static struct rev_info log_tree_opt;
 
-static int diff_tree_commit_sha1(const struct object_id *oid)
+static int diff_tree_commit_oid(const struct object_id *oid)
 {
        struct commit *commit = lookup_commit_reference(oid);
        if (!commit)
 
 int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 {
-       int nr_sha1;
        char line[1000];
        struct object *tree1, *tree2;
        static struct rev_info *opt = &log_tree_opt;
         * reverse the order of the objects if the second one
         * is marked UNINTERESTING.
         */
-       nr_sha1 = opt->pending.nr;
-       switch (nr_sha1) {
+       switch (opt->pending.nr) {
        case 0:
                if (!read_stdin)
                        usage(diff_tree_usage);
                break;
        case 1:
                tree1 = opt->pending.objects[0].item;
-               diff_tree_commit_sha1(&tree1->oid);
+               diff_tree_commit_oid(&tree1->oid);
                break;
        case 2:
                tree1 = opt->pending.objects[0].item;