Bug 410733

Summary: Setting anti-aliasing or hinting breaks emoji display in GTK applications
Product: [Applications] systemsettings Reporter: rca
Component: kcm_fontsAssignee: Unassigned bugs <unassigned-bugs-null>
Status: REPORTED ---    
Severity: normal CC: bshah, kde, nate, unassigned-bugs-null
Priority: NOR    
Version First Reported In: 5.16.4   
Target Milestone: ---   
Platform: openSUSE   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description rca 2019-08-08 18:12:22 UTC 
SUMMARY

Setting any font hinting or anti-aliasing settings via kcm_fonts and pressing "apply" will generate a ~/.config/fontconfig/fonts.conf file that then breaks emoji display in GTK applications.


STEPS TO REPRODUCE
1. Ensure ~/.config/fontconfig/fonts.conf is not present
2. Open a gtk2 application (e.g. claws-mail) or a gtk3 application (e.g. gedit)
3. Type or copy/paste an emoji that you are certain you have the font for
4. Observe that the emoji appears (in color if you have a color emoji font)
5. Close these GTK applications
6. Go to System Settings -> Fonts
7. Enable anti-aliasing, enable hinting to "full", for example. Click apply
9. Restart claws-mail/gedit and look at the same text


OBSERVED RESULT

10. Observe that emoji no longer show. Instead, nothing is displayed in their place


EXPECTED RESULT

10. Observe that emoji are displayed correctly according to the emoji fonts installed

SOFTWARE/OS VERSIONS

Operating System: openSUSE Tumbleweed 20190806
KDE Plasma Version: 5.16.4
KDE Frameworks Version: 5.60.0
Qt Version: 5.13.0
Kernel Version: 5.2.5-1-default
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-6600K CPU @ 3.50GHz
Memory: 15.6 GiB of RAM
Comment 1 kde 2022-01-27 16:21:42 UTC 
I can confirm this bug still happens - No Emojis in Gtk programs with aliasing on, emojis are there with aliasing off.

Software versions:
Operating System: openSUSE Tumbleweed 20220125
KDE Plasma Version: 5.23.5
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
Kernel Version: 5.16.1-1-default (64-bit)
Graphics Platform: X11
Comment 2 kde 2022-01-27 16:29:35 UTC 
Could this be related to
https://bugzilla.mozilla.org/show_bug.cgi?id=1454152
also something with antialias breaking emojis.