unifiedToolbar together with Qt::Tool does not work as expected

The expected result when setting a together with Qt::Tool would be a window with a small titlebar and a unified toolbar.

But what actually happens is a tiny titlebar and no toolbar at all.

With Leopard, every window, including tool windows can have unified title and toolbar.

See the native textedit.app => Edit => Special characters for a native example.

Reproducable with the following :

#include <QApplication>
#include <QMainWindow>

#include <QAction>
#include <QToolBar>

int main(int argc, char** argv) {
QApplication app(argc, argv);
QMainWindow mw;
QToolBar* bar(mw.addToolBar("Toolbar"));
bar->addAction(new QAction("Save", &mw));
mw.setUnifiedTitleAndToolBarOnMac(true);
mw.setWindowFlags(mw.windowFlags() | Qt::Tool);
mw.show();

return app.exec();
}