bug#66141: 29.1; Window size properties not set immediately for window in new frame

[Eli Zaretskii]

> Date: Thu, 21 Sep 2023 18:16:01 +0200
> From: Mattias Nyrell <mattias@nyrell.se>
> 
> Starting from emacs -Q, enter the following in *scratch*:
> 
> (let ((f (make-frame '((fullscreen . maximized)))))
>    (select-frame-set-input-focus f)
>    (message "window-body-width=%s" (window-body-width))
>    (sleep-for 1)
>    (message "window-body-width=%s" (window-body-width)) )
> 
> Execute with C-x C-e
> 
> Result:
> - A new frame is created.
> - The message "window-body-width=80" is printed
> - The message "window-body-width=190" is printed (exact value depending
> on screen size of course)
> 
> Expected result:
> The first printed message should be the same as the second printed message.

Isn't it because the actual resizing of the frame is done by the
window-system, and we can only ask it to do so?

IOW, I think your expectation is incorrect, as it assumes that frame
move/resize operations are executed immediately.