QML ComboBox menu is not aligned with top of ComboBox when popup extends up and scale is not 1

When a ComboBox popup menu goes up instead of down, it does not align with the ComboBox if the ComboBox scale is something other than 1.

It's pretty cool that the ComboBox popup menu automatically avoids extending outside the window frame, but it looks pretty ugly when the Item it's on is scaled proportionally to the window size. Run the attached code and drag the window larger; the control itself looks fine but the menu does not scale correctly at all. As you get close to 1:1 scaling, the menu lines up but is you shrink the window smaller than 1:1 it misaligns in the opposite direction.

// main.qml in attached 7z file
ApplicationWindow {
    id: window
    width: 320; height: 240
    visible: true
    title: qsTr("ComboBox Scale Defect")    Rectangle {
        anchors.centerIn: parent
        width: 180; height: 180
        color: "lightblue"
        scale: window.height/height  // scale proportionally to window height        ComboBox {
            id: comboBox
            anchors.bottom: parent.bottom
            model: [ "one", "two", "three" ]
//            popup.scale: parent.scale   // fixes popup's font size, but not position
            Component.onCompleted: popup.open()
        }
    }
}

I see two issues when ComboBox scale is not 1:

• popup menu does not align with top of ComboBox
  • this is the focus of this issue
• popup menu is not scaled to match ComboBox
  • workaround is simple: popup.scale: parent.scale