bug#31315: wrong font encoding for fallback font

[Werner LEMBERG <wl@gnu.org>]

>> I can only repeat that Emacs might tag a certain text with GB18030
>> so that the user can deduce a Chinese origin.  However, there is
>> *no* guarantee that the user gets a Chinese-flavoured font – at
>> least not from the xft interface.[**]
> 
> IME, there's no guarantee about anything in the Emacs font look up
> heuristics, except that empirically it does TRT in about 85% of
> uses.

If you don't install pan-CJK Unicode fonts, I fully agree :-)

> May I invite you to work on revisiting the design and implementation
> of the Emacs font-look up facilities, and on modernizing them?  I'm
> afraid we didn't have an active developer in this area for several
> years, and I fear that we will stagnate (or already are stagnating).

Alas, my Elisp knowledge is ... well ... not impressive.  Basically,
I'm just an Emacs user, not an Emacs developer.

With Xft, there is no possibility for improvement IMHO.  The probably
best choice is to switch to Pango for font access (in case you don't
do that already).  An Emacs charset essentially triggers a language
and script setting, and those two parameters can be passed to Pango,
AFAIK.


    Werner