Shadow ID pseudo-elements add a whitespace between the host element part and the pseudo-element when being serialized. E.g.: #a::-webkit-slider-thumb becomes #a ::webkit-slider-thumb which has a different meaning.
Created attachment 117386 [details] Patch
Comment on attachment 117386 [details] Patch ooh, good catch. Thanks!
Comment on attachment 117386 [details] Patch Clearing flags on attachment: 117386 Committed r101679: <http://trac.webkit.org/changeset/101679>
All reviewed patches have been landed. Closing bug.