Re: [PATCH] Segmentation fault on non-commit objects.

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 30, 2019, 02:44 UTC
Message-ID: <xmqqbltz3qbc.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20191029140621.GC2843@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 12 quoted lines

> This is definitely a strict improvement over the current behavior
> (though I agree with Dscho's comments on the error message). A few
> further thoughts:
>
>   - we'll have successfully completed the rest of the clone at this
>     point. Should we leave the objects and refs in place to allow the
>     user to fix it up, as we do when "git checkout" fails?
>
>     We'd have to leave _something_ in HEAD for it to be a valid repo. I
>     guess just "refs/heads/master" would be fine, or perhaps we could
>     fall back to whatever the other side had in their HEAD (i.e.,
>     pretending that "-b" wasn't specified).

Do we know for sure that the object at HEAD on the other side is a commit, or do we need to prepare for a case where it is not? I suspect it is the latter. HEAD needs to exist and point at a ref that is in refs/heads/ hierarchy, and the ref can even be unborn, so falling back on 'master' sounds like a good position.

Show 6 quoted lines

>   - there's a related case just above the lines you touched: what
>     happens if the other side feeds us a non-commit in their
>     refs/heads/? That shouldn't happen (i.e., their repo is broken), but
>     should we be protecting ourselves on the receiving side more?
>
>     Likewise in "else" below just above your lines.

Both are good points.

Thanks, all.