Index: trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 9294)
+++ trunk/src/org/openstreetmap/josm/actions/JoinAreasAction.java	(revision 9295)
@@ -1511,5 +1511,5 @@
         for (Way w : ways) {
             final Way wayWithoutTags = new Way(w);
-            w.removeAll();
+            wayWithoutTags.removeAll();
             cmds.add(new ChangeCommand(w, wayWithoutTags));
         }