bug#54441: 28.0.92; set-language-environment causes Apple Color Emoji cannot show up

[Will Chang]

> So it's a "C" (a.k.a. "Posix") language environment, looks like.
> Somewhat strange, but maybe this is "usual" on macOS?

On the previous Emacs Mac Port versions, Emacs doesn't need to set

the code below to enable Emoji and the UTF-8 environment doesn't affect it.

  (set-fontset-font "fontset-default" 'unicode "Apple Color Emoji" nil 'prepend)

Maybe it's a bug on that port, I CC'ed the maintainer Mituharu.

> What happens if you evaluate
>
>   (set-fontset-font "fontset-default" 'unicode "Apple Color Emoji" nil 'prepend)
>
> again, after changing the language environment?

It remains the same.

> AFAICT, this shows that "incorrect" means Emacs uses the Symbola font.

Thanks for the info.

> Does Apple Color Emoji on your system have glyphs for the #x1F300 and
> #x1F600 characters?  Those are the characters we request to be
> supported by a font that is used for emoji.

I believe it has.

Currently, I removed the UTF-8 code and set the Apple Color Emoji font for a

temporary solution.

Again, thanks for your help, I learned a lot with your conversation, you're so kind. ;)

On Sat, Mar 19, 2022 at 2:53 PM Eli Zaretskii <eliz@gnu.org> wrote:

[Please use Reply All so that the bug tracker is CC'ed.]

> From: Will Chang <will.b.chang@gmail.com>
> Date: Sat, 19 Mar 2022 11:06:06 +0800
>
> >does this happen in "emacs -Q", if you evaluate the above
> immediately upon entering Emacs?
>
> Yes. Tested it on:
> "GNU Emacs 28.0.92 (build 2, x86_64-apple-darwin21.4.0, Carbon Version 165
> AppKit 2113.4)
>  of 2022-03-18"
> "GNU Emacs 28.0.92 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60
> Version 10.14.6 (Build 18G95))
>  of 2022-03-14"
>
> > what is the language environment before the evaluation of
>     set-language-environment above?
>
> I run describe-language-environment and got:
>
> English language environment
>
> Nothing special is needed to handle English.
>
> Sample text:
>   Hello!, Hi!, How are you?
>
> Input methods:
>   programmer-dvorak ("DVP@" in mode line)
>   english-dvorak ("DV@" in mode line)
>
> Character sets:
>   ascii: ASCII (ISO646 IRV)
>
> Coding systems:
>   nothing specific to English

So it's a "C" (a.k.a. "Posix") language environment, looks like.
Somewhat strange, but maybe this is "usual" on macOS?

> > what is the output of "M-x describe-fontset RET fontset-default RET"
>     after evaluating set-language-environment, in particular in the
>     Emoji block starting from #x1F600?
>
> 😀 .. 🙏 (#x1F600 .. #x1F64F)
>     -*-Apple Color Emoji-*-*-*-*-*-*-*-*-*-*-*-*
>     -*-Noto Color Emoji-*-*-*-*-*-*-*-*-*-*-iso10646-1
>     -*-Symbola-*-*-*-*-*-*-*-*-*-*-iso10646-1
> [-*-Symbola-normal-normal-semicondensed-*-12-*-*-*-p-0-iso10646-1]

It sounds like Emacs used Symbola, although Apple Color Emoji is in
the list, and is first in the list.  Which probably means Emacs
examined Apple Color Emoji and rejected it for some reason.

What happens if you evaluate

  (set-fontset-font "fontset-default" 'unicode "Apple Color Emoji" nil 'prepend)

again, after changing the language environment?

> >what did you mean by "emoji doesn't show up correctly"? how was it
>     displayed "incorrectly"?
>
> The screenshots:
> - default: https://i.imgur.com/jLcwEDk.png
> - English with fontset(correctly): https://i.imgur.com/qgqhCHF.png
> - UTF-8 with fontset: https://i.imgur.com/tkjOVGv.png

AFAICT, this shows that "incorrect" means Emacs uses the Symbola font.

Does Apple Color Emoji on your system have glyphs for the #x1F300 and
#x1F600 characters?  Those are the characters we request to be
supported by a font that is used for emoji.