[Qt-interest] Wasted pixels in QMainWindow Toolbar on Mac

[KC Jones]

On Mac (OS X 10.5.8, Qt 4.5.2) My app has both a menu and a toolbar.
Of course, the menu gets the Mac treatment and is not part of the
QMainWindow window frame.  I am using the unified toolbar formatting
with:
    setUnifiedTitleAndToolBarOnMac(true);

Looks pretty good.  But the unified toolbar appears to "waste" about
10-12 pixels vertically compared with other Mac apps.  We would like
to eliminate this waste.

The lozenge on the window frame hides/shows the toolbar correctly.
The remaining window frame is correct.

There is a context menu on the toolbar that hides the toolbar, but
some flab remains.  What is that flab and how can I get rid of it?  Is
it some vestigal remains of the app menu?