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

diff --git a/merge.c b/merge.c
index b0cffe16fe368ee86e609d5d9fbd3b29620bba8c..1d441ad94254257ad2ac28b8a17dc0b8e5ce14f9 100644 (file)
--- a/merge.c
+++ b/merge.c
@@ -79,10 +79,10 @@ int checkout_fast_forward(const struct object_id *head,
        opts.fn = twoway_merge;
        setup_unpack_trees_porcelain(&opts, "merge");
 
-       trees[nr_trees] = parse_tree_indirect(head->hash);
+       trees[nr_trees] = parse_tree_indirect(head);
        if (!trees[nr_trees++])
                return -1;
-       trees[nr_trees] = parse_tree_indirect(remote->hash);
+       trees[nr_trees] = parse_tree_indirect(remote);
        if (!trees[nr_trees++])
                return -1;
        for (i = 0; i < nr_trees; i++) {