completion: drop the hard coded list of config vars

diff --git a/builtin/diff.c b/builtin/diff.c
index 16bfb22f7381ee8e6967ab836686c5def7cff892..bfefff3a84896a79fbed42eec1121286edcc86dd 100644 (file)
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -398,7 +398,7 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
                if (!obj)
                        die(_("invalid object '%s' given."), name);
                if (obj->type == OBJ_COMMIT)
-                       obj = &((struct commit *)obj)->tree->object;
+                       obj = &get_commit_tree(((struct commit *)obj))->object;
 
                if (obj->type == OBJ_TREE) {
                        obj->flags |= flags;