bug#32337: 26.1; display-line-numbers-mode makes cursor ill-aligned when number face is changed

[Eli Zaretskii <eliz@gnu.org>]

> From: Carlos Pita <carlosjosepita@gmail.com>
> Date: Tue, 31 Jul 2018 16:19:39 -0300
> 
> With the new display-line-numbers-mode, if you customize faces to
> something like, say:
> 
>  '(line-number ((t (:height 0.85))))
>  '(line-number-current-line ((t (:height 0.85))))
> 
> Then the cursor will be ill-aligned (a bit shifted to the right) when
> it's in the last line of the buffer. This line has no number and it
> seems to be that the spacing is miscalculated using the default face
> size.

The empty "line" beyond EOB has the line-number field displayed using
the default face, indeed.  That's by design: using the same face as
for line numbers produces ugly effects, IMO, e.g., if the line-number
face defines a background color.  So I decided to use the default face
for that single place.  It doesn't look too bad, IMO, even in the case
you reported, as there's no text after the cursor.

I'd rather not introduce more complexity (like user options etc.),
unless the current display is deemed entirely unacceptable in such
cases.

Thanks.