To call raise() on an application's main window doesn't raise it on OS X

If your application's main window is 'hidden' behind other applications and you then call:

activateWindow();
raise();

You would expect to show up in front of all the other applications, and this is the case on Linux (Windows is a different story, as explained in the Qt documentation). However, on OS X, the application still remains behind the other applications. In other words, it would seem that raise() has no effect whatsoever on the application. FWIW, it used to be fine using Qt 4.8.x.

Attached is the source code of a small application which illustrates the issue. Build it, start it and hide it behind some other applications. 3 seconds later, it will try to raise itself, and will do it again 3 seconds later, etc.