1.1 --- a/lemon/core.h	Fri Jun 25 06:00:56 2010 +0200
     1.2 +++ b/lemon/core.h	Fri Jun 25 06:41:55 2010 +0200
     1.3 @@ -394,6 +394,7 @@
     1.4        template <typename From, typename NodeRefMap, typename ArcRefMap>
     1.5        static void copy(const From& from, Digraph &to,
     1.6                         NodeRefMap& nodeRefMap, ArcRefMap& arcRefMap) {
     1.7 +        to.clear();
     1.8          for (typename From::NodeIt it(from); it != INVALID; ++it) {
     1.9            nodeRefMap[it] = to.addNode();
    1.10          }
    1.11 @@ -421,6 +422,7 @@
    1.12        template <typename From, typename NodeRefMap, typename EdgeRefMap>
    1.13        static void copy(const From& from, Graph &to,
    1.14                         NodeRefMap& nodeRefMap, EdgeRefMap& edgeRefMap) {
    1.15 +        to.clear();
    1.16          for (typename From::NodeIt it(from); it != INVALID; ++it) {
    1.17            nodeRefMap[it] = to.addNode();
    1.18          }

     2.1 --- a/test/graph_copy_test.cc	Fri Jun 25 06:00:56 2010 +0200
     2.2 +++ b/test/graph_copy_test.cc	Fri Jun 25 06:41:55 2010 +0200
     2.3 @@ -29,6 +29,7 @@
     2.4  void digraph_copy_test() {
     2.5    const int nn = 10;
     2.6  
     2.7 +  // Build a digraph
     2.8    SmartDigraph from;
     2.9    SmartDigraph::NodeMap<int> fnm(from);
    2.10    SmartDigraph::ArcMap<int> fam(from);
    2.11 @@ -51,6 +52,7 @@
    2.12      }
    2.13    }
    2.14  
    2.15 +  // Test digraph copy
    2.16    ListDigraph to;
    2.17    ListDigraph::NodeMap<int> tnm(to);
    2.18    ListDigraph::ArcMap<int> tam(to);
    2.19 @@ -68,6 +70,9 @@
    2.20      nodeRef(nr).arcRef(er).
    2.21      nodeCrossRef(ncr).arcCrossRef(ecr).
    2.22      node(fn, tn).arc(fa, ta).run();
    2.23 +  
    2.24 +  check(countNodes(from) == countNodes(to), "Wrong copy.");
    2.25 +  check(countArcs(from) == countArcs(to), "Wrong copy.");
    2.26  
    2.27    for (SmartDigraph::NodeIt it(from); it != INVALID; ++it) {
    2.28      check(ncr[nr[it]] == it, "Wrong copy.");
    2.29 @@ -90,11 +95,18 @@
    2.30    }
    2.31    check(tn == nr[fn], "Wrong copy.");
    2.32    check(ta == er[fa], "Wrong copy.");
    2.33 +
    2.34 +  // Test repeated copy
    2.35 +  digraphCopy(from, to).run();
    2.36 +  
    2.37 +  check(countNodes(from) == countNodes(to), "Wrong copy.");
    2.38 +  check(countArcs(from) == countArcs(to), "Wrong copy.");
    2.39  }
    2.40  
    2.41  void graph_copy_test() {
    2.42    const int nn = 10;
    2.43  
    2.44 +  // Build a graph
    2.45    SmartGraph from;
    2.46    SmartGraph::NodeMap<int> fnm(from);
    2.47    SmartGraph::ArcMap<int> fam(from);
    2.48 @@ -122,6 +134,7 @@
    2.49      }
    2.50    }
    2.51  
    2.52 +  // Test graph copy
    2.53    ListGraph to;
    2.54    ListGraph::NodeMap<int> tnm(to);
    2.55    ListGraph::ArcMap<int> tam(to);
    2.56 @@ -144,6 +157,10 @@
    2.57      nodeCrossRef(ncr).arcCrossRef(acr).edgeCrossRef(ecr).
    2.58      node(fn, tn).arc(fa, ta).edge(fe, te).run();
    2.59  
    2.60 +  check(countNodes(from) == countNodes(to), "Wrong copy.");
    2.61 +  check(countEdges(from) == countEdges(to), "Wrong copy.");
    2.62 +  check(countArcs(from) == countArcs(to), "Wrong copy.");
    2.63 +
    2.64    for (SmartGraph::NodeIt it(from); it != INVALID; ++it) {
    2.65      check(ncr[nr[it]] == it, "Wrong copy.");
    2.66      check(fnm[it] == tnm[nr[it]], "Wrong copy.");
    2.67 @@ -180,6 +197,13 @@
    2.68    check(tn == nr[fn], "Wrong copy.");
    2.69    check(ta == ar[fa], "Wrong copy.");
    2.70    check(te == er[fe], "Wrong copy.");
    2.71 +
    2.72 +  // Test repeated copy
    2.73 +  graphCopy(from, to).run();
    2.74 +  
    2.75 +  check(countNodes(from) == countNodes(to), "Wrong copy.");
    2.76 +  check(countEdges(from) == countEdges(to), "Wrong copy.");
    2.77 +  check(countArcs(from) == countArcs(to), "Wrong copy.");
    2.78  }
    2.79  
    2.80