see attached screenshots.
Created attachment 232480 [details]
Created attachment 232481 [details]
The second screenshot demonstrates what happens when something gets selected around the broken strikethrough area.
Created attachment 232482 [details]
Created attachment 233844 [details]
Comment on attachment 233844 [details]
Clearing flags on attachment: 233844
Committed r170456: <http://trac.webkit.org/changeset/170456>
All reviewed patches have been landed. Closing bug.