text: #!/usr/bin/env python3
  
  # Test whether a CONNECT with a zero length client id results in the correct CONNACK packet.
  # MQTT V3.1 only - zero length is invalid.
  from mosq_test_helper import *
  
  def do_test(proto_ver):
      rc = 1
      keepalive = 10
      connect_packet = mosq_test.gen_connect("", keepalive=keepalive, proto_ver=proto_ver)
      if proto_ver == 3:
          connack_packet = mosq_test.gen_connack(rc=2, proto_ver=proto_ver)
      elif proto_ver == 4:
          connack_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver, properties=None)
  
      port = mosq_test.get_port()
      broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port)
  
      try:
          sock = mosq_test.do_client_connect(connect_packet, connack_packet, port=port)
          sock.close()
          rc = 0
      except mosq_test.TestError:
          pass
      finally:
          broker.terminate()
          broker.wait()
          (stdo, stde) = broker.communicate()
          if rc:
              print(stde.decode('utf-8'))
              print("proto_ver=%d" % (proto_ver))
              exit(rc)
  
  
  do_test(proto_ver=3)
  do_test(proto_ver=4)
  exit(0)
  