bug#41250: 28.0.50; Dired displays unconditionally ls-switches on modeline

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Fri, 02 Oct 2020 16:14:31 +0200
> Cc: 41250@debbugs.gnu.org, Arthur Miller <arthur.miller@live.com>
> 
> >   (let ((ellipsis (cond
> >                    (truncate-string-ellipsis)
> >                    ((char-displayable-p ?…) "…")
> >                    ("..."))))
> >     (truncate-string-to-width string max nil nil ellipsis))
> >
> > Preferably, this should be fixed with this patch:
> 
> Your patch is a distinct improvement on the current state of affairs, so
> please go ahead and push to master (with a NEWS item).
> 
> A new function that's more pixel-aware can be added at a later date, and
> is pretty much an orthogonal issue anyway.

To be pixel-aware, we need to use window-text-pixel-size.