Bug 489678

Summary:	Telegram fails to redraw damaged screen regions
Product:	[Plasma] kwin	Reporter:	Lev <kyle1>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	nate
Priority:	NOR
Version First Reported In:	5.27.11
Target Milestone:	---
Platform:	Debian testing
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	6.0
Sentry Crash Report:

Description Lev 2024-07-03 14:10:42 UTC

SUMMARY

Latest Telegram desktop client (5.2+) doesn't update damaged screen regions on kwin-wayland. The bug was reported to Telegram developers and their reply was:

This means your compositor has a bugged implementation of damage tracking with fractional scaling. I don't think disabling fractional scaling support or partial damage support just because old distros have bugs is a good idea so I think you should either switch to a distro with latest Plasma or report the bug to kwin package via your distro bugtracker.

https://github.com/telegramdesktop/tdesktop/issues/28113#issuecomment-2203232661

STEPS TO REPRODUCE
1.  Run latest Telegram desktop in Wayland session.
2.  Scroll a chat or open any menu.

OBSERVED RESULT

Parts of Telegram window are not updated.

EXPECTED RESULT

Program window should be updated according to user interaction.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13

Comment 1 Nate Graham 2024-07-03 21:00:10 UTC

>  I think you should either switch to a distro with latest Plasma
Yep, good advice. :) Fractional scaling support on Wayland has hugely improve since 5.27.