diff -r 3a98a1aa5a8f -r ef09eee53b09 src/hugo/vector_map.h
--- a/src/hugo/vector_map.h	Wed Sep 22 07:32:57 2004 +0000
+++ b/src/hugo/vector_map.h	Wed Sep 22 08:04:31 2004 +0000
@@ -69,10 +69,6 @@
     /// The pointer type of the map;
     typedef typename Container::const_pointer ConstPointerType;
 
-    /** Default constructor for the map.
-     */
-    VectorMap() {}
-		
     /** Graph and Registry initialized map constructor.
      */
     VectorMap(const Graph& g, MapRegistry& r) 
@@ -98,8 +94,10 @@
      */
     template <typename TT>
     VectorMap& operator=(const VectorMap<MapRegistry, TT>& c) {
-      container.resize(c.container.size());
-      MapBase::operator=(c);
+      if (MapBase::getGraph() != c.getGraph()) {
+	MapBase::operator=(c);
+	container.resize(c.container.size());
+      }
       for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {
 	int id = KeyInfo<Graph, KeyIt>::id(*MapBase::getGraph(), it);
 	container[id] = c.container[id];