The code that implements multi-strategy support in "git merge" has
been clean-up a bit.
* en/merge-multi-strategies:
merge: small code readability improvement
merge: cleanup confusing logic for handling successful merges
The auto-stashed local changes created by "git merge --autostash"
was mixed into a conflicted state left in the working tree, which
has been corrected.
* en/merge-unstash-only-on-clean-merge:
merge: only apply autostash when appropriate
After our loop through the selected strategies, we compare best_strategy
to wt_strategy. This is fine, but the fact that the code setting
best_strategy sets it to use_strategies[i]->name requires a little bit
of extra checking to determine that at the time of setting, that's the
same as wt_strategy. Just setting best_strategy to wt_strategy makes it
a little easier to verify what the loop is doing, at least for this
reader.
Further, use_strategies[i]->name is used in a number of places, where we
could just use wt_strategy. The latter takes less time for this reader
to parse (one variable name instead of three), so just use wt_strategy
to make the code slightly faster for human readers to parse.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/merge.c has a loop over the specified strategies, where if they
all fail with conflicts, it picks the one with the least number of
conflicts.
In the codepath that finds a successful merge, if an automatic commit
was wanted, the code breaks out of the above loop, which makes sense.
However, if the user requested there be no automatic commit, the loop
would continue. That seems weird; --no-commit should not affect the
choice of merge strategy, but the code as written makes one think it
does. However, since the loop itself embeds "!merge_was_ok" as a
condition on continuing to loop, it actually would also exit early if
--no-commit was specified, it just exited from a different location.
Restructure the code slightly to make it clear that the loop will
immediately exit whenever we find a merge strategy that is successful.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a merge failed and we are leaving conflicts in the working directory
for the user to resolve, we should not attempt to apply any autostash.
Further, if we fail to apply the autostash (because either the merge
failed, or the user requested --no-commit), then we should instruct the
user how to apply it later.
Add a testcase verifying we have corrected this behavior.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, if the user:
* Had no local changes before starting the merge
* A merge strategy makes changes to the working tree/index but returns
with exit status 2
Then we'd call restore_state() to clean up the changes and either let
the next merge strategy run (if there is one), or exit telling the user
that no merge strategy could handle the merge. Unfortunately,
restore_state() did not clean up the changes as expected; that function
was a no-op if the stash was a null, and the stash would be null if
there were no local changes before starting the merge. So, instead of
"Rewinding the tree to pristine..." as the code claimed, restore_state()
would leave garbage around in the index and working tree (possibly
including conflicts) for either the next merge strategy or for the user
after aborting the merge. And in the case of aborting the merge, the
user would be unable to run "git merge --abort" to get rid of the
unintended leftover conflicts, because the merge control files were not
written as it was presumed that we had restored to a clean state
already.
Fix the main problem by making sure that restore_state() only skips the
stash application if the stash is null rather than skipping the whole
function.
However, there is a secondary problem -- since merge.c forks
subprocesses to do the cleanup, the in-memory index is left out-of-sync.
While there was a refresh_cache(REFRESH_QUIET) call that attempted to
correct that, that function would not handle cases where the previous
merge strategy added conflicted entries. We need to drop the index and
re-read it to handle such cases.
(Alternatively, we could stop forking subprocesses and instead call some
appropriate function to do the work which would update the in-memory
index automatically. For now, just do the simple fix.)
Also, add a testcase checking this, one for which the octopus strategy
fails on the first commit it attempts to merge, and thus which it
cannot handle at all and must completely bail on (as per the "exit 2"
code path of commit 98efc8f3d8 ("octopus: allow manual resolve on the
last round.", 2006-01-13)).
Reported-by: ZheNing Hu <adlternative@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge strategies can:
* succeed with a clean merge
* succeed with a conflicted merge
* fail to handle the given type of merge
If one is thinking in terms of automatic mergeability, they would use
the word "fail" instead of "succeed" for the second bullet, but I am
focusing here on ability of the merge strategy to handle the given
inputs, not on whether the given inputs are mergeable. The third
category is about the merge strategy failing to know how to handle the
given data; examples include:
* Passing more than 2 branches to 'recursive' or 'ort'
* Passing 2 or fewer branches to 'octopus'
* Trying to do more complicated merges with 'resolve' (I believe
directory/file conflicts will cause it to bail.)
* Octopus running into a merge conflict for any branch OTHER than
the final one (see the "exit 2" codepath of commit 98efc8f3d8
("octopus: allow manual resolve on the last round.", 2006-01-13))
That final one is particularly interesting, because it shows that the
merge strategy can muck with the index and working tree, and THEN bail
and say "sorry, this strategy cannot handle this type of merge; use
something else".
Further, we do not currently expect the individual strategies to clean
up after themselves, but instead expect builtin/merge.c to do so. For
it to be able to, it needs to save the state before trying the merge
strategy so it can have something to restore to. Therefore, remove the
shortcut bypassing the save_state() call.
There is another bug on the restore_state() side of things, so no
testcase will be added until the next commit when we have addressed that
issue as well.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are multiple issues at play here:
1) If `git merge` is invoked with staged changes, it should abort
without doing any merging, and the user's working tree and index
should be the same as before merge was invoked.
2) Merge strategies are responsible for enforcing the index == HEAD
requirement. (See 9822175d2b ("Ensure index matches head before
invoking merge machinery, round N", 2019-08-17) for some history
around this.)
3) Merge strategies can bail saying they are not an appropriate
handler for the merge in question (possibly allowing other
strategies to be used instead).
4) Merge strategies can make changes to the index and working tree,
and have no expectation to clean up after themselves, *even* if
they bail out and say they are not an appropriate handler for
the merge in question. (The `octopus` merge strategy does this,
for example.)
5) Because of (3) and (4), builtin/merge.c stashes state before
trying merge strategies and restores it afterward.
Unfortunately, if users had staged changes before calling `git merge`,
builtin/merge.c could do the following:
* stash the changes, in order to clean up after the strategies
* try all the merge strategies in turn, each of which report they
cannot function due to the index not matching HEAD
* restore the changes via "git stash apply"
But that last step would have the net effect of unstaging the user's
changes. Fix this by adding the "--index" option to "git stash apply".
While at it, also squelch the stash apply output; we already report
"Rewinding the tree to pristine..." and don't need a detailed `git
status` report afterwards. Also while at it, switch to using strvec
so folks don't have to count the arguments to ensure we avoided an
off-by-one error, and so it's easier to add additional arguments to
the command.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there are stat-dirty files, but no files are modified,
`git stash create` exits with unsuccessful status. This causes merge
to fail. Copy some code from sequencer.c's create_autostash to refresh
the index first to avoid this problem.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/merge is setup to allow multiple strategies to be specified,
and it will find the "best" result and use it. This is defeated if
some of the merge strategies abort early when they cannot handle the
merge. Fix the logic that calls recursive and ort to not do such an
early abort, but instead return "2" or "unhandled" so that the next
strategy can try to handle the merge.
Coming up with a testcase for this is somewhat difficult, since
recursive and ort both handle nearly any two-headed merge (there is
a separate code path that checks for non-two-headed merges and
already returns "2" for them). So use a somewhat synthetic testcase
of having the index not match HEAD before the merge starts, since all
merge strategies will abort for that.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As noted in the last commit and the links therein (especially commit
9822175d2b ("Ensure index matches head before invoking merge machinery,
round N", 2019-08-17), we have had a very long history of problems with
failing to enforce the requirement that index matches HEAD when starting
a merge.
The "trivial merge" logic in builtin/merge.c is yet another such case
we previously missed. Add a check for it to ensure it aborts if the
index does not match HEAD, and add a testcase where this fix is needed.
Note that the fix here would also incidentally be an alternative fix
for the testcase added in the last patch, but the fix in the last patch
is still needed when multiple merge strategies are in use, so tweak the
testcase from the previous commit so that it continues to exercise the
codepath added in the last commit.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a coccinelle rule to remove "struct strbuf" initialization
followed by calling "strbuf_release()" function, without any uses of
the strbuf in the same function.
See the tests in contrib/coccinelle/tests/unused.{c,res} for what it's
intended to find and replace.
The inclusion of "contrib/scalar/scalar.c" is because "spatch" was
manually run on it (we don't usually run spatch on contrib).
Per the "buggy code" comment we also match a strbuf_init() before the
xmalloc(), but we're not seeking to be so strict as to make checks
that the compiler will catch for us redundant. Saying we'll match
either "init" or "xmalloc" lines makes the rule simpler.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a release_revisions() to various users of "struct rev_list" in
those straightforward cases where we only need to add the
release_revisions() call to the end of a block, and don't need to
e.g. refactor anything to use a "goto cleanup" pattern.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a Time-of-check to time-of-use (TOCTOU) race in code added in
680ee550d7 (commit: skip discarding the index if there is no
pre-commit hook, 2017-08-14).
This obscure race condition can occur if we e.g. ran the "pre-commit"
hook and it modified the index, but hook_exists() returns false later
on (e.g., because the hook itself went away, the directory became
unreadable, etc.). Then we won't call discard_cache() when we should
have.
The race condition itself probably doesn't matter, and users would
have been unlikely to run into it in practice. This problem has been
noted on-list when 680ee550d7 was discussed[1], but had not been
fixed.
This change is mainly intended to improve the readability of the code
involved, and to make reasoning about it more straightforward. It
wasn't as obvious what we were trying to do here, but by having an
"invoked_hook" it's clearer that e.g. our discard_cache() is happening
because of the earlier hook execution.
Let's also change this for the push-to-checkout hook. Now instead of
checking if the hook exists and either doing a push to checkout or a
push to deploy we'll always attempt a push to checkout. If the hook
doesn't exist we'll fall back on push to deploy. The same behavior as
before, without the TOCTOU race. See 0855331941 (receive-pack:
support push-to-checkout hook, 2014-12-01) for the introduction of the
previous behavior.
This leaves uses of hook_exists() in two places that matter. The
"reference-transaction" check in refs.c, see 6754159767 (refs:
implement reference transaction hook, 2020-06-19), and the
"prepare-commit-msg" hook, see 66618a50f9 (sequencer: run
'prepare-commit-msg' hook, 2018-01-24).
In both of those cases we're saving ourselves CPU time by not
preparing data for the hook that we'll then do nothing with if we
don't have the hook. So using this "invoked_hook" pattern doesn't make
sense in those cases.
The "reference-transaction" and "prepare-commit-msg" hook also aren't
racy. In those cases we'll skip the hook runs if we race with a new
hook being added, whereas in the TOCTOU races being fixed here we were
incorrectly skipping the required post-hook logic.
1. https://lore.kernel.org/git/20170810191613.kpmhzg4seyxy3cpq@sigill.intra.peff.net/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a minor bug introduced in bc40ce4de6 (merge: --no-verify to
bypass pre-merge-commit hook, 2019-08-07), when that change made the
--no-verify option bypass the "pre-merge-commit" hook it didn't update
the corresponding find_hook() (later hook_exists()) condition.
As can be seen in the preceding commit in 6098817fd7 (git-merge:
honor pre-merge-commit hook, 2019-08-07) the two should go hand in
hand. There's no point in invoking discard_cache() here if the hook
couldn't have possibly updated the index.
It's buggy that we use "hook_exist()" here, and as discussed in the
subsequent commit it's subject to obscure race conditions that we're
about to fix, but for now this change is a strict improvement that
retains any caveats to do with the use of "hooks_exist()" as-is.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use an internal call to reset_head() helper function instead of
spawning "git checkout" in "rebase", and update code paths that are
involved in the change.
* pw/use-in-process-checkout-in-rebase:
rebase -m: don't fork git checkout
rebase --apply: set ORIG_HEAD correctly
rebase --apply: fix reflog
reset_head(): take struct rebase_head_opts
rebase: cleanup reset_head() calls
create_autostash(): remove unneeded parameter
reset_head(): make default_reflog_action optional
reset_head(): factor out ref updates
reset_head(): remove action parameter
rebase --apply: don't run post-checkout hook if there is an error
rebase: do not remove untracked files on checkout
rebase: pass correct arguments to post-checkout hook
t5403: refactor rebase post-checkout hook tests
rebase: factor out checkout for up to date branch
More "config-based hooks".
* ab/config-based-hooks-2:
run-command: remove old run_hook_{le,ve}() hook API
receive-pack: convert push-to-checkout hook to hook.h
read-cache: convert post-index-change to use hook.h
commit: convert {pre-commit,prepare-commit-msg} hook to hook.h
git-p4: use 'git hook' to run hooks
send-email: use 'git hook run' for 'sendemail-validate'
git hook run: add an --ignore-missing flag
hooks: convert worktree 'post-checkout' hook to hook library
hooks: convert non-worktree 'post-checkout' hook to hook library
merge: convert post-merge to use hook.h
am: convert applypatch-msg to use hook.h
rebase: convert pre-rebase to use hook.h
hook API: add a run_hooks_l() wrapper
am: convert {pre,post}-applypatch to use hook.h
gc: use hook library for pre-auto-gc hook
hook API: add a run_hooks() wrapper
hook: add 'run' subcommand
The default_reflog parameter of create_autostash() is passed to
reset_head(). However as creating a stash does not involve updating
any refs the parameter is not used by reset_head(). Removing the
parameter from create_autostash() simplifies the callers.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There were two commit_lists created in cmd_merge() that were only
conditionally free()'d. Add a quick conditional call to
free_commit_list() for each of them at the end of the function.
Testing this commit against t6404 under valgrind shows that this patch
fixes the following two leaks:
16 bytes in 1 blocks are definitely lost in loss record 16 of 126
at 0x484086F: malloc (vg_replace_malloc.c:380)
by 0x69FFEB: do_xmalloc (wrapper.c:41)
by 0x6A0073: xmalloc (wrapper.c:62)
by 0x52A72D: commit_list_insert (commit.c:556)
by 0x47FC93: reduce_parents (merge.c:1114)
by 0x4801EE: collect_parents (merge.c:1214)
by 0x480B56: cmd_merge (merge.c:1465)
by 0x40686E: run_builtin (git.c:464)
by 0x406C51: handle_builtin (git.c:716)
by 0x406E96: run_argv (git.c:783)
by 0x40730A: cmd_main (git.c:914)
by 0x4E7DFA: main (common-main.c:56)
8 (16 direct, 32 indirect) bytes in 1 blocks are definitely lost in \
loss record 61 of 126
at 0x484086F: malloc (vg_replace_malloc.c:380)
by 0x69FFEB: do_xmalloc (wrapper.c:41)
by 0x6A0073: xmalloc (wrapper.c:62)
by 0x52A72D: commit_list_insert (commit.c:556)
by 0x52A8F2: commit_list_insert_by_date (commit.c:620)
by 0x5270AC: get_merge_bases_many_0 (commit-reach.c:413)
by 0x52716C: repo_get_merge_bases (commit-reach.c:438)
by 0x480E5A: cmd_merge (merge.c:1520)
by 0x40686E: run_builtin (git.c:464)
by 0x406C51: handle_builtin (git.c:716)
by 0x406E96: run_argv (git.c:783)
by 0x40730A: cmd_main (git.c:914)
There are still 3 leaks in chdir_notify_register() after this, but
chdir_notify_register() has been brought up on the list before and folks
were not a fan of fixing those, so I'm not touching them.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Similar message templates have been consolidated so that
translators need to work on fewer number of messages.
* ja/i18n-similar-messages:
i18n: turn even more messages into "cannot be used together" ones
i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
i18n: factorize "--foo outside a repository"
i18n: refactor "unrecognized %(foo) argument" strings
i18n: factorize "no directory given for --foo"
i18n: factorize "--foo requires --bar" and the like
i18n: tag.c factorize i18n strings
i18n: standardize "cannot open" and "cannot read"
i18n: turn "options are incompatible" into "cannot be used together"
i18n: refactor "%s, %s and %s are mutually exclusive"
i18n: refactor "foo and bar are mutually exclusive"
Teach post-merge to use the hook.h library instead of the
run-command.h library to run hooks.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The default merge message prepared by "git merge" records the name
of the current branch; the name can be overridden with a new option
to allow users to pretend a merge is made on a different branch.
* jc/merge-detached-head-name:
merge: allow to pretend a merge is made into a different branch
When a series of patches for a topic-B depends on having topic-A,
the workflow to prepare the topic-B branch would look like this:
$ git checkout -b topic-B main
$ git merge --no-ff --no-edit topic-A
$ git am <mbox-for-topic-B
When topic-A gets updated, recreating the first merge and rebasing
the rest of the topic-B, all on detached HEAD, is a useful
technique. After updating topic-A with its new round of patches:
$ git checkout topic-B
$ prev=$(git rev-parse 'HEAD^{/^Merge branch .topic-A. into}')
$ git checkout --detach $prev^1
$ git merge --no-ff --no-edit topic-A
$ git rebase --onto HEAD $prev @{-1}^0
$ git checkout -B @{-1}
This will
(0) check out the current topic-B.
(1) find the previous merge of topic-A into topic-B.
(2) detach the HEAD to the parent of the previous merge.
(3) merge the updated topic-A to it.
(4) reapply the patches to rebuild the rest of topic-B.
(5) update topic-B with the result.
without contaminating the reflog of topic-B too much. topic-B@{1}
is the "logically previous" state before topic-A got updated, for
example. At (4), comparison (e.g. range-diff) between HEAD and
@{-1} is a meaningful way to sanity check the result, and the same
can be done at (5) by comparing topic-B and topic-B@{1}.
But there is one glitch. The merge into the detached HEAD done in
the step (3) above gives us "Merge branch 'topic-A' into HEAD", and
does not say "into topic-B".
Teach the "--into-name=<branch>" option to "git merge" and its
underlying "git fmt-merge-message", to pretend as if we were merging
into <branch>, no matter what branch we are actually merging into,
when they prepare the merge message. The pretend name honors the
usual "into <target>" suppression mechanism, which can be seen in
the tests added here.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_pushl()" to add data to the "args" member.
This implements the same behavior as before in fewer lines of code,
and moves us further towards being able to remove the "argv" member in
a subsequent commit.
Since we've entirely removed the "argv" variable(s) we can be sure
that no potential logic errors of the type discussed in a preceding
commit are being introduced here, i.e. ones where the local "argv" was
being modified after the assignment to "struct child_process"'s
"argv".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Bunch of tests are marked as "passing leak check".
* ab/mark-leak-free-tests-more:
merge: add missing strbuf_release()
ls-files: add missing string_list_clear()
ls-files: fix a trivial dir_clear() leak
tests: fix test-oid-array leak, test in SANITIZE=leak
tests: fix a memory leak in test-oidtree.c
tests: fix a memory leak in test-parse-options.c
tests: fix a memory leak in test-prio-queue.c
Mostly preliminary clean-up in the hook API.
* ab/config-based-hooks-1:
hook-list.h: add a generated list of hooks, like config-list.h
hook.c users: use "hook_exists()" instead of "find_hook()"
hook.c: add a hook_exists() wrapper and use it in bugreport.c
hook.[ch]: move find_hook() from run-command.c to hook.c
Makefile: remove an out-of-date comment
Makefile: don't perform "mv $@+ $@" dance for $(GENERATED_H)
Makefile: stop hardcoding {command,config}-list.h
Makefile: mark "check" target as .PHONY
Various fixes in code paths that move untracked files away to make room.
* en/removing-untracked-fixes:
Documentation: call out commands that nuke untracked files/directories
Comment important codepaths regarding nuking untracked files/dirs
unpack-trees: avoid nuking untracked dir in way of locally deleted file
unpack-trees: avoid nuking untracked dir in way of unmerged file
Change unpack_trees' 'reset' flag into an enum
Remove ignored files by default when they are in the way
unpack-trees: make dir an internal-only struct
unpack-trees: introduce preserve_ignored to unpack_trees_options
read-tree, merge-recursive: overwrite ignored files by default
checkout, read-tree: fix leak of unpack_trees_options.dir
t2500: add various tests for nuking untracked files
We strbuf_reset() this "struct strbuf" in a loop earlier, but never
freed it. Plugs a memory leak that's been here ever since this code
got introduced in 1c7b76be7d (Build in merge, 2008-07-07).
This takes us from 68 failed tests in "t7600-merge.sh" to 59 under
SANITIZE=leak, and makes "t7604-merge-custom-message.sh" pass!
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change several commands to remove ignored files by default when they are
in the way. Since some commands (checkout, merge) take a
--no-overwrite-ignore option to allow the user to configure this, and it
may make sense to add that option to more commands (and in the case of
merge, actually plumb that configuration option through to more of the
backends than just the fast-forwarding special case), add little
comments about where such flags would be used.
Incidentally, this fixes a test failure in t7112.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, every caller of unpack_trees() that wants to ensure ignored
files are overwritten by default needs to:
* allocate unpack_trees_options.dir
* flip the DIR_SHOW_IGNORED flag in unpack_trees_options.dir->flags
* call setup_standard_excludes
AND then after the call to unpack_trees() needs to
* call dir_clear()
* deallocate unpack_trees_options.dir
That's a fair amount of boilerplate, and every caller uses identical
code. Make this easier by instead introducing a new boolean value where
the default value (0) does what we want so that new callers of
unpack_trees() automatically get the appropriate behavior. And move all
the handling of unpack_trees_options.dir into unpack_trees() itself.
While preserve_ignored = 0 is the behavior we feel is the appropriate
default, we defer fixing commands to use the appropriate default until a
later commit. So, this commit introduces several locations where we
manually set preserve_ignored=1. This makes it clear where code paths
were previously preserving ignored files when they should not have been;
a future commit will flip these to instead use a value of 0 to get the
behavior we want.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the new hook_exists() function instead of find_hook() where the
latter was called in boolean contexts. This make subsequent changes in
a series where we further refactor the hook API clearer, as we won't
conflate wanting to get the path of the hook with checking for its
existence.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the find_hook() function from run-command.c to a new hook.c
library. This change establishes a stub library that's pretty
pointless right now, but will see much wider use with Emily Shaffer's
upcoming "configuration-based hooks" series.
Eventually all the hook related code will live in hook.[ch]. Let's
start that process by moving the simple find_hook() function over
as-is.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The run-command API has been updated so that the callers can easily
ask the file descriptors open for packfiles to be closed immediately
before spawning commands that may trigger auto-gc.
* js/run-command-close-packs:
Close object store closer to spawning child processes
run_auto_maintenance(): implicitly close the object store
run-command: offer to close the object store before running
run-command: prettify the `RUN_COMMAND_*` flags
pull: release packs before fetching
commit-graph: when closing the graph, also release the slab
Various mergy operations have been prepared to work efficiently
with the sparse index.
* ds/mergies-with-sparse-index:
sparse-index: integrate with cherry-pick and rebase
sequencer: ensure full index if not ORT strategy
t1092: add cherry-pick, rebase tests
merge-ort: expand only for out-of-cone conflicts
merge: make sparse-aware with ORT
diff: ignore sparse paths in diffstat
Code clean up to migrate callers from older advice_config[] based
API to newer advice_if_enabled() and advice_enabled() API.
* ab/retire-advice-config:
advice: move advice.graftFileDeprecated squashing to commit.[ch]
advice: remove use of global advice_add_embedded_repo
advice: remove read uses of most global `advice_` variables
advice: add enum variants for missing advice variables
Allow 'git merge' to operate without expanding a sparse index, at least
not immediately. The index still will be expanded in a few cases:
1. If the merge strategy is 'recursive', then we enable
command_requires_full_index at the start of the merge_recursive()
method. We expect sparse-index users to also have the 'ort' strategy
enabled.
2. With the 'ort' strategy, if the merge results in a conflicted file,
then we expand the index before updating the working tree. The loop
that iterates over the worktree replaces index entries and tracks
'origintal_cache_nr' which can become completely wrong if the index
expands in the middle of the operation. This safety valve is
important before that loop starts. A later change will focus this
to only expand if we indeed have a conflict outside of the
sparse-checkout cone.
3. Other merge strategies are executed as a 'git merge-X' subcommand,
and those strategies are currently protected with the
'command_requires_full_index' guard.
Some test updates are required, including a mistaken 'git checkout -b'
that did not specify the base branch, causing merges to be fast-forward
merges.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before spawning the auto maintenance, we need to make sure that we
release all open file handles to all the `.pack` files (and MIDX files
and commit-graph files and...) so that the maintenance process has the
freedom to delete those files.
So far, we did this manually every time before calling
`run_auto_maintenance()`. With the new `close_object_store` flag, we can
do that implicitly in that function, which is more robust because future
callers won't be able to forget to close the object store.
Note: this changes behavior slightly, as we previously _always_ closed
the object store, but now we only close the object store when actually
running the auto maintenance. In practice, this should not matter (if
anything, it might speed up operations where auto maintenance is
disabled).
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use `ort` instead of `recursive` as the default merge strategy.
* en/ort-becomes-the-default:
Update docs for change of default merge backend
Change default merge backend from recursive to ort
Documentation updates.
* en/merge-strategy-docs:
Update error message and code comment
merge-strategies.txt: add coverage of the `ort` merge strategy
git-rebase.txt: correct out-of-date and misleading text about renames
merge-strategies.txt: fix simple capitalization error
merge-strategies.txt: avoid giving special preference to patience algorithm
merge-strategies.txt: do not imply using copy detection is desired
merge-strategies.txt: update wording for the resolve strategy
Documentation: edit awkward references to `git merge-recursive`
directory-rename-detection.txt: small updates due to merge-ort optimizations
git-rebase.txt: correct antiquated claims about --rebase-merges
"git pull" had various corner cases that were not well thought out
around its --rebase backend, e.g. "git pull --ff-only" did not stop
but went ahead and rebased when the history on other side is not a
descendant of our history. The series tries to fix them up.
* en/pull-conflicting-options:
pull: fix handling of multiple heads
pull: update docs & code for option compatibility with rebasing
pull: abort by default when fast-forwarding is not possible
pull: make --rebase and --no-rebase override pull.ff=only
pull: since --ff-only overrides, handle it first
pull: abort if --ff-only is given and fast-forwarding is impossible
t7601: add tests of interactions with multiple merge heads and config
t7601: test interaction of merge/rebase/fast-forward flags and options
Add and apply a semantic patch for using xopen() instead of calling
open(2) and die() or die_errno() explicitly. This makes the error
messages more consistent and shortens the code.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In c4a09cc9cc (Merge branch 'hw/advise-ng', 2020-03-25), a new API for
accessing advice variables was introduced and deprecated `advice_config`
in favor of a new array, `advice_setting`.
This patch ports all but two uses which read the status of the global
`advice_` variables over to the new `advice_enabled` API. We'll deal
with advice_add_embedded_repo and advice_graft_file_deprecated
separately.
Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
d540b70c85 (merge: cleanup messages like commit, 2019-04-17) adds
a way to change part of the helper text using a single call to
strbuf_add_commented_addf but with two formats with varying number
of parameters.
this trigger a warning in old versions of Xcode (ex 8.0), so use
instead two independent calls with a matching number of parameters
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few reasons to switch the default:
* Correctness
* Extensibility
* Performance
I'll provide some summaries about each.
=== Correctness ===
The original impetus for a new merge backend was to fix issues that were
difficult to fix within recursive's design. The success with this goal
is perhaps most easily demonstrated by running the following:
$ git grep -2 KNOWN_FAILURE t/ | grep -A 4 GIT_TEST_MERGE_ALGORITHM
$ git grep test_expect_merge_algorithm.failure.success t/
$ git grep test_expect_merge_algorithm.success.failure t/
In order, these greps show:
* Seven sets of submodule tests (10 total tests) that fail with
recursive but succeed with ort
* 22 other tests that fail with recursive, but succeed with ort
* 0 tests that pass with recursive, but fail with ort
=== Extensibility ===
Being able to perform merges without touching the working tree or index
makes it possible to create new features that were difficult with the
old backend:
* Merging, cherry-picking, rebasing, reverting in bare repositories...
or just on branches that aren't checked out.
* `git diff AUTO_MERGE` -- ability to see what changes the user has
made to resolve conflicts so far (see commit 5291828df8 ("merge-ort:
write $GIT_DIR/AUTO_MERGE whenever we hit a conflict", 2021-03-20)
* A --remerge-diff option for log/show, used to show diffs for merges
that display the difference between what an automatic merge would
have created and what was recorded in the merge. (This option will
often result in an empty diff because many merges are clean, but for
the non-clean ones it will show how conflicts were fixed including
the removal of conflict markers, and also show additional changes
made outside of conflict regions to e.g. fix semantic conflicts.)
* A --remerge-diff-only option for log/show, similar to --remerge-diff
but also showing how cherry-picks or reverts differed from what an
automatic cherry-pick or revert would provide.
The last three have been implemented already (though only one has been
submitted upstream so far; the others were waiting for performance work
to complete), and I still plan to implement the first one.
=== Performance ===
I'll quote from the summary of my final optimization for merge-ort
(while fixing the testcase name from 'no-renames' to 'few-renames'):
Timings
Infinite
merge- merge- Parallelism
recursive recursive of rename merge-ort
v2.30.0 current detection current
---------- --------- ----------- ---------
few-renames: 18.912 s 18.030 s 11.699 s 198.3 ms
mega-renames: 5964.031 s 361.281 s 203.886 s 661.8 ms
just-one-mega: 149.583 s 11.009 s 7.553 s 264.6 ms
Speedup factors
Infinite
merge- merge- Parallelism
recursive recursive of rename
v2.30.0 current detection merge-ort
---------- --------- ----------- ---------
few-renames: 1 1.05 1.6 95
mega-renames: 1 16.5 29 9012
just-one-mega: 1 13.6 20 565
And, for partial clone users:
Factor reduction in number of objects needed
Infinite
merge- merge- Parallelism
recursive recursive of rename
v2.30.0 current detection merge-ort
---------- --------- ----------- ---------
mega-renames: 1 1 1 181.3
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There were two locations in the code that referred to 'merge-recursive'
but which were also applicable to 'merge-ort'. Update them to more
general wording.
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The local changes stashed by "git merge --autostash" were lost when
the merge failed in certain ways, which has been corrected.
* pb/merge-autostash-more:
merge: apply autostash if merge strategy fails
merge: apply autostash if fast-forward fails
Documentation: define 'MERGE_AUTOSTASH'
merge: add missing word "strategy" to a message
