ScrollBar behaves weirdly with certain paddings

import QtQuick 2.6
import Qt.labs.controls 1.0

ApplicationWindow {
    visible: true

    ListView {
        anchors.fill: parent
        model: 100
        delegate: Text {
            text: modelData
        }

        ScrollBar.vertical: ScrollBar {
            topPadding: 30
        }
    }
}