From 58b4b81ccd532190898d05890c088e8f643d421f Mon Sep 17 00:00:00 2001
From: Andreas Fabri <andreas.fabri@geometryfactory.com>
Date: Mon, 13 Mar 2017 17:06:19 +0100
Subject: [PATCH] fix in_edges() and out_edges()

---
 BGL/include/CGAL/boost/graph/Dual.h     | 10 ++++----
 BGL/include/CGAL/boost/graph/iterator.h | 34 +++++++++++++++++++++++++
 BGL/test/BGL/test_bgl_dual.cpp          | 15 ++++++++++-
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/BGL/include/CGAL/boost/graph/Dual.h b/BGL/include/CGAL/boost/graph/Dual.h
index b4d7ea60c4e..4d5dee0cc05 100644
--- a/BGL/include/CGAL/boost/graph/Dual.h
+++ b/BGL/include/CGAL/boost/graph/Dual.h
@@ -103,8 +103,8 @@ public:
   typedef typename GTP::halfedge_iterator halfedge_iterator;
   typedef typename GTP::edge_iterator     edge_iterator;
 
-  typedef CGAL::Halfedge_around_face_iterator<Primal>      in_edge_iterator;
-  typedef CGAL::Opposite_edge_around_face_iterator<Primal> out_edge_iterator;
+  typedef CGAL::Edge_around_face_iterator<Primal>      out_edge_iterator;
+  typedef CGAL::Opposite_edge_around_face_iterator<Primal> in_edge_iterator;
 
   static vertex_descriptor   null_vertex()   { return vertex_descriptor(); }
   static face_descriptor     null_face()     { return face_descriptor(); }
@@ -446,16 +446,16 @@ out_edges(typename boost::graph_traits<Dual<P> >::vertex_descriptor v,
           const Dual<P>& dual)
 {
   const typename Dual<P>::Primal& primal = dual.primal();
-  return opposite_edges_around_face(halfedge(v,primal),primal);
+  return edges_around_face(halfedge(v,primal),primal);
 }
 
 template <typename P>
-Iterator_range<typename boost::graph_traits<Dual<P> >::out_edge_iterator>
+Iterator_range<typename boost::graph_traits<Dual<P> >::in_edge_iterator>
 in_edges(typename boost::graph_traits<Dual<P> >::vertex_descriptor v,
          const Dual<P>& dual)
 {
   const typename Dual<P>::Primal& primal = dual.primal();
-  return halfedges_around_face(halfedge(v,primal),primal);
+  return opposite_edges_around_face(halfedge(v,primal),primal);
 }
        
 template <typename P>
diff --git a/BGL/include/CGAL/boost/graph/iterator.h b/BGL/include/CGAL/boost/graph/iterator.h
index d27a36cd23a..74d5ba5324b 100644
--- a/BGL/include/CGAL/boost/graph/iterator.h
+++ b/BGL/include/CGAL/boost/graph/iterator.h
@@ -1122,6 +1122,40 @@ opposite_edges_around_face(typename boost::graph_traits<Graph>::halfedge_descrip
   return make_range(I(h,g), I(h,g,1));
 }
 
+template <typename Graph>
+class Edge_around_face_iterator
+#ifndef DOXYGEN_RUNNING
+  : public boost::iterator_adaptor<
+            Edge_around_face_iterator<Graph>                       // Derived
+             , Halfedge_around_face_iterator<Graph>                // Base
+             , typename boost::graph_traits<Graph>::edge_descriptor  // Value
+             , std::bidirectional_iterator_tag                       // CategoryOrTraversal
+             , typename boost::graph_traits<Graph>::edge_descriptor  // Reference
+             >
+#endif
+{
+  typedef typename boost::graph_traits<Graph>::halfedge_descriptor halfedge_descriptor;
+  internal::Edge<Graph> fct;
+public:
+
+  Edge_around_face_iterator()
+  {}
+
+  Edge_around_face_iterator(halfedge_descriptor h, const Graph& g, int n = 0)
+    : Edge_around_face_iterator::iterator_adaptor_(Halfedge_around_face_iterator<Graph>(h,g,(h==halfedge_descriptor())?1:n)), fct(g)
+  {}
+private:
+  friend class boost::iterator_core_access;
+  typename  boost::graph_traits<Graph>::edge_descriptor dereference() const { return fct(*this->base_reference()); }
+}; 
+
+template<typename Graph>
+Iterator_range<Edge_around_face_iterator<Graph> >
+edges_around_face(typename boost::graph_traits<Graph>::halfedge_descriptor h, const Graph& g)
+{
+  typedef Edge_around_face_iterator<Graph> I;
+  return make_range(I(h,g), I(h,g,1));
+}
 
 
 
diff --git a/BGL/test/BGL/test_bgl_dual.cpp b/BGL/test/BGL/test_bgl_dual.cpp
index 407caa60eab..1456eec0cc7 100644
--- a/BGL/test/BGL/test_bgl_dual.cpp
+++ b/BGL/test/BGL/test_bgl_dual.cpp
@@ -13,6 +13,8 @@ typedef CGAL::Dual<Mesh>               Dual;
 typedef boost::graph_traits<Dual>::face_descriptor face_descriptor;
 typedef boost::graph_traits<Dual>::vertex_descriptor vertex_descriptor;
 typedef boost::graph_traits<Dual>::halfedge_descriptor halfedge_descriptor;
+typedef boost::graph_traits<Dual>::out_edge_iterator out_edge_iterator;
+typedef boost::graph_traits<Dual>::in_edge_iterator in_edge_iterator;
 
 int main()
 {
@@ -38,7 +40,18 @@ int main()
   BOOST_FOREACH(halfedge_descriptor lhd, halfedges_around_target(halfedge(vd,dual),dual)){
     assert(target(lhd,dual) == vd); 
   }
-  
+
+  {
+    out_edge_iterator b,e;
+    boost::tie(b,e) = out_edges(vd,dual);
+    std::cerr << vd << " " << source(*b,dual) << std::endl;
+  }
+
+  {
+    in_edge_iterator b,e;
+    boost::tie(b,e) = in_edges(vd,dual);
+    std::cerr << vd << " " << source(*b,dual) << std::endl;
+  }
   std::cerr << "done"<< std::endl;
   return 0;
 }