ListView's Delegate has invalid spacing for huge elements number

import QtQuick 2.4
import QtQuick.Controls 1.3
import QtQuick.Window 2.2

ApplicationWindow {
    title: qsTr("Example 2")
    width: 640
    height: 480
    visible: true

    toolBar: Text {
        width: toolBar.width
        wrapMode: Text.WordWrap
        text: "Description: Scroll down. Spacing between delegates is invalid"
    }

    ScrollView {
        anchors { fill: parent }
        flickableItem.interactive: true

        ListView {
            id: listView

            anchors { fill: parent }

            spacing: 10

            model: 1000000
            delegate: Rectangle {
                width: listView.width
                height: 90 //e.g. for 118 layouting work correctly (118 + 10(spacing) = 128) ?
                border.color: "black"
                color: "gray"

                Text {
                    anchors.centerIn: parent
                    color: "black"
                    text: index
                }
            }
        }
    }
}