Added check against the validity of the _inverse matrix pointer.
Added check against the validity of the _inverse matrix pointer.


ghub/osg,artoolkit/osg,XiaoCC/osg,stmh/osg,XiaoCC/osg,omega-hub/osg,stmh/osg,XiaoCC/osg,ghub/osg,XiaoCC/osg,artoolkit/osg,artoolkit/osg,omega-hub/osg,XiaoCC/osg,artoolkit/osg,koshman86/osg,stmh/osg,ntoand/osg,koshman86/osg,omega-hub/osg,koshman86/osg,ntoand/osg,stmh/osg,ghub/osg,omega-hub/osg,koshman86/osg,ntoand/osg,ntoand/osg,stmh/osg,ghub/osg