Fix listener not being reassociated with client.

This occurred when reloading a persistence file and
`per_listener_settings true` is set and the client did not set a
username.

Closes #1891. Thanks to Mikkel Nepper-Christensen.

ChangeLog.txt

@@ -1,5 +1,8 @@
 Broker:
 - Fix crash on Windows if loading a plugin fails. Closes #1866.
+- Fix listener not being reassociated with client when reloading a persistence
+  file and `per_listener_settings true` is set and the client did not set a
+  username. Closes #1891.
 
 
 1.6.12 - 2020-08-19

src/persist_read.c

@@ -199,13 +199,13 @@ static int persist__client_chunk_restore(struct mosquitto_db *db, FILE *db_fptr)
 			/* username is not freed here, it is now owned by context */
 			context->username = chunk.username;
 			chunk.username = NULL;
-			/* in per_listener_settings mode, try to find the listener by persisted port */
-			if(db->config->per_listener_settings && !context->listener && chunk.F.listener_port > 0){
-				for(i=0; i < db->config->listener_count; i++){
-					if(db->config->listeners[i].port == chunk.F.listener_port){
-						context->listener = &db->config->listeners[i];
-						break;
-					}
+		}
+		/* in per_listener_settings mode, try to find the listener by persisted port */
+		if(db->config->per_listener_settings && !context->listener && chunk.F.listener_port > 0){
+			for(i=0; i < db->config->listener_count; i++){
+				if(db->config->listeners[i].port == chunk.F.listener_port){
+					context->listener = &db->config->listeners[i];
+					break;
 				}
 			}
 		}

src/persist_write.c

@@ -177,9 +177,9 @@ static int persist__client_save(struct mosquitto_db *db, FILE *db_fptr)
 			if(context->username){
 				chunk.F.username_len = strlen(context->username);
 				chunk.username = context->username;
-				if(context->listener){
-					chunk.F.listener_port = context->listener->port;
-				}
+			}
+			if(context->listener){
+				chunk.F.listener_port = context->listener->port;
 			}
 
 			rc = persist__chunk_client_write_v6(db_fptr, &chunk);