Re: [PATCH v6] tracking branches: add advice to ambiguous refspec error

[Tao Klerks <tao@klerks.biz>]

On Fri, Apr 1, 2022 at 1:57 AM Glen Choo <chooglen@google.com> wrote:
>
> Junio C Hamano <gitster@pobox.com> writes:
>
> > "Tao Klerks via GitGitGadget" <gitgitgadget@gmail.com> writes:
> >
> >>      if (!remote_find_tracking(remote, &tracking->spec)) {
> >> -            if (++tracking->matches == 1) {
> >> +            switch (++tracking->matches) {
> >> +            case 1:
> >>                      string_list_append(tracking->srcs, tracking->spec.src);
> >>                      tracking->remote = remote->name;
> >> -            } else {
> >> +                    break;
> >> +            case 2:
> >> +                    /* there are at least two remotes; backfill the first one */
> >> +                    string_list_append(&ftb->ambiguous_remotes, tracking->spec.src);
> >> +                    /* fall through */
> >> +            default:
> >> +                    string_list_append(&ftb->ambiguous_remotes, remote->name);
> >>                      free(tracking->spec.src);
> >>                      string_list_clear(tracking->srcs, 0);
> >> +            break;
> >
> > Just to sanity check this part,
> >
> >  - During the first iteration, we append tracking->spec.src to
> >    tracking->srcs, and set tracking->remote to remote->name;
> >
> >  - In later iterations, we do not want to touch tracking->srcs, and
> >    want to collect remote->name.
> >
> > And "backfill" assumes that tracking->spec.src at that point in the
> > second iteration is the same as what we got in remote->name in the
> > first round.  If that were a correct assumption, then it is curious
> > that the first iteration uses tracking->spec.src and remote->name
> > separately for different purposes, which makes me want to double
> > check if the assumption is indeed correct.
> >
> > If it were tracking->remote (which was assigned the value of
> > remote->name during the first iteration) that is used to backfill
> > before we append remote->name in the second iteration, I wouldn't
> > find it "curious", but the use of tracking->spec.src there makes me
> > feel confused.
> >
> > Thanks.
>
> Thanks for bringing this up, I also found this unusual when I was
> reading v5.

If you never hear from me again, please know it's because I crawled
back under the rock I had crawled out from. This is clearly a bug from
a silly typo, and I've managed to look at the resulting output twice
without noticing the wrong thing was printed. I'm guessing the use of
the word "unusual" here is a polite euphemism for "you numskull, what
you wrote makes no sense!" :)

I did not think adding an automated test for advise() output made
sense, but I guess I have proved myself wrong.