Jeff King <peff@xxxxxxxx> wrote: > On Wed, Jan 28, 2009 at 12:05:33AM -0800, Junio C Hamano wrote: > > Jeff King <peff@xxxxxxxx> writes: > > > > > > C--D > > > / > > > A--B > > > \ > > > E--F > > Don't the other changes have similar parallel use cases? [2/2] also deals > with tag lookup. Wouldn't you also expect, if you had a tag "T" pointing > to "E" in the above scenario that "git rev-list T..D" would barf? I > really think you don't want to ignore missing negations _ever_ unless > the caller knows that such a miss is really only about optimization and > not correctness. Exactly what I just said in my other message. > Side note: > > As you described, we expect to reach this situation from a partial > transfer. Which means that you don't actually have a _ref_ for "T" (or > "F"). So it is unlikely to come up in normal use (you would have to > manually specify the sha1 of a broken portion of the graph). True, but in the send-pack case we are discussing the remote side has specified the SHA-1 of broken portions of the graph to us, and we've taken that into consideration. So we have to fix that assumption we've made. > But what is more important is that your repository _is_ corrupted, Depends. If the SHA-1 came from the remote side during send-pack, it doesn't matter that we have a broken chain along that path, it may have been a dumb transport fetch that was interrupted. Our local repository isn't corrupt, it just has some extra crap laying around that hasn't gc'd yet. If the SHA-1 came from the user, then it depends on the context of why the user is giving it to us. In pretty much every case, yes, its a corruption and we should be aborting. :-) Actually, the only time where it *isn't* a corruption is when its input to "git bundle create A.bdl ... -not $SOMEBADID" as that is the exact same thing as coming from the other side via send-pack. > I > think we are losing an important method by which the user finds out. Git > is usually very good at informing you of a problem in the repo early, > and I think unconditionally ignoring missing objects would lose that. Yup, I agree. But as you and Junio have already pointed out, C Git can miss some types of corruption because the revision machinary has some gaps. *sigh* I'd really like to see those gaps closed. But I don't have a good enough handle on the code structure of the C Git revision machinary to do that myself in a short period of time. I know JGit's well... but that's only because I wrote it. ;-) Its now on my wish list of things I wish I had time for in C Git. But perhaps someone who is more familiar with the revision machinary will get to it first. -- Shawn. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
