Disabling display compositing causes render errors

[Karl Krach]

I ve upgraded from Xubuntu 21.04 to 21.10 and after that programs like KeePassXC, Firefox or all Qt5 examples have ugly render problems.

It turned out that I ve disabled the "display compositing" (XFCE settings --> Window Manager Tweaks --> Compositor --> Enable display compositing).

diff -Naur .config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml .config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml
--- .config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml 2021-12-29 16:25:36.634389272 +0100
+++ .config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml 2021-06-30 09:48:33.925160991 +0200
@@ -47,7 +47,7 @@
     <property name="title_vertical_offset_active" type="empty"/>
     <property name="title_vertical_offset_inactive" type="empty"/>
     <property name="urgent_blink" type="empty"/>
- <property name="use_compositing" type="empty"/>
+ <property name="use_compositing" type="bool" value="false"/>
     <property name="workspace_count" type="int" value="6"/>
     <property name="wrap_resistance" type="empty"/>
     <property name="wrap_windows" type="empty"/>

When I ve enabled the display compositing, the problems are gone.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: xfce4-settings 4.16.2-1ubuntu1
ProcVersionSignature: Ubuntu 5.13.0-22.22-generic 5.13.19
Uname: Linux 5.13.0-22-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: XFCE
Date: Wed Dec 29 18:07:12 2021
InstallationDate: Installed on 2020-07-09 (537 days ago)
InstallationMedia: Xubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
SourcePackage: xfce4-settings
UpgradeStatus: Upgraded to impish on 2021-12-18 (10 days ago)