When giving arguments without "--" disambiguation, object names
that come earlier on the command line must not be interpretable as
pathspecs and pathspecs that come later on the command line must
not be interpretable as object names. Tweak the disambiguation
rule so that ":/" (no other string before or after) is always
interpreted as a pathspec, to avoid having to say "git cmd -- :/".
* nd/magic-pathspec-from-root:
grep: avoid accepting ambiguous revision
Update :/abc ambiguity check
A header file that has the definition of a static array was
included in two places, wasting the space.
* jc/help:
help: include <common-cmds.h> only in one file
Most Git commands that can be used with or without pathspec operate
tree-wide by default, the pathspec being used to restrict their
scope. A few exceptions are: 'git grep', 'git clean', 'git add -u'
and 'git add -A'. When run in a subdirectory without pathspec, they
operate only on paths in the current directory.
The inconsistency of 'git add -u' and 'git add -A' is particularly
problematic since other 'git add' subcommands (namely 'git add -p'
and 'git add -e') are tree-wide by default. It also means that "git
add -u && git commit" will record a state that is different from
what is recorded with "git commit -a".
Flipping the default now is unacceptable, so let's start training
users to type 'git add -u|-A :/' or 'git add -u|-A .' explicitly, to
prepare for the next steps:
* forbid 'git add -u|-A' without pathspec (like 'git add' without
option)
* much later, maybe, re-allow 'git add -u|-A' without pathspec, that
will add all tracked and modified files, or all files, tree-wide.
A nice side effect of this patch is that it makes the :/ magic
pathspec easier to discover for users.
When the command is called from the root of the tree, there is no
ambiguity and no need to change the behavior, hence no need to warn.
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we look up a sha1 object for reading via parse_object() =>
read_sha1_file() => read_object() callpath, we first check
packfiles, and then loose objects. If we still haven't found it, we
re-scan the list of packfiles in `objects/pack`. This final step
ensures that we can co-exist with a simultaneous repack process
which creates a new pack and then prunes the old object.
This extra re-scan usually does not have a performance impact for
two reasons:
1. If an object is missing, then typically the re-scan will find a
new pack, then no more misses will occur. Or if it truly is
missing, then our next step is usually to die().
2. Re-scanning is cheap enough that we do not even notice.
However, these do not always hold. The assumption in (1) is that the
caller is expecting to find the object. This is usually the case,
but the call to `parse_object` in `everything_local` does not follow
this pattern. It is looking to see whether we have objects that the
remote side is advertising, not something we expect to
have. Therefore if we are fetching from a remote which has many refs
pointing to objects we do not have, we may end up re-scanning the
pack directory many times.
Even with this extra re-scanning, the impact is often not noticeable
due to (2); we just readdir() the packs directory and skip any packs
that are already loaded. However, if there are a large number of
packs, even enumerating the directory can be expensive, especially
if we do it repeatedly.
Having this many packs is a good sign the user should run `git gc`,
but it would still be nice to avoid having to scan the directory at
all.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We generally try to run "gc --auto" after any commands that
might introduce a large number of new objects. An obvious
place to do so is after running "fetch", which may introduce
new loose objects or packs (depending on the size of the
fetch).
While an active developer repository will probably
eventually trigger a "gc --auto" on another action (e.g.,
git-rebase), there are two good reasons why it is nicer to
do it at fetch time:
1. Read-only repositories which track an upstream (e.g., a
continuous integration server which fetches and builds,
but never makes new commits) will accrue loose objects
and small packs, but never coalesce them into a more
efficient larger pack.
2. Fetching is often already perceived to be slow to the
user, since they have to wait on the network. It's much
more pleasant to include a potentially slow auto-gc as
part of the already-long network fetch than in the
middle of productive work with git-rebase or similar.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Usually a commit that makes it to logmsg_reencode will have
been parsed, and the commit->buffer struct member will be
valid. However, some code paths will free commit buffers
after having used them (for example, the log traversal
machinery will do so to keep memory usage down).
Most of the time this is fine; log should only show a commit
once, and then exits. However, there are some code paths
where this does not work. At least two are known:
1. A commit may be shown as part of a regular ref, and
then it may be shown again as part of a submodule diff
(e.g., if a repo contains refs to both the superproject
and subproject).
2. A notes-cache commit may be shown during "log --all",
and then later used to access a textconv cache during a
diff.
Lazily loading in logmsg_reencode does not necessarily catch
all such cases, but it should catch most of them. Users of
the commit buffer tend to be either parsing for structure
(in which they will call parse_commit, and either we will
already have parsed, or we will load commit->buffer lazily
there), or outputting (either to the user, or fetching a
part of the commit message via format_commit_message). In
the latter case, we should always be using logmsg_reencode
anyway (and typically we do so via the pretty-print
machinery).
If there are any cases that this misses, we can fix them up
to use logmsg_reencode (or handle them on a case-by-case
basis if that is inappropriate).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The logmsg_reencode function will return the reencoded
commit buffer, or NULL if reencoding failed or no reencoding
was necessary. Since every caller then ends up checking for NULL
and just using the commit's original buffer, anyway, we can
be a bit more helpful and just return that buffer when we
would have returned NULL.
Since the resulting string may or may not need to be freed,
we introduce a logmsg_free, which checks whether the buffer
came from the commit object or not (callers either
implemented the same check already, or kept two separate
pointers, one to mark the buffer to be used, and one for the
to-be-freed string).
Pushing this logic into logmsg_* simplifies the callers, and
will let future patches lazily load the commit buffer in a
single place.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git-commit is asked to reuse a commit message via "-c",
we call read_commit_message, which looks up the commit and
hands back either the re-encoded result, or a copy of the
original. We make a copy in the latter case so that the
ownership semantics of the return value are clear (in either
case, it can be freed).
However, since we return a "const char *", and since the
resulting buffer's lifetime is the same as that of the whole
program, we never bother to free it at all.
Let's just drop the copy. That saves us a copy in the common
case. While it does mean we leak in the re-encode case, it
doesn't matter, since we are relying on program exit to free
the memory anyway.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that "already exists" errors are given only when a push tries to
update an existing ref in refs/tags/ hierarchy, we can say "the
tag", instead of "the destination reference", and that is far easier
to understand.
Pointed out by Chris Rorvick.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we push to update an existing ref, if:
* the object at the tip of the remote is not a commit; or
* the object we are pushing is not a commit,
it won't be correct to suggest to fetch, integrate and push again,
as the old and new objects will not "merge". We should explain that
the push must be forced when there is a non-committish object is
involved in such a case.
If we do not have the current object at the tip of the remote, we do
not even know that object, when fetched, is something that can be
merged. In such a case, suggesting to pull first just like
non-fast-forward case may not be technically correct, but in
practice, most such failures are seen when you try to push your work
to a branch without knowing that somebody else already pushed to
update the same branch since you forked, so "pull first" would work
as a suggestion most of the time. And if the object at the tip is
not a commit, "pull first" will fail, without making any permanent
damage. As a side effect, it also makes the error message the user
will get during the next "push" attempt easier to understand, now
the user is aware that a non-commit object is involved.
In these cases, the current code already rejects such a push on the
client end, but we used the same error and advice messages as the
ones used when rejecting a non-fast-forward push, i.e. pull from
there and integrate before pushing again.
Introduce new rejection reasons and reword the messages
appropriately.
[jc: with help by Peff on message details]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an extra hook so that "git push" that is run without making
sure what is being pushed is sane can be checked and rejected (as
opposed to the user deciding not pushing).
* as/pre-push-hook:
Add sample pre-push hook script
push: Add support for pre-push hooks
hooks: Add function to check if a hook exists
Add a new command "git check-ignore" for debugging .gitignore
files.
The variable names may want to get cleaned up but that can be done
in-tree.
* as/check-ignore:
clean.c, ls-files.c: respect encapsulation of exclude_list_groups
t0008: avoid brace expansion
add git-check-ignore sub-command
setup.c: document get_pathspec()
add.c: extract new die_if_path_beyond_symlink() for reuse
add.c: extract check_path_for_gitlink() from treat_gitlinks() for reuse
pathspec.c: rename newly public functions for clarity
add.c: move pathspec matchers into new pathspec.c for reuse
add.c: remove unused argument from validate_pathspec()
dir.c: improve docs for match_pathspec() and match_pathspec_depth()
dir.c: provide clear_directory() for reclaiming dir_struct memory
dir.c: keep track of where patterns came from
dir.c: use a single struct exclude_list per source of excludes
Conflicts:
builtin/ls-files.c
dir.c
This doesn't save any lines, but does keep us from doing
error-prone pointer arithmetic with constants.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The resulting code ends up about the same length, but it is
a little more self-explanatory. It now explicitly documents
and checks the pre-condition that the incoming var starts
with "man.", and drops the magic offset "4".
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Various 'reset' optimizations and clean-ups, followed by a change
to allow "git reset" to work even on an unborn branch.
* mz/reset-misc:
reset: update documentation to require only tree-ish with paths
reset [--mixed]: use diff-based reset whether or not pathspec was given
reset: allow reset on unborn branch
reset $sha1 $pathspec: require $sha1 only to be treeish
reset.c: inline update_index_refresh()
reset.c: finish entire cmd_reset() whether or not pathspec is given
reset [--mixed]: only write index file once
reset.c: move lock, write and commit out of update_index_refresh()
reset.c: move update_index_refresh() call out of read_from_tree()
reset.c: replace switch by if-else
reset: avoid redundant error message
reset --keep: only write index file once
reset.c: share call to die_if_unmerged_cache()
reset.c: extract function for updating {ORIG_,}HEAD
reset.c: remove unnecessary variable 'i'
reset.c: extract function for parsing arguments
reset: don't allow "git reset -- $pathspec" in bare repo
reset.c: pass pathspec around instead of (prefix, argv) pair
reset $pathspec: exit with code 0 if successful
reset $pathspec: no need to discard index
"git clean" states what it is going to remove and then goes on to
remove it, but sometimes it only discovers things that cannot be
removed after recursing into a directory, which makes the output
confusing and even wrong.
* zk/clean-report-failure:
git-clean: Display more accurate delete messages
Unlike other commands that take both revs and pathspecs without "--"
disamiguators only when the boundary is clear, "git grep" treated
what can be interpreted as a rev as-is, without making sure that it
could also have meant a pathspec. E.g.
$ git grep -e foo master
when 'master' is in the working tree, should have triggered an
ambiguity error, but it didn't, and searched in the tree of the
commit named by 'master'.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a configuration variable to set default clean-up mode other
than "strip".
* rt/commit-cleanup-config:
commit: make default of "cleanup" option configurable
Teach commands in the "log" family to optionally pay attention to
the mailmap.
* ap/log-mailmap:
log --use-mailmap: optimize for cases without --author/--committer search
log: add log.mailmap configuration option
log: grep author/committer using mailmap
test: add test for --use-mailmap option
log: add --use-mailmap option
pretty: use mailmap to display username and email
mailmap: add mailmap structure to rev_info and pp
mailmap: simplify map_user() interface
mailmap: remove email copy and length limitation
Use split_ident_line to parse author and committer
string-list: allow case-insensitive string list
This header not only declares but also defines the contents of the
array that holds the list of command names and help text. Do not
include it in multiple places to waste text space.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add support for a pre-push hook which can be used to determine if the
set of refs to be pushed is suitable for the target repository. The
hook is run with two arguments specifying the name and location of the
destination repository.
Information about what is to be pushed is provided by sending lines of
the following form to the hook's standard input:
<local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF
If the hook exits with a non-zero status, the push will be aborted.
This will allow the script to determine if the push is acceptable based
on the target repository and branch(es), the commits which are to be
pushed, and even the source branches in some cases.
Signed-off-by: Aaron Schrab <aaron@schrab.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When resetting with paths, we no longer require a commit argument, but
only a tree-ish. Update the documentation and synopsis accordingly.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some users do want to write a line that begin with a pound sign, #,
in their commit log message. Many tracking system recognise
a token of #<bugid> form, for example.
The support we offer these use cases is not very friendly to the end
users. They have a choice between
- Don't do it. Avoid such a line by rewrapping or indenting; and
- Use --cleanup=whitespace but remove all the hint lines we add.
Give them a way to set a custom comment char, e.g.
$ git -c core.commentchar="%" commit
so that they do not have to do either of the two workarounds.
[jc: although I started the topic, all the tests and documentation
updates, many of the call sites of the new strbuf_add_commented_*()
functions, and the change to git-submodule.sh scripted Porcelain are
from Ralf.]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Consumers of the dir.c traversal API should avoid assuming knowledge
of the internal implementation of exclude_list_groups. Therefore
when adding items to an exclude list, it should be accessed via the
pointer returned from add_exclude_list(), rather than by referencing
a location within dir.exclude_list_groups[EXC_CMDL].
Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Thanks to b65982b (Optimize "diff-index --cached" using cache-tree,
2009-05-20), resetting with paths is much faster than resetting
without paths. Some timings for the linux-2.6 repo to illustrate this
(best of five, warm cache):
reset reset .
real 0m0.219s 0m0.080s
user 0m0.140s 0m0.040s
sys 0m0.070s 0m0.030s
These two commands should do the same thing, so instead of having the
user type the trailing " ." to get the faster do_diff_cache()-based
implementation, always use it when doing a mixed reset, with or
without paths (so "git reset $rev" would also be faster).
Timing "git reset" shows that it indeed becomes as fast as
"git reset ." after this patch.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some users seem to think, knowingly or not, that being on an unborn
branch is like having a commit with an empty tree checked out, but
when run on an unborn branch, "git reset" currently fails with:
fatal: Failed to resolve 'HEAD' as a valid ref.
Instead of making users figure out that they should run
git rm --cached -r .
, let's teach "git reset" without a revision argument, when on an
unborn branch, to behave as if the user asked to reset to an empty
tree. Don't take the analogy with an empty commit too far, though, but
still disallow explictly referring to HEAD in "git reset HEAD".
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Resetting with paths does not update HEAD and there is nothing else
that a commit should be needed for. Relax the argument parsing so only
a tree is required.
The sha1 is only passed to read_from_tree(), which already only
requires a tree.
The "rev" variable we pass to run_add_interactive() will resolve to a
tree. This is fine since interactive_reset only needs the parameter to
be a treeish and doesn't use it for display purposes.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that there is only one caller left to the single-line method
update_index_refresh(), inline it.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By not returning from inside the "if (pathspec)" block, we can let the
pathspec-aware and pathspec-less code share a bit more, making it
easier to make future changes that should affect both cases. This also
highlights the similarity between read_from_tree() and reset_index().
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When doing a mixed reset without paths, the index is locked, read,
reset, and written back as part of the actual reset operation (in
reset_index()). Then, when showing the list of worktree modifications,
we lock the index again, refresh it, and write it.
Change this so we only write the index once, making "git reset" a
little faster. It does mean that the index lock will be held a little
longer, but the difference is small compared to the time spent
refreshing the index.
There is one minor functional difference: We used to say "Could not
write new index file." if the first write failed, and "Could not
refresh index" if the second write failed. Now, we will only use the
first message.
This speeds up "git reset" a little on the linux-2.6 repo (best of
five, warm cache):
Before After
real 0m0.239s 0m0.214s
user 0m0.160s 0m0.130s
sys 0m0.070s 0m0.080s
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for the/a following patch, move the locking, writing
and committing of the index file out of update_index_refresh(). The
code duplication caused will soon be taken care of. What remains of
update_index_refresh() is just one line, but it is still called from
two places, so let's leave it for now.
In the process, we expose and fix the minor UI bug that makes us print
"Could not refresh index" when we fail to write the index file when
invoked with a pathspec. Copy the error message from the pathspec-less
codepath ("Could not write new index file.").
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The final part of cmd_reset() essentially looks like:
if (pathspec) {
...
read_from_tree(...);
} else {
...
reset_index(...);
update_index_refresh(...);
...
}
where read_from_tree() internally also calls
update_index_refresh(). Move the call to update_index_refresh() out of
read_from_tree for symmetry with the 'else' block, making
read_from_tree() and reset_index() closer in functionality.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The switch statement towards the end of reset.c is missing case arms
for KEEP and MERGE for no obvious reason, and soon the only non-empty
case arm will be the one for HARD. So let's proactively replace it by
if-else, which will let us move one if statement out without leaving
funny-looking left-overs.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If writing or committing the new index file fails, we print "Could not
write new index file." followed by "Could not reset index file to
revision $rev.". The first message seems to imply the second, so print
only the first message.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git reset --keep" calls reset_index_file() twice, first doing a
two-way merge to the target revision, updating the index and worktree,
and then resetting the index. After each call, we write the index
file.
In the unlikely event that the second call to reset_index_file()
fails, the index will have been merged to the target revision, but
HEAD will not be updated, leaving the user with a dirty index.
By moving the locking, writing and committing out of
reset_index_file() and into the caller, we can avoid writing the index
twice, thereby making the sure we don't end up in the half-way reset
state. As a bonus, we speed up "git reset --keep" a little on the
linux-2.6 repo (best of five, warm cache):
Before After
real 0m0.315s 0m0.296s
user 0m0.290s 0m0.280s
sys 0m0.020s 0m0.010s
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use a single condition to guard the call to die_if_unmerged_cache for
both --soft and --keep. This avoids the small distraction of the
precondition check from the logic following it.
Also change an instance of
if (e)
err = err || f();
to the almost as short, but clearer
if (e && !err)
err = f();
(which is equivalent since we only care whether exit code is 0)
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By extracting the code for updating the HEAD and ORIG_HEAD symbolic
references to a separate function, we declutter cmd_reset() a bit and
we make it clear that e.g. the four variables {,sha1_}{,old_}orig are
only used by this code.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Throughout most of parse_args(), the variable 'i' remains at 0. Many
references are still made to the variable even when it could only have
the value 0. This made at least me, who has relatively little
experience with C programming styles, think that parts of the function
was meant to be part of a loop. To avoid such confusion, remove the
variable and also the 'argc' parameter and check for NULL trailing
argv instead.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Declutter cmd_reset() a bit by moving out the argument parsing to its
own function.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running e.g. "git reset ." in a bare repo results in an index file
being created from the HEAD commit. The differences compared to the
index are then printed as usual, but since there is no worktree, it
will appear as if all files are deleted. For example, in a bare clone
of git.git:
Unstaged changes after reset:
D .gitattributes
D .gitignore
D .mailmap
...
This happens because the check for is_bare_repository() happens after
we branch off into read_from_tree() to reset with paths. Fix by moving
the branching point after the check.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use the path arguments in two places in reset.c: in
interactive_reset() and read_from_tree(). Both of these call
get_pathspec(), so we pass the (prefix, argv) pair to both
functions. Move the call to get_pathspec() out of these methods, for
two reasons: 1) One argument is simpler than two. 2) It lets us use
the (arguably clearer) "if (pathspec)" in place of "if (i < argc)".
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git reset $pathspec" currently exits with a non-zero exit code if the
worktree is dirty after resetting, which is inconsistent with reset
without pathspec, and it makes it harder to know whether the command
really failed. Change it to exit with code 0 regardless of whether the
worktree is dirty so that non-zero indicates an error.
This makes the 4 "disambiguation" test cases in t7102 clearer since
they all used to "fail", 3 of which "failed" due to changes in the
work tree. Now only the ambiguous one fails.
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 34110cd (Make 'unpack_trees()' have a separate source and
destination index, 2008-03-06), the index no longer gets clobbered by
do_diff_cache() and we can remove the code for discarding and
re-reading it.
There are two paths to update_index_refresh() from cmd_reset(), but on
both paths, either read_cache() or read_cache_unmerged() will have
been called, so the call to read_cache() in this method is redundant
(although practically free).
This speeds up "git reset -- ." a little on the linux-2.6 repo (best
of five, warm cache):
Before After
real 0m0.093s 0m0.080s
user 0m0.040s 0m0.020s
sys 0m0.050s 0m0.050s
Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create find_hook() function to determine if a given hook exists and is
executable. If it is, the path to the script will be returned,
otherwise NULL is returned.
This encapsulates the tests that are used to check for the existence of
a hook in one place, making it easier to modify those checks if that is
found to be necessary. This also makes it simple for places that can
use a hook to check if a hook exists before doing, possibly lengthy,
setup work which would be pointless if no such hook is present.
The returned value is left as a static value from get_pathname() rather
than a duplicate because it is anticipated that the return value will
either be used as a boolean, immediately added to an argv_array list
which would result in it being duplicated at that point, or used to
actually run the command without much intervening work. Callers which
need to hold onto the returned value for a longer time are expected to
duplicate the return value themselves.
Signed-off-by: Aaron Schrab <aaron@schrab.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
