bug#14590: function-arity fails for adviced functions

[Juanma Barranquero]

Package: emacs
Version: 24.3.50


emacs -Q

(progn
  (defun test (a &optional b) nil)
  (function-arity 'test))

=> (1 . 2)

(progn
  (defadvice test (around test activate) ad-do-it)
  (function-arity 'test))

=>

Debugger entered--Lisp error: (wrong-type-argument sequencep 128)
  function-arity(test)
  (progn (progn (ad-add-advice (quote test) (quote (test nil t (advice
lambda nil ad-do-it))) (quote around) (quote nil)) (ad-activate (quote
test) nil) (quote test)) (function-arity (quote test)))
  eval((progn (progn (ad-add-advice (quote test) (quote (test nil t
(advice lambda nil ad-do-it))) (quote around) (quote nil))
(ad-activate (quote test) nil) (quote test)) (function-arity (quote
test))) nil)
  eval-last-sexp-1(nil)
  eval-last-sexp(nil)
  call-interactively(eval-last-sexp nil nil)
  command-execute(eval-last-sexp)