--- netkit-rsh-0.17/rcp/rcp.c	2021-06-20 10:00:32.217461994 +0100
+++ netkit-rsh-0.17/rcp/rcp.c	2021-06-20 10:10:32.927584394 +0100
@@ -717,8 +717,9 @@
 			size = size * 10 + (*cp++ - '0');
 		if (*cp++ != ' ')
 			SCREWUP("size not delimited");
-		if ((strchr(cp, '/') != NULL) || (strcmp(cp, "..") == 0)) {
-			error("rcp: unexpected filename: %s", cp);
+		if (*cp == '\0' || strchr(cp, '/') != NULL ||
+		    strcmp(cp, ".") == 0 || strcmp(cp, "..") == 0) {
+			error("error: unexpected filename: %s", cp);
 			exit(1);
 		}
 		if (targisdir) {