refression: QComboBox doesn't respect the item data's BackgroundRole in QCleanlooksStyle

#include <QtGui>

int main(int argc, char** argv) {
        QApplication app(argc, argv);
        app.setStyle(new QCleanlooksStyle);
        QWidget mw;
        QVBoxLayout *layout = new QVBoxLayout;
        QComboBox * comboBox = new QComboBox;
        layout->addWidget(comboBox);
        mw.setLayout(layout);

        comboBox->setEditable(true);
        comboBox->addItem("yellow");
        comboBox->addItem("green");
        comboBox->setItemData(0, Qt::yellow, Qt::BackgroundRole);
        comboBox->setItemData(1, Qt::green, Qt::BackgroundRole);
        qWarning() << qApp->style();


        mw.show();
        app.exec();
}