[477] Send will messages for connected clients when broker stops.

Thanks to mikeS7.

Bug: https://github.com/eclipse/mosquitto/issues/477

ChangeLog.txt

@@ -14,6 +14,8 @@ Broker:
 - Set persistence file to only be readable by owner, except on Windows. Closes
   #468.
 - Fix CONNECT check for reserved=0, as per MQTT v3.1.1 check MQTT-3.1.2-3.
+- When the broker stop, wills for any connected clients are now "sent". Closes
+  #477.
 
 Clients:
 - Don't use / in auto-generated client ids.

src/context.c

@@ -143,6 +143,8 @@ void mqtt3_context_cleanup(struct mosquitto_db *db, struct mosquitto *context, b
 		context->address = NULL;
 	}
 
+	mqtt3_context_send_will(db, context);
+
 	if(context->id){
 		assert(db); /* db can only be NULL here if the client hasn't sent a
 					   CONNECT and hence wouldn't have an id. */
@@ -163,12 +165,6 @@ void mqtt3_context_cleanup(struct mosquitto_db *db, struct mosquitto *context, b
 		context->out_packet = context->out_packet->next;
 		_mosquitto_free(packet);
 	}
-	if(context->will){
-		if(context->will->topic) _mosquitto_free(context->will->topic);
-		if(context->will->payload) _mosquitto_free(context->will->payload);
-		_mosquitto_free(context->will);
-		context->will = NULL;
-	}
 	if(do_free || context->clean_session){
 		msg = context->msgs;
 		while(msg){
@@ -185,7 +181,8 @@ void mqtt3_context_cleanup(struct mosquitto_db *db, struct mosquitto *context, b
 	}
 }
 
-void mqtt3_context_disconnect(struct mosquitto_db *db, struct mosquitto *ctxt)
+
+void mqtt3_context_send_will(struct mosquitto_db *db, struct mosquitto *ctxt)
 {
 	if(ctxt->state != mosq_cs_disconnecting && ctxt->will){
 		if(mosquitto_acl_check(db, ctxt, ctxt->will->topic, MOSQ_ACL_WRITE) == MOSQ_ERR_SUCCESS){
@@ -199,6 +196,13 @@ void mqtt3_context_disconnect(struct mosquitto_db *db, struct mosquitto *ctxt)
 		_mosquitto_free(ctxt->will);
 		ctxt->will = NULL;
 	}
+}
+
+
+void mqtt3_context_disconnect(struct mosquitto_db *db, struct mosquitto *ctxt)
+{
+	mqtt3_context_send_will(db, ctxt);
+
 	ctxt->disconnect_t = time(NULL);
 	_mosquitto_socket_close(db, ctxt);
 }

src/mosquitto.c

@@ -387,12 +387,6 @@ int main(int argc, char *argv[])
 	_mosquitto_log_printf(NULL, MOSQ_LOG_INFO, "mosquitto version %s terminating", VERSION);
 	mqtt3_log_close(&config);
 
-#ifdef WITH_PERSISTENCE
-	if(config.persistence){
-		mqtt3_db_backup(&int_db, true);
-	}
-#endif
-
 #ifdef WITH_WEBSOCKETS
 	for(i=0; i<int_db.config->listener_count; i++){
 		if(int_db.config->listeners[i].ws_context){
@@ -428,6 +422,12 @@ int main(int argc, char *argv[])
 #endif
 	mosquitto__free_disused_contexts(&int_db);
 
+#ifdef WITH_PERSISTENCE
+	if(config.persistence){
+		mqtt3_db_backup(&int_db, true);
+	}
+#endif
+
 	mqtt3_db_close(&int_db);
 
 	if(listensock){

src/mosquitto_broker.h

@@ -452,6 +452,7 @@ void mqtt3_context_cleanup(struct mosquitto_db *db, struct mosquitto *context, b
 void mqtt3_context_disconnect(struct mosquitto_db *db, struct mosquitto *context);
 void mosquitto__add_context_to_disused(struct mosquitto_db *db, struct mosquitto *context);
 void mosquitto__free_disused_contexts(struct mosquitto_db *db);
+void mqtt3_context_send_will(struct mosquitto_db *db, struct mosquitto *context);
 
 /* ============================================================
  * Logging functions