start-sandbox: If starting a cluster node that isn't the first one in the cluster, change the first's wsrep_cluster_address. This stops /tmp/12345/stop; /tmp/12345/start from creating a second cluster -- instead, it rejoins the original

sandbox/start-sandbox

@@ -52,6 +52,10 @@ make_sandbox() {
       if [ -n "${master_port}" ]; then
          local master_listen_port=$(($master_port + 10))
          cluster_address="gcomm://$ip:$master_listen_port"
+
+         local this_listen_port=$(($port + 10))
+         local this_cluster_address="gcomm://$ip:$this_listen_port"
+         sed -e "s!gcomm://\$!$this_cluster_address!g" -i.bak "/tmp/$master_port/my.sandbox.cnf"
       fi
 
       sed -e "s/ADDR/$ip/g" -i.bak "/tmp/$port/my.sandbox.cnf"
@@ -118,7 +122,7 @@ make_sandbox() {
       debug_sandbox $port
       exit 1
    fi
-
+   
    # If the sandbox is a slave, start the slave.
    if [ "$type" = "slave" ]; then
       /tmp/$port/use -e "change master to master_host='127.0.0.1', master_user='msandbox', master_password='msandbox', master_port=$master_port"

sandbox/test-env

@@ -299,6 +299,12 @@ case $opt in
          exit_status=$((exit_status | $?))
 
          if [ "${2:-""}" = "cluster" ]; then
+            # Bit of magic here. 'start-sandbox cluster new_node old_node'
+            # changes old_node's my.sandbox.cnf's wsrep_cluster_address to
+            # point to new_node. This is especially useful because otherwise,
+            # calling stop/start like below on 12345 would create a new cluster.
+            /tmp/12345/stop  >/dev/null
+            /tmp/12345/start >/dev/null
             echo -n "Checking that the cluster size is correct... "
             size=$(/tmp/12345/use -ss -e "SHOW STATUS LIKE 'wsrep_cluster_size'" | awk '{print $2}')
             if [ ${size:-0} -ne 3 ]; then