QWidget::windowModified propagation

If you have a widget with a parent window.
When you call setWindowModified(true) on this widget, this will get propogated to the window.
But if you call setWindowModified(false) on the widget it will not change the Window modified state back to not be modified.
This could be implemented if the window checked the state of all its children to see if there is another widget that is modified, if not it could set its state back to not modified.