But the parent git process will die, and the usual EIO
trouble happens.

So we really want the parent git process to wait_for_pager(),
but of course it doesn't know anything about the pager at
all, since it was started by the child.  However, we can
have it wait on the git-log child, which in turn is waiting
on the pager. And that's what this patch does.

There are a few design decisions here worth explaining:

  1. The new feature is attached to run-command's
     clean_on_exit feature. Partly this is convenience,
     since that feature already has a signal handler that
     deals with child cleanup.

     But it's also a meaningful connection. The main reason
     that dashed externals use clean_on_exit is to bind the
     two processes together. If somebody kills the parent
     with a signal, we propagate that to the child (in this
     instance with SIGINT, we do propagate but it doesn't
     matter because the original signal went to the whole
     process group). Likewise, we do not want the parent
     to go away until the child has done so.

     In a traditional Unix world, we'd probably accomplish
     this binding by just having the parent execve() the
     child directly. But since that doesn't work on Windows,
     everything goes through run_command's more spawn-like
     interface.

  2. We do _not_ automatically waitpid() on any
     clean_on_exit children. For dashed externals this makes
     sense; we know that the parent is doing nothing but
     waiting for the child to exit anyway. But with other
     children, it's possible that the child, after getting
     the signal, could be waiting on the parent to do
     something (like closing a descriptor). If we were to
     wait on such a child, we'd end up in a deadlock. So
     this errs on the side of caution, and lets callers
     enable the feature explicitly.

  3. When we send children the cleanup signal, we send all
     the signals first, before waiting on any children. This
     is to avoid the case where one child might be waiting
     on another one to exit, causing a deadlock. We inform
     all of them that it's time to die before reaping any.

     In practice, there is only ever one dashed external run
     from a given process, so this doesn't matter much now.
     But it future-proofs us if other callers start using
     the wait_after_clean mechanism.

There's no automated test here, because it would end up racy
and unportable. But it's easy to reproduce the situation by
running the log command given above and hitting ^C.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-09 13:41:40 -08:00
Jeff King 246f0edec0 execv_dashed_external: stop exiting with negative code
When we try to exec a git sub-command, we pass along the
status code from run_command(). But that may return -1 if we
ran into an error with pipe() or execve(). This tends to
work (and end up as 255 due to twos-complement wraparound
and truncation), but in general it's probably a good idea to
avoid negative exit codes for portability.

We can easily translate to the normal generic "128" code we
get when syscalls cause us to die.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-09 13:41:35 -08:00
Jeff King 2b296c93d4 execv_dashed_external: use child_process struct
When we run a dashed external, we use the one-liner
run_command_v_opt() to do so. Let's switch to using a
child_process struct, which has two advantages:

  1. We can drop all of the allocation and cleanup code for
     building our custom argv array, and just rely on the
     builtin argv_array (at the minor cost of doing a few
     extra mallocs).

  2. We have access to the complete range of child_process
     options, not just the ones that the "_opt()" form can
     forward.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-09 13:41:33 -08:00
Brandon Williams 0281e487fd grep: optionally recurse into submodules
Allow grep to recognize submodules and recursively search for patterns in
each submodule.  This is done by forking off a process to recursively
call grep on each submodule.  The top level --super-prefix option is
used to pass a path to the submodule which can in turn be used to
prepend to output or in pathspec matching logic.

Recursion only occurs for submodules which have been initialized and
checked out by the parent project.  If a submodule hasn't been
initialized and checked out it is simply skipped.

In order to support the existing multi-threading infrastructure in grep,
output from each child process is captured in a strbuf so that it can be
later printed to the console in an ordered fashion.

To limit the number of theads that are created, each child process has
half the number of threads as its parents (minimum of 1), otherwise we
potentailly have a fork-bomb.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-22 11:47:33 -08:00
Stefan Beller 89c8626557 submodule helper: support super prefix
Just like main commands in Git, the submodule helper needs
access to the superproject prefix. Enable this in the git.c
but have its own fuse in the helper code by having a flag to
turn on the super prefix.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-09 14:52:57 -08:00
Junio C Hamano 95c2b13a5f Merge branch 'jk/common-main'
Fix for a small regression in a topic already in 'master'.

* jk/common-main:
  common-main: stop munging argv[0] path
2016-11-29 12:22:13 -08:00
Jeff King 6854a8f5c9 common-main: stop munging argv[0] path
Since 650c44925 (common-main: call git_extract_argv0_path(),
2016-07-01), the argv[0] that is seen in cmd_main() of
individual programs is always the basename of the
executable, as common-main strips off the full path. This
can produce confusing results for git-daemon, which wants to
re-exec itself.

For instance, if the program was originally run as
"/usr/lib/git/git-daemon", it will try just re-execing
"git-daemon", which will find the first instance in $PATH.
If git's exec-path has not been prepended to $PATH, we may
find the git-daemon from a different version (or no
git-daemon at all).

Normally this isn't a problem. Git commands are run as "git
daemon", the git wrapper puts the exec-path at the front of
$PATH, and argv[0] is already "daemon" anyway. But running
git-daemon via its full exec-path, while not really a
recommended method, did work prior to 650c44925. Let's make
it work again.

The real goal of 650c44925 was not to munge argv[0], but to
reliably set the argv0_path global. The only reason it
munges at all is that one caller, the git.c wrapper,
piggy-backed on that computation to find the command
basename.  Instead, let's leave argv[0] untouched in
common-main, and have git.c do its own basename computation.

While we're at it, let's drop the return value from
git_extract_argv0_path(). It was only ever used in this one
callsite, and its dual purposes is what led to this
confusion in the first place.

Note that by changing the interface, the compiler can
confirm for us that there are no other callers storing the
return value. But the compiler can't tell us whether any of
the cmd_main() functions (besides git.c) were relying on the
basename munging. However, we can observe that prior to
650c44925, no other cmd_main() functions did that munging,
and no new cmd_main() functions have been introduced since
then. So we can't be regressing any of those cases.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-11-29 11:01:48 -08:00
Junio C Hamano eb0224c617 archive: read local configuration
Since b9605bc4f2 ("config: only read .git/config from configured
repos", 2016-09-12), we do not read from ".git/config" unless we
know we are in a repository.  "git archive" however didn't do the
repository discovery and instead relied on the old behaviour.

Teach the command to run a "gentle" version of repository discovery
so that local configuration variables are honoured.

[jc: stole tests from peff]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-11-22 13:55:20 -08:00
Junio C Hamano 3f0ec0687d mailinfo: read local configuration
Since b9605bc4f2 ("config: only read .git/config from configured
repos", 2016-09-12), we do not read from ".git/config" unless we
know we are in a repository.  "git mailinfo" however didn't do the
repository discovery and instead relied on the old behaviour.  This
was mostly OK because it was merely run as a helper program by other
porcelain scripts that first chdir's up to the root of the working
tree.

Teach the command to run a "gentle" version of repository discovery
so that local configuration variables like mailinfo.scissors are
honoured.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-11-22 13:13:16 -08:00
Junio C Hamano a03973893b Merge branch 'jc/cocci-xstrdup-or-null'
Code cleanup.

* jc/cocci-xstrdup-or-null:
  cocci: refactor common patterns to use xstrdup_or_null()
2016-10-26 13:14:45 -07:00
Junio C Hamano 1c2b1f7018 Merge branch 'bw/ls-files-recurse-submodules'
"git ls-files" learned "--recurse-submodules" option that can be
used to get a listing of tracked files across submodules (i.e. this
only works with "--cached" option, not for listing untracked or
ignored files).  This would be a useful tool to sit on the upstream
side of a pipe that is read with xargs to work on all working tree
files from the top-level superproject.

* bw/ls-files-recurse-submodules:
  ls-files: add pathspec matching for submodules
  ls-files: pass through safe options for --recurse-submodules
  ls-files: optionally recurse into submodules
  git: make super-prefix option
2016-10-26 13:14:44 -07:00
Junio C Hamano 13092a916d cocci: refactor common patterns to use xstrdup_or_null()
d64ea0f83b ("git-compat-util: add xstrdup_or_null helper",
2015-01-12) added a handy wrapper that allows us to get a duplicate
of a string or NULL if the original is NULL, but a handful of
codepath predate its introduction or just weren't aware of it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-12 11:22:10 -07:00
Brandon Williams e77aa336f1 ls-files: optionally recurse into submodules
Allow ls-files to recognize submodules in order to retrieve a list of
files from a repository's submodules.  This is done by forking off a
process to recursively call ls-files on all submodules. Use top-level
--super-prefix option to pass a path to the submodule which it can
use to prepend to output or pathspec matching logic.

Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-10 12:14:58 -07:00
Brandon Williams 74866d7579 git: make super-prefix option
Add a super-prefix environment variable 'GIT_INTERNAL_SUPER_PREFIX'
which can be used to specify a path from above a repository down to its
root.  When such a super-prefix is specified, the paths reported by Git
are prefixed with it to make them relative to that directory "above".
The paths given by the user on the command line
(e.g. "git subcmd --output-file=path/to/a/file" and pathspecs) are taken
relative to the directory "above" to match.

The immediate use of this option is by commands which have a
--recurse-submodule option in order to give context to submodules about
how they were invoked.  This option is currently only allowed for
builtins which support a super-prefix.

Signed-off-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-10 12:14:58 -07:00
Junio C Hamano d845d727cb Merge branch 'jk/setup-sequence-update'
There were numerous corner cases in which the configuration files
are read and used or not read at all depending on the directory a
Git command was run, leading to inconsistent behaviour.  The code
to set-up repository access at the beginning of a Git process has
been updated to fix them.

* jk/setup-sequence-update:
  t1007: factor out repeated setup
  init: reset cached config when entering new repo
  init: expand comments explaining config trickery
  config: only read .git/config from configured repos
  test-config: setup git directory
  t1302: use "git -C"
  pager: handle early config
  pager: use callbacks instead of configset
  pager: make pager_program a file-local static
  pager: stop loading git_default_config()
  pager: remove obsolete comment
  diff: always try to set up the repository
  diff: handle --no-index prefixes consistently
  diff: skip implicit no-index check when given --no-index
  patch-id: use RUN_SETUP_GENTLY
  hash-object: always try to set up the git repository
2016-09-21 15:15:24 -07:00
Jeff King 4a73aaaf18 patch-id: use RUN_SETUP_GENTLY
Patch-id does not require a repository because it is just
processing the incoming diff on stdin, but it may look at
git config for keys like patchid.stable.

Even though we do not setup_git_directory(), this works from
the top-level of a repository because we blindly look at
".git/config" in this case. But as the included test
demonstrates, it does not work from a subdirectory.

We can fix it by using RUN_SETUP_GENTLY. We do not take any
filenames from the user on the command line, so there's no
need to adjust them via prefix_filename().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-13 15:45:45 -07:00
Junio C Hamano d7ed183a91 Merge branch 'rt/help-unknown'
"git nosuchcommand --help" said "No manual entry for gitnosuchcommand",
which was not intuitive, given that "git nosuchcommand" said "git:
'nosuchcommand' is not a git command".

* rt/help-unknown:
  help: make option --help open man pages only for Git commands
  help: introduce option --exclude-guides
2016-09-08 21:49:48 -07:00
Ralf Thielow 2c6b6d9f7d help: make option --help open man pages only for Git commands
If option --help is passed to a Git command, we try to open
the man page of that command.  However, we do it for both commands
and concepts.  Make sure it is an actual command.

This makes "git <concept> --help" not working anymore, while
"git help <concept>" still works.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-30 16:09:41 -07:00
Jeff King 5ce5f5fa5a common-main: call git_setup_gettext()
This should be part of every program, as otherwise users do
not get translated error messages. However, some external
commands forgot to do so (e.g., git-credential-store). This
fixes them, and eliminates the repeated code in programs
that did remember to use it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King 12e0437f23 common-main: call restore_sigpipe_to_default()
This is another safety/sanity setup that should be in force
everywhere, but which we only applied in git.c. This did
catch most cases, since even external commands are typically
run via "git ..." (and the restoration applies to
sub-processes, too). But there were cases we missed, such as
somebody calling git-upload-pack directly via ssh, or
scripts which use dashed external commands directly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King 57f5d52a94 common-main: call sanitize_stdfds()
This is setup that should be done in every program for
safety, but we never got around to adding it everywhere (so
builtins benefited from the call in git.c, but any external
commands did not). Putting it in the common main() gives us
this safety everywhere.

Note that the case in daemon.c is a little funny. We wait
until we know whether we want to daemonize, and then either:

 - call daemonize(), which will close stdio and reopen it to
   /dev/null under the hood

 - sanitize_stdfds(), to fix up any odd cases

But that is way too late; the point of sanitizing is to give
us reliable descriptors on 0/1/2, and we will already have
executed code, possibly called die(), etc. The sanitizing
should be the very first thing that happens.

With this patch, git-daemon will sanitize first, and can
remove the call in the non-daemonize case. It does mean that
daemonize() may just end up closing the descriptors we
opened, but that's not a big deal (it's not wrong to do so,
nor is it really less optimal than the case where our parent
process redirected us from /dev/null ahead of time).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King 650c449250 common-main: call git_extract_argv0_path()
Every program which links against libgit.a must call this
function, or risk hitting an assert() in system_path() that
checks whether we have configured argv0_path (though only
when RUNTIME_PREFIX is defined, so essentially only on
Windows).

Looking at the diff, you can see that putting it into the
common main() saves us having to do it individually in each
of the external commands. But what you can't see are the
cases where we _should_ have been doing so, but weren't
(e.g., git-credential-store, and all of the t/helper test
programs).

This has been an accident-waiting-to-happen for a long time,
but wasn't triggered until recently because it involves one
of those programs actually calling system_path(). That
happened with git-credential-store in v2.8.0 with ae5f677
(lazily load core.sharedrepository, 2016-03-11). The
program:

  - takes a lock file, which...

  - opens a tempfile, which...

  - calls adjust_shared_perm to fix permissions, which...

  - lazy-loads the config (as of ae5f677), which...

  - calls system_path() to find the location of
    /etc/gitconfig

On systems with RUNTIME_PREFIX, this means credential-store
reliably hits that assert() and cannot be used.

We never noticed in the test suite, because we set
GIT_CONFIG_NOSYSTEM there, which skips the system_path()
lookup entirely.  But if we were to tweak git_config() to
find /etc/gitconfig even when we aren't going to open it,
then the test suite shows multiple failures (for
credential-store, and for some other test helpers). I didn't
include that tweak here because it's way too specific to
this particular call to be worth carrying around what is
essentially dead code.

The implementation is fairly straightforward, with one
exception: there is exactly one caller (git.c) that actually
cares about the result of the function, and not the
side-effect of setting up argv0_path. We can accommodate
that by simply replacing the value of argv[0] in the array
we hand down to cmd_main().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King 3f2e2297b9 add an extra level of indirection to main()
There are certain startup tasks that we expect every git
process to do. In some cases this is just to improve the
quality of the program (e.g., setting up gettext()). In
others it is a requirement for using certain functions in
libgit.a (e.g., system_path() expects that you have called
git_extract_argv0_path()).

Most commands are builtins and are covered by the git.c
version of main(). However, there are still a few external
commands that use their own main(). Each of these has to
remember to include the correct startup sequence, and we are
not always consistent.

Rather than just fix the inconsistencies, let's make this
harder to get wrong by providing a common main() that can
run this standard startup.

We basically have two options to do this:

 - the compat/mingw.h file already does something like this by
   adding a #define that replaces the definition of main with a
   wrapper that calls mingw_startup().

   The upside is that the code in each program doesn't need
   to be changed at all; it's rewritten on the fly by the
   preprocessor.

   The downside is that it may make debugging of the startup
   sequence a bit more confusing, as the preprocessor is
   quietly inserting new code.

 - the builtin functions are all of the form cmd_foo(),
   and git.c's main() calls them.

   This is much more explicit, which may make things more
   obvious to somebody reading the code. It's also more
   flexible (because of course we have to figure out _which_
   cmd_foo() to call).

   The downside is that each of the builtins must define
   cmd_foo(), instead of just main().

This patch chooses the latter option, preferring the more
explicit approach, even though it is more invasive. We
introduce a new file common-main.c, with the "real" main. It
expects to call cmd_main() from whatever other objects it is
linked against.

We link common-main.o against anything that links against
libgit.a, since we know that such programs will need to do
this setup. Note that common-main.o can't actually go inside
libgit.a, as the linker would not pick up its main()
function automatically (it has no callers).

The rest of the patch is just adjusting all of the various
external programs (mostly in t/helper) to use cmd_main().
I've provided a global declaration for cmd_main(), which
means that all of the programs also need to match its
signature. In particular, many functions need to switch to
"const char **" instead of "char **" for argv. This effect
ripples out to a few other variables and functions, as well.

This makes the patch even more invasive, but the end result
is much better. We should be treating argv strings as const
anyway, and now all programs conform to the same signature
(which also matches the way builtins are defined).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-01 15:09:10 -07:00
Jeff King 46c3cd44d7 setup: make startup_info available everywhere
Commit a60645f (setup: remember whether repository was
found, 2010-08-05) introduced the startup_info structure,
which records some parts of the setup_git_directory()
process (notably, whether we actually found a repository or
not).

One of the uses of this data is for functions to behave
appropriately based on whether we are in a repo. But the
startup_info struct is just a pointer to storage provided by
the main program, and the only program that sets it up is
the git.c wrapper. Thus builtins have access to
startup_info, but externally linked programs do not.

Worse, library code which is accessible from both has to be
careful about accessing startup_info. This can be used to
trigger a die("BUG") via get_sha1():

	$ git fast-import <<-\EOF
	tag foo
	from HEAD:./whatever
	EOF

	fatal: BUG: startup_info struct is not initialized.

Obviously that's fairly nonsensical input to feed to
fast-import, but we should never hit a die("BUG"). And there
may be other ways to trigger it if other non-builtins
resolve sha1s.

So let's point the storage for startup_info to a static
variable in setup.c, making it available to all users of the
library code. We _could_ turn startup_info into a regular
extern struct, but doing so would mean tweaking all of the
existing use sites. So let's leave the pointer indirection
in place.  We can, however, drop any checks for NULL, as
they will always be false (and likewise, we can drop the
test covering this case, which was a rather artificial
situation using one of the test-* programs).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-03-06 17:17:37 -08:00
Junio C Hamano 11529ecec9 Merge branch 'jk/tighten-alloc'
Update various codepaths to avoid manually-counted malloc().

* jk/tighten-alloc: (22 commits)
  ewah: convert to REALLOC_ARRAY, etc
  convert ewah/bitmap code to use xmalloc
  diff_populate_gitlink: use a strbuf
  transport_anonymize_url: use xstrfmt
  git-compat-util: drop mempcpy compat code
  sequencer: simplify memory allocation of get_message
  test-path-utils: fix normalize_path_copy output buffer size
  fetch-pack: simplify add_sought_entry
  fast-import: simplify allocation in start_packfile
  write_untracked_extension: use FLEX_ALLOC helper
  prepare_{git,shell}_cmd: use argv_array
  use st_add and st_mult for allocation size computation
  convert trivial cases to FLEX_ARRAY macros
  use xmallocz to avoid size arithmetic
  convert trivial cases to ALLOC_ARRAY
  convert manual allocations to argv_array
  argv-array: add detach function
  add helpers for allocating flex-array structs
  harden REALLOC_ARRAY and xcalloc against size_t overflow
  tree-diff: catch integer overflow in combine_diff_path allocation
  ...
2016-02-26 13:37:16 -08:00
Junio C Hamano dede29612a Merge branch 'ak/git-strip-extension-from-dashed-command'
Code simplification.

* ak/git-strip-extension-from-dashed-command:
  git.c: simplify stripping extension of a file in handle_builtin()
2016-02-26 13:37:13 -08:00
Jeff King 850d2fec53 convert manual allocations to argv_array
There are many manual argv allocations that predate the
argv_array API. Switching to that API brings a few
advantages:

  1. We no longer have to manually compute the correct final
     array size (so it's one less thing we can screw up).

  2. In many cases we had to make a separate pass to count,
     then allocate, then fill in the array. Now we can do it
     in one pass, making the code shorter and easier to
     follow.

  3. argv_array handles memory ownership for us, making it
     more obvious when things should be free()d and and when
     not.

Most of these cases are pretty straightforward. In some, we
switch from "run_command_v" to "run_command" which lets us
directly use the argv_array embedded in "struct
child_process".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:50:32 -08:00
Alexander Kuleshov 63ca1c099c git.c: simplify stripping extension of a file in handle_builtin()
The handle_builtin() starts from stripping of command extension if
STRIP_EXTENSION is enabled. Actually STRIP_EXTENSION does not used
anywhere else.

This patch introduces strip_extension() helper to strip STRIP_EXTENSION
extension from argv[0] with the strip_suffix() instead of manually
stripping.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-21 23:52:43 -08:00
Junio C Hamano dbda66b0e2 Merge branch 'nd/clear-gitenv-upon-use-of-alias'
The automatic typo correction applied to an alias was broken
with a recent change already in 'master'.

* nd/clear-gitenv-upon-use-of-alias:
  restore_env(): free the saved environment variable once we are done
  git: simplify environment save/restore logic
  git: protect against unbalanced calls to {save,restore}_env()
  git: remove an early return from save_env_before_alias()
2016-02-17 10:13:31 -08:00
Junio C Hamano 8384c139cb restore_env(): free the saved environment variable once we are done
Just like we free orig_cwd, which is the value of the original
working directory saved in save_env_before_alias(), once we are
done with it, the contents of orig_env[] array, saved in the
save_env_before_alias() function should be freed; otherwise,
the second and subsequent calls to save/restore pair will leak
the memory allocated in save_env_before_alias().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-02 15:42:59 -08:00
Junio C Hamano 441981bc85 git: simplify environment save/restore logic
The only code that cares about the value of the global variable
saved_env_before_alias after the previous fix is handle_builtin()
that turns into a glorified no-op when the variable is true, so the
logic could safely be lifted to its caller, i.e. the caller can
refrain from calling it when the variable is set.

This variable tells us if save_env_before_alias() was called (with
or without matching restore_env()), but the sole caller of the
function, handle_alias(), always calls it as the first thing, so we
can consider that the variable essentially keeps track of the fact
that handle_alias() has ever been called.

It turns out that handle_builtin() and handle_alias() are called
only from one function in a way that the value of the variable
matters, which is run_argv(), and it already keeps track of the
fact that it already called handle_alias().

So we can simplify the whole thing by:

- Change handle_builtin() to always make a direct call to the
  builtin implementation it finds, and make sure the caller
  refrains from calling it if handle_alias() has ever been
  called;

- Remove saved_env_before_alias variable, and instead use the
  local "done_alias" variable maintained inside run_argv() to
  make the same decision.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-27 15:45:55 -08:00
Junio C Hamano 2e1175d43d git: protect against unbalanced calls to {save,restore}_env()
We made sure that save_env_before_alias() does not skip saving the
environment when asked to (which led to use-after-free of orig_cwd
in restore_env() in the buggy version) with the previous step.

Protect against future breakage where somebody adds new callers of
these functions in an unbalanced fashion.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-27 15:19:03 -08:00
Junio C Hamano 9d1d2b7fad git: remove an early return from save_env_before_alias()
When help.autocorrect is in effect, an attempt to auto-execute an
uniquely corrected result of a misspelt alias will result in an
irrelevant error message.  The codepath that causes this calls
save_env_before_alias() and restore_env() in handle_alias(), and
that happens twice.  A global variable orig_cwd is allocated to hold
the return value of getcwd() in save_env_before_alias(), which is
then used in restore_env() to go back to that directory and finally
free(3)'d there.

However, save_env_before_alias() is not prepared to be called twice.
It returns early when it knows it has already been called, leaving
orig_cwd undefined, which is then checked in the second call to
restore_env(), and by that time, the memory that used to hold the
contents of orig_cwd is either freed or reused to hold something
else, and this is fed to chdir(2), causing it to fail.  Even if it
did not fail (i.e. reading of the already free'd piece of memory
yielded a directory path that we can chdir(2) to), it then gets
free(3)'d.

Fix this by making sure save_env() does do the saving when called.

While at it, add a minimal test for help.autocorrect facility.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-27 15:12:37 -08:00
Junio C Hamano 5135d1c3d2 Merge branch 'nd/clear-gitenv-upon-use-of-alias'
d95138e6 (setup: set env $GIT_WORK_TREE when work tree is set, like
$GIT_DIR, 2015-06-26) attempted to work around a glitch in alias
handling by overwriting GIT_WORK_TREE environment variable to
affect subprocesses when set_git_work_tree() gets called, which
resulted in a rather unpleasant regression to "clone" and "init".
Try to address the same issue by always restoring the environment
and respawning the real underlying command when handling alias.

* nd/clear-gitenv-upon-use-of-alias:
  run-command: don't warn on SIGPIPE deaths
  git.c: make sure we do not leak GIT_* to alias scripts
  setup.c: re-fix d95138e (setup: set env $GIT_WORK_TREE when ..
  git.c: make it clear save_env() is for alias handling only
2016-01-20 11:43:26 -08:00
Nguyễn Thái Ngọc Duy 57ea7123c8 git.c: make sure we do not leak GIT_* to alias scripts
The unfortunate commit d95138e (setup: set env $GIT_WORK_TREE when
work tree is set, like $GIT_DIR - 2015-06-26) exposes another problem,
besides git-clone that's described in the previous commit. If
GIT_WORK_TREE (or even GIT_DIR) is exported to an alias script, it may
mislead git commands in the script where the repo is. Granted, most
scripts work on the repo where the alias is summoned from. But nowhere
do we forbid the script to visit another repository.

The revert of d95138e in the previous commit is sufficient as a
fix. However, to protect us from accidentally leaking GIT_*
environment variables again, we restore certain sensitive env before
calling the external script.

GIT_PREFIX is let through because there's another setup side effect
that we simply accepted so far: current working directory is
moved. Maybe in future we can introduce a new alias format that
guarantees no cwd move, then we can unexport GIT_PREFIX.

Reported-by: Gabriel Ganne <gabriel.ganne@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-22 13:40:32 -08:00
Nguyễn Thái Ngọc Duy 86d26f240f setup.c: re-fix d95138e (setup: set env $GIT_WORK_TREE when ..
Commit d95138e [1] attempted to fix a .git file problem by
setting GIT_WORK_TREE whenever GIT_DIR is set. It sounded harmless
because we handle GIT_DIR and GIT_WORK_TREE side by side for most
commands, with two exceptions: git-init and git-clone.

"git clone" is not happy with d95138e. This command ignores GIT_DIR
but respects GIT_WORK_TREE [2] [3] which means it used to run fine
from a hook, where GIT_DIR was set but GIT_WORK_TREE was not (*).
With d95138e, GIT_WORK_TREE is set all the time and git-clone
interprets that as "I give you order to put the worktree here",
usually against the user's intention.

The solution in d95138e is reverted earlier, and instead we reuse
the solution from c056261 [4].  It fixed another setup-messed-
up-by-alias by saving and restoring env and spawning a new process,
but for git-clone and git-init only.

Now we conclude that setup-messed-up-by-alias is always evil. So the
env restoration is done for _all_ commands, including external ones,
whenever aliases are involved. It fixes what d95138e tried to fix,
without upsetting git-clone-inside-hooks.

The test from d95138e remains to verify it's not broken by this. A new
test is added to make sure git-clone-inside-hooks remains happy.

(*) GIT_WORK_TREE was not set _most of the time_. In some cases
    GIT_WORK_TREE is set and git-clone will behave differently. The
    use of GIT_WORK_TREE to direct git-clone to put work tree
    elsewhere looks like a mistake because it causes surprises this
    way. But that's a separate story.

[1] d95138e (setup: set env $GIT_WORK_TREE when work tree is set, like
             $GIT_DIR - 2015-06-26)
[2] 2beebd2 (clone: create intermediate directories of destination
             repo - 2008-06-25)
[3] 20ccef4 (make git-clone GIT_WORK_TREE aware - 2007-07-06)
[4] c056261 (git potty: restore environments after alias expansion -
             2014-06-08)

Reported-by: Anthony Sottile <asottile@umich.edu>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-22 13:40:32 -08:00
Nguyễn Thái Ngọc Duy 0d5466d244 git.c: make it clear save_env() is for alias handling only
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-22 13:40:32 -08:00
Junio C Hamano 65e1449614 Merge branch 'sb/submodule-helper'
The infrastructure to rewrite "git submodule" in C is being built
incrementally.  Let's polish these early parts well enough and make
them graduate to 'next' and 'master', so that the more involved
follow-up can start cooking on a solid ground.

* sb/submodule-helper:
  submodule: rewrite `module_clone` shell function in C
  submodule: rewrite `module_name` shell function in C
  submodule: rewrite `module_list` shell function in C
2015-10-05 12:30:19 -07:00
John Keeping cbd9fc2366 interpret-trailers: allow running outside a repository
It may be useful to run git-interpret-trailers without needing to be in
a repository.

Signed-off-by: John Keeping <john@keeping.me.uk>
Acked-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-08 11:16:47 -07:00