bug#5174: Mail warning from M-x report-emacs-bug

[Glenn Morris]

Perhaps this?

*** simple.el.~1.1036.~ 2009-12-07 19:24:00.000000000 -0800
--- simple.el   2009-12-10 18:14:30.000000000 -0800
***************
*** 5649,5655 ****
                        mail-default-reply-to mail-mailing-lists
                        mail-self-blind mail-setup-with-from))
           (and (boundp var)
!               (symbol-value var)
                (push var warn-vars)))
         (when warn-vars
           (display-warning 'mail
--- 5649,5656 ----
                        mail-default-reply-to mail-mailing-lists
                        mail-self-blind mail-setup-with-from))
           (and (boundp var)
!                 (not (eq (symbol-value var)
!                          (car-safe (get var 'standard-value))))
                (push var warn-vars)))
         (when warn-vars
           (display-warning 'mail