From: Lars Ingebrigtsen <larsi@gnus.org>
Date: Thu, 23 Jul 2020 15:12:33 +0000 (+0200)
Subject: Fix viewing of encrypted S/MIME messages
X-Git-Tag: emacs-27.1-rc1~12
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=96a3b473fa5e152bf2f069f9eca10c370b311c25;p=emacs.git

Fix viewing of encrypted S/MIME messages

* lisp/gnus/mm-decode.el (mm-possibly-verify-or-decrypt): Don't
add a content-type header if there already is one (bug#41659).
---

diff --git a/lisp/gnus/mm-decode.el b/lisp/gnus/mm-decode.el
index d33bb56dc9e..a340418507f 100644
--- a/lisp/gnus/mm-decode.el
+++ b/lisp/gnus/mm-decode.el
@@ -1680,8 +1680,14 @@ If RECURSIVE, search recursively."
 		    (t (y-or-n-p
 			(format "Decrypt (S/MIME) part? "))))
 		   (mm-view-pkcs7 parts from))
-	  (goto-char (point-min))
-	  (insert "Content-type: text/plain\n\n")
+	  ;; Normally there will be a Content-type header here, but
+	  ;; some mailers don't add that to the encrypted part, which
+	  ;; makes the subsequent re-dissection fail here.
+	  (save-restriction
+	    (mail-narrow-to-head)
+	    (unless (mail-fetch-field "content-type")
+	      (goto-char (point-max))
+	      (insert "Content-type: text/plain\n\n")))
 	  (setq parts (mm-dissect-buffer t)))))
      ((equal subtype "signed")
       (unless (and (setq protocol