Index: trunk/src/org/openstreetmap/josm/data/coor/Coordinate.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/coor/Coordinate.java	(revision 6166)
+++ trunk/src/org/openstreetmap/josm/data/coor/Coordinate.java	(revision 6167)
@@ -16,5 +16,5 @@
  * @since 6162
  */
-abstract class Coordinate implements Serializable {
+abstract class Coordinate implements Cloneable, Serializable {
 
     protected final double x;
Index: trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java	(revision 6166)
+++ trunk/src/org/openstreetmap/josm/data/coor/EastNorth.java	(revision 6167)
@@ -130,3 +130,8 @@
         return (Math.abs(x - other.x) < e && Math.abs(y - other.y) < e);
     }
+
+    @Override
+    public EastNorth clone() {
+        return new EastNorth(x, y);
+    }
 }
Index: trunk/src/org/openstreetmap/josm/data/coor/LatLon.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/coor/LatLon.java	(revision 6166)
+++ trunk/src/org/openstreetmap/josm/data/coor/LatLon.java	(revision 6167)
@@ -395,3 +395,8 @@
         return true;
     }
+
+    @Override
+    protected LatLon clone() {
+        return new LatLon(x, y);
+    }
 }