diff -r cd72eae05bdf -r 3c00344f49c9 lemon/planarity.h
--- a/lemon/planarity.h	Mon Jul 16 16:21:40 2018 +0200
+++ b/lemon/planarity.h	Wed Oct 17 19:14:07 2018 +0200
@@ -2,7 +2,7 @@
  *
  * This file is a part of LEMON, a generic C++ optimization library.
  *
- * Copyright (C) 2003-2010
+ * Copyright (C) 2003-2013
  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
  * (Egervary Research Group on Combinatorial Optimization, EGRES).
  *
@@ -72,7 +72,6 @@
       }
 
       void discover(const Arc& arc) {
-        Node source = _graph.source(arc);
         Node target = _graph.target(arc);
 
         _tree_map[arc] = true;
@@ -2384,7 +2383,7 @@
       PlanarEmbedding<Graph> pe(_graph);
       if (!pe.run()) return false;
 
-      run(pe);
+      run(pe.embeddingMap());
       return true;
     }
 
@@ -2399,6 +2398,15 @@
     void run(const EmbeddingMap& embedding) {
       typedef SmartEdgeSet<Graph> AuxGraph;
 
+      if (countNodes(_graph) < 3) {
+        int y = 0;
+        for (typename Graph::NodeIt n(_graph); n != INVALID; ++n) {
+          _point_map[n].x = 0;
+          _point_map[n].y = y++;
+        }
+        return;
+      }
+
       if (3 * countNodes(_graph) - 6 == countEdges(_graph)) {
         drawing(_graph, embedding, _point_map);
         return;