Bug 407055 - KDE Plasma ignores local fonts.conf file when trying to use Opentype alternate features
Summary: KDE Plasma ignores local fonts.conf file when trying to use Opentype alternat...
Status: CONFIRMED
Alias: None
Product: plasmashell
Classification: Plasma
Component: general (show other bugs)
Version: 5.15.3
Platform: Other Linux
: NOR normal
Target Milestone: 1.0
Assignee: David Edmundson
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-04-29 16:55 UTC by Matt
Modified: 2025-03-21 21:49 UTC (History)
12 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Screenshot showing both text editors, Gedit shows the Opentype features, Kate does not. (457.69 KB, image/png)
2019-04-29 16:55 UTC, Matt
Details
Screenshot showing that IBM Plex Mono is the font in use in Kate (296.71 KB, image/png)
2019-04-29 16:57 UTC, Matt
Details
Screenshot showing IBM Plex Mono is the font in use in Gedit (156.21 KB, image/png)
2019-04-29 16:57 UTC, Matt
Details
Kate in Budgie also does not display the Opentype features (70.41 KB, image/png)
2019-04-29 20:19 UTC, Matt
Details

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Description Matt 2019-04-29 16:55:40 UTC
Created attachment 119715 [details]
Screenshot showing both text editors, Gedit shows the Opentype features, Kate does not.

SUMMARY
I'm trying to use IBM Plex Mono's Alternate stylistic set OpenType feature to get slashed zeroes. I have edited ~/.config/fontconfig/fonts.conf as described in [this wiki entry](https://wiki.archlinux.org/index.php/Font_configuration/Examples) but I can't seem to get  KDE to change the font this way. When I added the fonts.conf with the code from the wiki above in ~/.config/fontconfig/fonts.conf I get slashed zeroes on Solus Budgie. I tried logging in to the Plasma DE on Solus and I do not get the slashed zero. I also have this same issue on other distros I use with KDE Plasma. In Solus, when I open Gnome apps even in KDE they respect the local fontconfig but KDE apps do not. I have attached a screenshot to show how GTK apps show the alternate Opentype features but KDE ones do not.

Just in case anyone is wondering I am sure I am not just using a different font in Gedit. I have two other opentype features enabled (as you can see in the fonts.conf that cause an alternate a and g in the Gnome apps that respect the setting like Gedit).

STEPS TO REPRODUCE
1. Specify an Opentype alternate feature in ~/.config/fontconfig/fonts.conf
2. Observe that the feature is not showing up in KDE apps

OBSERVED RESULT
Opentype alternate stylistic settings specified in ~/.config/fontconfig/fonts.conf are not displayed in KDE apps.

EXPECTED RESULT
To see the Opentype alternate stylistic settings specified in ~/.config/fontconfig/fonts.conf displayed in KDE apps.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.15.3
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 Matt 2019-04-29 16:57:05 UTC
Created attachment 119716 [details]
Screenshot showing that IBM Plex Mono is the font in use in Kate
Comment 2 Matt 2019-04-29 16:57:33 UTC
Created attachment 119717 [details]
Screenshot showing IBM Plex Mono is the font in use in Gedit
Comment 3 David Edmundson 2019-04-29 17:09:32 UTC
> When I added the fonts.conf with the code from the wiki above in ~/.config/fontconfig/fonts.conf I get slashed zeroes on Solus Budgie.

What had the correct slashed zeroes? Kate running on budgie?
Comment 4 Matt 2019-04-29 17:12:57 UTC
(In reply to David Edmundson from comment #3)
> > When I added the fonts.conf with the code from the wiki above in ~/.config/fontconfig/fonts.conf I get slashed zeroes on Solus Budgie.
> 
> What had the correct slashed zeroes? Kate running on budgie?

Sorry for not specifying. The correct zeroes were in Gedit on Budgie (and the Budgie UI if I set IBM Plex Sans (used by the UI) to also have slashed zeroes).
Comment 5 David Edmundson 2019-04-29 17:19:18 UTC
If it's available, please can you test kate on budgie.

Alternatively unset  KDE_FULL_SESSION, XDG_CURRENT_DESKTOP from within plasma

I need to narrow down if you're saying it's all Qt apps (but in Qt QPA loading fontconfig) or a bug in plasma-integration, a Qt plugin loaded into all Qt apps via plasma to set default fonts.
Comment 6 Matt 2019-04-29 20:18:14 UTC
(In reply to David Edmundson from comment #5)
> If it's available, please can you test kate on budgie.
> 
> Alternatively unset  KDE_FULL_SESSION, XDG_CURRENT_DESKTOP from within plasma
> 
> I need to narrow down if you're saying it's all Qt apps (but in Qt QPA
> loading fontconfig) or a bug in plasma-integration, a Qt plugin loaded into
> all Qt apps via plasma to set default fonts.

It looks like Kate in Budgie also does not display the alternate style glyphs. I will attach another screenshot.
Comment 7 Matt 2019-04-29 20:19:08 UTC
Created attachment 119727 [details]
Kate in Budgie also does not display the Opentype features
Comment 8 Matt 2019-04-29 21:29:05 UTC
Comment on attachment 119727 [details]
Kate in Budgie also does not display the Opentype features

Notice how the title bar (Budgie) differs from the application itself. Same font, different Opentype alternate style for a and g.
Comment 9 Bug Janitor Service 2019-05-14 04:33:08 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 10 Matt 2019-05-14 06:45:41 UTC
Just wanted to add that if I type the command:
fc-match -v 'IBM Plex Mono'

into Konsole the fontfeatures are listed in the output, for example:

fontfeatures: "ss03"(w)
Comment 11 Nate Graham 2020-10-12 22:10:44 UTC
Not 100% where this needs to be moved to--possibly some Framework. But it's possible that Plasma or plasma-integration could be involved somehow too. Either way, moving out of System Settings.
Comment 12 elman 2021-05-04 14:05:52 UTC
I'm facing the same problem. I have Fira Sans as default font and then I set fontfeatures in ~/.config/fontconfig/conf.d/80-fira-sans-fontfeatures.conf (tnum on and zero on).

I have tested my config with fc-match and pango-view and everything seems to be OK.

GTK apps respect my settings (I have tried Filezilla and PulseEffects), however Qt apps don't respect my settings (I have tried Plasma, Dolphin, Kate, Double Commander Qt and KFind)
Comment 13 D. Debnath 2021-05-25 07:18:20 UTC
I can confirm this bug.

    $ fc-match --verbose 'Source Code Pro'

shows
    fontfeatures: "zero on"(w)
among other things.

but Konsole, Kate or KDE in general doesn't render the slashed zero feature of Source Code Pro, which is expected when the zero feature is turned on.

GIMP (gtk application) on the same system did show the slashed zero feature. Therefore, I can confirm that this is a KDE bug.
Comment 14 Akseli Lahtinen 2022-08-12 09:02:47 UTC
 I also have this issue. 

I've added the following to my file:

 <!-- ibm plex config -->
 
  <match target="font">
   <test name="family">
    <string>IBM Plex Sans</string>
   </test>
   <edit mode="assign_replace" name="fontfeatures">
    <string>ss02</string>
   </edit>
  </match>
 
  <match target="font">
   <test name="family">
    <string>IBM Plex Mono</string>
   </test>
   <edit mode="assign_replace" name="fontfeatures">
    <string>ss02</string>
   </edit>
  </match>

In GTK apps the glyphs show up as changed, but in KDE apps they do not.

System info:
Operating System: Fedora Linux 36
KDE Plasma Version: 5.25.4
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5
Kernel Version: 5.18.16-200.fc36.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 12 × AMD Ryzen 5 3600 6-Core Processor
Memory: 15,5 GiB of RAM
Graphics Processor: AMD DIMGREY_CAVEFISH
Comment 15 Luis 2025-02-24 04:55:20 UTC
Same here, I enable multiple features of the Commit Mono font, but it's all ignored.
Comment 16 Alexey Arutyunov 2025-03-21 21:49:19 UTC
I am also facing this issue now that I am trying to use Inter Display font with disambiguation feature (ss04) enabled.
With fontconfig changes GTK apps and Firefox have this feature enabled but KDE apps haven't.

Another side effect of this issue is that Digital Clock widget seems to have tabular numbers feature (tnum) forcefully enabled and there is no option to disable it. This behaviour seems illogical because clock looks completely different for lockscreen and SDDM. I'd prefer at least to have a checkbox in widget settings for it. Should I report a separate bug for that?

System info:
Operating System: Fedora Linux 41
KDE Plasma Version: 6.3.3
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.2
Graphics Platform: Wayland