Re: [PATCH] builtin-fast-export.c: add default case to avoid crash on corrupt repo

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 21, 2009, 23:54 UTC
Message-ID: <7vd4cabffl.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <1237675051-6688-1-git-send-email-kusmabite@gmail.com>

Erik Faye-Lund <kusmabite@gmail.com> writes:

> This small issue was discovered by Benjamin Kramers Clang-runs on the
> git code-base. If a tag object points to an object that is not a commit
> or a blob, an invalid pointer is dereferenced in the code that followed.

A tag can point at anything, so this is not an issue about "crash on a _corrupt_ repository".

I am not very familiar with this program, but the codepath involved should be prepared to _see_ any type of object instead of dying.

What to do after _seeing_ a type of object is a different matter. It appears that there is no way to feed a tree object to fast-import, but I think the fast-import language can represent a tag that points at another tag just fine. So the best you can do is perhaps to issue a warning "skipping a tag that points at a tree object" and impoement a proper handling of a tag that points at a tag.