When an interactive rebase wants to recreate a root commit, it
- first creates a new, empty root commit,
- checks it out,
- converts the next `pick` command so that it amends the empty root
commit
Introduce support in the sequencer to handle such an empty root commit,
by looking for the file <GIT_DIR>/rebase-merge/squash-onto; if it exists
and contains a commit name, the sequencer will compare the HEAD to said
root commit, and if identical, a new root commit will be created.
While converting scripted code into proper, portable C, we also do away
with the old "amend with an empty commit message, then cherry-pick
without committing, then amend again" dance and replace it with code
that uses the internal API properly to do exactly what we want: create a
new root commit.
To keep the implementation simple, we always spawn `git commit` to create
new root commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We previously relied on the localized versions of
# This is a combination of <N> commits
(which we write into the commit messages during fixup/squash chains)
to contain <N> encoded in ASCII.
This is not true in general, and certainly not true when compiled with
GETTEXT_POISON=TryToKillMe, as demonstrated by the regression test we
just introduced in t3418.
So let's decouple keeping track of the count from the (localized) commit
messages by introducing a new file called 'current-fixups' that keeps
track of the current fixup/squash chain. This file contains a bit more
than just the count (it contains a list of "fixup <commit>"/"squash
<commit>" lines). This is done on purpose, as it will come in handy for
a fix for the bug where `git rebase --skip` on a final fixup/squash will
leave the commit message in limbo.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running `git rebase --rebase-merges` non-interactively with an
ancestor of HEAD as <upstream> (or leaving the todo list unmodified),
we would ideally recreate the exact same commits as before the rebase.
However, if there are commits in the commit range <upstream>.. that do not
have <upstream> as direct ancestor (i.e. if `git log <upstream>..` would
show commits that are omitted by `git log --ancestry-path <upstream>..`),
this is currently not the case: we would turn them into commits that have
<upstream> as direct ancestor.
Let's illustrate that with a diagram:
C
/ \
A - B - E - F
\ /
D
Currently, after running `git rebase -i --rebase-merges B`, the new branch
structure would be (pay particular attention to the commit `D`):
--- C' --
/ \
A - B ------ E' - F'
\ /
D'
This is not really preserving the branch topology from before! The
reason is that the commit `D` does not have `B` as ancestor, and
therefore it gets rebased onto `B`.
This is unintuitive behavior. Even worse, when recreating branch
structure, most use cases would appear to want cousins *not* to be
rebased onto the new base commit. For example, Git for Windows (the
heaviest user of the Git garden shears, which served as the blueprint
for --rebase-merges) frequently merges branches from `next` early, and
these branches certainly do *not* want to be rebased. In the example
above, the desired outcome would look like this:
--- C' --
/ \
A - B ------ E' - F'
\ /
-- D' --
Let's introduce the term "cousins" for such commits ("D" in the
example), and let's not rebase them by default. For hypothetical
use cases where cousins *do* need to be rebased, `git rebase
--rebase=merges=rebase-cousins` needs to be used.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sequencer just learned new commands intended to recreate branch
structure (similar in spirit to --preserve-merges, but with a
substantially less-broken design).
Let's allow the rebase--helper to generate todo lists making use of
these commands, triggered by the new --rebase-merges option. For a
commit topology like this (where the HEAD points to C):
- A - B - C
\ /
D
the generated todo list would look like this:
# branch D
pick 0123 A
label branch-point
pick 1234 D
label D
reset branch-point
pick 2345 B
merge -C 3456 D # C
To keep things simple, we first only implement support for merge commits
with exactly two parents, leaving support for octopus merges to a later
patch series.
All merge-rebasing todo lists start with a hard-coded `label onto` line.
This makes it convenient to refer later on to the revision onto which
everything is rebased, e.g. as starting point for branches other than
the very first one.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sequencer infrastructure is shared across "git cherry-pick",
"git rebase -i", etc., and has always spawned "git commit" when it
needs to create a commit. It has been taught to do so internally,
when able, by reusing the codepath "git commit" itself uses, which
gives performance boost for a few tens of percents in some sample
scenarios.
* pw/sequencer-in-process-commit:
sequencer: run 'prepare-commit-msg' hook
t7505: add tests for cherry-pick and rebase -i/-p
t7505: style fixes
sequencer: assign only free()able strings to gpg_sign
sequencer: improve config handling
t3512/t3513: remove KNOWN_FAILURE_CHERRY_PICK_SEES_EMPTY_COMMIT=1
sequencer: try to commit without forking 'git commit'
sequencer: load commit related config
sequencer: simplify adding Signed-off-by: trailer
commit: move print_commit_summary() to libgit
commit: move post-rewrite code to libgit
Add a function to update HEAD after creating a commit
commit: move empty message checks to libgit
t3404: check intermediate squash messages
Commit 356ee4659b ("sequencer: try to commit without forking 'git
commit'", 2017-11-24) forgot to run the 'prepare-commit-msg' hook when
creating the commit. Fix this by writing the commit message to a
different file and running the hook. Using a different file means that
if the commit is cancelled the original message file is
unchanged. Also move the checks for an empty commit so the order
matches 'git commit'.
Reported-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous config handling relied on global variables, called
git_default_config() even when the key had already been handled by
git_sequencer_config() and did not initialize the diff configuration
variables. Improve this by: i) loading the default values for message
cleanup and gpg signing of commits into struct replay_opts;
ii) restructuring the code to return immediately once a key is
handled; and iii) calling git_diff_basic_config(). Note that
unfortunately it is not possible to return early if the key is handled
by git_gpg_config() as it does not indicate to the caller if the key
has been handled or not.
The sequencer should probably have been calling
git_diff_basic_config() before as it creates a patch when there are
conflicts. The shell version uses 'diff-tree' to create the patch so
calling git_diff_basic_config() should match that. Although 'git
commit' calls git_diff_ui_config() I don't think the output of
print_commit_summary() is affected by anything that is loaded by that
as print_commit_summary() always turns on rename detection so would
ignore the value in the user's configuration anyway. The other values
loaded by git_diff_ui_config() are about the formatting of patches so
are not relevant to print_commit_summary().
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git rebase -i` already know how to interpret single-letter command
names. Teach it to generate the todo list with these same abbreviated
names.
Based-on-patch-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent work on `git-rebase--interactive` aims to convert shell code to
C. Even if this is most likely not a big performance enhancement, let's
convert it too since a coming change to abbreviate command names
requires it to be updated.
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update functions used in the rebase--helper so that they take a generic
'flags' parameter instead of a growing list of options.
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The transform_todo_ids function is a little hard to read. Lets try
to make it easier by using more of the strbuf API. Also, since we'll
soon be adding command abbreviations, let's rename the function so
it's name reflects that change.
Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Load default values for message cleanup and gpg signing of commits in
preparation for committing without forking 'git commit'. Note that we
interpret commit.cleanup=scissors to mean COMMIT_MSG_CLEANUP_SPACE to
be consistent with 'git commit'
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move print_commit_summary() from builtin/commit.c to sequencer.c so it
can be shared with other commands. The function is modified by
changing the last argument to a flag so callers can specify whether
they want to show the author date in addition to specifying if this is
an initial commit.
If the sequencer dies in print_commit_summary() (which can only happen
when cherry-picking or reverting) then neither the todo list nor the
abort safety file are updated to reflect the commit that was just
made. print_commit_summary() can die if:
- The commit that was just created cannot be found or parsed.
- HEAD cannot be resolved either because some other process is
updating it (which is bad news in the middle of a cherry-pick) or
because it is corrupt.
- log_tree_commit() cannot read some objects.
In all those cases dying will leave the sequencer in a sane state for
aborting; 'git cherry-pick --abort' will rewind HEAD to the last
successful commit before there was a problem with HEAD or the object
database. If the user somehow fixes the problem and runs 'git
cherry-pick --continue' then the sequencer will try and pick the same
commit again which may or may not be what the user wants depending on
what caused print_commit_summary() to die. If print_commit_summary()
returned an error instead then update_abort_safety_file() would try to
resolve HEAD which may or may not be successful. If it is successful
then running 'git rebase --abort' would not rewind HEAD to the last
successful commit which is not what we want.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move run_rewrite_hook() from bulitin/commit.c to sequencer.c so it can
be shared with other commands and add a new function
commit_post_rewrite() based on the code in builtin/commit.c that
encapsulates rewriting notes and running the post-rewrite hook. Once
the sequencer learns how to create commits without forking 'git
commit' these functions will be used when squashing commits.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add update_head_with_reflog() based on the code that updates HEAD
after committing in builtin/commit.c that can be called by 'git
commit' and other commands.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the functions that check for empty messages from bulitin/commit.c
to sequencer.c so they can be shared with other commands. The
functions are refactored to take an explicit cleanup mode and template
filename passed by the caller.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This operation has quadratic complexity, which is especially painful
on Windows, where shell scripts are *already* slow (mainly due to the
overhead of the POSIX emulation layer).
Let's reimplement this with linear complexity (using a hash map to
match the commits' subject lines) for the common case; Sadly, the
fixup/squash feature's design neglected performance considerations,
allowing arbitrary prefixes (read: `fixup! hell` will match the
commit subject `hello world`), which means that we are stuck with
quadratic performance in the worst case.
The reimplemented logic also happens to fix a bug where commented-out
lines (representing empty patches) were dropped by the previous code.
While at it, clarify how the fixup/squash feature works in `git rebase
-i`'s man page.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Note: The original code did not try to skip unnecessary picks of root
commits but punts instead (probably --root was not considered common
enough of a use case to bother optimizing). We do the same, for now.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is crucial to improve performance on Windows, as the speed is now
mostly dominated by the SHA-1 transformation (because it spawns a new
rev-parse process for *every* line, and spawning processes is pretty
slow from Git for Windows' MSYS2 Bash).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The first step of an interactive rebase is to generate the so-called "todo
script", to be stored in the state directory as "git-rebase-todo" and to
be edited by the user.
Originally, we adjusted the output of `git log <options>` using a simple
sed script. Over the course of the years, the code became more
complicated. We now use shell scripting to edit the output of `git log`
conditionally, depending whether to keep "empty" commits (i.e. commits
that do not change any files).
On platforms where shell scripting is not native, this can be a serious
drag. And it opens the door for incompatibilities between platforms when
it comes to shell scripting or to Unix-y commands.
Let's just re-implement the todo script generation in plain C, using the
revision machinery directly.
This is substantially faster, improving the speed relative to the
shell script version of the interactive rebase from 2x to 3x on Windows.
Note that the rearrange_squash() function in git-rebase--interactive
relied on the fact that we set the "format" variable to the config setting
rebase.instructionFormat. Relying on a side effect like this is no good,
hence we explicitly perform that assignment (possibly again) in
rearrange_squash().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When calling `git rebase -i -v`, the user wants to see some statistics
after the commits were rebased. Let's show some.
The strbuf we use to perform that task will be used for other things
in subsequent commits, hence it is declared and initialized in a wider
scope than strictly needed here.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch introduces a new action for the sequencer. It really does not
do a whole lot of its own right now, but lays the ground work for
patches to come. The intention, of course, is to finally make the
sequencer the work horse of the interactive rebase (the original idea
behind the "sequencer" concept).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The subcommands are used exactly once, at the very beginning of
sequencer_pick_revisions(), to determine what to do. This is an
unnecessary level of indirection: we can simply call the correct
function to begin with. So let's do that.
While at it, ensure that the subcommands return an error code so that
they do not have to die() all over the place (bad practice for library
functions...).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sequencer is our attempt to lib-ify cherry-pick. Yet it behaves
like a one-shot command when it reads its configuration: memory is
allocated and released only when the command exits.
This is kind of okay for git-cherry-pick, which *is* a one-shot
command. All the work to make the sequencer its work horse was
done to allow using the functionality as a library function, though,
including proper clean-up after use.
To remedy that, take custody of the option values in question,
allocating and duping literal constants as needed and freeing them
at end.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This change is not completely faithful: instead of initializing all fields
to 0, we choose to initialize command and subcommand to -1 (instead of
defaulting to REPLAY_REVERT and REPLAY_NONE, respectively). Practically,
it makes no difference at all, but future-proofs the code to require
explicit assignments for both fields.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/conflict-hint:
merge & sequencer: turn "Conflicts:" hint into a comment
builtin/commit.c: extract ignore_non_trailer() helper function
merge & sequencer: unify codepaths that write "Conflicts:" hint
builtin/merge.c: drop a parameter that is never used
git-tag.txt: Add a missing hyphen to `-s`
Two identical loops in suggest_conflicts() in merge, and
do_recursive_merge() in sequencer, can use a single helper function
extracted from the latter that prepares the "Conflicts:" hint that
is meant to remind the user the paths for which merge conflicts had
to be resolved to write a better commit log message.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nicolas Vigier <boklm@mars-attacks.org>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach append_signoff how to detect a duplicate s-o-b in the commit footer.
This is in preparation to unify the append_signoff implementations in
log-tree.c and sequencer.c.
Fixes test in t3511.
Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Turn many file-scope private symbols to static to reduce the
global namespace contamination.
* jc/make-static:
sequencer.c: mark a private file-scope symbol as static
ident.c: mark private file-scope symbols as static
trace.c: mark a private file-scope symbol as static
wt-status.c: mark a private file-scope symbol as static
read-cache.c: mark a private file-scope symbol as static
strbuf.c: mark a private file-scope symbol as static
sha1-array.c: mark a private file-scope symbol as static
symlinks.c: mark private file-scope symbols as static
notes.c: mark a private file-scope symbol as static
rerere.c: mark private file-scope symbols as static
graph.c: mark private file-scope symbols as static
diff.c: mark a private file-scope symbol as static
commit.c: mark a file-scope private symbol as static
builtin/notes.c: mark file-scope private symbols as static
In case 'git cherry-pick -s <commit>' failed, the user had to use 'git
commit -s' (i.e. state the -s option again), which is easy to forget
about. Instead, write the signed-off-by line early, so plain 'git
commit' will have the same result.
Also update 'git commit -s', so that in case there is already a relevant
Signed-off-by line before the Conflicts: line, it won't add one more at
the end of the message. If there is no such line, then add it before the
the Conflicts: line.
Signed-off-by: Miklos Vajna <vmiklos@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Scripts such as "git rebase -i" cannot currently cherry-pick commits
which have an empty commit message, as git cherry-pick calls git
commit without the --allow-empty-message option.
Add an --allow-empty-message option to git cherry-pick which is passed
through to git commit, so this behaviour can be overridden.
Signed-off-by: Chris Webb <chris@arachsys.com>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-cherry-pick --allow-empty command by default only preserves empty
commits that were originally empty, i.e only those commits for which
<commit>^{tree} and <commit>^^{tree} are equal. By default commits which are
non-empty, but were made empty by the inclusion of a prior commit on the current
history are filtered out. This option allows us to override that behavior and
include redundant commits as empty commits in the change history.
Note that this patch changes the default behavior of git cherry-pick slightly.
Prior to this patch all commits in a cherry-pick sequence were applied and git
commit was run. The implication here was that, if a commit was redundant, and
the commit did not trigger the fast forward logic, the git commit operation, and
therefore the git cherry-pick operation would fail, displaying the cherry pick
advice (i.e. run git commit --allow-empty). With this patch however, such
redundant commits are automatically skipped without stopping, unless
--keep-redundant-commits is specified, in which case, they are automatically
applied as empty commits.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git cherry-pick fails when picking a non-ff commit that is empty. The advice
given with the failure is that a git-commit --allow-empty should be issued to
explicitly add the empty commit during the cherry pick. This option allows a
user to specify before hand that they want to keep the empty commit. This
eliminates the need to issue both a cherry pick and a commit operation.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose the cherry-picking machinery through a public
sequencer_pick_revisions() (renamed from pick_revisions() in
builtin/revert.c), so that cherry-picking and reverting are special
cases of a general sequencer operation. The cherry-pick builtin is
now a thin wrapper that does command-line argument parsing before
calling into sequencer_pick_revisions(). In the future, we can write
a new "foo" builtin that calls into the sequencer like:
memset(&opts, 0, sizeof(opts));
opts.action = REPLAY_FOO;
opts.revisions = xmalloc(sizeof(*opts.revs));
parse_args_populate_opts(argc, argv, &opts);
init_revisions(opts.revs);
sequencer_pick_revisions(&opts);
This patch does not intend to make any functional changes. Check
with:
$ git blame -s -C HEAD^..HEAD -- sequencer.c | grep -C3 '^[^^]'
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that "git reset" no longer implicitly removes .git/sequencer that
the operator may or may not have wanted to keep, the logic to write a
backup copy of .git/sequencer and remove it when stale is not needed
any more. Simplify the sequencer API and repository layout by
dropping it.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The option to "git cherry-pick" and "git revert" to discard the
sequencer state introduced by v1.7.8-rc0~141^2~6 (revert: Introduce
--reset to remove sequencer state, 2011-08-04) has a confusing name.
Change it now, while we still have the time.
The new name for "cherry-pick, please get out of my way, since I've
long forgotten about the sequence of commits I was cherry-picking when
you wrote that old .git/sequencer directory" is --quit. Mnemonic:
this is analagous to quiting a program the user is no longer using ---
we just want to get out of the multiple-command cherry-pick procedure
and not to reset HEAD or rewind any other old state.
The "--reset" option is kept as a synonym to minimize the impact. We
might consider dropping it for simplicity in a separate patch, though.
Adjust documentation and tests to use the newly preferred name (--quit)
instead of --reset. While at it, let's clarify the short descriptions
of these operations in "-h" output.
Before:
--reset forget the current operation
--continue continue the current operation
After:
--quit end revert or cherry-pick sequence
--continue resume revert or cherry-pick sequence
Noticed-by: Phil Hord <phil.hord@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To explicitly remove the sequencer state for a fresh cherry-pick or
revert invocation, introduce a new subcommand called "--reset" to
remove the sequencer state.
Take the opportunity to publicly expose the sequencer paths, and a
generic function called "remove_sequencer_state" that various git
programs can use to remove the sequencer state in a uniform manner;
"git reset" uses it later in this series. Introducing this public API
is also in line with our long-term goal of eventually factoring out
functions from revert.c into a generic commit sequencer.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Johannes Schindelin
Junio C Hamano
Phillip Wood
Liam Beguin
Nicolas Vigier
Brandon Casey
Miklos Vajna
Chris Webb
Neil Horman
Ramkumar Ramachandra
Jonathan Nieder