Re: [PATCH v2 2/8] builtin/multi-pack-index.c: support `--stdin-packs` mode

> Thanks for the series! I have a couple of questions:
>
>
> On 2021.09.15 14:24, Taylor Blau wrote:
> > To power a new `--write-midx` mode, `git repack` will want to write a
> > multi-pack index containing a certain set of packs in the repository.
> >
> > This new option will be used by `git repack` to write a MIDX which
> > contains only the packs which will survive after the repack (that is, it
> > will exclude any packs which are about to be deleted).
> >
> > This patch effectively exposes the function implemented in the previous
> > commit via the `git multi-pack-index` builtin. An alternative approach
> > would have been to call that function from the `git repack` builtin
> > directly, but this introduces awkward problems around closing and
> > reopening the object store, so the MIDX will be written out-of-process.
>
> Could you elaborate a bit on the "awkward problems" here? I'm afraid I'm
> missing the context here.

> > +static void read_packs_from_stdin(struct string_list *to)
> > +{
> > +	struct strbuf buf = STRBUF_INIT;
> > +	while (strbuf_getline(&buf, stdin) != EOF)
> > +		string_list_append(to, buf.buf);
> > +	string_list_sort(to);
> > +
> > +	strbuf_release(&buf);
> > +}
> > +
>
> I'm presuming that the packfile list is going to be generated
> automatically, but what happens if that becomes corrupt somehow, and we
> skip a packfile that should have been included? Will that cause
> incorrect behavior, or will we just miss out on some of the bitmap
> performance benefits?