Changing the window opacity of a QDockWidget containing an openGL widget causes the titlebar widget area to not redraw.

In my program when dragging to undock a QDockWidget I am calling setWindowOpacity(0) on the QDockWidget because I am creating my own drag feedback. When the QDockWidget is released I call setWindowOpacity(1).

This was working great in 5.0.1, but now in 5.0.2 if the QDockWidget contains an OpenGL widget then the now docked QDockWidget's titlebar is no longer redrawing.

As you can see from the attached image. The title bar area still contains the blue highlight from when it was docked.

The titlebar still functions, as does the close button on the title bar. It's just that you can't see them.