[Interest] "QXcbClipboard::setMimeData: Cannot set X11 selection owner"

[René J. V. Bertin]

Thiago Macieira wrote:

> Obviously no GTK application is going to print something about
> "QXcbClipboard".

Yeah, DOH :) I don't have the GTk sources on my system currently but it's likely 
that somewhere there will be a call to xcb_set_selection_owner() in there too, 
no? That's where the error message I see comes from: the call fails (doesn't 
have the expected effect).

> Can you see any other symptom besides the warning?

Sadly, yes. Copying to the clipboard no longer works in affected applications. 
Instead I get that error message.

Fortunately this doesn't happen often, but that's also annoying for debugging. 
I'm now dumping the immediately relevant variables when the error does occur, 
and also use xcb_set_selection_owner_checked() and xcb_request_check() in hope 
that will tell us what really goes wrong.

R.