QStyle::subControlRect() gives incorrect result for slider handle

 QStyle *style = slider->style();
    QStyleOptionSlider *option = new QStyleOptionSlider;
    option->rect = slider->rect();
    option->maximum=slider->maximum();
    option->minimum=slider->minimum();
    option->sliderValue=slider->value();
    QRect handle = style->subControlRect(QStyle::CC_Slider, option,
                                         QStyle::SC_SliderHandle, slider);