CSS selectors that use :lang, :not, and namespaces do not serialize correctly. I noticed this while working on another bug awhile back and created a test case and fixes.
Created attachment 13709 [details] patch, with change log and test case
Comment on attachment 13709 [details] patch, with change log and test case The outer if block needs braces. + if (m_match == CSSSelector::None || !prefix.isNull() || localName != starAtom) + if (prefix.isNull()) + str = localName; + else + str = prefix + "|" + localName; r=me
Committed revision 20477.