activeFocusChanged signal is not emitted for FocusScope (with testcase)

import QtQuick 1.1

FocusScope {
  id: a
  width: 360
  height: 360

  onActiveFocusChanged: console.log("activeFocusChanged (a) " + activeFocus)

  Text {
    id: t
    focus: true
    anchors.centerIn: parent
    text: "a: " + a.activeFocus + " t: " + activeFocus

    onActiveFocusChanged: console.log("activeFocusChanged (t) " + activeFocus)

    MouseArea {
      anchors.fill: parent
      onClicked: a.forceActiveFocus()
    }
  }
}