Index: /trunk/src/org/openstreetmap/josm/actions/downloadtasks/DownloadOsmTask.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/actions/downloadtasks/DownloadOsmTask.java	(revision 17602)
+++ /trunk/src/org/openstreetmap/josm/actions/downloadtasks/DownloadOsmTask.java	(revision 17603)
@@ -376,6 +376,6 @@
                     MainApplication.worker.submit(new UpdatePrimitivesTask(layer, primitivesToUpdate));
                 }
-                layer.onPostDownloadFromServer();
-            }
+            }
+            layer.onPostDownloadFromServer(); // for existing and newly added layer, see #19816
         }