diff -r 887cd09ea943 -r 5baba2a107a1 kruskalbox.cc
--- a/kruskalbox.cc	Tue Jul 11 22:14:52 2006 +0000
+++ b/kruskalbox.cc	Wed Aug 23 16:16:16 2006 +0000
@@ -16,7 +16,7 @@
      )
     {
 
-      Graph g=mapstorage->graph;
+      const Graph &g=mapstorage->graph;
       Graph::EdgeMap<double> * inputmap=
 	((mapstorage->edgemap_storage)[(edgemapcbts[INPUT])->get_active_text()]);
       Graph::EdgeMap<bool> outputmap(g);