bug#71569: 30.0.50; Noto Color Emoji does not work in Emacs for Android

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> Cc: 71569@debbugs.gnu.org
>> Date: Sun, 16 Jun 2024 10:24:04 +0800
>> From:  Po Lu via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
>> 
>> Antonio Romano <n58r@pm.me> writes:
>> 
>> > Good evening, I've been trying to view emojis on Emacs for Android and
>> > noticed that colored emojis do not appear, while monochrome emojis do
>> > appear instead. I've only experimented with Noto Emoji Colore and Noto
>> > Emojis so far.
>> >
>> >
>> > Steps to reproduce:
>> >
>> > 1. Install both Noto Emoji (monochrome emojis) and Noto Emoji Color
>> > (colored emojis) and copy the two .TTF files to ~/fonts
>> >
>> > 2. Restart Emacs with -Q
>> >
>> > 3. Execute the following
>> >
>> > (set-fontset-font t 'emoji '("Noto Color Emoji" . "iso10646-1") nil
>> > 'prepend)
>> >
>> > 4. Try to insert emojis and notice that blank "spaces" are inserted,
>> > instead
>> >
>> > 5. Repeat step 3 but with "Noto Emoji" font and see how the blank
>> > spaces
>> > are filled with the respective monochrome emojis
>> >
>> >
>> > I'm using the latest SourceForge release of Emacs for Android.
>> >
>> > If this is not a big but a known limitation known I believe
>> > it's appropriate to specify it under Android section of the Emacs
>> > manual
>> 
>> The font driver doesn't yet grok color fonts, yes.  I'll see to
>> documenting this restriction.
>
> Did you have an opportunity to document this (in PROBLEMS, I guess?)

I did in the Android appendix of the user manual.