[PATCH v2 0/8] rebase: make reflog messages independent of the backend

Thanks to Christian and Elijah for their comments on V1.

I've updated commit message for patch 1 to try and be clearer about the removal of a call to strbuf_release() and spilt out the test changes from the old patch 2 into a separate preparatory patch.

V1 Cover Letter:

This is a series of rebase reflog related patches with the aim of unifying the reflog messages from the two rebase backends.

 * improve rebase reflog test coverage
 * rebase --merge: fix reflog messages for --continue and --skip
 * rebase --apply: respect GIT_REFLOG_ACTION
 * rebase --abort: improve reflog message
 * unify reflog messages between the two rebase backends

This series is based on pw/use-inprocess-checkout-in-rebase

Phillip Wood (8):
  rebase --apply: remove duplicated code
  t3406: rework rebase reflog tests
  rebase --merge: fix reflog when continuing
  rebase --merge: fix reflog message after skipping
  rebase --apply: respect GIT_REFLOG_ACTION
  rebase --apply: make reflog messages match rebase --merge
  rebase --abort: improve reflog message
  rebase: cleanup action handling

 builtin/rebase.c          | 144 ++++++++++++-----------------
 sequencer.c               |   5 ++
 t/t3406-rebase-message.sh | 185 +++++++++++++++++++++++++++++++-------
 3 files changed, 214 insertions(+), 120 deletions(-)

base-commit: 38c541ce94048cf72aa4f465be9314423a57f445
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1150%2Fphillipwood%2Fwip%2Frebase-reflog-fixes-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1150/phillipwood/wip/rebase-reflog-fixes-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1150

Range-diff vs v1:

 1:  243e7b0c372 ! 1:  a4320f2fcf3 rebase --apply: remove duplicated code
     @@ Commit message
          to do as we have already updated HEAD.
      
          Note that the removal of "strbuf_release(&msg)" is safe as there is an
     -    identical call just above this hunk.
     +    identical call just above this hunk which can be seen by viewing the
     +    diff with -U6.
      
          Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
      
 2:  493254ffbb8 ! 2:  0904b50a377 rebase --merge: fix reflog when continuing
     @@ Metadata
      Author: Phillip Wood <phillip.wood@dunelm.org.uk>
      
       ## Commit message ##
     -    rebase --merge: fix reflog when continuing
     +    t3406: rework rebase reflog tests
      
     -    The reflog message for a conflict resolution committed by "rebase
     -    --continue" looks like
     +    Refactor the tests in preparation for adding more tests in the next
     +    few commits. The reworked tests use the same function for testing both
     +    the "merge" and "apply" backends. The test coverage for the "apply"
     +    backend now includes setting GIT_REFLOG_ACTION.
      
     -            rebase (continue): commit subject line
     -
     -    Unfortunately the reflog message each subsequent pick look like
     -
     -            rebase (continue) (pick): commit subject line
     -
     -    Fix this by setting the reflog message for "rebase --continue" in
     -    sequencer_continue() so it does not affect subsequent commits. This
     -    introduces a memory leak similar to the one leaking GIT_REFLOG_ACTION
     -    in pick_commits(). Both of these will be fixed in a future series that
     -    stops the sequencer calling setenv().
     +    Note that rebasing the "conflicts" branch does not create any
     +    conflicts yet. A commit to do that will be added in the next commit
     +    and the diff ends up smaller if we have don't rename the branch when
     +    it is added.
      
          Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
      
     - ## builtin/rebase.c ##
     -@@ builtin/rebase.c: int cmd_rebase(int argc, const char **argv, const char *prefix)
     - 		int fd;
     - 
     - 		options.action = "continue";
     --		set_reflog_action(&options);
     --
     - 		/* Sanity check */
     - 		if (get_oid("HEAD", &head))
     - 			die(_("Cannot read HEAD"));
     -
     - ## sequencer.c ##
     -@@ sequencer.c: int sequencer_continue(struct repository *r, struct replay_opts *opts)
     - 	if (read_populate_opts(opts))
     - 		return -1;
     - 	if (is_rebase_i(opts)) {
     -+		char *previous_reflog_action;
     -+
     - 		if ((res = read_populate_todo(r, &todo_list, opts)))
     - 			goto release_todo_list;
     - 
     -@@ sequencer.c: int sequencer_continue(struct repository *r, struct replay_opts *opts)
     - 			unlink(rebase_path_dropped());
     - 		}
     - 
     -+		previous_reflog_action = xstrdup(getenv(GIT_REFLOG_ACTION));
     -+		setenv(GIT_REFLOG_ACTION, reflog_message(opts, "continue", NULL), 1);
     - 		if (commit_staged_changes(r, opts, &todo_list)) {
     - 			res = -1;
     - 			goto release_todo_list;
     - 		}
     -+		setenv(GIT_REFLOG_ACTION, previous_reflog_action, 1);
     - 	} else if (!file_exists(get_todo_path(opts)))
     - 		return continue_single_pick(r, opts);
     - 	else if ((res = read_populate_todo(r, &todo_list, opts)))
     -
       ## t/t3406-rebase-message.sh ##
      @@ t/t3406-rebase-message.sh: export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
       test_expect_success 'setup' '
     @@ t/t3406-rebase-message.sh: export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
       
      +	git checkout -b conflicts O &&
      +	test_commit P &&
     -+	test_commit conflict-X fileX &&
      +	test_commit Q &&
      +
       	git checkout -b topic O &&
     @@ t/t3406-rebase-message.sh: test_expect_success 'error out early upon -C<n> or --
      +			GIT_REFLOG_ACTION="$reflog_action" &&
      +			export GIT_REFLOG_ACTION
      +		fi &&
     -+		test_must_fail git rebase $mode main &&
     -+		echo resolved >fileX &&
     -+		git add fileX &&
     -+		git rebase --continue
     ++		git rebase $mode main
      +	) &&
      +
     -+	git log -g --format=%gs -5 >actual &&
     ++	git log -g --format=%gs -4 >actual &&
      +	write_reflog_expect <<-EOF &&
      +	${reflog_action:-rebase} (finish): returning to refs/heads/conflicts
      +	${reflog_action:-rebase} (pick): Q
     -+	${reflog_action:-rebase} (continue): conflict-X
      +	${reflog_action:-rebase} (pick): P
      +	${reflog_action:-rebase} (start): checkout main
       	EOF
 -:  ----------- > 3:  6c15f00e170 rebase --merge: fix reflog when continuing
 3:  f4e6e94bc2c = 4:  d3afa85ffc5 rebase --merge: fix reflog message after skipping
 4:  58c560d0e19 = 5:  afa67abe01a rebase --apply: respect GIT_REFLOG_ACTION
 5:  1c3ec165422 = 6:  95161f21e00 rebase --apply: make reflog messages match rebase --merge
 6:  c863cebbdc8 = 7:  d2c1dfbcd5e rebase --abort: improve reflog message
 7:  d26a221a79d = 8:  b0d21affa78 rebase: cleanup action handling