merge from trunk r49317 fixing a bug reported in http://root.cern.ch/phpBB3/posting.php?mode=reply&f=3&t=16308


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49318 27541ba8-7e3a-0410-8455-c3a389f83636