At http://www.macworldexpo.com/, the right edge of the “What’s New” sidebar is clipped off whenever the contents of the “Featured Exhibitor” box at the bottom of the middle column changes.
Caused by <http://trac.webkit.org/changeset/47440>.
<rdar://problem/7503279>
Created attachment 45691 [details] Reduction
Created attachment 45693 [details] Set RenderTableSection::m_hasOverflowingCell correctly
style-queue ran check-webkit-style on attachment 45693 [details] without any errors.
Fixed in <http://trac.webkit.org/projects/webkit/changeset/52683>.