Currently it returns a path to a directory on both platforms.
Not going to fix the GTK behavior on this bug. I want to hear from GTK maintainers first.
Created attachment 171442 [details] Patch
Comment on attachment 171442 [details] Patch Clearing flags on attachment: 171442 Committed r133035: <http://trac.webkit.org/changeset/133035>
All reviewed patches have been landed. Closing bug.