bug#49731: 28.0.50; Filter xref results by filename

[Eli Zaretskii]

> Cc: 49731@debbugs.gnu.org
> Date: Sat, 31 Jul 2021 18:45:35 +0200
> From:  Daniel Martín via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Dmitry Gutov <dgutov@yandex.ru> writes:
> 
> >
> > But do we want it to be implemented using outline-mode? Because we
> > want the corresponding visuals? Because otherwise a dedicated
> > implementation shouldn't take much more code either (probably roughly
> > the size of xref-truncation-width feature we added recently).
> >
> 
> Yes, I think implementing the feature using outline-mode is not a good
> idea.

How about using selective-display?