Screen Sharing / Casting distorted when using Gnome's Fractional Scaling.
Affected version
Fedora 34 (But also noticed on Fedora 32-33) Gnome 3.6 - 40 Mutter 40 (And a few versions below, see Gnome version above) Wayland
Bug summary
Fractional Scaling in Mutter causes gnome screen sharing/casting to become distorted/duplicated
Steps to reproduce
- Enable Gnome fractional scaling in Wayland to 200%
- Share the screen via VNC, OBS, or native gnome screen recording
What happened
When screen sharing using 200% scaling in Wayland, the output displays what appears to be two 1920x1080 renders of the desktop side by side and the bottom half of the 3960x2160 canvas are blank/empty. See this example: https://user-images.githubusercontent.com/6511230/83958150-8b280900-a8c2-11ea-83f7-c4d4861bf3ca.png
I don't think the issue is exclusive to pipewire as I saw the issue as far back as Fedora 31. So my best guess is it's something to do with Mutter. When using Pipewire in OBS to share just a window, the image is not distorted by the cursor is.
I originally opened and issue on the flatpak for OBS here: https://github.com/flathub/com.obsproject.Studio/issues/71 But now I believe the issue is not with OBS as the same thing occurs in both Pipewire and what ever was used to screensharing before Pipewire in Gnome.
What did you expect to happen
For it not to distort.
Relevant logs, screenshots, screencasts etc.
Original issue and screenshots here: https://github.com/flathub/com.obsproject.Studio/issues/71