currentItemChanged signal not gererated when clicking on check box of QTreeWidget

QTreeWidget is not working as expected when clicking on check-box of non-leaf item. My QTreeWidget has two level of child and each item in the tree widget can be checked (check-box is enabled for each item). In this QTreeWidget, leaf items are user selectable, but non-leaf items are not selectable and all items are enabled and user check-able.

• []Family node1
  • []Primary node1
    • []child1
  • []Secondary node1
    • []child1
• []Family node2
  • []Primary node2
    • []child2
  • []Secondary node2
    • []child2

Leaf items flag setting

Qt::ItemIsSelectable | Qt::ItemIsUserCheckable | Qt::ItemIsEnabled

Non-leaf items flag setting

Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsTristate

When we directly click on leaf item's associated check-box, Qt is generating currentItemChanged() signal. But, when we click directly on non-leaf item's associated check-box, then currentItemChanged() signal is not getting generated. This causes inconvenience in the non-leaf item handling.

It was working fine in Qt 4.7.4, but it is not working in Qt 4.8.1 on all platforms (Windows, Darwin, and Linux).

I attached a sample program to reproduce this bug.

Is this a bug or expected behavior?