m2m

Environment

• VerneMQ Version: 1.11.0
• OS:
  Distributor ID: Ubuntu
  Description: Ubuntu 18.04.5 LTS
  Release: 18.04
  Codename: bionic
• Erlang/OTP version (if building from source): 19
• VerneMQ configuration (vernemq.conf) or the changes from the default
• Cluster size/standalone:

Expected behaviour

Connection to Redis server running on unixsocket, configured within Lua scr

Hi,

For safety use, it's better to have null check for all variables which are used in this function.

if (!_sessionPriv.$clientAlarmList) {
    return;
}

↓

if (!_sessionPriv.$clientAlarmList
     || !_sessionPriv.$monitoredItemForAlarmList
     || !_sessionPriv.$subscriptionforAlarmList ) {
    return;
}

https://github.com/node-opcua/node-opcua/blob/master/pack