[Emacs-diffs] emacs/lisp/mail rmailedit.el

[Eli Zaretskii]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     Eli Zaretskii <eliz>    09/02/21 15:05:01

Modified files:
        lisp/mail      : rmailedit.el 

Log message:
        (rmail-cease-edit): Notice changes in buffer's encoding during editing.
        Make sure to use encoding that can safely encode the message.
        Rewrite MIME charset= header if the new encoding is different from the 
old one.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/lisp/mail/rmailedit.el?cvsroot=emacs&r1=1.52&r2=1.53

Patches:
Index: rmailedit.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/mail/rmailedit.el,v
retrieving revision 1.52
retrieving revision 1.53
diff -u -b -r1.52 -r1.53
--- rmailedit.el        15 Feb 2009 02:31:55 -0000      1.52
+++ rmailedit.el        21 Feb 2009 15:05:01 -0000      1.53
@@ -136,9 +136,18 @@
       (insert "\n")))
   (let ((old rmail-old-text)
        (pruned rmail-old-pruned)
+       ;; People who know what they are doing might have modified the
+       ;; buffer's encoding if editing the message included inserting
+       ;; characters that were unencodable by the original message's
+       ;; encoding.  Make note of the new encoding and use it for
+       ;; encoding the edited message.
+       (edited-coding buffer-file-coding-system)
        new-headers
        character-coding is-text-message coding-system
        headers-end limit)
+    ;; Make sure `edited-coding' can safely encode the edited message.
+    (setq edited-coding
+         (select-safe-coding-system (point-min) (point-max) edited-coding))
     ;; Go back to Rmail mode, but carefully.
     (force-mode-line-update)
     (let ((rmail-buffer-swapped nil)) ; Prevent change-major-mode-hook
@@ -154,6 +163,33 @@
                 (string= old (buffer-substring (point-min) (point-max))))
       (setq old nil)
       (goto-char (point-min))
+      ;; If they changed the message's encoding, rewrite the charset=
+      ;; header for them, so that subsequent rmail-show-message
+      ;; decodes it correctly.
+      (let ((buffer-read-only nil)
+           (new-coding (coding-system-base edited-coding))
+           old-coding mime-charset mime-beg mime-end)
+       (when (re-search-forward rmail-mime-charset-pattern
+                                (1- (save-excursion (search-forward "\n\n")))
+                                'move)
+           (setq mime-beg (match-beginning 1)
+                 mime-end (match-end 1)
+                 old-coding (coding-system-from-name (match-string 1))))
+       (setq mime-charset
+             (symbol-name
+              (or (coding-system-get new-coding :mime-charset)
+                  (if (coding-system-equal new-coding 'undecided)
+                      'us-ascii
+                    new-coding))))
+       (cond
+        ((null old-coding)
+         ;; If there was no charset= spec, insert one.
+         (insert "Content-type: text/plain; charset=" mime-charset "\n"))
+        ((not (coding-system-equal (coding-system-base old-coding)
+                                   new-coding))
+         (delete-region mime-beg mime-end)
+         (insert mime-charset))))
+      (goto-char (point-min))
       (search-forward "\n\n")
       (setq headers-end (point))
       (setq new-headers (rmail-edit-headers-alist t))
@@ -171,7 +207,12 @@
        (setq character-coding
              (mail-fetch-field "content-transfer-encoding")
              is-text-message (rmail-is-text-p)
-             coding-system (rmail-get-coding-system)))
+             coding-system (if (and edited-coding
+                                    (not (coding-system-equal
+                                          (coding-system-base edited-coding)
+                                          'undecided)))
+                               edited-coding
+                             (rmail-get-coding-system))))
       (if character-coding
          (setq character-coding (downcase character-coding)))