check channel values size before attempting the memcpy
check channel values size before attempting the memcpy

git-svn-id: 0026580bb7e4cc6a4dfc3b6e5daae18624e1a30c@33966 eb33c2ac-9c88-4c90-87e0-44a10359b0c3

ros-visualization/rviz,ros-visualization/rviz,ros-visualization/rviz,ros-visualization/rviz,ros-visualization/rviz