QDockWidgets don't work with QGLWidgets in same window

When using QDockWidget on a window with a QGLWidget, the dock widgets fail to work properly. Dragging immediately stops and the widget is completely blank. only redocking gets the content back.

To reproduce, I just added another dock widget with a QGLWidget to the dockwidgets example code. Note that the same bug appears if the widget is the central widget as well (this was just easier to program).

void MainWindow::createDockWindows()
{

...

dock = new QDockWidget(tr("GL"), this);
QGLWidget *gl = new QGLWidget(dock);
dock->setWidget(gl);
addDockWidget(Qt::RightDockWidgetArea, dock);
}

A related bug: QTBUG-33581