tftp: do not risk invoking Sorcerer's Apprentice syndrome

examples/udhcp/simple.script: fix incorrect test for $1

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

examples/udhcp/simple.script

@@ -3,7 +3,7 @@
 
 RESOLV_CONF="/etc/resolv.conf"
 
-[ -n "$1" ] || echo "Error: should be called from udhcpc" && exit 1
+[ -n "$1" ] || { echo "Error: should be called from udhcpc"; exit 1; }
 
 NETMASK=""
 [ -n "$subnet" ] && NETMASK="netmask $subnet"

networking/tftp.c

@@ -501,11 +501,14 @@ static int tftp_protocol(
 				}
 				continue; /* send ACK */
 			}
+/* Disabled to cope with servers with Sorcerer's Apprentice Syndrome */
+#if 0
 			if (recv_blk == (block_nr - 1)) {
 				/* Server lost our TFTP_ACK.  Resend it */
 				block_nr = recv_blk;
 				continue;
 			}
+#endif
 		}
 
 		if (CMD_PUT(option_mask32) && (opcode == TFTP_ACK)) {