selectively disabling HTML rendering?

[Mike Small]

Is there an easy way to selectively disable HTML rendering, dependent
upon header info? I've come up with the following, which does what I
want, but I don't like its chances across emacs upgrades:

(defun mms-gnus-mime-display-alternative (handle)
  "My own function for displaying mime multipart/alternative articles in Gnus
Use by placing in gnus-mime-multipart-functions.

Beware when upgrading. Some of this is copied out of and makes assumptions about
gnus-mime-display-part from version 5.13 of Gnus.  It also bypasses 
gnus-mime-display-multipart-as-mixed and 
gnus-mime-display-multipart-alternative-as-mixed."
  (let ((id (1+ (length gnus-article-mime-handle-alist)))
        (mm-discouraged-alternatives
         (if (string= (get-text-property 0 'from (car handle))
                      "wsmith@wordsmith.org")
             (list "text/html")
           mm-discouraged-alternatives)))
    (push (cons id handle) gnus-article-mime-handle-alist)
    (gnus-mime-display-alternative (cdr handle) nil nil id)))

-- 
Mike Small
smallm@panix.com