2011-01-29 Adam Barth <abarth@webkit.org>

2011-01-29  Adam Barth  <abarth@webkit.org>

        Reviewed by Daniel Bates.

        Fix XSSFilter crash when extracting the source for a token twice
        https://bugs.webkit.org/show_bug.cgi?id=53368

        Previously, it was unsafe to extract the source for the same token
        twice because the HTMLSourceTracker would advance its internal
        representation of the SegmentedString.  This patch introduces a cache
        to make calling HTMLSourceTracker::sourceForToken multiple times safe.

        * html/parser/HTMLSourceTracker.cpp:
        (WebCore::HTMLSourceTracker::end):
        (WebCore::HTMLSourceTracker::sourceForToken):
        * html/parser/HTMLSourceTracker.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@77076 268f45cc-cd09-0410-ab3c-d52691b4dbfc