combined use of MDI subwindows (maximized) and WA_DeleteOnClose can lead to inconsistent states

Steps to reproduce, with the attached example (slightly modified MDI example) :
problems encountered are marked with two stars in front (**)

> 1. Click on the "New" tool button. This creates a persistent window
> [document1.txt]; even after you click the [X] button in the subwindow frame,
> the window still exists, as you can see in the Window menu. If you select its
> entry in the Window menu the window will reappear.
>
> 2. Maximize the document1.txt subwindow.
>
> 3. Click document1.txt subwindow's [X] button to close it (without restoring
> it to Normal size).
>
> 4. Click the "New" tool button again to create a persistent document2.txt
> window.
>
> 5. Maximize the document2.txt subwindow.
>
> 6. Click the "New Transient" tool button (the New button with the "T" in it).
> This creates the document3.txt subwindow, which appears already maximized.
>
> 7. Click the document3.txt subwindow's [X] button to close it.
>
> ** The document2.txt subwindow is now shown. However, it is now shown in
> Normal state rather than maximized.
>
> 8. ** If you click anywhere in the document2.txt subwindow, including on the
> subwindow frame, the document2.txt window will now maximize itself.
>
> 9. Click on the [X] button of the document2.txt window and it will hide itself.
>
> ** But, you will now see the frame of document1.txt, however the internal
> QTextEdit is not visible. The QTextEdit will not appear until you select
> "document1.txt" from the Window menu.
>
> So, there seem to be three problems here: After the maximized transient window
> is closed, the previously maximized persistent window is shown in Normal mode.
> But it won't accept input until it maximizes itself on the next click inside
> of it. Closing the maximized persistent subwindow causes the frame of the
> previous persistent subwindow frame to appear, but the subwindow frame is
> empty.