Index: nix/nixnode.cc
--- nix/nixnode.cc.orig
+++ nix/nixnode.cc
@@ -156,7 +156,7 @@ Edge* pE;
   if (last.first == NODE_NONE)
     {
       prev = m_Adj.begin();
-      if (prev == (EdgeVec_it) NULL) // ! How can this happen?
+      if (prev == m_Adj.end()) // ! How can this happen?
         return(NodeWeight_t(NODE_NONE, 0));
       pE = *prev;
       if(0)printf("NextAdj returning first edge %ld\n",