BUG: 12772 fixes for change in Boost graph API

This fixes bug 12772, where an API change in Boost was causing
compilation failures using Boost 1.38. Thanks to Orion Poplawski for
reporting the issue and posting the patch.

Change-Id: I491b0f1650c0be19319533306eb10597dc96fa06

Infovis/vtkBoostBreadthFirstSearchTree.cxx

@@ -47,6 +47,15 @@ using namespace boost;
 vtkStandardNewMacro(vtkBoostBreadthFirstSearchTree);
 
 
+namespace {
+  vtkIdType unwrap_edge_id(vtkEdgeType const &e) {
+    return e.Id;
+  }
+  vtkIdType unwrap_edge_id(boost::detail::reverse_graph_edge_descriptor<vtkEdgeType> const &e) {
+    return e.underlying_desc.Id;
+  }
+}
+
 // Redefine the bfs visitor, the only visitor we
 // are using is the tree_edge visitor.
 template <typename IdMap>
@@ -95,7 +104,8 @@ public:
 
     // Copy the vertex and edge data from the graph to the tree.
     tree->GetVertexData()->CopyData(graph->GetVertexData(), v, tree_v);
-    tree->GetEdgeData()->CopyData(graph->GetEdgeData(), e.Id, tree_e.Id);
+    tree->GetEdgeData()->CopyData(graph->GetEdgeData(),
+                                  unwrap_edge_id(e), tree_e.Id);
   }
 
 private: