QCoreApplication::setAttribute(Qt::AA_DontUseNativeMenuBar, false);
QCoreApplication::setAttribute(Qt::AA_DontShowIconsInMenus, true); // probono: need to use myAction->setIconVisibleInMenu(true); for menu items that shall get the icon nevertheless
In Menu:
action->setIcon(QIcon(IconCand));
action->setIconVisibleInMenu(true); // So that an icon is shown even though the theme sets Qt::AA_DontShowIconsInMenus
In QtPlugin:
In Menu: