Jeff King <peff@xxxxxxxx> 于2021年9月10日周五 下午10:26写道：
>
> On Thu, Sep 09, 2021 at 10:45:15PM +0800, ZheNing Hu wrote:
>
> > @@ -2735,6 +2723,7 @@ void pretty_print_ref(const char *name, const
> > struct object_id *oid,
> >
> > ref_item = new_ref_array_item(name, oid);
> > ref_item->kind = ref_kind_from_refname(name);
> > + read_ref_full(name, 0, NULL, &ref_item->flag);
> > if (format_ref_array_item(ref_item, format, &output, &err))
> > die("%s", err.buf);
> > fwrite(output.buf, 1, output.len, stdout);
>
> IMHO this is the wrong place to do it, since the caller may already have
> the flags (and looking up the ref again is a non-trivial cost).
>
Well, but not doing this means that we have to pass the flag from the
pretty_print_ref() call stack.
> The caller in builtin/tag.c should switch to using read_ref_full() and
> pass in the flags.
>
Agree.
> The caller in builtin/verify-tag.c _probably_ should resolve the ref in
> the same way and pass in that full refname and flags. I do worry that
> this may be a compatibility problem, but the current behavior seems so
> broken to me.
>
Yeah.
> > > - I suspect people may be relying on the current behavior. The
> > > original was added to be able to compare the internal tagname to the
> > > refname. I.e., that:
> > >
> > > git tag -v --format='%(refname) %(tag)' foo
> > >
> > > would show "foo foo". Now that _should_ be "%(refname:strip=2)", I
> > > think, but we'd probably be breaking scripts. OTOH, it really feels
> > > like _not_ handing over a real, fully-qualified refname to the
> > > ref-filter code will mean other things are broken (e.g.,
> > > ATOM_UPSTREAM is assuming we have a fully-qualified ref).
> > >
> >
> > This is indeed a sad thing: A bug becomes a feature.
> >
> > > I think a backwards-compatible way of fixing it would be to have
> > > this call hand over the full refname to the ref-filter code, but
> > > tell it that %(refname) should default to strip=2. And then anybody
> > > who wants the full name can use %(refname:strip=0).
> > >
> >
> > Doesn't this make things more complicated? Those callers of git for-each-ref,
> > wouldn't our changes like this destroy them?
>
> My proposal was that we'd have a specific flag in ref-filter to say
> "default refname:strip to this value". And then _only_ "tag --verify"
> would set that (to "2"), leaving for-each-ref, etc unaffected.
>
Indeed this may be a feasible solution. I will try to do this first.
> So yes, it's complicated. And it must be explained to the user that
> "%(refname)" behaves slightly differently with "git tag --verify", but
> that is unavoidable if we do not want to break scripts (it _already_
> behaves slightly differently, and we just never told anyone).
>
> The other option is to declare the current behavior a bug and fix it. I
> am quite tempted by that route, given the inconsistency with other
> formatters, including even "git tag --list --format=%(refname)"!
I don't know, I think both fix methods are okay.
>
> -Peff
Thanks.
--
ZheNing Hu
