Problem updating QDockWidget's title with translations

There seems to be a bug with the function of Qt's QDockwidget class, QWidget::setWindowTitle() when dynamically translating the application. The dock widget does not have the correct translation when it is docked to the main window. However, it has the correct translation when undocked (floating). See the attached screenshots.

The problem happens when the following conditions are met:

• Inheritate QDockWidget class into a custom class.
• Intercepting the language change event (dynamically translate the application in runtime) using the QWidget::changeEvent() in that custom class and call the QWidget::setWindowTitle() function.

For more informations please see this thread. I attached the sample project I made that can reproduce the bug.