* nnmairix.el: Remove old documentation in the commentary block.

[gnus] / lisp / mm-encode.el

diff --git a/lisp/mm-encode.el b/lisp/mm-encode.el
index 2597a5d..39b83ff 100644 (file)
--- a/lisp/mm-encode.el
+++ b/lisp/mm-encode.el
@@ -1,26 +1,24 @@
 ;;; mm-encode.el --- Functions for encoding MIME things
 
 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;;   2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
 
 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;;     MORIOKA Tomohiko <morioka@jaist.ac.jp>
 ;; This file is part of GNU Emacs.
 
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 3, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.         See the
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-;; Boston, MA 02110-1301, USA.
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 
@@ -29,9 +27,8 @@
 (eval-when-compile (require 'cl))
 (require 'mail-parse)
 (require 'mailcap)
-(eval-and-compile
-  (autoload 'mm-body-7-or-8 "mm-bodies")
-  (autoload 'mm-long-lines-p "mm-bodies"))
+(autoload 'mm-body-7-or-8 "mm-bodies")
+(autoload 'mm-long-lines-p "mm-bodies")
 
 (defcustom mm-content-transfer-encoding-defaults
   '(("text/x-patch" 8bit)
@@ -96,14 +93,19 @@ This variable should never be set directly, but bound before a call to
       "application/octet-stream"
     (mailcap-extension-to-mime (match-string 0 file))))
 
-(defun mm-safer-encoding (encoding)
+(defun mm-safer-encoding (encoding &optional type)
   "Return an encoding similar to ENCODING but safer than it."
   (cond
    ((eq encoding '7bit) '7bit) ;; 7bit is considered safe.
-   ((memq encoding '(8bit quoted-printable)) 'quoted-printable)
+   ((memq encoding '(8bit quoted-printable))
+    ;; According to RFC2046, 5.2.1, RFC822 Subtype, "quoted-printable" is not
+    ;; a valid encoding for message/rfc822:
+    ;; No encoding other than "7bit", "8bit", or "binary" is permitted for the
+    ;; body of a "message/rfc822" entity.
+    (if (string= type "message/rfc822") '8bit 'quoted-printable))
    ;; The remaining encodings are binary and base64 (and perhaps some
    ;; non-standard ones), which are both turned into base64.
-   (t 'base64)))
+   (t (if (string= type "message/rfc822") 'binary 'base64))))
 
 (defun mm-encode-content-transfer-encoding (encoding &optional type)
   "Encode the current buffer with ENCODING for MIME type TYPE.
@@ -178,7 +180,7 @@ The encoding used is returned."
                            (mm-qp-or-base64)
                          (cadr (car rules)))))
                   (if mm-use-ultra-safe-encoding
-                      (mm-safer-encoding encoding)
+                      (mm-safer-encoding encoding type)
                     encoding))))
        (pop rules)))))