"git replay" (experimental) learns, in addition to "pick" and
"replay", a new operating mode "revert".
* sa/replay-revert:
replay: add --revert mode to reverse commit changes
sequencer: extract revert message formatting into shared function
Due to the use of DEFAULT_ABBREV, we cannot get rid of our usage of
USE_THE_REPOSITORY_VARIABLE. We have removed all other uses of
the_repository before, but without removing that definition, they keep
coming back.
Define the_repository to make it a compilation error so that they don't
come back any more; the repo parameter plumbed through the various
functions can be used instead.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a `--revert <branch>` mode to git replay that undoes the changes
introduced by the specified commits. Like --onto and --advance, --revert
is a standalone mode: it takes a branch argument and updates that branch
with the newly created revert commits.
At GitLab, we need this in Gitaly for reverting commits directly on bare
repositories without requiring a working tree checkout.
The approach is the same as sequencer.c's do_pick_commit() -- cherry-pick
and revert are just the same three-way merge with swapped arguments:
- Cherry-pick: merge(ancestor=parent, ours=current, theirs=commit)
- Revert: merge(ancestor=commit, ours=current, theirs=parent)
We swap the base and pickme trees passed to merge_incore_nonrecursive()
to reverse the diff direction.
Revert commit messages follow the usual git revert conventions: prefixed
with "Revert" (or "Reapply" when reverting a revert), and including
"This reverts commit <hash>.". The author is set to the current user
rather than preserving the original author, matching git revert behavior.
Helped-by: Christian Couder <christian.couder@gmail.com>
Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Elijah Newren <newren@gmail.com>
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Siddharth Asthana <siddharthasthana31@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the changes in a commit being replayed are already in the branch
that the commits are being replayed onto, then "git replay" creates an
empty commit. This is confusing because the commit message no longer
matches the contents of the commit. Drop the commit instead. Commits
that start off empty are not dropped. This matches the behavior of
"git rebase --reapply-cherry-pick --empty=drop" and "git cherry-pick
--empty-drop".
If a branch points to a commit that is dropped it will be updated
to point to the last commit that was not dropped. This can be seen
in the new test where "topic1" is updated to point to the rebased
"C" as "F" is dropped because it is already upstream. While this is
a breaking change, "git replay" is marked as experimental to allow
improvements like this that change the behavior.
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a subsequent commit we're about to introduce a new git-history(1)
command, which will by default work on all local branches and HEAD. This
is already well-supported by the replay machinery for most of the part:
updating branches is one of its prime use cases, and the HEAD ref is
also updated in case it points to any of the branches.
However, what's not supported yet is to update HEAD in case it is not a
symbolic ref. We determine the refs that need to be updated by iterating
through the decorations of the original commit, but we only update those
refs that are `DECORATION_REF_LOCAL`, which covers local branches.
Address this gap by also handling `DECORATION_REF_HEAD`. Note though
that this needs to only happen in case we're working on a detached HEAD.
If HEAD is pointing to a branch, then we'd already update that branch
via `DECORATION_REF_LOCAL`.
Refactor the loop that iterates through the decorations a bit to make
the individual conditions easier to understand.
Based-on-patch-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a subsequent commit we're about to introduce a new user of the replay
subsystem. With that new user, the range of commits that we'll want to
replay will be identified implicitly via a single commit, and will
include all descendants of that commit to any branch. If that commit has
no descendants (because it's the tip of some branch), then the range of
revisions that we're asked to replay becomes empty. This case does not
make sense with git-replay(1), but with the new command it will.
This case is not currently supported by `replay_revisions()` though
because we zero-initialize `struct merge_result`. This includes its
`.clean` member, which indicates whether the merge ran into a conflict
or not. But given that we don't have any revision to replay, we won't
ever perform any merge at all, and consequently that member will never
be set to `1`. We thus later think that there's been a merge conflict
and return an error from `replay_commits()`.
Address this issue by initializing the `.clean` member to `1`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Perform a small set of cleanups so that the "replay" logic compiles with
"-Wsign-compare" and doesn't use `the_repository` anymore. Note that
there are still some implicit dependencies on `the_repository`, e.g.
because we use `get_commit_output_encoding()`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the core logic used to replay commits into "libgit.a" so that it
can be easily reused by other commands. It will be used in a subsequent
commit where we're about to introduce a new git-history(1) command.
Note that with this change we have no sign-comparison warnings anymore,
and neither do we depend on `the_repository`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
