(mime-content-transfer-encoding-priority-list): New variable.

(mime-edit-translate-single-part-tag): Change return value to `nil' or a cons
which include content-type and encoding.
(mime-edit-translate-region): Generate `encodeing' from return value of
`mime-edit-translate-single-part-tag'.

diff --git a/mime-edit.el b/mime-edit.el
index bca7c68..c101699 100644 (file)
--- a/mime-edit.el
+++ b/mime-edit.el
@@ -506,6 +506,11 @@ If encoding is nil, it is determined from its contents."
 (make-variable-buffer-local 'mime-transfer-level-string)
 
 
+;;; @@ about content transfer encoding
+
+(defvar mime-content-transfer-encoding-priority-list
+  '(nil "8bit" "binary"))
+
 ;;; @@ about message inserting
 ;;;
 
@@ -1958,8 +1963,12 @@ Content-Transfer-Encoding: 7bit
            (if encoding
                (insert "Content-Transfer-Encoding: " encoding "\n"))
            (eword-encode-header)
-           ))
-       t)))
+           )
+         (cons (and contype
+                    (downcase contype))
+               (and encoding
+                    (downcase encoding))))
+       )))
 
 (defun mime-edit-translate-region (beg end &optional boundary multipart)
   (or boundary
@@ -1995,22 +2004,26 @@ Content-Transfer-Encoding: 7bit
         (t
          ;; It's a multipart message.
          (goto-char (point-min))
-         (and (mime-edit-translate-single-part-tag boundary)
-              (while (mime-edit-translate-single-part-tag boundary "\n")))
-         ;; Define Content-Type as "multipart/mixed".
-         (setq contype
-               (concat "multipart/mixed;\n boundary=\"" boundary "\""))
-         ;; Content-Transfer-Encoding must be "7bit".
-         ;; The following encoding can be `nil', but is
-         ;; specified as is since there is no way that a user
-         ;; specifies it.
-         (setq encoding "7bit")
-         ;; Insert the trailer.
-         (goto-char (point-max))
-         (insert "\n--" boundary "--\n")
-         ))
-       (list contype encoding boundary nparts)
-       ))))
+         (let ((prio mime-content-transfer-encoding-priority-list)
+               part-info nprio)
+           (when (setq part-info
+                       (mime-edit-translate-single-part-tag boundary))
+             (and (setq nprio (member (cdr part-info) prio))
+                  (setq prio nprio))
+             (while (setq part-info
+                          (mime-edit-translate-single-part-tag boundary "\n"))
+               (and (setq nprio (member (cdr part-info) prio))
+                    (setq prio nprio))))
+           ;; Define Content-Type as "multipart/mixed".
+           (setq contype
+                 (concat "multipart/mixed;\n boundary=\"" boundary "\""))
+           (setq encoding (car prio))
+           ;; Insert the trailer.
+           (goto-char (point-max))
+           (insert "\n--" boundary "--\n")
+           )))
+        (list contype encoding boundary nparts)
+        ))))
 
 (defun mime-edit-normalize-body ()
   "Normalize the body part by inserting appropriate message tags."