From Paul de Repentigny, fix for dvide by zero crash under windows when toggle full screen in ogviewer. From Robert Osfield, tweak to the fix to add comment describing the extra check, and addition of check against width, and change to ==0 rather than <= 0.
From Paul de Repentigny, fix for dvide by zero crash under windows when toggle full screen in ogviewer.
From Robert Osfield, tweak to the fix to add comment describing the extra check, and addition of check against width, and change to ==0 rather than <= 0.


git-svn-id: 23b6355f2bb369032457de4eb5f713ee134f73a8@5648 16af8721-9629-0410-8352-f15c8da7e697

joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg,joevandyk/osg