bug#39799: 28.0.50; Most emoji sequences don’t render correctly

[Mike FABIAN]

Eli Zaretskii <eliz@gnu.org> さんはかきました:

> If Gedit selects a font by looking at more than one codepoint (and I'm
> not sure this is how it works in Gedit), then Emacs doesn't work that
> way.

Yes, Gedit does this somehow with pango. It tries to avoid switching
fonts in places where it would look bad. For example, if you have a
default font supporting only ASCII and then there is a word containing
some non-ASCII character like “grün” it chooses a font containing the
“ü” for the whole word to avoid the “ü” looking out of place.

> In any case, are these sequences displayed as composed characters?
> Does "C-u C-x =" tell that the base character U+24C2 was composed with
> the following variation selector?  According to the setup in
> japanese.el, they should compose, if the font used for U+24C2 also
> supports the variation selectors.

Yes, it does tell that it was composed with the following character:

             position: 255 of 257 (99%), column: 0
            character: Ⓜ (displayed as Ⓜ) (codepoint 9410, #o22302, #x24c2)
              charset: unicode (Unicode (ISO10646))
code point in charset: 0x24C2
               script: symbol
               syntax: w        which means: word
             category: .:Base, L:Left-to-right (strong), l:Latin
             to input: type "C-x 8 RET 24c2" or "C-x 8 RET CIRCLED LATIN 
CAPITAL LETTER M"
          buffer code: #xE2 #x93 #x82
            file code: #xE2 #x93 #x82 (encoded by coding system utf-8-unix)
              display: composed to form "Ⓜ️" (see below)

Composed with the following character(s) "️" using this font:
  ftcrhb:-GOOG-Noto Color Emoji-normal-normal-normal-*-16-*-*-*-m-0-iso10646-1
by these glyphs:
  [0 1 9410 50 20 0 20 15 4 nil]

Character code properties: customize what to show
  name: CIRCLED LATIN CAPITAL LETTER M
  general-category: So (Symbol, Other)
  decomposition: (circle 77) (circle 'M')

There are text properties here:
  fontified            nil

-- 
Mike FABIAN <mfabian@redhat.com>
睡眠不足はいい仕事の敵だ。