bug#25115: 26.0.50; ibuffer fails to show confirmation buffer when there are side windows

[Mark Oteiza]

martin rudalics <rudalics@gmx.at> writes:

>> Steps to reproduce:
>>
>> 1. emacs -Q
>> 2. eval the following code in *scratch* to create a side window.
>> (pop-to-buffer "test"
>>                 '(display-buffer-in-side-window
>>                   (side . right)
>>                   (width . 0.2)))
>> 3. Now the side window has been created and selected. Press 'C-x o' to 
>> switch to the other window in the left, which displays *scratch*.
>> 4. M-x ibuffer. Then press 'd' to mark two or more buffers for killing.
>> 5. Press 'x'. Then an error 'ibuffer-confirm-operation-on: Cannot split side 
>> window or parent of side window' is issued.
>
> Confirmed.  ‘ibuffer-confirm-operation-on’ selects the last window of
> the selected frame's ‘window-list’ and tries to split that window.  In
> your scenario the last window is the side window and cannot be split by
> ‘split-window’.
>
> I pushed a fix for that on master, please have a look.
>
> But someone who's using ibuffer on a regular basis should really try to
> make it use ‘display-buffer’ instead.  There is absolutely no evidence
> that the last window of a frame can be split more easily than the one
> used by ibuffer itself and if no window can be split some other window
> should be reused for displaying the buffer list.

I don't use ibuffer often, but I have been changing instances of
switch-to-buffer to pop-to-buffer-same-window since reading Bug#22244.

Makes me wonder about switch-to-buffer's future