Created attachment 108548 [details]
Wrong slider handler calculation only in org.kde.desktop style

When using "from" property with negative values and org.kde.desktop style, the handler is positioned to the positive side. This is the code tested:

import QtQuick 2.7
import QtQuick.Controls 2.0

ApplicationWindow {
    id: window
    width: 400
    height: 30
    color: palette.window

    SystemPalette {
        id: palette
    }

    Slider {
        anchors.fill: parent
        from: -10
        value: 0
        to: 10
        stepSize: 1
    }
}

And attached a comparison with other styles.