[1941577] Fix for crashes when resizing screen.

git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@4346 c06c8d41-db1a-0410-9941-cceddc491573

Created by  ennewalker  on April 18, 2008
325MMZ56C7O4XJSIVKTRHWL2Z5FUVVXATBE7PEHXZGX4XXR2NOJQC
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