bug#7231: 23.3; Don't rebuild buffer list in iswitchb-visit-buffer

[Stefan Monnier <monnier@iro.umontreal.ca>]

> -	    ;; Else `kill-buffer' succeeds so re-make the buffer list
> -	    ;; taking into account packages like uniquify may rename
> -	    ;; buffers
> -	    (iswitchb-make-buflist iswitchb-default))))))
> +	    ;; else buffer was killed
> +	    (setq iswitchb-buflist
> +		  (delq nil (mapcar (lambda (b)
> +				      (if (bufferp b)
> +					  (buffer-name b)
> +					b))
> +				    bufobjs))))))))
 
I was about to install that change when I realized that this is
fundamentally not the right approach: since some of the buffers may have
changed name, the new list of matching buffers may be different (some
buffers that didn't match before may match now and vice-versa).

So iswitchb-make-buflist is more correct.  To deal with the problem of
ordering, we'll need to combine the two: call iswitchb-make-buflist to
get the new list of matches, and then use bufobjs to sort the new
iswitchb-buflist.

Something like

	    (iswitchb-make-buflist iswitchb-default))))))
	    ;; Try to preserve the previous sort order.
	    (setq iswitchb-buflist
		  (sort iswitchb-buflist
                        (lambda (bn1 bn2)
                          (< (length (or (memq (get-buffer bn1) bufobjs)
                                         ;; Place new buffers at the end.
                                         bufobjs))
                             (length (or (memq (get-buffer bn2) bufobjs)
                                         bufobjs))))))



        Stefan