GTK is most likely converting both UTF8_STRING and text/plain;charset=utf-8 to TARGET_UTF8_STRING before calling back into Scintilla thus causing the same action for either request.
I'm not sure it is, lets see what they say to my query [here](https://gitlab.gnome.org/GNOME/gtk/-/commit/0c1ea9221976b838101d2593754b6588...)
Without documentation of the correct way to implement clipboard types, I see lots of potential for causing new problems. Compatibility seems to be getting worse with updates to applications, toolkits, and window systems.
Couldn't agree more.
Maybe different target lists should be provided on X, Wayland, Win32 and macOS.
Can Scintilla tell if its X or Wayland, thats a runtime check IIUC?
If the Geany project tries the patch out on your supported platforms and are happy with it then it can go in.
Ok, but the patch [here](https://gitlab.gnome.org/GNOME/gtk/-/issues/5397) is for an issue in Scite.