From: Junio C Hamano Date: Fri, 08 May 2009 23:36:16 GMT Subject: Re: [PATCH] Fix segfault in merge-recursive Message-ID: <7vocu3p3pr.fsf@alter.siamese.dyndns.org> In-Reply-To: Johannes Schindelin writes: > When there is no "common" tree (for whatever reason), we must not > throw a segmentation fault. You described why the old code was wrong (i.e. "init_tree_desc_from_tree is called with common == NULL"), but there is no mention why the new code is correct. For the purpose of satisfying the above statement, you could have just exit(0) as well ;-) > + else { > + opts.merge = 0; > + opts.head_idx = 1; > + init_tree_desc_from_tree(t+0, head); > + init_tree_desc_from_tree(t+1, merge); > + rc = unpack_trees(2, t, &opts); > + } This looks more like a half of branch-switch from HEAD to MERGE, not a merge between HEAD and MERGE as two equal histories. Shouldn't it be doing a three-way tree merge using an empty tree object as the common ancestor instead, just like merge_recursive.c::merge_recursive() itself does?