When the current branch is renamed with 'git branch -m/-M' or deleted
with 'git update-ref -m<msg> -d', the event is recorded in HEAD's log
with an empty message. In preparation for adding a more meaningful
message to HEAD's log in these cases, update delete_ref() to take a
message argument and pass it along to ref_transaction_delete().
Modify all callers to pass NULL for the new message argument; no
change in behavior is intended.
Note that this is relevant for HEAD's log but not for the deleted
ref's log, which is currently deleted along with the ref. Even if it
were not, an entry for the deletion wouldn't be present in the deleted
ref's log. files_transaction_commit() writes to the log if
REF_NEEDS_COMMIT or REF_LOG_ONLY are set, but lock_ref_for_update()
doesn't set REF_NEEDS_COMMIT for the deleted ref because REF_DELETING
is set. In contrast, the update for HEAD has REF_LOG_ONLY set by
split_head_update(), resulting in the deletion being logged.
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Unlike "git am --abort", "git cherry-pick --abort" moved HEAD back
to where cherry-pick started while picking multiple changes, when
the cherry-pick stopped to ask for help from the user, and the user
did "git reset --hard" to a different commit in order to re-attempt
the operation.
* sb/sequencer-abort-safety:
Revert "sequencer: remove useless get_dir() function"
sequencer: remove useless get_dir() function
sequencer: make sequencer abort safer
t3510: test that cherry-pick --abort does not unsafely change HEAD
am: change safe_to_abort()'s not rewinding error into a warning
am: fix filename in safe_to_abort() error message
The error message tells the user that something went terribly wrong
and the --abort could not be performed. But the --abort is performed,
only without rewinding. By simply changing the error into a warning,
we indicate the user that she must not try something like
"git am --abort --force", instead she just has to check the HEAD.
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Callers of the hold_locked_index() function pass 0 when they want to
prepare to write a new version of the index file without wishing to
die or emit an error message when the request fails (e.g. somebody
else already held the lock), and pass 1 when they want the call to
die upon failure.
This option is called LOCK_DIE_ON_ERROR by the underlying lockfile
API, and the hold_locked_index() function translates the paramter to
LOCK_DIE_ON_ERROR when calling the hold_lock_file_for_update().
Replace these hardcoded '1' with LOCK_DIE_ON_ERROR and stop
translating. Callers other than the ones that are replaced with
this change pass '0' to the function; no behaviour change is
intended with this patch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Among the callers of hold_locked_index() that passes 0:
- diff.c::refresh_index_quietly() at the end of "git diff" is an
opportunistic update; it leaks the lockfile structure but it is
just before the program exits and nobody should care.
- builtin/describe.c::cmd_describe(),
builtin/commit.c::cmd_status(),
sequencer.c::read_and_refresh_cache() are all opportunistic
updates and they are OK.
- builtin/update-index.c::cmd_update_index() takes a lock upfront
but we may end up not needing to update the index (i.e. the
entries may be fully up-to-date), in which case we do not need to
issue an error upon failure to acquire the lock. We do diagnose
and die if we indeed need to update, so it is OK.
- wt-status.c::require_clean_work_tree() IS BUGGY. It asks
silence, does not check the returned value. Compare with
callsites like cmd_describe() and cmd_status() to notice that it
is wrong to call update_index_if_able() unconditionally.
The "unsigned char sha1[20]" to "struct object_id" conversion
continues. Notable changes in this round includes that ce->sha1,
i.e. the object name recorded in the cache_entry, turns into an
object_id.
It had merge conflicts with a few topics in flight (Christian's
"apply.c split", Dscho's "cat-file --filters" and Jeff Hostetler's
"status --porcelain-v2"). Extra sets of eyes double-checking for
mismerges are highly appreciated.
* bc/object-id:
builtin/reset: convert to use struct object_id
builtin/commit-tree: convert to struct object_id
builtin/am: convert to struct object_id
refs: add an update_ref_oid function.
sha1_name: convert get_sha1_mb to struct object_id
builtin/update-index: convert file to struct object_id
notes: convert init_notes to use struct object_id
builtin/rm: convert to use struct object_id
builtin/blame: convert file to use struct object_id
Convert read_mmblob to take struct object_id.
notes-merge: convert struct notes_merge_pair to struct object_id
builtin/checkout: convert some static functions to struct object_id
streaming: make stream_blob_to_fd take struct object_id
builtin: convert textconv_object to use struct object_id
builtin/cat-file: convert some static functions to struct object_id
builtin/cat-file: convert struct expand_data to use struct object_id
builtin/log: convert some static functions to use struct object_id
builtin/blame: convert struct origin to use struct object_id
builtin/apply: convert static functions to struct object_id
cache: convert struct cache_entry to use struct object_id
"git am" has been taught to make an internal call to "git apply"'s
innards without spawning the latter as a separate process.
* cc/apply-am: (41 commits)
builtin/am: use apply API in run_apply()
apply: learn to use a different index file
apply: pass apply state to build_fake_ancestor()
apply: refactor `git apply` option parsing
apply: change error_routine when silent
usage: add get_error_routine() and get_warn_routine()
usage: add set_warn_routine()
apply: don't print on stdout in verbosity_silent mode
apply: make it possible to silently apply
apply: use error_errno() where possible
apply: make some parsing functions static again
apply: move libified code from builtin/apply.c to apply.{c,h}
apply: rename and move opt constants to apply.h
builtin/apply: rename option parsing functions
builtin/apply: make create_one_file() return -1 on error
builtin/apply: make try_create_file() return -1 on error
builtin/apply: make write_out_results() return -1 on error
builtin/apply: make write_out_one_result() return -1 on error
builtin/apply: make create_file() return -1 on error
builtin/apply: make add_index_file() return -1 on error
...
Message cleanup.
* ah/misc-message-fixes:
unpack-trees: do not capitalize "working"
git-merge-octopus: do not capitalize "octopus"
git-rebase--interactive: fix English grammar
cat-file: put spaces around pipes in usage string
am: put spaces around pipe in usage string
This makes the style a little more consistent with other usage strings,
and will resolve a warning at
https://www.softcatala.org/recursos/quality/git.html
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert uses of unsigned char [20] to struct object_id. Rename the
generically-named "ptr" to "old_oid" and make it const.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This replaces run_apply() implementation with a new one that
uses the apply API that has been previously prepared in
apply.c and apply.h.
This shoud improve performance a lot in certain cases.
As the previous implementation was creating a new `git apply`
process to apply each patch, it could be slow on systems like
Windows where it is costly to create new processes.
Also the new `git apply` process had to read the index from
disk, and when the process was done the calling process
discarded its own index and read back from disk the new
index that had been created by the `git apply` process.
This could be very inefficient with big repositories that
have big index files, especially when the system decided
that it was a good idea to run the `git apply` processes on
a different processor core.
Also eliminating index reads enables further performance
improvements by using:
`git update-index --split-index`
For example here is a benchmark of a multi hundred commit
rebase on the Linux kernel on a Debian laptop with SSD:
command: git rebase --onto 1993b17 52bef0c 29dde7c
Vanilla "next" without split index: 1m54.953s
Vanilla "next" with split index: 1m22.476s
This series on top of "next" without split index: 1m12.034s
This series on top of "next" with split index: 0m15.678s
(using branch "next" from mid April 2016.)
Benchmarked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By splitting the part that reads from a file and the part that
parses the variable definitions from the contents, make the latter
can be more reusable in the future.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git am -3" calls "git merge-recursive" when it needs to fall back
to a three-way merge; this call has been turned into an internal
subroutine call instead of spawning a separate subprocess.
* js/am-3-merge-recursive-direct:
merge-recursive: flush output buffer even when erroring out
merge_trees(): ensure that the callers release output buffer
merge-recursive: offer an option to retain the output in 'obuf'
merge-recursive: write the commit title in one go
merge-recursive: flush output buffer before printing error messages
am -3: use merge_recursive() directly again
merge-recursive: switch to returning errors instead of dying
merge-recursive: handle return values indicating errors
merge-recursive: allow write_tree_from_memory() to error out
merge-recursive: avoid returning a wholesale struct
merge_recursive: abort properly upon errors
prepare the builtins for a libified merge_recursive()
merge-recursive: clarify code in was_tracked()
die(_("BUG")): avoid translating bug messages
die("bug"): report bugs consistently
t5520: verify that `pull --rebase` shows the helpful advice when failing
Not-so-recent rewrite of "git am" that started making internal
calls into the commit machinery had an unintended regression, in
that no matter how many seconds it took to apply many patches, the
resulting committer timestamp for the resulting commits were all
the same.
* jk/reset-ident-time-per-commit:
am: reset cached ident date for each patch
When we compute the date to go in author/committer lines of
commits, or tagger lines of tags, we get the current date
once and then cache it for the rest of the program. This is
a good thing in some cases, like "git commit", because it
means we do not racily assign different times to the
author/committer fields of a single commit object.
But as more programs start to make many commits in a single
process (e.g., the recently builtin "git am"), it means that
you'll get long strings of commits with identical committer
timestamps (whereas before, we invoked "git commit" many
times and got true timestamps).
This patch addresses it by letting callers reset the cached
time, which means they'll get a fresh time on their next
call to git_committer_info() or git_author_info(). The first
caller to do so is "git am", which resets the time for each
patch it applies.
It would be nice if we could just do this automatically
before filling in the ident fields of commit and tag
objects. Unfortunately, it's hard to know where a particular
logical operation begins and ends.
For instance, if commit_tree_extended() were to call
reset_ident_date() before getting the committer/author
ident, that doesn't quite work; sometimes the author info is
passed in to us as a parameter, and it may or may not have
come from a previous call to ident_default_date(). So in
those cases, we lose the property that the committer and the
author timestamp always match.
You could similarly put a date-reset at the end of
commit_tree_extended(). That actually works in the current
code base, but it's fragile. It makes the assumption that
after commit_tree_extended() finishes, the caller has no
other operations that would logically want to fall into the
same timestamp.
So instead we provide the tool to easily do the reset, and
let the high-level callers use it to annotate their own
logical operations.
There's no automated test, because it would be inherently
racy (it depends on whether the program takes multiple
seconds to run). But you can see the effect with something
like:
# make a fake 100-patch series
top=$(git rev-parse HEAD)
bottom=$(git rev-list --first-parent -100 HEAD | tail -n 1)
git log --format=email --reverse --first-parent \
--binary -m -p $bottom..$top >patch
# now apply it; this presumably takes multiple seconds
git checkout --detach $bottom
git am <patch
# now count the number of distinct committer times;
# prior to this patch, there would only be one, but
# now we'd typically see several.
git log --format=%ct $bottom.. | sort -u
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Helped-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Last October, we had to change this code to run `git merge-recursive`
in a child process: git-am wants to print some helpful advice when the
merge failed, but the code in question was not prepared to return, it
die()d instead.
We are finally at a point when the code *is* prepared to return errors,
and can avoid the child process again.
This reverts commit c63d4b2 (am -3: do not let failed merge from
completing the error codepath, 2015-10-09), with the necessary changes
to adjust for the fact that Git's source code changed in the meantime
(such as: using OIDs instead of hashes in the recursive merge, and a
removed gender bias).
Note: the code now calls merge_recursive_generic() again. Unlike
merge_trees() and merge_recursive(), this function returns 0 upon success,
as most of Git's functions. Therefore, the error value -1 naturally is
handled correctly, and we do not have to take care of it specifically.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One part of "git am" had an oddball helper function that called
stuff from outside "his" as opposed to calling what we have "ours",
which was not gender-neutral and also inconsistent with the rest of
the system where outside stuff is usuall called "theirs" in
contrast to "ours".
* js/am-call-theirs-theirs-in-fallback-3way:
am: counteract gender bias
General code clean-up around a helper function to write a
single-liner to a file.
* jk/write-file:
branch: use write_file_buf instead of write_file
use write_file_buf where applicable
write_file: add format attribute
write_file: add pointer+len variant
write_file: use xopen
write_file: drop "gently" form
branch: use non-gentle write_file for branch description
am: ignore return value of write_file()
config: fix bogus fd check when setting up default config
Since 47f0b6d5 (Fall back to three-way merge when applying a patch.,
2005-10-06), i.e. for almost 11 years already, we used a male form
to describe "the other tree".
While it was unintended, this gave the erroneous impression as if
the Git developers thought of users as male, and were unaware of the
important role in software development played by female actors such
as Ada Lovelace, Grace Hopper and Margaret Hamilton. In fact, the
first professional software developers were all female.
Let's change those unfortunate references to the gender neutral
"their tree". Doing so also makes the fallback_merge_recursive(),
which is an oddball, more in line with the other parts of the system
where we contrast what we have vs what we obtain from others by
saying "ours" vs "theirs". This inconsistency was also unintended.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are several places where we open a file, write some
content from a strbuf, and close it. These can be simplified
with write_file_buf(). As a bonus, many of these did not
catch write problems at close() time.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
write_file() either returns 0 or dies, so there is no point in checking
its return value. The callers of the wrappers write_state_text(),
write_state_count() and write_state_bool() consequently already ignore
their return values. Stop pretending we care and make them void.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Combined with "git format-patch --pretty=mboxrd", this should
allow us to round-trip commit messages with embedded mbox
"From " lines without corruption.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "v(iew)" subcommand of the interactive "git am -i" command was
broken in 2.6.0 timeframe when the command was rewritten in C.
* jc/am-i-v-fix:
am -i: fix "v"iew
pager: factor out a helper to prepare a child process to run the pager
pager: lose a separate argv[]
The 'v'iew subcommand of the interactive mode of "git am -i" was
broken by the rewrite to C we did at around 2.6.0 timeframe at
7ff26832 (builtin-am: implement -i/--interactive, 2015-08-04); we
used to spawn the pager via the shell, accepting things like
PAGER='less -S'
in the environment, but the rewrite forgot and tried to directly
spawn a command whose name is the entire string.
The previous refactoring of the new helper function makes it easier
for us to do the right thing.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A few options of "git diff" did not work well when the command was
run from a subdirectory.
* nd/diff-with-path-params:
diff: make -O and --output work in subdirectory
diff-no-index: do not take a redundant prefix argument
The preliminary clean-up for jc/peace-with-crlf topic.
* jc/strbuf-getline:
strbuf: give strbuf_getline() to the "most text friendly" variant
checkout-index: there are only two possible line terminations
update-index: there are only two possible line terminations
check-ignore: there are only two possible line terminations
check-attr: there are only two possible line terminations
mktree: there are only two possible line terminations
strbuf: introduce strbuf_getline_{lf,nul}()
strbuf: make strbuf_getline_crlf() global
strbuf: miniscule style fix
Now there is no direct caller to strbuf_getline(), we can demote it
to file-scope static that is private to strbuf.c and rename it to
strbuf_getdelim(). Rename strbuf_getline_crlf(), which is designed
to be the most "text friendly" variant, and allow it to take over
this simplest name, strbuf_getline(), so we can add more uses of it
without having to type _crlf over and over again in the coming
steps.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The strbuf_getline() interface allows a byte other than LF or NUL as
the line terminator, but this is only because I wrote these
codepaths anticipating that there might be a value other than NUL
and LF that could be useful when I introduced line_termination long
time ago. No useful caller that uses other value has emerged.
By now, it is clear that the interface is overly broad without a
good reason. Many codepaths have hardcoded preference to read
either LF terminated or NUL terminated records from their input, and
then call strbuf_getline() with LF or NUL as the third parameter.
This step introduces two thin wrappers around strbuf_getline(),
namely, strbuf_getline_lf() and strbuf_getline_nul(), and
mechanically rewrites these call sites to call either one of
them. The changes contained in this patch are:
* introduction of these two functions in strbuf.[ch]
* mechanical conversion of all callers to strbuf_getline() with
either '\n' or '\0' as the third parameter to instead call the
respective thin wrapper.
After this step, output from "git grep 'strbuf_getline('" would
become a lot smaller. An interim goal of this series is to make
this an empty set, so that we can have strbuf_getline_crlf() take
over the shorter name strbuf_getline().
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Often we read "text" files that are supplied by the end user
(e.g. commit log message that was edited with $GIT_EDITOR upon 'git
commit -e'), and in some environments lines in a text file are
terminated with CRLF. Existing strbuf_getline() knows to read a
single line and then strip the terminating byte from the result, but
it is handy to have a version that is more tailored for a "text"
input that takes both '\n' and '\r\n' as line terminator (aka
<newline> in POSIX lingo) and returns the body of the line after
stripping <newline>.
Recently reimplemented "git am" uses such a function implemented
privately; move it to strbuf.[ch] and make it available for others.
Note that we do not blindly replace calls to strbuf_getline() that
uses LF as the line terminator with calls to strbuf_getline_crlf()
and this is very much deliberate. Some callers may want to treat an
incoming line that ends with CR (and terminated with LF) to have a
payload that includes the final CR, and such a blind replacement
will result in misconversion when done without code audit.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before auto-gc'ing, we need to make sure that the pack files are
released in case they need to be repacked and garbage-collected.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
struct object is one of the major data structures dealing with object
IDs. Convert it to use struct object_id instead of an unsigned char
array. Convert get_object_hash to refer to the new member as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
"git am -3" had a small regression where it is aborted in its error
handling codepath when underlying merge-recursive failed in certain
ways, as it assumed that the internal call to merge-recursive will
never die, which is not the case (yet).
* jc/am-3-fallback-regression-fix:
am -3: do not let failed merge from completing the error codepath
A couple of commands still showed "[options]" in their usage string
to note where options should come on their command line, but we
spell that "[<options>]" in most places these days.
* rt/placeholder-in-usage:
am, credential-cache: add angle brackets to usage string
The internal stripspace() function has been moved to where it
logically belongs to, i.e. strbuf API, and the command line parser
of "git stripspace" has been updated to use the parse_options API.
* tk/stripspace:
stripspace: use parse-options for command-line parsing
strbuf: make stripspace() part of strbuf
"git am" used to spawn "git mailinfo" via run_command() API once
per each patch, but learned to make a direct call to mailinfo()
instead.
* jc/am-mailinfo-direct:
am: make direct call to mailinfo
The internal stripspace() function has been moved to where it
logically belongs to, i.e. strbuf API, and the command line parser
of "git stripspace" has been updated to use the parse_options API.
* tk/stripspace:
stripspace: use parse-options for command-line parsing
strbuf: make stripspace() part of strbuf
A couple of commands still showed "[options]" in their usage string
to note where options should come on their command line, but we
spell that "[<options>]" in most places these days.
* rt/placeholder-in-usage:
am, credential-cache: add angle brackets to usage string
"git am -3" had a small regression where it is aborted in its error
handling codepath when underlying merge-recursive failed in certain
ways, as it assumed that the internal call to merge-recursive will
never die, which is not the case (yet).
* jc/am-3-fallback-regression-fix:
am -3: do not let failed merge from completing the error codepath
And finally the endgame. Instead of spawning "git mailinfo" via the
run_command() API the same number of times as there are incoming
patches, make direct internal call to the libified mailinfo() from
"git am" to reduce the spawning overhead, which would matter on some
platforms.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "git am" was rewritten as a built-in, it stopped paying
attention to user.signingkey, which was fixed.
* pt/am-builtin:
am: configure gpg at startup
This function is also used in other builtins than stripspace, so it
makes sense to have it in a more generic place. Since it operates
on an strbuf and the function is declared in strbuf.h, move it to
strbuf.c and add the corresponding prefix to its name, just like
other API functions in the strbuf_* family.
Also switch all current users of stripspace() to the new function
name and keep a temporary wrapper inline function for any topic
branches still using stripspace().
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "git am" was rewritten as a built-in, it stopped paying
attention to user.signingkey, which was fixed.
* pt/am-builtin:
am: configure gpg at startup
When "am" was rewritten in C, the codepath for falling back to
three-way merge was mistakenly made to make an internal call to
merge-recursive, disabling the error reporting code for certain
types of errors merge-recursive detects and reports by calling
die().
This is a quick-fix for correctness. The ideal endgame would be to
replace run_command() in run_fallback_merge_recursive() with a
direct call after making sure that internal call to merge-recursive
does not die().
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The new builtin am ignores the user.signingkey variable: gpg is being
called with the committer details as the key ID, which may not be
correct. git_gpg_config is responsible for handling that variable and is
expected to be called on initialization by any modules that use gpg.
Signed-off-by: Renee Margaret McConahy <nepella@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent "git am" had regression when adding a Signed-off-by line
with its "-s" option by an unintended tightening of how an existing
trailer block is detected.
* jc/builtin-am-signoff-regression-fix:
am: match --signoff to the original scripted version
Linus noticed that the recently reimplemented "git am -s" defines
the trailer block too rigidly, resulting in an unnecessary blank
line between the existing sign-offs and his new sign-off. An e-mail
submission sent to Linus in real life ends with mixture of sign-offs
and commentaries, e.g.
title here
message here
Signed-off-by: Original Author <original@auth.or>
[rv: tweaked frotz and nitfol]
Signed-off-by: Re Viewer <rv@ew.er>
Signed-off-by: Other Reviewer <other@rev.ewer>
---
patch here
Because the reimplementation reused append_signoff() helper that is
used by other codepaths, which is unaware that people intermix such
comments with their sign-offs in the trailer block, such a message
was judged to end with a non-trailer, resulting in an extra blank
line before adding a new sign-off.
The original scripted version of "git am" used a lot looser
definition, i.e. "if and only if there is no line that begins with
Signed-off-by:, add a blank line before adding a new sign-off". For
the upcoming release, stop using the append_signoff() in "git am"
and reimplement the looser definition used by the scripted version
to use only in "git am" to fix this regression in "am" while
avoiding new regressions to other users of append_signoff().
In the longer term, we should look into loosening append_signoff()
so that other codepaths that add a new sign-off behave the same way
as "git am -s", but that is a task for post-release.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's a bug in builtin/am.c in which we take a lock on
MERGE_RR recursively. But rather than fix am.c, this patch
fixes the confusing interface from rerere.c that caused the
bug. Read on for the gory details.
The setup_rerere() function both reads the existing MERGE_RR
file, and takes MERGE_RR.lock. In the rerere() and
rerere_forget() functions, we end up in write_rr(), which
will then commit the lock file.
But for functions like rerere_clear() that do not write to
MERGE_RR, we expect the caller to have handled
setup_rerere(). That caller would then need to release the
lockfile, but it can't; the lock struct is local to
rerere.c.
For builtin/rerere.c, this is OK. We run a single rerere
operation and then exit immediately, which has the side
effect of rolling back the lockfile.
But in builtin/am.c, this is actively wrong. If we run "git
am -3 --skip", we call setup-rerere twice without releasing
the lock:
1. The "--skip" causes us to call am_rerere_clear(), which
calls setup_rerere(), but never drops the lock.
2. We then proceed to the next patch.
3. The "--3way" may cause us to call rerere() to handle
conflicts in that patch, but we are already holding the
lock. The lockfile code dies with:
BUG: prepare_tempfile_object called for active object
We could fix this by having rerere_clear() call
rollback_lock_file(). But it feels a bit odd for it to roll
back a lockfile that it did not itself take. So let's
simplify the interface further, and handle setup_rerere in
the function itself, taking away the question from the
caller over whether they need to do so.
We can give rerere_gc() the same treatment, as well (even
though it doesn't have any callers besides builtin/rerere.c
at this point). Note that these functions don't take flags
from their callers to pass along to setup_rerere; that's OK,
because the flags would not be meaningful for what they are
doing.
Both of those functions need to hold the lock because even
though they do not write to MERGE_RR, they are still writing
and should be protected from a simultaneous "rerere" run.
But rerere_remaining(), "rerere diff", and "rerere status"
are all read-only operations. They want to setup_rerere(),
but do not care about taking the lock in the first place.
Since our update of MERGE_RR is the usual atomic rename done
by commit_lock_file, they can just do a lockless read. For
that, we teach setup_rerere a READONLY flag to avoid the
lock.
As a bonus, this pushes builtin/rerere.c's setup_rerere call
closer to the functions that use it. Which means that "git
rerere totally-bogus-command" will no longer silently
exit(0) in a repository without rerere enabled.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
