rmailout.el barfs on some malformed messages

[Francesco Potorti`]

I stumbled upon a malformed (if I am not wrong) MIME message, on which
rmailout.el barfs.  Here is a patch:

diff -pu /opt/e21/lisp/mail/rmailout.el\~ /opt/e21/lisp/mail/rmailout.el
--- /opt/e21/lisp/mail/rmailout.el~     2003-02-04 11:52:35.000000000 +0100
+++ /opt/e21/lisp/mail/rmailout.el      2006-01-16 11:38:02.000000000 +0100
@@ -348,9 +348,10 @@ The optional fourth argument FROM-GNUS i
                                                 (mail-fetch-field "sender")
                                                 "unknown"))
                    " " (current-time-string) "\n"))
-         (if mime-version
-             (insert "MIME-Version: " mime-version
-                     "\nContent-type: " content-type "\n"))
+         (when mime-version
+           (insert "MIME-Version: " mime-version)
+           (when content-type
+             (insert "\nContent-type: " content-type "\n")))
          ;; ``Quote'' "\nFrom " as "\n>From "
          ;;  (note that this isn't really quoting, as there is no requirement
          ;;   that "\n[>]+From " be quoted in the same transparent way.)