Patch forthcoming.
Created attachment 207178 [details] work in progress This adds test, and some test support that I needed, when building them.
Created attachment 207180 [details] the patch I'll have -expected files shortly.
Created attachment 207185 [details] the patch and now, with tests!
Comment on attachment 207185 [details] the patch JavaScript is the best.
Landed in http://trac.webkit.org/changeset/152944