# git-stash segfaults ... 7 messages from 2007-08-20 to 2007-08-21. Participants: Pierre Habouzit, Alex Riesen, Junio C Hamano, Jeff King. Thread: https://gitlist.dev/t/9594 ## Pierre Habouzit, 2007-08-20 17:44 Subject: git-stash segfaults ... Message-ID: <20070820174427.GC7206@artemis.corp> URL: https://gitlist.dev/e/20070820174427.GC7206%40artemis.corp ``` When you don't use it from the root of the tree: I was in a subdir of my git tree, trying to do: git stash apply and I had: $ git stash apply error: missing object referenced by '0ca54c1fba7fea7dca8a1cc59bce2b2849f26d20' Segmentation fault going in the root of the repository (where .git is), all went fine. Cheers, -- ·O· Pierre Habouzit ··O madcoder@debian.org OOO http://www.madism.org ``` ## Alex Riesen, 2007-08-20 20:02 Subject: Re: git-stash segfaults ... Message-ID: <20070820200255.GD5544@steel.home> URL: https://gitlist.dev/e/20070820200255.GD5544%40steel.home In-Reply-To: <20070820174427.GC7206@artemis.corp> ``` Pierre Habouzit, Mon, Aug 20, 2007 19:44:27 +0200: > When you don't use it from the root of the tree: I was in a subdir of > my git tree, trying to do: > > git stash apply > > and I had: > > $ git stash apply > error: missing object referenced by > '0ca54c1fba7fea7dca8a1cc59bce2b2849f26d20' Segmentation fault > > going in the root of the repository (where .git is), all went fine. Can't reproduce, but... There are places where the result of the function which gives this message (deref_tag from tag.c) is not checked for NULL and used. merge-recursive (used by git-stash) is one of them (and sha1_name is another). Pierre, could you please try the patch below and see if the crash is replaced with a failure? BTW, is there something unusual happening to that repo? Like manual object removing, or removal of repo your repo was cloned from, using something like "git clone -l -s", maybe? diff --git a/merge-recursive.c b/merge-recursive.c index 16f6a0f..464fc4e 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -1701,6 +1701,8 @@ static struct commit *get_ref(const char *ref) if (get_sha1(ref, sha1)) die("Could not resolve ref '%s'", ref); object = deref_tag(parse_object(sha1), ref, strlen(ref)); + if (!object) + die("Could not resolve ref '%s' down to object", ref); if (object->type == OBJ_TREE) return make_virtual_commit((struct tree*)object, better_branch_name(ref)); ``` ## Junio C Hamano, 2007-08-20 20:44 Subject: Re: git-stash segfaults ... Message-ID: <7vmywmrl5l.fsf@gitster.siamese.dyndns.org> URL: https://gitlist.dev/e/7vmywmrl5l.fsf%40gitster.siamese.dyndns.org In-Reply-To: <20070820174427.GC7206@artemis.corp> ``` Pierre Habouzit writes: > When you don't use it from the root of the tree: I was in a subdir of > my git tree, trying to do: > > git stash apply > > and I had: > > $ git stash apply > error: missing object referenced by > '0ca54c1fba7fea7dca8a1cc59bce2b2849f26d20' Segmentation fault > > going in the root of the repository (where .git is), all went fine. I think this was fixed on Jul 25 with ceff079b and 1.5.3-rc4 should have it. ``` ## Pierre Habouzit, 2007-08-20 20:50 Subject: Re: git-stash segfaults ... Message-ID: <20070820205038.GA9024@artemis.corp> URL: https://gitlist.dev/e/20070820205038.GA9024%40artemis.corp In-Reply-To: <7vmywmrl5l.fsf@gitster.siamese.dyndns.org> ``` On Mon, Aug 20, 2007 at 08:44:22PM +0000, Junio C Hamano wrote: > Pierre Habouzit writes: > > > When you don't use it from the root of the tree: I was in a subdir of > > my git tree, trying to do: > > > > git stash apply > > > > and I had: > > > > $ git stash apply > > error: missing object referenced by > > '0ca54c1fba7fea7dca8a1cc59bce2b2849f26d20' Segmentation fault > > > > going in the root of the repository (where .git is), all went fine. > > I think this was fixed on Jul 25 with ceff079b and 1.5.3-rc4 > should have it. Oh ok, sorry for the noise then, I was using rc3 indeed, debian does not has rc4 packaged yet :) Cheers, -- ·O· Pierre Habouzit ··O madcoder@debian.org OOO http://www.madism.org ``` ## Jeff King, 2007-08-21 06:05 Subject: Re: git-stash segfaults ... Message-ID: <20070821060510.GA7323@coredump.intra.peff.net> URL: https://gitlist.dev/e/20070821060510.GA7323%40coredump.intra.peff.net In-Reply-To: <20070820200255.GD5544@steel.home> ``` On Mon, Aug 20, 2007 at 10:02:55PM +0200, Alex Riesen wrote: > diff --git a/merge-recursive.c b/merge-recursive.c > index 16f6a0f..464fc4e 100644 > --- a/merge-recursive.c > +++ b/merge-recursive.c > @@ -1701,6 +1701,8 @@ static struct commit *get_ref(const char *ref) > if (get_sha1(ref, sha1)) > die("Could not resolve ref '%s'", ref); > object = deref_tag(parse_object(sha1), ref, strlen(ref)); > + if (!object) > + die("Could not resolve ref '%s' down to object", ref); > if (object->type == OBJ_TREE) > return make_virtual_commit((struct tree*)object, > better_branch_name(ref)); I posted the exact same patch almost a month ago, but apparently nobody was interested in applying it: http://mid.gmane.org/20070726050726.GC32617@coredump.intra.peff.net -Peff ``` ## Junio C Hamano, 2007-08-21 06:54 Subject: Re: git-stash segfaults ... Message-ID: <7v6439pecf.fsf@gitster.siamese.dyndns.org> URL: https://gitlist.dev/e/7v6439pecf.fsf%40gitster.siamese.dyndns.org In-Reply-To: <20070821060510.GA7323@coredump.intra.peff.net> ``` Jeff King writes: > I posted the exact same patch almost a month ago, but apparently nobody > was interested in applying it: > > http://mid.gmane.org/20070726050726.GC32617@coredump.intra.peff.net I think you were told that your patch was a band-aid for the symptom, and was not the real fix, in the thread you quoted. The real fix would be to make merge-recursive operable from subdirectory (perhaps just the matter of cd-up, but I am not supposed to be looking at anything other than regression and documentation fixes this late in the 1.5.3 cycle). ``` ## Jeff King, 2007-08-21 07:08 Subject: Re: git-stash segfaults ... Message-ID: <20070821070809.GA8545@coredump.intra.peff.net> URL: https://gitlist.dev/e/20070821070809.GA8545%40coredump.intra.peff.net In-Reply-To: <7v6439pecf.fsf@gitster.siamese.dyndns.org> ``` On Mon, Aug 20, 2007 at 11:54:24PM -0700, Junio C Hamano wrote: > I think you were told that your patch was a band-aid for the > symptom, and was not the real fix, in the thread you quoted. To which I responded that it is still better to report an error than it is to segfault. In this case, the error message _isn't_ fixing the main problem, but at least it gives a better starting point for tracking problems than a segfault. Not to mention that it _does_ provide the correct error message in a variety of other situations (e.g., merge-recursive given bogus arguments). But really, merge-recursive isn't generally called by users, and so it shouldn't get bogus input, so perhaps it isn't worth caring about. -Peff ```