(rmail-output): Don't use content-type if it is nil.

1 files changed, 5 insertions, 3 deletions

diff --git a/lisp/mail/rmailout.el b/lisp/mail/rmailout.el
index 97654ae92c5..bd37a41aef8 100644
--- a/lisp/mail/rmailout.el
+++ b/lisp/mail/rmailout.el
@@ -349,9 +349,11 @@ The optional fourth argument FROM-GNUS is set when called from GNUS."
                                                  (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)
+            ;; Some malformed MIME messages set content-type to nil.
+            (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.)