Merge branch 'jc/maint-name-rev-all' into maint-1.7.6

* jc/maint-name-rev-all:
  name-rev --all: do not even attempt to describe non-commit object

Author: gitster

builtin/name-rev.c

@@ -289,7 +289,7 @@ int cmd_name_rev(int argc, const char **argv, const char *prefix)
 		max = get_max_object_index();
 		for (i = 0; i < max; i++) {
 			struct object *obj = get_indexed_object(i);
-			if (!obj)
+			if (!obj || obj->type != OBJ_COMMIT)
 				continue;
 			show_name(obj, NULL,
 				  always, allow_undefined, data.name_only);