From: René Scharfe <l.s.r@web.de>
Date: Sat, 15 Jul 2017 17:18:51 +0000 (+0200)
Subject: tree-diff: don't access hash of NULL object_id pointer
X-Git-Tag: v2.15.0-rc0~212^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fb04dced9c6510176f06953d2cd6a239703401f1;p=thirdparty%2Fgit.git

tree-diff: don't access hash of NULL object_id pointer

The object_id pointers can be NULL for invalid entries.  Don't try to
dereference them and pass NULL along to fill_tree_descriptor() instead,
which handles them just fine.

Found with Clang's UBSan.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/tree-diff.c b/tree-diff.c
index 467e381724..7f7ddda4ea 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -422,8 +422,9 @@ static struct combine_diff_path *ll_diff_tree_paths(
 	 *   diff_tree_oid(parent, commit) )
 	 */
 	for (i = 0; i < nparent; ++i)
-		tptree[i] = fill_tree_descriptor(&tp[i], parents_oid[i]->hash);
-	ttree = fill_tree_descriptor(&t, oid->hash);
+		tptree[i] = fill_tree_descriptor(&tp[i],
+				parents_oid[i] ? parents_oid[i]->hash : NULL);
+	ttree = fill_tree_descriptor(&t, oid ? oid->hash : NULL);
 
 	/* Enable recursion indefinitely */
 	opt->pathspec.recursive = DIFF_OPT_TST(opt, RECURSIVE);