From Andrei:

I fixed the problem of double delete of a matrix when exporting as .gdml or .C . Also added a small optimization in copying matrices that seems to have a non-negligible effect on the speed of stressGeometry


git-svn-id: http://root.cern.ch/svn/root/trunk@21853 27541ba8-7e3a-0410-8455-c3a389f83636