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
I believe, that needs to be turned off in KDE.
I’m not sure, if this actually turns of the copying or if it just turns off the pasting, but you could try turning off this setting:
I thought this was an old feature of Linux (maybe Unix?). Highlighted text gets copied to the buffer, which is useful when you’re on the command line (because Ctrl+C ends the current process).
I don’t know how you’d change this, but maybe that can give you some clues on what to do.
It’s been a hot minute, but wasn’t what you’re referring to done by a third-party app? The original consoles had no real concept of a mouse by default, let alone copy/paste from highlighted text. Any highlighting inside an app (e.g. vi/m) was buffered by the app and not the OS?
It was implemented as part of the X11 standard, so the concrete program would’ve been X.org…
I thought text selection was handled via keyboard. Also been a hot minute since I first learned about this, and not using that buffer has not exactly been a common discussion point, since being able to reuse text is typically a desirable trait!
What is the application and did you notice similar behavior outside of it, e.g. being able to paste the currently selected text? I would also check your clipboard manager’s configuration. Clipboards (usually) have a clipboard buffer (for CTRL + C -> CTRL + V) and a primary buffer (for selected text -> mouse middle button paste). Some problems arise from the confusing default settings of some clipboard managers, e.g. the synchronization of both buffers.
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.
What are the apps, exactly?
