Added the link to the previous segment.

src/opendrive_road.cpp

@@ -137,7 +137,6 @@ void COpendriveRoad::load(const std::string &filename)
       // link segments
       this->link_segments(*open_drive);
       // process junctions
-/*
       for(OpenDRIVE::junction_iterator junction_it(open_drive->junction().begin());junction_it!=open_drive->junction().end();++junction_it)
       {
         for(junction::connection_iterator connection_it(junction_it->connection().begin()); connection_it!=junction_it->connection().end();++connection_it)
@@ -182,7 +181,6 @@ void COpendriveRoad::load(const std::string &filename)
           }
         }
       }
-          */
     }catch (const xml_schema::exception& e){
       std::ostringstream os;
       os << e;

src/opendrive_road_segment.cpp

@@ -274,7 +274,11 @@ void COpendriveRoadSegment::link_segment(COpendriveRoadSegment &segment)
   for(unsigned int i=0;i<this->next.size();i++)
     if(this->next[i]->get_id()==segment.get_id())// the segment is already included
       return;
+  for(unsigned int i=0;i<segment.prev.size();i++)
+    if(segment.prev[i]->get_id()==this->id)
+      return;
   this->next.push_back(&segment);
+  segment.prev.push_back(this);
   // link lanes
   for(int i=-this->num_right_lanes;i<0;i++)
   {
@@ -313,7 +317,11 @@ void COpendriveRoadSegment::link_segment(COpendriveRoadSegment &segment,int from
   for(unsigned int i=0;i<this->next.size();i++)
     if(this->next[i]->get_id()==segment.get_id())// the segment is already included
       return;
+  for(unsigned int i=0;i<segment.prev.size();i++)
+    if(segment.prev[i]->get_id()==this->id)
+      return;
   this->next.push_back(&segment);
+  segment.prev.push_back(this);
   // link lanes
   if(this->lanes.find(from)!=this->lanes.end() && segment.lanes.find(to)!=segment.lanes.end())
     this->lanes[from]->link_lane(segment.lanes[to],OD_MARK_NONE);