bug#35816: 26.2; set-frame-font cannot set some fonts which autocomplete suggests due to dashes in names. I.e. gnu-unifont

[Eli Zaretskii]

> From: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Lars Ingebrigtsen <larsi@gnus.org>,  lockywolf@gmail.com,
>   35816@debbugs.gnu.org
> Date: Thu, 12 Aug 2021 09:31:44 +0200
> 
> On Aug 12 2021, Eli Zaretskii wrote:
> 
> > Another important API that accepts font names is
> > set-face-font, and you will see that there's already some heuristics
> > in set-face-attribute to support the likes of "Courier-10", which is a
> > Fontconfig format of specifying a font family.
> 
> Note that fontconfig requires a dash in the family name to be quoted.
> 
> $ fc-match 'Montserrat\-ExtraLightItalic'
> Montserrat-ExtraLightItalic.pfb: "Montserrat-ExtraLightItalic" "ExtraLight"
> $ fc-match 'Montserrat-ExtraLightItalic'
> Montserrat-Regular.otf: "Montserrat" "Regular"

That's not what Emacs requires, at least not according to the manual.
And the code doesn't seem to support such quoting, unless I'm missing
something.