Attach text files correctly in Message

* lisp/gnus/mml.el (mml-generate-mime-1): Detect which coding
system has been used in attached text files, and don't try to
do any encoding of these files (bug#13808).

diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index 6d13d892b5a15c66bfbc8e942c08242223ce5c57..6d9e24e708ec3e883aa06c941ce157ddcbef7391 100644 (file)
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -486,7 +486,8 @@ be \"related\" or \"alternate\"."
                 (equal (cdr (assq 'type (car cont))) "text/html"))
        (setq cont (mml-expand-html-into-multipart-related (car cont))))
       (prog1
-         (mm-with-multibyte-buffer
+         (with-temp-buffer
+           (set-buffer-multibyte nil)
            (setq message-options options)
            (cond
             ((and (consp (car cont))
@@ -605,15 +606,18 @@ be \"related\" or \"alternate\"."
                                   (intern (downcase charset))))))
          (if (and (not raw)
                   (member (car (split-string type "/")) '("text" "message")))
+             ;; We have a text-like MIME part, so we need to do
+             ;; charset encoding.
              (progn
                (with-temp-buffer
+                 (set-buffer-multibyte nil)
+                 ;; First insert the data into the buffer.
                  (cond
                   ((cdr (assq 'buffer cont))
                    (insert-buffer-substring (cdr (assq 'buffer cont))))
                   ((and filename
                         (not (equal (cdr (assq 'nofile cont)) "yes")))
-                   (let ((coding-system-for-read coding))
-                     (mm-insert-file-contents filename)))
+                   (mm-insert-file-contents filename))
                   ((eq 'mml (car cont))
                    (insert (cdr (assq 'contents cont))))
                   (t
@@ -667,21 +671,22 @@ be \"related\" or \"alternate\"."
                        ;; insert a "; format=flowed" string unless the
                        ;; user has already specified it.
                        (setq flowed (null (assq 'format cont)))))
-                   ;; Prefer `utf-8' for text/calendar parts.
-                   (if (or charset
-                           (not (string= type "text/calendar")))
-                       (setq charset (mm-encode-body charset))
-                     (let ((mm-coding-system-priorities
-                            (cons 'utf-8 mm-coding-system-priorities)))
-                       (setq charset (mm-encode-body))))
-                   (mm-disable-multibyte)
+                   (unless charset
+                     (setq charset
+                           ;; Prefer `utf-8' for text/calendar parts.
+                           (if (string= type "text/calendar")
+                               'utf-8
+                             (mm-coding-system-to-mime-charset
+                              (detect-coding-region
+                               (point-min) (point-max) t)))))
                    (setq encoding (mm-body-encoding
                                    charset (cdr (assq 'encoding cont))))))
                  (setq coded (buffer-string)))
                (mml-insert-mime-headers cont type charset encoding flowed)
                (insert "\n")
                (insert coded))
-           (mm-with-unibyte-buffer
+           (with-temp-buffer
+             (set-buffer-multibyte nil)
              (cond
               ((cdr (assq 'buffer cont))
                (insert (string-as-unibyte