Bug 1223434 - /etc/fonts/conf.d/21-emoji-rendering.conf makes emoji rendering in Firefox worse
Summary: /etc/fonts/conf.d/21-emoji-rendering.conf makes emoji rendering in Firefox worse
Status: NEW
Alias: None
Product: openSUSE Tumbleweed
Classification: openSUSE
Component: Firefox (show other bugs)
Version: Current
Hardware: x86-64 openSUSE Tumbleweed
: P5 - None : Normal (vote)
Target Milestone: ---
Assignee: Factory Mozilla
QA Contact: E-mail List
URL:
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Keywords:
Depends on:
Blocks:
 
Reported: 2024-04-26 15:57 UTC by Gerald Chen
Modified: 2024-04-30 09:58 UTC (History)
2 users (show)

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Found By: ---
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
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martin.sirringhaus: needinfo? (i)

Attachments
With 21.conf vs without 21.conf (424.22 KB, image/png)
2024-04-26 15:57 UTC, Gerald Chen 		Details
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Description Gerald Chen 2024-04-26 15:57:39 UTC 
Created attachment 874523 [details]
With 21.conf vs without 21.conf

I've noticed that emoji look weird in Firefox, as shown in the upper side of the attachment (look at those spooky triangle eyes!). After deleting /etc/fonts/conf.d/21-emoji-rendering.conf, emoji got rendered properly, as shown in the lower side of the attachment.

Other applications, such as Konsole and Chromium, don't have this problem.

/etc/fonts/conf.d/21-emoji-rendering.conf says that emoji fonts don't need hinting. It seems not to be the case.

My fontconfig file in home directory hasn't specified hinting or hintstyle.

System info:
Operating System: openSUSE Tumbleweed 20240423
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0
Qt Version: 6.7.0
Kernel Version: 6.8.7-1-default (64-bit)
Graphics Platform: Wayland

Other files in /etc/fonts/conf.d:
09-autohint-if-no-hinting.conf
10-hinting-slight.conf
10-rendering-options.conf
10-scale-bitmap-fonts.conf
10-sub-pixel-none.conf
10-yes-antialias.conf
11-base-rendering.conf
11-lcdfilter-default.conf
12-tt-monospace-rendering.conf
13-selective-rendering.conf
13-selective-rendering-ipa.conf
20-unhint-small-vera.conf
22-noto-cjk-rendering.conf
30-metric-aliases.conf
31-metric-aliases-bw.conf
32-emoji-reject.conf
32-symbol-substitution.conf
40-nonlatin.conf
45-generic.conf
45-latin.conf
48-spacing.conf
49-family-default.conf
49-family-default-emoji.conf
49-sansserif.conf
55-local.conf
56-user.conf
58-family-prefer-local.conf
59-family-prefer-lang-specific-cjk.conf
59-family-prefer-lang-specific.conf
59-family-prefer-lang-specific-noto.conf
60-family-prefer.conf
60-generic.conf
61-latin.conf
61-stix.conf
61-wine-aliases.conf
65-fonts-persian.conf
65-nonlatin.conf
69-unifont.conf
70-reject.conf
80-delicious.conf
90-synthetic.conf
README
Comment 1 Martin Sirringhaus 2024-04-30 09:58:31 UTC 
I can confirm on GNOME as well. 

It seems like it's not about hinting, but antialias. If I comment out 
```
      <edit name="antialias" mode="assign">
        <bool>false</bool>
      </edit>
```
emojis are 'pretty' again.

Not sure, if this is a Firefox-issue or a font-config issue, though.

This seems related to: https://github.com/openSUSE/fonts-config/issues/12

Marguerite, could you maybe take a look please?