bug#32850: 27.0.50; window-swap-states doesn't swap window prev/next-buffers

[martin rudalics]

>> Also note that the overhead induced by executing these functions then
>> becomes proportional to the value of the prefix argument (for each
>> single switch you call 'set-window-prev-buffers',
>> 'set-window-next-buffers' 'record-window-buffer',
>> 'unrecord-window-buffer' and run 'buffer-list-update-hook',
>> 'window-scroll-functions' and 'window-configuration-change-hook').
>
> Aren't hooks intended to run only once when the command is finished?

'post-command-hook' only.  'window-size-change-functions' is currently
run once for each redisplay.  The three I cited above are run for
every set_window_buffer when the buffer changes.  Note that you are
your own client here since you want to pretend that all these buffers
were indeed displayed.

martin