ping response in wrong buffer with lui-scroll-behavior 'post-scroll

[retroj]

I have observed a strange bug that happens when lui-scroll-behavior is 'post-scroll. The setup is as follows:

Two circe channel buffers on the same server are open in two separate frames. Switch from one frame to the other, and issue a /ping command. The ping response appears in the other buffer.

[jorgenschaefer]

Hm. Circe sets circe-server-last-active-buffer in an after-advice on select-window. I suspect switching frames does not involve select-window, so this is never used.

First of all, circe-server-last-active-buffer should return the current buffer if it's a Circe buffer and belongs to the same server(!). Furthermore, it could check if there is any buffer visible which is belonging to the current server.

Second, we can either add an advice to select-frame as well, or just default to the server buffer if the user is in a different buffer unrelated to the server the output is from. This would remove the hack and result in consistent, albeit in some cases weird, behavior.