bug#43177: Bug: Emacs 27.1 hangs forever in `FcCharSetSubtractCount' from '/usr/lib/libfontconfig.so.1'

[Eli Zaretskii]

> From: Robert Pluim <rpluim@gmail.com>
> Cc: 43177@debbugs.gnu.org,  schwab@linux-m68k.org,
>   emacs@Alexander.Shukaev.name
> Date: Mon, 07 Sep 2020 16:18:07 +0200
> 
>     Eli> Then I guess we should install it.
> 
> If anyone wants me to change the name or the verbiage, speak up,
> otherwise Iʼll push this tomorrow.

Speaking up:

> +** Fonts are no longer always searched for in all available backends.
> +Previously, when looking for a matching font, Emacs would check all
> +the available font backends, even if it had already found a match.
> +This could cause slowdowns with large numbers of fonts installed, and
> +in most cases the font found by later backends was never used.  This
> +behavior can be changed by setting 'font-query-all-backends' to t.

Please include in the text the description of the new behavior.  It is
hinted by what the text says, but I'd rather we said that explicitly.
Also, the last sentence would be more clear, IMO, if it started with
"To get back the old behavior, set ...".

And finally, I think you can mark this entry with "---", as I don't
think it should be in the manual.

Thanks.