bug#38384: (next|previous)-buffer silent about not switching

[martin rudalics]

>> Could that disrupt noninteractive calls?
>
> Yes, that's why added the notice in NEWS in the "Incompatible Lisp Changes".
>
> But, on one hand, programs should perhaps be using
> switch-to-(prev|next)-buffer. AFAICS, next-buffer and previous-buffer
> aren't even documented in the Elisp manual (they are briefly mentioned in
> the Emacs manual).
>
>   And on the other, if code is using (next|prev)-buffer, silently getting
> the same buffer is likely a subtle bug anyway. At least now they get notice.

Right.  'previous-buffer' and 'next-buffer' are intended for interactive use
only.  Maybe we should add appropriate warnings to their doc-strings.

martin