Re: Better emoji support

[Eli Zaretskii]

> From: Kévin Le Gouguec <kevin.legouguec@gmail.com>
> Cc: rpluim@gmail.com,  emacs-devel@gnu.org
> Date: Mon, 20 Sep 2021 08:20:54 +0200
> 
> *Right now* (as of commit 995a623594), I'd expect them to be displayed
>  with Noto Color Emoji, since
> 
> (1) (char-table-range char-script-table ?↔) yields "emoji",
> (2) fontset.el indiscriminately slaps "Noto Color Emoji" on the whole
>     "emoji" script.
> 
> IOW my expectation comes from trying to understand what the code
> currently does, not necessarily from thinking it's The Right Thing.

Heh, welcome to the club.  At this point, we are generally happy if we
get the display right, even if we don't understand why the wrong
settings of the fontset were effectively ignored ;-)

But if you actually want to understand, then the only way is to step
through the font-selection code in fontset.c and see why it rejects
Noto Color Emoji.  If you find anything interesting, please tell us.

> IIUC Robert's tentative patch[1] gets us closer to The Right Thing, by
> making sure (char-table-range char-script-table C) is "emoji" iff C's
> Emoji_Presentation property is "Yes".

IMO, that's what we want; the emoji sequences should be handled via
composition-function-table, not via the fontset.