Dbus control module: release linked-list elements

Fixes a memory leak where elements in the linked list of events where
never released, due to the release function being always called at the
end of the traversal instead of every iteration.

modules/control/dbus/dbus.c

@@ -673,8 +673,10 @@ static void ProcessEvents( intf_thread_t *p_intf,
             vlc_dictionary_insert( &player_properties, "Metadata", NULL );
             break;
         case SIGNAL_PLAYLIST_ITEM_APPEND:
+            if ( !last_append ) {
+                last_append = vlc_dictionary_value_for_key( &tracklist_properties, "TrackAdded" );
+            }
             if( !last_append ) {
-                assert (!vlc_dictionary_has_key( &tracklist_properties, "TrackAdded" ) );
                 vlc_dictionary_insert( &tracklist_properties, "TrackAdded", p_events[i]->items_appended );
 
                 last_append = p_events[i]->items_appended;

modules/control/dbus/dbus_tracklist.c

@@ -613,29 +613,31 @@ int TrackListPropertiesChangedEmit( intf_thread_t    * p_intf,
         tracklist_append_event_t *added_tracks =
             vlc_dictionary_value_for_key( p_changed_properties, "TrackAdded" );
 
-        while (added_tracks) {
+        while ( added_tracks ) {
             for (size_t i = 0; i < added_tracks->change_ev.count; ++i) {
                 TrackAddedSignal( p_intf,
                         added_tracks->change_ev.index + i,
                         added_tracks->items[i] );
             }
-            added_tracks = tracklist_append_event_next(added_tracks);
+            tracklist_append_event_t *next = tracklist_append_event_next( added_tracks );
+            tracklist_append_event_destroy( added_tracks );
+            added_tracks = next;
         }
-        tracklist_append_event_destroy( added_tracks );
     }
 
     if( vlc_dictionary_has_key( p_changed_properties, "TrackRemoved" ) ) {
         tracklist_remove_event_t *removed_tracks =
             vlc_dictionary_value_for_key( p_changed_properties, "TrackRemoved" );
 
-        while (removed_tracks) {
+        while ( removed_tracks ) {
             for (size_t i = 0; i < removed_tracks->change_ev.count; ++i) {
                 TrackRemovedSignal( p_intf, removed_tracks->change_ev.index + i );
             }
-            removed_tracks = tracklist_remove_event_next(removed_tracks);
+            tracklist_remove_event_t *next = tracklist_remove_event_next( removed_tracks );
+            tracklist_remove_event_destroy( removed_tracks );
+            removed_tracks = next;
         }
 
-        tracklist_remove_event_destroy( removed_tracks );
     }
 
     return VLC_SUCCESS;