bug#40097: 28.0.50; Preferred font ignored for specific charset

[Eli Zaretskii <eliz@gnu.org>]

> From: Sergey Organov <sorganov@gmail.com>
> Cc: Kenichi Handa <handa@gnu.org>,  40097@debbugs.gnu.org
> Date: Wed, 18 Mar 2020 07:43:39 +0300
> 
> > We could perhaps introduce a customizable variable that would allow
> > users who want that to disable the preference of charset-supporting
> > fonts when the text has the 'charset' property.  CC'ing Handa-san who
> > could comment on how important is this feature nowadays.
> 
> When I wrote original question, I was sure I've read somewhere in the
> docs that Emacs does prefer fonts with particular encoding, and then I
> missed it and can't find it anymore. I wonder if it is even documented,
> or did I read it somewhere else, maybe in some relevant discussion?
> 
> I mean if it's even undocumented and is not important nowadays, maybe
> it's indeed better to drop it rather than bother with customizations.
> And if it is to be customizable, it should probably be a fontset feature
> rather than global?

The customizable option indeed only makes sense if the feature is
still useful to some users in some use cases; otherwise we should just
remove this.

The fact that this is or isn't documented has no importance: we don't
document the internal implementation details, but we keep them as long
as they do what users expect and like.