RE: use and doc of function symbol properties [was: bug#11381: 23.3; isearch-search-and-update issue?]

[Drew Adams]

> But it would no doubt be better to instead rotate through
> the list until we reach a non-identical entry (if there is one).

I.e.,
(cond ...

 ((eq type 'yank)
  ;; Before a yank command.  Make sure we do not yank
  ;; the same region that we are going to delete.
  ;; That would make yank a no-op.
  (let ((tail  kill-ring))
    (while (and tail  (string= (buffer-substring-no-properties
                                (point) (mark))
                               (car tail)))
      (current-kill 1)
      (setq tail  (cdr tail))))
  (delete-active-region))

 ...)