Avoid crash on shutdown (#179)

* stop shutdown_costmap_timer on destructor
* explicitly call costmap_nav_srv destructor

mbf_costmap_nav/src/mbf_costmap_nav/costmap_wrapper.cpp

@@ -64,6 +64,7 @@ CostmapWrapper::CostmapWrapper(const std::string &name, const TFPtr &tf_listener
 
 CostmapWrapper::~CostmapWrapper()
 {
+  shutdown_costmap_timer_.stop();
 }
 
 

mbf_costmap_nav/src/move_base_server_node.cpp

@@ -75,5 +75,9 @@ int main(int argc, char **argv)
 #endif
   costmap_nav_srv_ptr = boost::make_shared<mbf_costmap_nav::CostmapNavigationServer>(tf_listener_ptr);
   ros::spin();
+
+  // explicitly call destructor here, otherwise costmap_nav_srv_ptr will be
+  // destructed after tearing down internally allocated static variables
+  costmap_nav_srv_ptr.reset();
   return EXIT_SUCCESS;
 }