Fixed crash in loop subdivision

src/OpenMesh/Tools/Subdivider/Uniform/LoopT.hh

@@ -363,6 +363,7 @@ private: // topological modifiers
 
     _m.set_face_handle( new_heh, _m.face_handle(heh) );
     _m.set_halfedge_handle( vh, new_heh);
+    if ( !_m.is_boundary(heh) )
       _m.set_halfedge_handle( _m.face_handle(heh), heh );
     _m.set_halfedge_handle( vh1, opp_new_heh );