fix possible race condition per ticket #3802

git-svn-id: https://code.ros.org/svn/ros-pkg/stacks/laser_pipeline/trunk@27698 eb33c2ac-9c88-4c90-87e0-44a10359b0c3

src/laser_geometry.cpp

@@ -152,6 +152,8 @@ namespace laser_geometry
 
 const boost::numeric::ublas::matrix<double>& LaserProjection::getUnitVectors_(double angle_min, double angle_max, double angle_increment, unsigned int length)
   {
+    boost::mutex::scoped_lock guv_lock(this->guv_mutex_);
+
     //construct string for lookup in the map
     std::stringstream anglestring;
     anglestring <<angle_min<<","<<angle_max<<","<<angle_increment<<","<<length;