To reproduce, one needs to enter any Moscow address in Russian - nothing will be found.
This was probably caused by my work on form encoding. KURL::init() works differently depending on what path is given to it - e.g. absolute paths like "/foo.html" get UTF-encoded twice! It is likely that this affects more than just XMLHttpRequest.
Created attachment 21269 [details]
Committed in <http://trac.webkit.org/changeset/33966>.