bug#39340: 26.3; "Noto Emoji" font not displayed

[Eli Zaretskii]

> From: ynyaaa@gmail.com
> Cc: 39340@debbugs.gnu.org
> Date: Thu, 30 Jan 2020 14:13:47 +0900
> 
> >> Evaluating the following form, only "©® ⃣〰〽㊗㊙" can be displayed.
> >>   (set-fontset-font t '(#x80 . #x1FFFF) "Noto Emoji")
> >> 
> >> Other characters listed below are displayed with other fonts or boxed
> >> hex numbers.
> >
> > Please tell more details, in particular what do you mean by "can be
> > displayed", and also which of the characters you show are displayed
> > with other fonts and which with boxes with hex codepoints.
> 
> 'C-u C-x =' on displayable characters shows a font name in *Help* buffer:
>             character: © (displayed as ©) (codepoint 169, #o251, #xa9)
>     uniscribe:-outline-Noto 
> Emoji-normal-normal-normal-mono-13-*-*-*-c-*-iso8859-1 (#x11)
> Starting with 'emacs -Q', the font name is shown as below.
>             character: © (displayed as ©) (codepoint 169, #o251, #xa9)
>     uniscribe:-outline-Courier 
> New-normal-normal-normal-mono-13-*-*-*-c-*-iso8859-1 (#x8B)
> 
> As for U+20E3( ⃣:COMBINING ENCLOSING KEYCAP), the glyph in "Noto Emoji"
> is drawn as a 3D button. I can see visually the glyph difference from
> other fonts.
> 
> >> non-displayable characters
> >
> > What does "non-displayable" mean in this context?
> 
> I attach an HTML file noto-emoji.html, which contains characters easy to
> see the difference, and screen shots of the file.
> 
> "Noto Emoji" does not have ASCII alphabets nor glyphs for characters
> from U+1F641 to U+1F645.(It has ASCII digits.)

Thanks, I think setting use-default-font-for-symbols to nil will solve
this issue as well, because all the characters you show in those
examples are symbols (as are all Emoji).

Please also note that the call to set-fontset-font you show above
makes no sense: this font is for displaying Emoji, so you should only
define it for the Emoji blocks.  Otherwise you will see strange
problems, because the heuristics we have in our font selection doesn't
assume such strange settings and doesn't cater to them.