QQuickWidget inside QDockWidget causes crash when docking/undocking

 	Qt5Guid.dll!QScopedPointer<QOpenGLFramebufferObjectPrivate,QScopedPointerDeleter<QOpenGLFramebufferObjectPrivate> >::data() Line 135	C++
 	Qt5Guid.dll!qGetPtrHelper<QScopedPointer<QOpenGLFramebufferObjectPrivate,QScopedPointerDeleter<QOpenGLFramebufferObjectPrivate> > >(const QScopedPointer<QOpenGLFramebufferObjectPrivate,QScopedPointerDeleter<QOpenGLFramebufferObjectPrivate> > & p) Line 983	C++
 	Qt5Guid.dll!QOpenGLFramebufferObject::d_func() Line 54	C++
 	Qt5Guid.dll!QOpenGLFramebufferObject::handle() Line 1330	C++
>	Qt5QuickWidgetsd.dll!QQuickWidgetPrivate::render(bool needsSync) Line 210	C++
 	Qt5QuickWidgetsd.dll!QQuickWidget::showEvent(QShowEvent * __formal) Line 1076	C++
 	Qt5Widgetsd.dll!QWidget::event(QEvent * event) Line 8881	C++
 	Qt5QuickWidgetsd.dll!QQuickWidget::event(QEvent * e) Line 1170	C++
 	Qt5Widgetsd.dll!QApplicationPrivate::notify_helper(QObject * receiver, QEvent * e) Line 3717	C++
 	Qt5Widgetsd.dll!QApplication::notify(QObject * receiver, QEvent * e) Line 3682	C++
 	Qt5Cored.dll!000000006695ab44()	Unknown
 	Qt5Cored.dll!0000000066965183()	Unknown
 	Qt5Widgetsd.dll!QWidgetPrivate::show_helper() Line 7811	C++
 	Qt5Widgetsd.dll!QWidgetPrivate::show_recursive() Line 7681	C++
 	Qt5Widgetsd.dll!QWidgetPrivate::showChildren(bool spontaneous) Line 8177	C++
 	Qt5Widgetsd.dll!QWidgetPrivate::show_helper() Line 7760	C++
 	Qt5Widgetsd.dll!QWidget::setVisible(bool visible) Line 8097	C++
 	Qt5Widgetsd.dll!QWidget::show() Line 7658	C++
 	Qt5Widgetsd.dll!QDockWidgetPrivate::setWindowState(bool floating, bool unplug, const QRect & rect) Line 1048	C++
 	Qt5Widgetsd.dll!QDockWidgetPrivate::plug(const QRect & rect) Line 995	C++
 	Qt5Widgetsd.dll!QMainWindowLayout::animationFinished(QWidget * widget) Line 1608	C++
 	Qt5Widgetsd.dll!QWidgetAnimator::abort(QWidget * w) Line 64	C++
 	Qt5Widgetsd.dll!QWidgetAnimator::animationFinished() Line 71	C++
 	Qt5Widgetsd.dll!QWidgetAnimator::qt_static_metacall(QObject * _o, QMetaObject::Call _c, int _id, void * * _a) Line 74	C++

void QQuickWidgetPrivate::render(bool needsSync)
{
    if (!context->makeCurrent(offscreenSurface)) {
        qWarning("QQuickWidget: Cannot render due to failing makeCurrent()");
        return;
    }

    QOpenGLContextPrivate::get(context)->defaultFboRedirect = fbo->handle();   //<<----error here fbo is NULL

    if (needsSync) {
        renderControl->polishItems();
        renderControl->sync();
    }

    renderControl->render();

    if (resolvedFbo) {
        QRect rect(QPoint(0, 0), fbo->size());
        QOpenGLFramebufferObject::blitFramebuffer(resolvedFbo, rect, fbo, rect);
    }

    static_cast<QOpenGLExtensions *>(context->functions())->flushShared();

    QOpenGLContextPrivate::get(context)->defaultFboRedirect = 0;
}