bug#26605: 25.1; emacs picks unsuitable fallback fonts for monospace default font

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sun, 17 Nov 2019 08:50:53 +0100
> Cc: 26605@debbugs.gnu.org
> 
> Ralf Jung <post@ralfj.de> writes:
> 
> > Ideally, emacs' default configuration would be such that it prefers
> > monospace over non-monospace fonts when falling back from a monospace font.
> 
> That does sound reasonable.  Has Emacs grown such a feature in the years
> since this bug was reported?

No, I don't think so.  The fallback uses the fontsets, so defining
those to put monospaced fonts before variable-pitch ones is the way to
go.  AFAIK, there's no logic in Emacs to select fallback fonts without
using the fontsets (the default ones if the user didn't customize
them).