Re: Emacs pretest: highlight line number in display-line-numbers-mode?

[Eli Zaretskii]

> Date: Thu, 19 Oct 2017 10:18:25 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: help-gnu-emacs@gnu.org
> 
> If the default value of face `line-number-current-line'
> looked different from that of face `line-number' then
> there would be little need to pose the question of whether
> you can highlight the current line number differently.

This face is by default the same as line-number because of 2 reasons:

  . linum-mode did the same
  . using a different face makes redisplay slightly slower (because it
    disallows some redisplay optimizations)

> To find the face used, I use `list-faces-display' and look
> for either a face name that is a likely candidate
> (`line-number' is pretty obvious, in this case) or a face
> appearance that matches what I see.

There are other places where this doesn't work, e.g. on the mode line.