Complain (and more importantly don't blindly run) if AP or Client IP is unset

bin/cros_run_wifi_tests.sh

 #!/bin/bash
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Wrapper script around run_remote_tests.sh that knows how to find
 # device test cells.
 
 
@@ skipping 105 matching lines @@
 
 # Retrieve the testbed config from the server and match either the client
 # or the cell number to one of the entries
 ret=$(curl -s $lab_url | \
 while read line; do
   # Each line from the server is made up of:
   # client_name router_name server_name client_addr router_addr server_addr
   set $line
   if [ "${FLAGS_cell}" = "$cell_no" -o "${FLAGS_client}" = "$1" -o \
        "${FLAGS_client}" = "$4" ] ; then
+    if [ "$5" = "0.0.0.0" -o "$4" = "0.0.0.0" ]; then
+      # Error -- these should never be zeroes
+      break
+    fi
     echo "$4"
     echo "router_addr=$5"
     if [ "$6" != "0.0.0.0" ] ; then
       echo "server_addr=$6"
     fi
     break
   fi
   cell_no=$[cell_no + 1]
 done)
 
 if [ -z "$ret" ] ; then
   echo ">>> Cell or host not found at $lab_url"
   exit 1
 fi
 
 set $ret
 remote=$1
 shift
 for arg in $*; do
     append_arg $arg
 done
 
 eval "exec ${script_root}/run_remote_tests.sh \
       --args=\"${run_remote_args}\" --remote=${remote} $run_remote_flags \
       $FLAGS_ARGV"