Subject: bug#11780: 24.1.50; vc-annotate fails for files in RCS. ("cl.el" `flet' problem?)

From: Glenn Morris <[email-masked]>
Date: Tue, 26 Jun 2012 18:41:51 -0400

Here's what the expansion of

(flet ((sw () (skip-chars-forward " \t\n")))
  (sw))

looks like in 24.1:

(let*
    ((--cl-letf-bound--
      (fboundp 'sw))
     (--cl-letf-save--
      (and --cl-letf-bound--
         (symbol-function 'sw))))
  (unwind-protect
      (progn
      (fset 'sw
            (function*
                   (lambda nil
                            (block sw
                                      (skip-chars-forward "  \n")))))
                                      (sw))
    (if --cl-letf-bound--
    (fset 'sw --cl-letf-save--)
      (fmakunbound 'sw))))

whereas in the current trunk it looks like this:

(let*
    ((x
      (cl-function
       (lambda nil
        (cl-block sw
           (skip-chars-forward "    \n")))))
     (x
      (symbol-function 'sw)))
  (unwind-protect
      (progn
      (fset 'sw x)
      (sw))
    (fset 'sw x)))

So there's a couple of things wrong with the new version:
`x' used twice as a local variable.
(symbol-function 'sw) not guarded by an (fboundp 'sw) check.

The latter is the immediate source of the error AFAICS.