While fixing a problem with a Wayland app I noticed that the programm got a notification from a Wayland fd whenever I selected some text in any other window (not belonging to the app) and was able to read the contents of the selection.
As I’m not a fan of sharing data without explicit actions (so Ctrl+C, Ctrl+V), is there a way to disable this behaviour of Wayland?
OS info: Fedora 43 KDE
The application was MPV. At random time it started consuming 100% of one core for a long time. I could track it down to the clipboard thread where a loop polls Wayland to get the latest content of the clipboard (selected text). Seems like a bug in some other application spamms this clipboard buffer from time to time and so caused the MPV loop to run continously.
This way I learned about that Wayland API and as MPV can emit logs whenever the poll loop got new data, I was able to see that it fired whenever I selected text in some application.
Good to know the name of this feature; primary buffer. Now I need to find a way to disable it.