In Firefox 61, a bunch of emoji don't display correctly in colour anymore. Downgrading Firefox to 60.0.1 fixes this and no-other applications seem to be affected.
Might be related to T6597.
Broken emoji
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ☺️ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ☹️ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Working emoji
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Screenshot
This doesn't seem related to T6597 as disabling system hunspell doesn't fix the issue. If I had to guess our freetype2 or fontconfig need updating, or firefox may be providing it's own fontconfig similarly to chromium.
If Firefox doesn’t bundle fontconfig, any ideas for why the latest update is causing emoji to break?
Doesn't work at all in the latest Chrome, so the fact that it works partially points to freetype2, yeah.
Updating harfbuzz, fontconfig and freetype2 to the latest versions and rebuilding firefox against them doesn't fix the issue. However, it could be related to this https://bugzilla.mozilla.org/show_bug.cgi?id=1358240
After updating Firefox to v61.0-r133, this issue still persists, so it indeed seems unrelated.
This looks like it could be the reason. If Firefox now uses Twemoji because of EmojiOne's new proprietary license, perhaps Solus should include Twemoji too?
Twemoji is open-source and actively maintained by Twitter Inc. It looks very similar too.
https://github.com/twitter/twemoji
Other distributions let users choose their emoji font. This is a good idea and lets users select what they prefer. See T5848.
Plasma allows to select what emojis to use (only in Qt apps, I believe).
Anyways yeah, this is the EmojiOne EULA, while Twemojis is licensed with MIT + CC.