Re: [PATCH 6/8] sequencer: handle autosquash and post-rewrite for merge commands

> On Thu, Jan 18, 2018 at 7:35 AM, Johannes Schindelin
> <johannes.schindelin@gmx.de> wrote:
> > In the previous patches, we implemented the basic functionality of the
> > `git rebase -i --recreate-merges` command, in particular the `merge`
> > command to create merge commits in the sequencer.
> >
> > The interactive rebase is a lot more these days, though, than a simple
> > cherry-pick in a loop. For example, it calls the post-rewrite hook (if
> > any) after rebasing with a mapping of the old->new commits. And the
> > interactive rebase also supports the autosquash mode, where commits
> > whose oneline is of the form `fixup! <oneline>` or `squash! <oneline>`
> > are rearranged to amend commits whose oneline they match.
> >
> > This patch implements the post-rewrite and autosquash handling for the
> > `merge` command we just introduced. The other commands that were added
> > recently (`label`, `reset` and `bud`) do not create new commits,
> > therefore post-rewrite & autosquash do not need to handle them.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> >  refs.c                            |  3 ++-
> >  sequencer.c                       | 10 +++++++---
> >  t/t3430-rebase-recreate-merges.sh | 39 +++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 48 insertions(+), 4 deletions(-)
> >
> > diff --git a/refs.c b/refs.c
> > index 20ba82b4343..e8b84c189ff 100644
> > --- a/refs.c
> > +++ b/refs.c
> > @@ -600,7 +600,8 @@ int dwim_log(const char *str, int len, struct object_id *oid, char **log)
> >  static int is_per_worktree_ref(const char *refname)
> >  {
> >         return !strcmp(refname, "HEAD") ||
> > -               starts_with(refname, "refs/bisect/");
> > +               starts_with(refname, "refs/bisect/") ||
> > +               starts_with(refname, "refs/rewritten/");
> >  }
> 
> Would this part make more sense to move into the commit that
> introduces writing these refs, or does it only matter once you start
> this step here?
> 
> >
> >  static int is_pseudoref_syntax(const char *refname)
> > diff --git a/sequencer.c b/sequencer.c
> > index 1bef16647b4..b63bfb9a141 100644
> > --- a/sequencer.c
> > +++ b/sequencer.c
> > @@ -2413,10 +2413,13 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
> >                         res = do_reset(item->arg, item->arg_len);
> >                 else if (item->command == TODO_BUD)
> >                         res = do_reset("onto", 4);
> > -               else if (item->command == TODO_MERGE)
> > +               else if (item->command == TODO_MERGE) {
> >                         res = do_merge(item->commit,
> >                                        item->arg, item->arg_len, opts);
> > -               else if (!is_noop(item->command))
> > +                       if (item->commit)
> > +                               record_in_rewritten(&item->commit->object.oid,
> > +                                                   peek_command(todo_list, 1));
> > +               } else if (!is_noop(item->command))
> >                         return error(_("unknown command %d"), item->command);
> >
> >                 todo_list->current++;
> > @@ -3556,7 +3559,8 @@ int rearrange_squash(void)
> >                 struct subject2item_entry *entry;
> >
> >                 next[i] = tail[i] = -1;
> > -               if (item->command >= TODO_EXEC) {
> > +               if (item->command >= TODO_EXEC &&
> > +                   (item->command != TODO_MERGE || !item->commit)) {
> >                         subjects[i] = NULL;
> >                         continue;
> >                 }
> > diff --git a/t/t3430-rebase-recreate-merges.sh b/t/t3430-rebase-recreate-merges.sh
> > index 46ae52f88b3..76e615bd7c1 100755
> > --- a/t/t3430-rebase-recreate-merges.sh
> > +++ b/t/t3430-rebase-recreate-merges.sh
> > @@ -143,4 +143,43 @@ test_expect_success 'with a branch tip that was cherry-picked already' '
> >         EOF
> >  '
> >
> > +test_expect_success 'refs/rewritten/* is worktree-local' '
> > +       git worktree add wt &&
> > +       cat >wt/script-from-scratch <<-\EOF &&
> > +       label xyz
> > +       exec GIT_DIR=../.git git rev-parse --verify refs/rewritten/xyz >a || :
> > +       exec git rev-parse --verify refs/rewritten/xyz >b
> > +       EOF
> > +
> > +       test_config -C wt sequence.editor \""$PWD"/replace-editor.sh\" &&
> > +       git -C wt rebase -i HEAD &&
> > +       test_must_be_empty wt/a &&
> > +       test_cmp_rev HEAD "$(cat wt/b)"
> > +'
> > +
> 
> Same for the test here, I can't figure out why this is necessary in
> this patch as opposed to the patch which first introduced the
> refs/rewritten/<label> refs.