bug#50178: 28.0.50; Size of echo area does not account for line-spacing

[Eli Zaretskii]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Date: Tue, 24 Aug 2021 04:08:41 +0200
> 
> Seems that on some circunstances the vertical space calculated for the
> text on the echo area does not account for the value of line-spacing:
> 
> emacs -Q
> M-x icomplete-vertical-mode
> M-x fido-mode
> (set-default 'line-spacing 0.1)
> 
> Now M-x will display a list of candidates with the last candidate
> partially visible for lack of vertical space.

And why is that a problem?  Emacs displays partially visible lines at
end of window in many cases; as long as the list of completion
candidates is long enough, you cannot see all of them anyway.

Or maybe you have a specific recipe in mind where this works
incorrectly, in which case please show that recipe.

Thanks.