The latest Qt 5.10 beta includes [1] which breaks a bunch of unit tests, since url.setPath("//foo") will now result in an invalid (empty) QUrl.
This patch fixes the KIO::mkpath() case.
[1]: http://code.qt.io/cgit/qt/qtbase.git/commit/?id=f62768d046528636789f901ac79e2cfa1843a7b7