Fix argument specs to `File`
@@ -474,7 +474,7 @@ mrb_init_file(mrb_state *mrb)
io = mrb_class_get(mrb, "IO");
file = mrb_define_class(mrb, "File", io);
MRB_SET_INSTANCE_TT(file, MRB_TT_DATA);
- mrb_define_class_method(mrb, file, "umask", mrb_file_s_umask, MRB_ARGS_REQ(1));
+ mrb_define_class_method(mrb, file, "umask", mrb_file_s_umask, MRB_ARGS_OPT(1));
mrb_define_class_method(mrb, file, "delete", mrb_file_s_unlink, MRB_ARGS_ANY());
mrb_define_class_method(mrb, file, "unlink", mrb_file_s_unlink, MRB_ARGS_ANY());
mrb_define_class_method(mrb, file, "rename", mrb_file_s_rename, MRB_ARGS_REQ(2));
