SUMMARY *** XWayland apps, such a Discord, MEGA and Wine drawing dark pixels on rounded corners of KWin *** STEPS TO REPRODUCE 1. Under Wayland session launch Winecfg 2. Set bright wallpaper with consistent color, such a blue sky 3. Move window header-bar to that clean color 4. Unfocus Winecfg OBSERVED RESULT Rounded corners in theme like Breeze drawing dark pixels in transparent area if XWayland application is unfocused EXPECTED RESULT As on X11 - X-apps drawing fully transparent pixels in rounded area SOFTWARE/OS VERSIONS Linux/KDE Plasma: CachyOS (Arch Linux) (available in About System) KDE Plasma Version: 5.26.90 KDE Frameworks Version: 5.102.0 Qt Version: 5.15.8 AMD RX 6600 XT, With Mesa-Git drivers
Created attachment 155963 [details] White pixels in transparent area
Created attachment 155964 [details] Dark pixels on winecfg
Cannot reproduce with Discord using XWayland.
(In reply to Nate Graham from comment #3) > Cannot reproduce with Discord using XWayland. Set dark theme, with bright consistent wallpaper Move XWayland window upon other application (window content upon dark application, and headerbar upon wallpaper) So with this action I can see dark pixels
(In reply to Nate Graham from comment #3) > Cannot reproduce with Discord using XWayland. The window manager on XWayland cloning background pixels from window background, but in wrong place
Created attachment 156172 [details] Video demo of the bug using Slack under Xwayland Can confirm this as well. Attached a video to further showcase it. Application: Slack Window decorations: Sierra Breeze Enhanced Application style: kvantum-dark Color scheme: Dracula
Oh I see, you're using a 3rd-party window decoration theme. That's quite relevant.
Created attachment 156186 [details] Comparison of Xwayland window with Breeze (dark pixel) and native Wayland window with Breeze No, it isn't. In the video, I'm not using an aurorae decoration, but Sierra Breeze Enhanced, which is a native decoration forked from Breeze. Also, the dark pixel still appears in Breeze, it is just (a lot) less noticeable, because the corners aren't as rounded. Even on the zoomed-in screenshot it's very hard to detect if you're not looking for it. But this bug is very much present regardless.
Also, not sure how relevant this is, but if using the third-party KWin effect LightlyShaders ( https://github.com/a-parhom/LightlyShaders ), which rounds all corners of a window, this problem disappears entirely (regardless of which decoration is being used), which leads me to believe that this may actually be an effect misbehaving, rather than the decorations.
Created attachment 160609 [details] round third party windoe decoration is filled with dark pixels Observed the same problem when using a rounded window decoration theme (Lavanda-Sea) with Wine applications in a Wayland session.
*** This bug has been marked as a duplicate of bug 478080 ***