Tabbed UI with Tab's page in component does not get correct parent size

[Arto Jalkanen]

This problem is shown with QtCreator's built-in template for "Tabbed UI" with minimal changes to demonstrate the bug.

Please see the attached example. It is much clearer than the confusing description I am about to unleash:

If Tabs' Tab's page property is not directly embedded, but is either a Component loaded using Loader or a Component in another file, the size of the parent is not correct which easily results in elements missing as they are under the header.

See the "First tab" in the included example. It works correctly if uncommenting the marked lines, showing the text, but if using the component the text is not shown (as it will somehow get under the header).