Re: [RFC PATCH 3/9] rebase -i: comment out squash!/fixup! subjects from squash message

>
> On Fri, Jan 08, 2021 at 02:53:41PM +0530, Charvi Mendiratta wrote:
> > From: Phillip Wood <phillip.wood@dunelm.org.uk>
> >
> > When squashing commit messages the squash!/fixup! subjects are not of
> > interest so comment them out to stop them becoming part of the final
> > message.
> >
> > This change breaks a bunch of --autosquash tests which rely on the
> > "squash! <subject>" line appearing in the final commit message. This is
> > addressed by adding a second line to the commit message of the "squash!
> > ..." commits and testing for that.
> >
> > Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> > Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
> > ---
> >  sequencer.c                  | 25 ++++++++++++++++++++++++-
> >  t/t3415-rebase-autosquash.sh | 27 +++++++++++++--------------
> >  t/t3900-i18n-commit.sh       |  4 ----
> >  3 files changed, 37 insertions(+), 19 deletions(-)
> >
> > diff --git a/sequencer.c b/sequencer.c
> > index 5062976d10..b050a9a212 100644
> > --- a/sequencer.c
> > +++ b/sequencer.c
> > @@ -1718,15 +1718,38 @@ static int is_pick_or_similar(enum todo_command command)
> >       }
> >  }
> >
> > +static size_t subject_length(const char *body)
> > +{
> > +     size_t i, len = 0;
> > +     char c;
> > +     int blank_line = 1;
> > +     for (i = 0, c = body[i]; c; c = body[++i]) {
> > +             if (c == '\n') {
> > +                     if (blank_line)
> > +                             return len;
> > +                     len = i + 1;
> > +                     blank_line = 1;
> > +             } else if (!isspace(c)) {
> > +                     blank_line = 0;
> > +             }
> > +     }
> > +     return blank_line ? len : i;
> > +}
> > +
>
> OK, so this gets the length of the subject in "body", which is defined
> as the run of characters before a newline and then a space character. So
> "foo bar\n\nbaz" would return 7, but "foo bar\nbaz" would return 11.
>
> Makes sense. (Apologies for stating the obvious here, I just had to read
> this function to myself a couple of times to make sure that I understood
> what it was doing.)
>

> >  static void append_squash_message(struct strbuf *buf, const char *body,
> >                                 struct replay_opts *opts)
> >  {
> > +     size_t commented_len = 0;
> > +
> >       unlink(rebase_path_fixup_msg());
> > +     if (starts_with(body, "squash!") || starts_with(body, "fixup!"))
> > +             commented_len = subject_length(body);
> >       strbuf_addf(buf, "\n%c ", comment_line_char);
> >       strbuf_addf(buf, _("This is the commit message #%d:"),
> >                   ++opts->current_fixup_count + 1);
> >       strbuf_addstr(buf, "\n\n");
> > -     strbuf_addstr(buf, body);
> > +     strbuf_add_commented_lines(buf, body, commented_len);
> > +     strbuf_addstr(buf, body + commented_len);
>
> Very nice; the subject gets commented when it starts with "squash!" or
> "fixup!", but the body remains uncommented. Makes sense to me.
>

> > @@ -224,7 +223,7 @@ test_expect_success 'auto squash that matches longer sha1' '
> >       git cat-file blob HEAD^:file1 >actual &&
> >       test_cmp expect actual &&
> >       git cat-file commit HEAD^ >commit &&
> > -     grep squash commit >actual &&
> > +     grep "extra para" commit >actual &&
> >       test_line_count = 1 actual
> >  '
>
> Worth checking that "squash" doesn't appear in an uncommented part of
> actual? Or better yet, checking that "# squash ..." _does_ appear.
>
> I.e., that we would leave this as:
>
>     -   grep squash commit >actual &&
>     +   grep "^# squash" commit >actual &&
>     +   grep "extra para" commit >actual &&
>
> > @@ -342,8 +341,8 @@ test_expect_success C_LOCALE_OUTPUT 'autosquash with custom inst format' '
> >       git cat-file blob HEAD^:file1 >actual &&
> >       test_cmp expect actual &&
> >       git cat-file commit HEAD^ >commit &&
> > -     grep squash commit >actual &&
> > -     test_line_count = 2 actual
> > +     grep first commit >actual &&
> > +     test_line_count = 3 actual
> >  '
>
> Ditto.