Bug 405091

Summary:	Subpixel rendering gets disabled when changing fonts
Product:	[Applications] systemsettings	Reporter:	Filip Fila <filipfila.kde>
Component:	kcm_fonts	Assignee:	Unassigned bugs <unassigned-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	bshah, nate, unassigned-bugs-null
Priority:	HI	Keywords:	usability
Version First Reported In:	5.16.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Filip Fila 2019-03-04 21:08:27 UTC

SUMMARY
After updating to Plasma 5.15 subpixel rendering gets disabled every time when changing fonts.

STEPS TO REPRODUCE
1. Change the system fonts -> the font previews lose subpixel rendering: https://i.ibb.co/27BBDvm/Screenshot-20190304-220033.png
2. Hit apply -> System Settings as a whole loses subpixel rendering: https://i.ibb.co/YTDhb6V/Screenshot-20190304-220100.png
3. Fire up System Settings again to see what it's supposed to look like (subpixel rendering works): https://i.ibb.co/cLYxxTf/Screenshot-20190304-220116.png

OBSERVED RESULT
Subpixel rendering does not work, first for the previews and then for the whole System Settings when the change is applied.

EXPECTED RESULT
Subpixel rendering always works, like before 5.15.

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux 
KDE Plasma Version: 5.15.2
KDE Frameworks Version: 5.55.0
Qt Version: 5.12.1

Comment 1 Filip Fila 2019-03-04 21:15:24 UTC

I've just reproduced it in master as well. Tested with the latest KDE Neon Unstable Dev.

Comment 2 Bhushan Shah 2019-06-12 07:13:48 UTC

Can you check if this is still reproducible with git master/ Neon dev unstable?

Thanks.

Comment 3 Filip Fila 2019-06-12 08:29:51 UTC

(In reply to Bhushan Shah from comment #2)
> Can you check if this is still reproducible with git master/ Neon dev
> unstable?
> 
> Thanks.

It definitely is. Checked with updated Neon dev unstable.

And not only is subpixel rendering off after changing a font, you can see font metrics are also affected.

When changing to a different font: https://i.ibb.co/wKC7BvS/Screenshot-20190612-102530.png

When starting System Settings again: https://i.ibb.co/HLZ02rc/Screenshot-20190612-102542.png

Comment 4 Filip Fila 2020-02-25 09:33:12 UTC

Doesn't seem to be a problem anymore in 5.18.1 although I haven't seen a commit that directly addressed this.

Comment 5 Nate Graham 2020-02-25 15:58:08 UTC

Same. Probably fixed by the recent KConfigXT stuff.