Index: applications/editors/josm/plugins/terracer/src/org/openstreetmap/josm/plugins/terracer/TerracerAction.java
===================================================================
--- applications/editors/josm/plugins/terracer/src/org/openstreetmap/josm/plugins/terracer/TerracerAction.java	(revision 35559)
+++ applications/editors/josm/plugins/terracer/src/org/openstreetmap/josm/plugins/terracer/TerracerAction.java	(revision 35560)
@@ -104,4 +104,5 @@
     @Override
     public void actionPerformed(ActionEvent e) {
+        cleanup();
         Collection<OsmPrimitive> sel = getLayerManager().getEditDataSet().getSelected();
         Way outline = null;
@@ -220,7 +221,4 @@
             } catch (UserCancelException ex) {
                 Logging.trace(ex);
-            } finally {
-                this.commands.clear();
-                this.commands = null;
             }
         } else {
@@ -230,4 +228,11 @@
                     associatedStreet, housenumbers, title).dialog.showDialog();
         }
+        cleanup();
+    }
+
+    private void cleanup() {
+        commands = null;
+        primitives = null;
+        tagsInConflict = null;
     }