--- ray/src/hd/rholo4.c	1997/11/20 11:40:11	3.6
+++ ray/src/hd/rholo4.c	1997/11/20 18:07:00	3.7
@@ -125,6 +125,8 @@ int	block;
 		if (msg.nbytes)
 			error(INTERNAL, "bad DR_SHUTDOWN from display process");
 		return(0);		/* zero return signals shutdown */
+	case DR_NOOP:
+		break;
 	default:
 		error(INTERNAL, "unrecognized request from display process");
 	}