bug#33732: 27.0.50; line-number-current-line face bug

[Eli Zaretskii]

Ping!  Jonas, did you have a chance to test the change?

> Date: Fri, 14 Dec 2018 10:46:30 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 33732@debbugs.gnu.org
> 
> > From: Jonas Westlund <jonaswestlund101@gmail.com>
> > Date: Thu, 13 Dec 2018 22:49:03 +0100
> > 
> > When using the built-in display-line-number, placing the point at the
> > last line of the file/end of buffer will make the rest of
> > the display-number area adopt the line-number-current-line
> > face. Modifying the face's background thus produces this kind of effect:
> > 
> > https://i.imgur.com/pO214Wf.png
> 
> Thanks, I tried to fix this on the emacs-26 branch with the patch
> below.
> 
>     Fix display of line numbers in empty lines beyond EOB
>     
>     * src/xdisp.c (maybe_produce_line_number): When the current
>     line is at EOB, use the 'line-number-current-line' face only
>     on that single line, but not on the rest of empty lines beyond
>     EOB.  (Bug#33732)
> 
> diff --git a/src/xdisp.c b/src/xdisp.c
> index 808eab7..435ab2c 100644
> --- a/src/xdisp.c
> +++ b/src/xdisp.c
> @@ -21185,7 +21185,10 @@ maybe_produce_line_number (struct it *it)
>        if (lnum_face_id != current_lnum_face_id
>         && (EQ (Vdisplay_line_numbers, Qvisual)
>             ? this_line == 0
> -           : this_line == it->pt_lnum))
> +           : this_line == it->pt_lnum)
> +       /* Avoid displaying the line-number-current-line face on
> +          empty lines beyond EOB.  */
> +       && it->what != IT_EOB)
>       tem_it.face_id = current_lnum_face_id;
>        else
>       tem_it.face_id = lnum_face_id;
> 
> 
> 
>