SUMMARY When using a small custom image in Firefox as the cursor, only on KWin on Wayland, rests of the previous cursor remain on the area not covered by it. STEPS TO REPRODUCE 1. On Firefox, running on Wayland, go to https://crisal.io/tmp/svg-cursor-kwin.html, and hover over the website area. For convenience, since I plan to workaround this bug in Firefox: ``` $ pip install --user mozregression $ MOZ_ENABLE_WAYLAND=1 mozregression --launch 120 -a https://crisal.io/tmp/svg-cursor-kwin.html ``` OBSERVED RESULT Pieces of the old cursor remain. EXPECTED RESULT Only the specified cursor surface is used. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.27.9 KDE Frameworks Version: 5.112.0 Qt Version: 5.15.11 Kernel Version: 6.6.2-arch1-1 (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION I'd attach a screenshot, but annoyingly, neither OBS nor Spectacle show the artifacts.
I've been debugging this issue a while ago and I wanted to discuss it with you on matrix, but I couldn't find you. The culprit of this bug is that firefox reports incomplete damage when the cursor shrinks.
I'd been debugging*
Another website with similar issue: http://9front.org/
Huh, I somehow got kicked from the kwin matrix room or something a while ago it seems? We only call gtk APIs for this so probably other gtk applications suffer from the same issue. But thanks, that's a great pointer, I can debug it a little bit more on the gtk side.
https://gitlab.gnome.org/GNOME/gtk/-/issues/6242