Mac, Embedded Widget, Qt changes Window attributes and WindowClass

When a Qt widget is embedded to the provided window from a Non-Qt-Application, Qt changes the window attributes and WindowClass of the provided window. E.g., the Non-Qt-Application creates a kFloatingWindowClass, but Qt will change it to kDocumentWindowClass.

This is wrong. In this scenario we'll never know what kind of WndClass we'll get from the Non-Qt-Application.

Another result from this change is that Qt adds a Maximum and Minimum button to the provided window. Here, the qt application never knows which attributes the Non-Qt-Application has configured its provided window.

A possible workaround / solution is to remove line 4759 ("if (!(q->data->window_flags & Qt::CustomizeWindowHint))

") of "qwidget_mac.mm".

With this one comment, the provided window works like expected.