;;; mm-encode.el --- Functions for encoding MIME things
-;; Copyright (C) 1998 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003
+;; Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
-;; This file is not yet part of GNU Emacs.
+;; This file is part of GNU Emacs.
;; 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
;;; Code:
-(defvar mm-header-encoding-alist
- '(("X-Nsubject" . iso-2022-jp-2)
- ("Newsgroups" . nil)
- ("Message-ID" . nil)
- (t . mime))
- "*Header/encoding method alist.
-The list is traversed sequentially. The keys can either be a
-header regexp or `t'.
-
-The values can be:
-
-1) nil, in which case no encoding is done;
-2) `mime', in which case the header will be encoded according to RFC1522;
-3) a charset, in which case it will be encoded as that charse;
-4) `default', in which case the field will be encoded as the rest
- of the article.")
-
-(defvar mm-mime-mule-charset-alist
- '((us-ascii ascii)
- (iso-8859-1 latin-iso8859-1)
- (iso-8859-2 latin-iso8859-2)
- (iso-8859-3 latin-iso8859-3)
- (iso-8859-4 latin-iso8859-4)
- (iso-8859-5 cyrillic-iso8859-5)
- (koi8-r cyrillic-iso8859-5)
- (iso-8859-6 arabic-iso8859-6)
- (iso-8859-7 greek-iso8859-7)
- (iso-8859-8 hebrew-iso8859-8)
- (iso-8859-9 latin-iso8859-9)
- (iso-2022-jp latin-jisx0201
- japanese-jisx0208-1978 japanese-jisx0208)
- (euc-kr korean-ksc5601)
- (cn-gb-2312 chinese-gb2312)
- (cn-big5 chinese-big5-1 chinese-big5-2)
- (iso-2022-jp-2 latin-iso8859-1 greek-iso8859-7
- latin-jisx0201 japanese-jisx0208-1978
- chinese-gb2312 japanese-jisx0208
- korean-ksc5601 japanese-jisx0212)
- (iso-2022-int-1 latin-iso8859-1 greek-iso8859-7
- latin-jisx0201 japanese-jisx0208-1978
- chinese-gb2312 japanese-jisx0208
- korean-ksc5601 japanese-jisx0212
- chinese-cns11643-1 chinese-cns11643-2)
- (iso-2022-int-1 latin-iso8859-1 latin-iso8859-2
- cyrillic-iso8859-5 greek-iso8859-7
- latin-jisx0201 japanese-jisx0208-1978
- chinese-gb2312 japanese-jisx0208
- korean-ksc5601 japanese-jisx0212
- chinese-cns11643-1 chinese-cns11643-2
- chinese-cns11643-3 chinese-cns11643-4
- chinese-cns11643-5 chinese-cns11643-6
- chinese-cns11643-7))
- "Alist of MIME-charset/MULE-charsets.")
-
-(defvar mm-mime-charset-encoding-alist
- '((us-ascii . nil)
- (iso-8859-1 . Q)
- (iso-8859-2 . Q)
- (iso-8859-3 . Q)
- (iso-8859-4 . Q)
- (iso-8859-5 . Q)
- (koi8-r . Q)
- (iso-8859-7 . Q)
- (iso-8859-8 . Q)
- (iso-8859-9 . Q)
- (iso-2022-jp . B)
- (iso-2022-kr . B)
- (gb2312 . B)
- (cn-gb . B)
- (cn-gb-2312 . B)
- (euc-kr . B)
- (iso-2022-jp-2 . B)
- (iso-2022-int-1 . B))
- "Alist of MIME charsets to MIME encodings.
-Valid encodings are nil, `Q' and `B'.")
-
-(defvar mm-mime-encoding-function-alist
- '((Q . quoted-printable-encode-region)
- (B . base64-encode-region)
- (nil . ignore))
- "Alist of MIME encodings to encoding functions.")
-
-(defun mm-encode-message-header ()
- "Encode the message header according to `mm-header-encoding-alist'."
- (when (featurep 'mule)
- (save-excursion
- (save-restriction
- (message-narrow-to-headers)
- (let ((alist mm-header-encoding-alist)
- elem method)
- (while (not (eobp))
- (save-restriction
- (message-narrow-to-field)
- (when (find-non-ascii-charset-region (point-min) (point-max))
- ;; We found something that may perhaps be encoded.
- (while (setq elem (pop alist))
- (when (or (and (stringp (car elem))
- (looking-at (car elem)))
- (eq (car elem) t))
- (setq alist nil
- method (cdr elem))))
- (when method
- (cond
- ((eq method 'mime)
- (mm-encode-words-region (point-min) (point-max)))
- ;; Hm.
- (t))))
- (goto-char (point-max)))))))))
-
-(defun mm-encode-words-region (b e)
- "Encode all encodable words in REGION."
- (let (prev c start qstart qprev qend)
- (save-excursion
- (goto-char b)
- (while (re-search-forward "[^ \t\n]+" nil t)
- (save-restriction
- (narrow-to-region (match-beginning 0) (match-end 0))
- (goto-char (setq start (point-min)))
- (setq prev nil)
- (while (not (eobp))
- (unless (eq (setq c (char-charset (following-char))) 'ascii)
- (cond
- ((eq c prev)
- )
- ((null prev)
- (setq qstart (or qstart start)
- qend (point-max)
- qprev c)
- (setq prev c))
- (t
- ;(mm-encode-word-region start (setq start (point)) prev)
- (setq prev c)
- )))
- (forward-char 1)))
- (when (and (not prev) qstart)
- (mm-encode-word-region qstart qend qprev)
- (setq qstart nil)))
- (when qstart
- (mm-encode-word-region qstart qend qprev)
- (setq qstart nil)))))
-
-(defun mm-encode-words-string (string)
- "Encode words in STRING."
- (with-temp-buffer
- (insert string)
- (mm-encode-words-region (point-min) (point-max))
- (buffer-string)))
-
-(defun mm-mule-charset-to-mime-charset (charset)
- "Return the MIME charset corresponding to MULE CHARSET."
- (let ((alist mm-mime-mule-charset-alist)
- out)
- (while alist
- (when (memq charset (cdar alist))
- (setq out (caar alist)
- alist nil))
- (pop alist))
- out))
-
-(defun mm-encode-word-region (b e charset)
- "Encode the word in the region with CHARSET."
- (let* ((mime-charset (mm-mule-charset-to-mime-charset charset))
- (encoding (cdr (assq mime-charset mm-mime-charset-encoding-alist))))
- (save-restriction
- (narrow-to-region b e)
- (funcall (cdr (assq encoding mm-mime-encoding-function-alist))
- b e)
+(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"))
+
+(defcustom mm-content-transfer-encoding-defaults
+ '(("text/x-patch" 8bit)
+ ("text/.*" qp-or-base64)
+ ("message/rfc822" 8bit)
+ ("application/emacs-lisp" 8bit)
+ ("application/x-emacs-lisp" 8bit)
+ ("application/x-patch" 8bit)
+ (".*" base64))
+ "Alist of regexps that match MIME types and their encodings.
+If the encoding is `qp-or-base64', then either quoted-printable
+or base64 will be used, depending on what is more efficient."
+ :type '(repeat (list (regexp :tag "MIME type")
+ (choice :tag "encoding"
+ (const 7bit)
+ (const 8bit)
+ (const qp-or-base64)
+ (const quoted-printable)
+ (const base64))))
+ :group 'mime)
+
+(defvar mm-use-ultra-safe-encoding nil
+ "If non-nil, use encodings aimed at Procrustean bed survival.
+
+This means that textual parts are encoded as quoted-printable if they
+contain lines longer than 76 characters or starting with \"From \" in
+the body. Non-7bit encodings (8bit, binary) are generally disallowed.
+This is to reduce the probability that a broken MTA or MDA changes the
+message.
+
+This variable should never be set directly, but bound before a call to
+`mml-generate-mime' or similar functions.")
+
+(defun mm-insert-rfc822-headers (charset encoding)
+ "Insert text/plain headers with CHARSET and ENCODING."
+ (insert "MIME-Version: 1.0\n")
+ (insert "Content-Type: text/plain; charset="
+ (mail-quote-string (downcase (symbol-name charset))) "\n")
+ (insert "Content-Transfer-Encoding: "
+ (downcase (symbol-name encoding)) "\n"))
+
+(defun mm-insert-multipart-headers ()
+ "Insert multipart/mixed headers."
+ (let ((boundary "=-=-="))
+ (insert "MIME-Version: 1.0\n")
+ (insert "Content-Type: multipart/mixed; boundary=\"" boundary "\"\n")
+ boundary))
+
+(defun mm-default-file-encoding (file)
+ "Return a default encoding for FILE."
+ (if (not (string-match "\\.[^.]+$" file))
+ "application/octet-stream"
+ (mailcap-extension-to-mime (match-string 0 file))))
+
+(defun mm-safer-encoding (encoding)
+ "Return an encoding similar to ENCODING but safer than it."
+ (cond
+ ((memq encoding '(7bit 8bit quoted-printable)) 'quoted-printable)
+ ;; The remaining encodings are binary and base64 (and perhaps some
+ ;; non-standard ones), which are both turned into base64.
+ (t 'base64)))
+
+(defun mm-encode-content-transfer-encoding (encoding &optional type)
+ "Encode the current buffer with ENCODING for MIME type TYPE.
+ENCODING can be: nil (do nothing); one of `quoted-printable', `base64';
+`7bit', `8bit' or `binary' (all do nothing); a function to do the encoding."
+ (cond
+ ((eq encoding 'quoted-printable)
+ ;; This used to try to make a multibyte buffer unibyte. That's
+ ;; completely wrong, since you'd get QP-encoded emacs-mule. If
+ ;; this gets run on multibyte text it's an error that needs
+ ;; fixing, and the encoding function will signal an error.
+ ;; Likewise base64 below.
+ (quoted-printable-encode-region (point-min) (point-max) t))
+ ((eq encoding 'base64)
+ (when (equal type "text/plain")
(goto-char (point-min))
- (insert "=?" (upcase (symbol-name mime-charset)) "?"
- (symbol-name encoding) "?")
- (goto-char (point-max))
- (insert "?="))))
+ (while (search-forward "\n" nil t)
+ (replace-match "\r\n" t t)))
+ (base64-encode-region (point-min) (point-max)))
+ ((memq encoding '(7bit 8bit binary))
+ ;; Do nothing.
+ )
+ ((null encoding)
+ ;; Do nothing.
+ )
+ ;; Fixme: Ignoring errors here looks bogus.
+ ((functionp encoding)
+ (ignore-errors (funcall encoding (point-min) (point-max))))
+ (t
+ (error "Unknown encoding %s" encoding))))
+
+(defun mm-encode-buffer (type)
+ "Encode the buffer which contains data of MIME type TYPE.
+TYPE is a string or a list of the components.
+The encoding used is returned."
+ (let* ((mime-type (if (stringp type) type (car type)))
+ (encoding
+ (or (and (listp type)
+ (cadr (assq 'encoding type)))
+ (mm-content-transfer-encoding mime-type)))
+ (bits (mm-body-7-or-8)))
+ ;; We force buffers that are 7bit to be unencoded, no matter
+ ;; what the preferred encoding is.
+ ;; Only if the buffers don't contain lone lines.
+ (when (and (eq bits '7bit) (not (mm-long-lines-p 76)))
+ (setq encoding bits))
+ (mm-encode-content-transfer-encoding encoding mime-type)
+ encoding))
+
+(defun mm-insert-headers (type encoding &optional file)
+ "Insert headers for TYPE."
+ (insert "Content-Type: " type)
+ (when file
+ (insert ";\n\tname=\"" (file-name-nondirectory file) "\""))
+ (insert "\n")
+ (insert (format "Content-Transfer-Encoding: %s\n" encoding))
+ (insert "Content-Disposition: inline")
+ (when file
+ (insert ";\n\tfilename=\"" (file-name-nondirectory file) "\""))
+ (insert "\n")
+ (insert "\n"))
+
+(defun mm-content-transfer-encoding (type)
+ "Return a CTE suitable for TYPE to encode the current buffer."
+ (let ((rules mm-content-transfer-encoding-defaults))
+ (catch 'found
+ (while rules
+ (when (string-match (caar rules) type)
+ (throw 'found
+ (let ((encoding
+ (if (eq (cadr (car rules)) 'qp-or-base64)
+ (mm-qp-or-base64)
+ (cadr (car rules)))))
+ (if mm-use-ultra-safe-encoding
+ (mm-safer-encoding encoding)
+ encoding))))
+ (pop rules)))))
+
+(defun mm-qp-or-base64 ()
+ "Return the type with which to encode the buffer.
+This is either `base64' or `quoted-printable'."
+ (if (equal mm-use-ultra-safe-encoding '(sign . "pgp"))
+ ;; perhaps not always accurate?
+ 'quoted-printable
+ (save-excursion
+ (let ((limit (min (point-max) (+ 2000 (point-min))))
+ (n8bit 0))
+ (goto-char (point-min))
+ (skip-chars-forward "\x20-\x7f\r\n\t" limit)
+ (while (< (point) limit)
+ (incf n8bit)
+ (forward-char 1)
+ (skip-chars-forward "\x20-\x7f\r\n\t" limit))
+ (if (or (< (* 6 n8bit) (- limit (point-min)))
+ ;; Don't base64, say, a short line with a single
+ ;; non-ASCII char when splitting parts by charset.
+ (= n8bit 1))
+ 'quoted-printable
+ 'base64)))))
(provide 'mm-encode)
+;;; arch-tag: 7d01bba4-d469-4851-952b-dc863f84ed66
;;; mm-encode.el ends here
projects / gnus / blobdiff