Re: [PATCH 30/33] tree-diff: convert diff_tree_paths to struct object_id

-- >8 --
Subject: [PATCH] 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 <redacted>
---
fill_tree_descriptor() can easily be converted to object_id, by the
way, which would get us rid of the extra check introduced here, but
this patch is meant as a minimal fix.

 tree-diff.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tree-diff.c b/tree-diff.c
index bd6d65a409..2357f72899 100644
--- a/tree-diff.c
+++ b/tree-diff.c

@@ -421,8 +421,9 @@ 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);