The Coq mailing list

[Clément Pit-Claudel <cpitclaudel AT gmail.com>]

On 2017-03-12 08:04, Ralf Jung wrote:
> This also helps with emacs 24:

Yup, this is more or less isomorphic to the snippet in company-coq's README 
:) (though your particular mutation looks incorrect to me)

>   ; Appending to the 'unicode list makes emacs unbearably slow.
>   (set-fontset-font ft nil (font-spec :name "DejaVu Sans Mono"))

Can you post a message to https://debbugs.gnu.org/cgi/bugreport.cgi?bug=21028 
about this ?  I've been trying to get this bug fixed for a (long) while, 
there is a patch, and all that's missing is evidence that the bug is worth 
fixing, so independent reproduction helps bump its priority.  Bonus points if 
you test the patch at https://github.com/cpitclaudel/emacs , of course :)

> ; If we 'append this to all fontsets, it picks Symbola even for some
> cases where DejaVu could be used.

That's because your setup uses "nil" for the fontset, which means "don't use 
DejaVu unless it's the only available option"

>   Unfortunately, the behavior of these emacs fontset-lists is entirely
> non-intuitive, 

That I do agree with :)

> But at least it's working, and not picking the bad TeX fonts.

Adding a regexp matching TeX fonts to face-ignored-fonts is a decent 
alternative for that specific purpose, though of course your snippet above 
does a lot more :)

Cheers,
Clément.