bug#15420: 24.3; Symbols like 🚴 (U+1F6B4) are not displayed by default

[Eli Zaretskii <eliz@gnu.org>]

> From: Mike FABIAN <maiku.fabian@gmail.com>
> Date: Thu, 15 Aug 2019 11:25:09 +0200
> Cc: Lars Ingebrigtsen <larsi@gnus.org>, 15420@debbugs.gnu.org
> 
> For years I did build with my little extra  patch on top of git master,
> like this:
> 
> commit 258c86a974f788a33a019a082473781a2a603043
> Author: Mike FABIAN <mfabian@redhat.com>
> Date:   Tue Sep 17 18:41:50 2013 +0200
> 
>     Display some symbols correctly by default
>     
>     For example display U+1F6B4 BICYCLIST and Egyptian Hieroglyphs
>     correctly by default.
> 
> diff --git a/lisp/international/fontset.el b/lisp/international/fontset.el
> index 0413646dfb3..bba5c58c79a 100644
> --- a/lisp/international/fontset.el
> +++ b/lisp/international/fontset.el
> @@ -912,6 +912,10 @@ setup-default-fontset
>  		    '("gnu-unifont" . "iso10646-1") nil 'prepend)
>    (set-fontset-font "fontset-default" nil
>  		    '("mutt-clearlyu" . "iso10646-1") nil 'prepend)
> +  (set-fontset-font "fontset-default" nil
> +		    '("Symbola" . "iso10646-1") nil 'prepend)
> +  (set-fontset-font "fontset-default" nil
> +		    '("Noto Sans Egyptian Hieroglyphs" . "iso10646-1") nil 'prepend)
>    (set-fontset-font "fontset-default" '(#x20000 . #x2FFFF)
>  		    '(nil . "unicode-sip"))
>  
> 
> But now I tried again with current master without that patch and it
> worked. Symbola was used for the bicycles and "Noto Sans  Egyption
> Hieroglyphs" for the  hieroglyph even without my patch. So something
> seems to have been fixed.

You will see in lisp/international/fontset.el that the #x1F680 --
#x1F6FF block is now configured to use Symbola by default, which is
why the BICYCLE and BICYCLIST are displayed without any changes.  As
for the Egyptian Hieroglyphs, we don't do anything about them, so if
you see a change in behavior, that must be due to some changes on your
system not directly related to Emacs.  In general, the hieroglyphs
still require fontset customizations, because most fonts that support
them don't explicitly announce that support (and the number of fonts
supporting Egyptian Hieroglyphs is very small anyway, and most of them
aren't free).

In any case, this is not a bug, and I see nothing we can do here to
make the situation significantly better.  Users who want the
hieroglyphs will have to customize their fontset.