- Fix a problem reported by Sergey Linev:
When I work with new browser and edit text file, it 
ask to save modified file when browser is closed.
If I press "Yes" or "No", everything is ok, but if 
I press "Cancel", I get segmentation violation. 
Same is happening, if I press "Yes", but in file 
dialog press "Cancel".


git-svn-id: http://root.cern.ch/svn/root/trunk@20634 27541ba8-7e3a-0410-8455-c3a389f83636