>> Another user reported an apparently similar problem in bug#60585.  It 
>> disappears when scroll-bars are turned off.  Is that by any chance also 
>> the case for the problem you see, Dmitry?  It's not a proper solution 
>> of course, but it might perhaps hint at a proper solution.
>
> I checked with and without the last patch (the base behavior of 
> emacs-29): the scroll-bar doesn't seem to make a difference.
>

Okay, thanks.

>
> The original complaint was about height shrinking anyway, and the only 
> scroll-bar visible by default is the vertical one (on the right). It 
> doesn't seem likely that it would affect the calculation of the window's 
> height.
>

Hmmm...  Then can you perhaps also try with and without the menu-bar and 
the tool-bar?  Unless both are already disabled in your configuration, of 
course.