+(defun get-next-valid-buffer (list &optional buffer visible-ok frame)
+ "Search LIST for a valid buffer to display in FRAME.
+Return nil when all buffers in LIST are undesirable for display,
+otherwise return the first suitable buffer in LIST.
+
+Buffers not visible in windows are preferred to visible buffers,
+unless VISIBLE-OK is non-nil.
+If the optional argument FRAME is nil, it defaults to the selected frame.
+If BUFFER is non-nil, ignore occurrences of that buffer in LIST."
+ ;; This logic is more or less copied from other-buffer.
+ (setq frame (or frame (selected-frame)))
+ (let ((pred (frame-parameter frame 'buffer-predicate))
+ found buf)
+ (while (and (not found) list)
+ (setq buf (car list))
+ (if (and (not (eq buffer buf))
+ (buffer-live-p buf)
+ (or (null pred) (funcall pred buf))
+ (not (eq (aref (buffer-name buf) 0) ?\s))
+ (or visible-ok (null (get-buffer-window buf 'visible))))
+ (setq found buf)
+ (setq list (cdr list))))
+ (car list)))
+
+(defun last-buffer (&optional buffer visible-ok frame)
+ "Return the last non-hidden displayable buffer in the buffer list.
+If BUFFER is non-nil, last-buffer will ignore that buffer.
+Buffers not visible in windows are preferred to visible buffers,
+unless optional argument VISIBLE-OK is non-nil.
+If the optional third argument FRAME is non-nil, use that frame's
+buffer list instead of the selected frame's buffer list.
+If no other buffer exists, the buffer `*scratch*' is returned."
+ (setq frame (or frame (selected-frame)))
+ (or (get-next-valid-buffer (frame-parameter frame 'buried-buffer-list)
+ buffer visible-ok frame)
+ (get-next-valid-buffer (nreverse (buffer-list frame))
+ buffer visible-ok frame)
+ (progn
+ (set-buffer-major-mode (get-buffer-create "*scratch*"))
+ (get-buffer "*scratch*"))))
+