ManaPlus/data/graphics/gui/dropdown.xml

<?xml version="1.0" encoding="utf-8"?>
<skinset name="Default" image="window.png">
    <widget type="Window" xpos="89" ypos="100">
        <option name="padding" value="1" />
        <option name="frameSize" value="2" />
        <option name="imagePadding" value="2" />

        <part type="down" xpos="0" ypos="32" width="12" height="12" />
        <part type="up" xpos="0" ypos="48" width="12" height="12" />
    </widget>
</skinset>