Fix LWT not being sent on client takeover.

This was not happening for the case when the existing session wasn't
being continued.

Closes #1946. Thanks to Rory Piper.

ChangeLog.txt

@@ -1,6 +1,8 @@
 Broker:
 - Fix excessive CPU use on non-Linux systems when the open file limit is set
  high. Closes #1947.
+- Fix LWT not being sent on client takeover when the existing session wasn't
+ being continued. Closes #1946.
 
 Apps:
 - Fix `mosquitto_passwd -b` using username as password (not if `-c` is also

src/handle_connect.c

@@ -165,6 +165,14 @@ int connect__on_authorised(struct mosquitto *context, void *auth_data_out, uint1
  if(context->clean_start == true){
  sub__clean_session(found_context);
  }
+ if((found_context->protocol == mosq_p_mqtt5 && found_context->session_expiry_interval == 0)
+ || (found_context->protocol != mosq_p_mqtt5 && found_context->clean_start == true)
+ || (context->clean_start == true)
+ ){
+
+ context__send_will(found_context);
+ }
+
  session_expiry__remove(found_context);
  will_delay__remove(found_context);
  will__clear(found_context);

test/broker/07-will-takeover.py

@@ -5,25 +5,42 @@
 from mosq_test_helper import *
 
 
-def do_test(proto_ver, clean_session):
+def do_test(proto_ver, clean_session1, clean_session2):
  rc = 1
  keepalive = 60
 
  mid = 1
  connect1_packet = mosq_test.gen_connect("will-helper", keepalive=keepalive, proto_ver=proto_ver)
  connack1_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
 
- connect2_packet = mosq_test.gen_connect("will-test", keepalive=keepalive, proto_ver=proto_ver, will_topic="will/test", will_payload=b"LWT", clean_session=clean_session)
- connack2a_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
- if clean_session == False and proto_ver == 4:
- connack2b_packet = mosq_test.gen_connack(rc=0, flags=1, proto_ver=proto_ver)
+ if proto_ver == 5:
+ if clean_session1 == False:
+ connect_props1 = mqtt5_props.gen_uint32_prop(mqtt5_props.PROP_SESSION_EXPIRY_INTERVAL, 60)
+ else:
+ connect_props1 = mqtt5_props.gen_uint32_prop(mqtt5_props.PROP_SESSION_EXPIRY_INTERVAL, 0)
+
+ if clean_session2 == False:
+ connect_props2 = mqtt5_props.gen_uint32_prop(mqtt5_props.PROP_SESSION_EXPIRY_INTERVAL, 60)
+ else:
+ connect_props2 = mqtt5_props.gen_uint32_prop(mqtt5_props.PROP_SESSION_EXPIRY_INTERVAL, 0)
  else:
- connack2b_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+ connect_props1 = b""
+ connect_props2 = b""
+
+ connect2_packet = mosq_test.gen_connect("will-test", keepalive=keepalive, proto_ver=proto_ver, will_topic="will/test", will_payload=b"LWT", clean_session=clean_session1, properties=connect_props1)
+ connack2_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
+
+ connect3_packet = mosq_test.gen_connect("will-test", keepalive=keepalive, proto_ver=proto_ver, clean_session=clean_session2, properties=connect_props2)
+ if clean_session1 == False and clean_session2 == False:
+ connack3_packet = mosq_test.gen_connack(rc=0, flags=1, proto_ver=proto_ver)
+ else:
+ connack3_packet = mosq_test.gen_connack(rc=0, proto_ver=proto_ver)
 
  subscribe_packet = mosq_test.gen_subscribe(mid, "will/test", 0, proto_ver=proto_ver)
  suback_packet = mosq_test.gen_suback(mid, 0, proto_ver=proto_ver)
 
  publish_packet = mosq_test.gen_publish(topic="will/test", qos=0, payload="Client ready", proto_ver=proto_ver)
+ publish_lwt_packet = mosq_test.gen_publish(topic="will/test", qos=0, payload="LWT", proto_ver=proto_ver)
 
  port = mosq_test.get_port()
  broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port)
@@ -34,17 +51,21 @@ def do_test(proto_ver, clean_session):
  mosq_test.do_send_receive(sock1, subscribe_packet, suback_packet, "suback")
 
  # Connect client with will
- sock2 = mosq_test.do_client_connect(connect2_packet, connack2a_packet, timeout=5, port=port)
+ sock2 = mosq_test.do_client_connect(connect2_packet, connack2_packet, timeout=5, port=port)
 
  # Send a "ready" message
  sock2.send(publish_packet)
  mosq_test.expect_packet(sock1, "publish 1", publish_packet)
 
  # Connect client with will again as a separate connection, this should
- # take over from the previous one but not trigger a Will.
- sock3 = mosq_test.do_client_connect(connect2_packet, connack2b_packet, timeout=5, port=port)
+ # take over from the previous one but only trigger a Will if we are taking
+ # over a clean session/session-expiry-interval==0 client
+ sock3 = mosq_test.do_client_connect(connect3_packet, connack3_packet, timeout=5, port=port)
  sock2.close()
 
+ if clean_session1 == True or clean_session2 == True:
+ mosq_test.expect_packet(sock1, "publish LWT", publish_lwt_packet)
+
  # Send the "ready" message again
  sock3.send(publish_packet)
  mosq_test.expect_packet(sock1, "publish 2", publish_packet)
@@ -63,11 +84,15 @@ def do_test(proto_ver, clean_session):
  (stdo, stde) = broker.communicate()
  if rc:
  print(stde.decode('utf-8'))
- print("proto_ver=%d clean_session=%d" % (proto_ver, clean_session))
+ print("proto_ver=%d clean_session1=%d clean_session2=%d" % (proto_ver, clean_session1, clean_session2))
  exit(rc)
 
 
-do_test(proto_ver=4, clean_session=True)
-do_test(proto_ver=4, clean_session=False)
-do_test(proto_ver=5, clean_session=True)
-do_test(proto_ver=5, clean_session=False)
+do_test(proto_ver=4, clean_session1=True, clean_session2=True)
+do_test(proto_ver=4, clean_session1=False, clean_session2=True)
+do_test(proto_ver=4, clean_session1=True, clean_session2=False)
+do_test(proto_ver=4, clean_session1=False, clean_session2=False)
+do_test(proto_ver=5, clean_session1=True, clean_session2=True)
+do_test(proto_ver=5, clean_session1=False, clean_session2=True)
+do_test(proto_ver=5, clean_session1=True, clean_session2=False)
+do_test(proto_ver=5, clean_session1=False, clean_session2=False)