Help tooltip switches to different function overloading while typing parameters

1. Open a source file with the following lines:

   QMessageBox mb;
   mb.addButton(
   

2. Place your cursor at the end of the second line and press Ctrl+Space.
   Creator shows a tooltip with the parameters of the function.
3. Let's say you want to use the second overloading of the function. Press "Down" arrow.
   The tooltip now shows the second overloading.
4. Type a string parameter and then a comma to proceed to the next parameter.
   The tooltip switches back to the first overloading of the function.

When the user selected an overloading, Creator should stick to that.