QML Item::contains() always returns true

import QtQuick 2.3

Rectangle {
    width: 400
    height: 400
    color: "green"

    Rectangle {
        id: block
        width: 50
        height: 50
        color: "red"

        anchors.centerIn: parent
    }

    MouseArea {
        anchors.fill: parent

        onClicked: {
            var pnt = mapToItem( block, mouse.x, mouse.y );
            console.log( "pnt x:", pnt.x, "y:", pnt.y );
            if ( block.contains( pnt ) ) {
                console.log( "Inside" );
            } else {
                console.log( "Outside" );
            }
        }
    }
}