Re: [PATCH] Don't dereference NULL upon lookup_tree failure.

Junio C Hamano [off-list ref] wrote:

Jim Meyering [off-list ref] writes:

quoted

Junio C Hamano [off-list ref] wrote:
...

quoted

Sorry, I asked for a wrong thing.  parse_object() reads and
finds out the type, so type there is presumably the right type
of the object (which is OBJ_TREE).  Then parse_object_buffer()
checks if it has already seen the object of the same SHA-1 and
finds that somebody had earlier told that SHA-1 name is of a
commit object.  Either you found a SHA-1 collision (highly
unlikely) or the earlier caller had lied.  And I think what
really needs to be fixed is that lying caller.  That is not in
the above call chain.

I presume that parsecvs is the culprit, in constructing
an invalid repository...

Independent of who creates a "invalid repository", our tools
should be prepared to be fed bad data and not get upset.
Somebody in our code read a non-commit (or it did not read
anything) and told the object layer it is a commit.  That
codepath needs to be tightened up, no?

Yes, of course.
Unfortunately, I won't have time to investigate for a while.