bug#54970: 28.1; Some emoji no longer display

[Eli Zaretskii]

> From: Howard Melman <hmelman@gmail.com>
> Date: Sun, 17 Apr 2022 10:49:35 -0400
> 
> 
> > On Apr 17, 2022, at 10:44 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> > 
> > Emacs also displays tofu if it finds no suitable font.  What you
> > describe sounds like Emacs found some font that claimed to have a
> > glyph for this codepoint, but the glyph displays as blank.  Which is,
> > of course, in contradiction with the "no font available" part, so I
> > admit I don't understand what happened on your system.  Was that in
> > "emacs -Q"?
> 
> Yes it was.

Does this empty display happen with every character for which you have
no fonts?  For example, what about this string: 𓂋𓏤𓈖𓆎𓅓‌𓏏𓊖?

On my system, characters for which Emacs cannot find a font display as
"tofu": small squares that show the codepoint of the character in
hex.  That's what should happen by default in those cases.