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

[Stephen Berman]

On Thu, 15 Aug 2019 17:38:50 +0300 Eli Zaretskii <eliz@gnu.org> wrote:

>> 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,
[...]
>> 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,

Is this for technical reasons (e.g. redisplay speed) or a policy
decision such as not enough free fonts?  I ask because e.g. Firefox
seems to automatically find an installed font; for example, on my system
Firefox displays the hieroglyphs on
<https://en.wikipedia.org/wiki/Egyptian_Hieroglyphs_(Unicode_block)>,
presumably using the Aegyptus fonts installed in my system, while EWW
does not display the hieroglyphs (but does e.g. display the emoticons on
<https://en.wikipedia.org/wiki/Emoticons_(Unicode_block)>, some using
DejaVu, some using Symbola).

Steve Berman