Re: [PATCH 3/3] commit-graph: error out on invalid commit oids in 'write --stdin-commits'

[Jeff King <peff@peff.net>]

On Mon, Apr 13, 2020 at 01:39:34PM -0600, Taylor Blau wrote:

> > > Hm, are you trying to go in the direction where '--stdin-commits'
> > > would keep erroring out on any non-full-hex-oid, but would accept and
> > > silently ignore any hex oids that are not commits (perhaps even when
> > > there is no such object, dunno)?  I think that would support the use
> > > cases you mentioned, while it would still save me when I do the 'echo
> > > <ref>' thing (somehow I regularly do that, remember doing it the day
> > > before yesterday!).
> >
> > Yes, exactly. The case you care about and the case I care about are
> > different ones, so there's no inherent conflict between them.
> 
> I was looking back again at this today, and I think we need something
> more or less like the following on top. I'll send it out later today or
> early tomorrow...

Yes, the behavior there looks fine to me. Though you may want to catch
the parse_oid_hex() separately and return its own error message. Telling
the user "I don't understand non-hex object names" instead of just
"invalid commit object" may be useful. I think it would also make the
flow of the function easier to follow.

If we were writing from scratch, I'd actually suggest that
builtin/commit-graph.c do parse_oid_hex() call as we read lines, and
then commit-graph could just be working with an oid_array or oidset,
which would reduce overall memory usage. I don't know if that would
cause other complications, but it could be worth looking into.

> +               if (ret || (ctx->check_oids && !result)) {
>                         error(_("invalid commit object id: %s"),
>                             commit_hex->items[i].string);
>                         return -1;

We could also take this a step further and just ditch check_oids
entirely (under the assumption that nobody really wants it; they just
wanted to catch bad names in the first place).

-Peff