QFileDialog::getOpenFileName initial directory is ignored when using native Gtk file requester

When calling getOpenFileName and specifying an initial directory, the supplied directory is ignored by the Gtk native wrapper. The native Gtk file requester opens on "recent files" instead. Gtk file chooser does have an API to set the initial directory, but apparently it is not being used here. Specifying DontUseNativeDialog in the options causes the initial directory to be used, but forces the user of non-native file requesters.