Yep, Coverity knows those won't do anything.

src/sbbs3/zmodem.c

@@ -1061,13 +1061,9 @@ int zmodem_recv_hex(zmodem_t* zm)
 	n1 = zmodem_recv_nibble(zm);
 	if (n1 < 0)
 		return n1;
-	if (n1 > 15)
-		return -1;
 	n0 = zmodem_recv_nibble(zm);
 	if(n0 < 0)
 		return n0;
-	if (n1 > 15)
-		return -1;
 
 	ret = (n1 << 4) | n0;