Connect claims to have connected although connection was immediately closed

[msedv]

When having:

if MQTT.Connect then

one get's True as return value even if the connect failed. Suggestion: in CONNACK the "Connect Return code" should be checked; any value other than 0 means that the server closed the connection because of a failure during connect. See http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718035