bug#38181: Actual height of mode-line not taken into account

[Eli Zaretskii]

> From: Carlos Pita <carlosjosepita2@gmail.com>
> Date: Sat, 16 Oct 2021 18:27:10 -0300
> Cc: 38181@debbugs.gnu.org
> 
> In practice this seems to nicely cover the relevant cases:
> 
> (defun my-redisplay-hack (&rest _)
>   (when mode-line-format
>     (redisplay t)))
> (advice-add #'split-window :after #'my-redisplay-hack)

I wonder how this fixes anything, since split-window already triggers
redisplay.  Martin, do you understand the difference?

> but there is some flickering because the window is displayed before
> the fit and then immediately replaced by the fitted version.

Which means there are two redisplay cycles, and the first one (which
produces incorrect display) is the one from your hack.  So once again,
I wonder why that call to 'redisplay' is needed.