[bpt/emacs.git] / lisp / gnus / mm-bodies.el

;;; mm-bodies.el --- Functions for decoding MIME things
;; Copyright (C) 1998, 1999, 2000 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
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, 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
;; 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., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(eval-and-compile
  (or (fboundp  'base64-decode-region)
      (require 'base64)))

(eval-when-compile
  (defvar mm-uu-decode-function)
  (defvar mm-uu-binhex-decode-function))

(require 'mm-util)
(require 'rfc2047)
(require 'mm-encode)

;; 8bit treatment gets any char except: 0x32 - 0x7f, CR, LF, TAB, BEL,
;; BS, vertical TAB, form feed, and ^_
(defvar mm-7bit-chars "\x20-\x7f\r\n\t\x7\x8\xb\xc\x1f")

(defcustom mm-body-charset-encoding-alist
  '((iso-2022-jp . 7bit)
    (iso-2022-jp-2 . 7bit))
  "Alist of MIME charsets to encodings.
Valid encodings are `7bit', `8bit', `quoted-printable' and `base64'."
  :type '(repeat (cons (symbol :tag "charset")
		       (choice :tag "encoding"
			       (const 7bit)
			       (const 8bit)
			       (const quoted-printable)
			       (const base64))))
  :group 'mime)

(defun mm-encode-body ()
  "Encode a body.
Should be called narrowed to the body that is to be encoded.
If there is more than one non-ASCII MULE charset, then list of found
MULE charsets are returned.
If successful, the MIME charset is returned.
If no encoding was done, nil is returned."
  (if (not (mm-multibyte-p))
      ;; In the non-Mule case, we search for non-ASCII chars and
      ;; return the value of `mail-parse-charset' if any are found.
      (save-excursion
	(goto-char (point-min))
	(if (re-search-forward "[^\x0-\x7f]" nil t)
	    (or mail-parse-charset
		(mm-read-charset "Charset used in the article: "))
	  ;; The logic in `mml-generate-mime-1' confirms that it's OK
	  ;; to return nil here.
	  nil))
    (save-excursion
      (goto-char (point-min))
      (let ((charsets (mm-find-mime-charset-region (point-min) (point-max)))
	    charset)
	(cond
	 ;; No encoding.
	 ((null charsets)
	  nil)
	 ;; Too many charsets.
	 ((> (length charsets) 1)
	  charsets)
	 ;; We encode.
	 (t
	  (let ((charset (car charsets))
		start)
	    (when (or t
		      ;; We always decode.
		      (not (mm-coding-system-equal
			    charset buffer-file-coding-system)))
	      (while (not (eobp))
		(if (eq (mm-charset-after) 'ascii)
		    (when start
		      (save-restriction
			(narrow-to-region start (point))
			(mm-encode-coding-region
			 start (point) (mm-charset-to-coding-system charset))
			(goto-char (point-max)))
		      (setq start nil))
		  (unless start
		    (setq start (point))))
		(forward-char 1))
	      (when start
		(mm-encode-coding-region start (point)
					 (mm-charset-to-coding-system charset))
		(setq start nil)))
	    charset)))))))

(eval-when-compile (defvar message-posting-charset))

(defun mm-body-encoding (charset &optional encoding)
  "Do Content-Transfer-Encoding and return the encoding of the current buffer."
  (let ((bits (mm-body-7-or-8)))
    (require 'message)
    (cond
     ((and (not mm-use-ultra-safe-encoding) (eq bits '7bit))
      bits)
     ((and (not mm-use-ultra-safe-encoding)
	   (or (eq t (cdr message-posting-charset))
	       (memq charset (cdr message-posting-charset))
	       (eq charset mail-parse-charset)))
      bits)
     (t
      (let ((encoding (or encoding
			  (cdr (assq charset mm-body-charset-encoding-alist))
			  (mm-qp-or-base64))))
	(when mm-use-ultra-safe-encoding
	  (setq encoding (mm-safer-encoding encoding)))
	(mm-encode-content-transfer-encoding encoding "text/plain")
	encoding)))))

(defun mm-body-7-or-8 ()
  "Say whether the body is 7bit or 8bit."
  (cond
   ((not (featurep 'mule))
    (if (save-excursion
	  (goto-char (point-min))
	  (skip-chars-forward mm-7bit-chars)
	  (eobp))
	'7bit
      '8bit))
   (t
    ;; Mule version
    (if (and (null (delq 'ascii
			 (mm-find-charset-region (point-min) (point-max))))
	     ;;!!!The following is necessary because the function
	     ;;!!!above seems to return the wrong result under
	     ;;!!!Emacs 20.3.  Sometimes.
	     (save-excursion
	       (goto-char (point-min))
	       (skip-chars-forward mm-7bit-chars)
	       (eobp)))
	'7bit
      '8bit))))

;;;
;;; Functions for decoding
;;;

(defun mm-decode-content-transfer-encoding (encoding &optional type)
  (prog1
      (condition-case error
	  (cond
	   ((eq encoding 'quoted-printable)
	    (quoted-printable-decode-region (point-min) (point-max)))
	   ((eq encoding 'base64)
	    (base64-decode-region
	     (point-min)
	     ;; Some mailers insert whitespace
	     ;; junk at the end which
	     ;; base64-decode-region dislikes.
	     ;; Also remove possible junk which could
	     ;; have been added by mailing list software.
	     (save-excursion
	       (goto-char (point-min))
	       (while (re-search-forward "^[\t ]*\r?\n" nil t)
		 (delete-region (match-beginning 0) (match-end 0)))
	       (goto-char (point-max))
	       (when (re-search-backward "^[A-Za-z0-9+/]+=*[\t ]*$" nil t)
		 (forward-line)
		 (delete-region (point) (point-max)))
	       (point-max))))
	   ((memq encoding '(7bit 8bit binary))
	    ;; Do nothing.
	    )
	   ((null encoding)
	    ;; Do nothing.
	    )
	   ((memq encoding '(x-uuencode x-uue))
	    (require 'mm-uu)
	    (funcall mm-uu-decode-function (point-min) (point-max)))
	   ((eq encoding 'x-binhex)
	    (require 'mm-uu)
	    (funcall mm-uu-binhex-decode-function (point-min) (point-max)))
	   ((functionp encoding)
	    (funcall encoding (point-min) (point-max)))
	   (t
	    (message "Unknown encoding %s; defaulting to 8bit" encoding)))
	(error
	 (message "Error while decoding: %s" error)
	 nil))
    (when (and
	   (memq encoding '(base64 x-uuencode x-uue x-binhex))
	   (equal type "text/plain"))
      (goto-char (point-min))
      (while (search-forward "\r\n" nil t)
	(replace-match "\n" t t)))))

(defun mm-decode-body (charset &optional encoding type)
  "Decode the current article that has been encoded with ENCODING.
The characters in CHARSET should then be decoded."
  (if (stringp charset)
      (setq charset (intern (downcase charset))))
  (if (or (not charset) 
	  (eq 'gnus-all mail-parse-ignored-charsets)
	  (memq 'gnus-all mail-parse-ignored-charsets)
	  (memq charset mail-parse-ignored-charsets))
      (setq charset mail-parse-charset))
  (save-excursion
    (when encoding
      (mm-decode-content-transfer-encoding encoding type))
    (when (featurep 'mule)
      (let ((coding-system (mm-charset-to-coding-system charset)))
	(if (and (not coding-system)
		 (listp mail-parse-ignored-charsets)
		 (memq 'gnus-unknown mail-parse-ignored-charsets))
	    (setq coding-system 
		  (mm-charset-to-coding-system mail-parse-charset)))
	(when (and charset coding-system
		   ;; buffer-file-coding-system
		   ;;Article buffer is nil coding system
		   ;;in XEmacs
		   (mm-multibyte-p)
		   (or (not (eq coding-system 'ascii))
		       (setq coding-system mail-parse-charset))
		   (not (eq coding-system 'gnus-decoded)))
	  (mm-decode-coding-region (point-min) (point-max) coding-system))))))

(defun mm-decode-string (string charset)
  "Decode STRING with CHARSET."
  (when (stringp charset)
    (setq charset (intern (downcase charset))))
  (when (or (not charset) 
	    (eq 'gnus-all mail-parse-ignored-charsets)
	    (memq 'gnus-all mail-parse-ignored-charsets)
	    (memq charset mail-parse-ignored-charsets))
    (setq charset mail-parse-charset))
  (or
   (when (featurep 'mule)
     (let ((coding-system (mm-charset-to-coding-system charset)))
       (if (and (not coding-system)
		(listp mail-parse-ignored-charsets)
		(memq 'gnus-unknown mail-parse-ignored-charsets))
	   (setq coding-system 
		 (mm-charset-to-coding-system mail-parse-charset)))
       (when (and charset coding-system
		  (mm-multibyte-p)
		  (or (not (eq coding-system 'ascii))
		      (setq coding-system mail-parse-charset)))
	 (mm-decode-coding-string string coding-system))))
   string))

(provide 'mm-bodies)

;; mm-bodies.el ends here
Commit	Line	Data
c113de23 GM	1	;;; mm-bodies.el --- Functions for decoding MIME things
	2	;; Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
	3
	4	;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
	5	;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
	6	;; This file is part of GNU Emacs.
	7
	8	;; GNU Emacs is free software; you can redistribute it and/or modify
	9	;; it under the terms of the GNU General Public License as published by
	10	;; the Free Software Foundation; either version 2, or (at your option)
	11	;; any later version.
	12
	13	;; GNU Emacs is distributed in the hope that it will be useful,
	14	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	;; GNU General Public License for more details.
	17
	18	;; You should have received a copy of the GNU General Public License
	19	;; along with GNU Emacs; see the file COPYING. If not, write to the
	20	;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	21	;; Boston, MA 02111-1307, USA.
	22
	23	;;; Commentary:
	24
	25	;;; Code:
	26
	27	(eval-and-compile
	28	(or (fboundp 'base64-decode-region)
058635a9	29	(require 'base64)))
8f716686	30
776ca44f DL	31	(eval-when-compile
	32	(defvar mm-uu-decode-function)
	33	(defvar mm-uu-binhex-decode-function))
c113de23 GM	34
	35	(require 'mm-util)
	36	(require 'rfc2047)
058635a9	37	(require 'mm-encode)
c113de23 GM	38
	39	;; 8bit treatment gets any char except: 0x32 - 0x7f, CR, LF, TAB, BEL,
	40	;; BS, vertical TAB, form feed, and ^_
	41	(defvar mm-7bit-chars "\x20-\x7f\r\n\t\x7\x8\xb\xc\x1f")
	42
	43	(defcustom mm-body-charset-encoding-alist
	44	'((iso-2022-jp . 7bit)
	45	(iso-2022-jp-2 . 7bit))
	46	"Alist of MIME charsets to encodings.
	47	Valid encodings are `7bit', `8bit', `quoted-printable' and `base64'."
	48	:type '(repeat (cons (symbol :tag "charset")
	49	(choice :tag "encoding"
	50	(const 7bit)
	51	(const 8bit)
	52	(const quoted-printable)
	53	(const base64))))
	54	:group 'mime)
	55
	56	(defun mm-encode-body ()
	57	"Encode a body.
	58	Should be called narrowed to the body that is to be encoded.
	59	If there is more than one non-ASCII MULE charset, then list of found
	60	MULE charsets are returned.
	61	If successful, the MIME charset is returned.
	62	If no encoding was done, nil is returned."
def5ff36	63	(if (not (mm-multibyte-p))
c113de23 GM	64	;; In the non-Mule case, we search for non-ASCII chars and
	65	;; return the value of `mail-parse-charset' if any are found.
	66	(save-excursion
	67	(goto-char (point-min))
	68	(if (re-search-forward "[^\x0-\x7f]" nil t)
	69	(or mail-parse-charset
	70	(mm-read-charset "Charset used in the article: "))
	71	;; The logic in `mml-generate-mime-1' confirms that it's OK
	72	;; to return nil here.
	73	nil))
	74	(save-excursion
	75	(goto-char (point-min))
	76	(let ((charsets (mm-find-mime-charset-region (point-min) (point-max)))
	77	charset)
	78	(cond
	79	;; No encoding.
	80	((null charsets)
	81	nil)
	82	;; Too many charsets.
	83	((> (length charsets) 1)
	84	charsets)
	85	;; We encode.
	86	(t
	87	(let ((charset (car charsets))
	88	start)
	89	(when (or t
	90	;; We always decode.
	91	(not (mm-coding-system-equal
	92	charset buffer-file-coding-system)))
	93	(while (not (eobp))
	94	(if (eq (mm-charset-after) 'ascii)
	95	(when start
	96	(save-restriction
	97	(narrow-to-region start (point))
058635a9 DL	98	(mm-encode-coding-region
058635a9 DL	99	start (point) (mm-charset-to-coding-system charset))
c113de23 GM	100	(goto-char (point-max)))
	101	(setq start nil))
	102	(unless start
	103	(setq start (point))))
	104	(forward-char 1))
	105	(when start
058635a9 DL	106	(mm-encode-coding-region start (point)
058635a9 DL	107	(mm-charset-to-coding-system charset))
c113de23 GM	108	(setq start nil)))
	109	charset)))))))
	110
058635a9 DL	111	(eval-when-compile (defvar message-posting-charset))
058635a9 DL	112
c113de23 GM	113	(defun mm-body-encoding (charset &optional encoding)
	114	"Do Content-Transfer-Encoding and return the encoding of the current buffer."
	115	(let ((bits (mm-body-7-or-8)))
058635a9	116	(require 'message)
c113de23 GM	117	(cond
	118	((and (not mm-use-ultra-safe-encoding) (eq bits '7bit))
	119	bits)
	120	((and (not mm-use-ultra-safe-encoding)
	121	(or (eq t (cdr message-posting-charset))
	122	(memq charset (cdr message-posting-charset))
	123	(eq charset mail-parse-charset)))
	124	bits)
	125	(t
	126	(let ((encoding (or encoding
	127	(cdr (assq charset mm-body-charset-encoding-alist))
	128	(mm-qp-or-base64))))
	129	(when mm-use-ultra-safe-encoding
	130	(setq encoding (mm-safer-encoding encoding)))
	131	(mm-encode-content-transfer-encoding encoding "text/plain")
	132	encoding)))))
	133
	134	(defun mm-body-7-or-8 ()
	135	"Say whether the body is 7bit or 8bit."
	136	(cond
	137	((not (featurep 'mule))
	138	(if (save-excursion
	139	(goto-char (point-min))
	140	(skip-chars-forward mm-7bit-chars)
	141	(eobp))
	142	'7bit
	143	'8bit))
	144	(t
	145	;; Mule version
	146	(if (and (null (delq 'ascii
	147	(mm-find-charset-region (point-min) (point-max))))
	148	;;!!!The following is necessary because the function
	149	;;!!!above seems to return the wrong result under
	150	;;!!!Emacs 20.3. Sometimes.
	151	(save-excursion
	152	(goto-char (point-min))
	153	(skip-chars-forward mm-7bit-chars)
	154	(eobp)))
	155	'7bit
	156	'8bit))))
	157
	158	;;;
	159	;;; Functions for decoding
	160	;;;
	161
	162	(defun mm-decode-content-transfer-encoding (encoding &optional type)
	163	(prog1
	164	(condition-case error
	165	(cond
	166	((eq encoding 'quoted-printable)
	167	(quoted-printable-decode-region (point-min) (point-max)))
	168	((eq encoding 'base64)
	169	(base64-decode-region
	170	(point-min)
	171	;; Some mailers insert whitespace
	172	;; junk at the end which
	173	;; base64-decode-region dislikes.
	174	;; Also remove possible junk which could
	175	;; have been added by mailing list software.
	176	(save-excursion
	177	(goto-char (point-min))
	178	(while (re-search-forward "^[\t ]*\r?\n" nil t)
	179	(delete-region (match-beginning 0) (match-end 0)))
	180	(goto-char (point-max))
181	(when (re-search-backward "^[A-Za-z0-9+/]+=[\t ]$" nil t)
182	(forward-line)
183	(delete-region (point) (point-max)))
184	(point-max))))
185	((memq encoding '(7bit 8bit binary))
186	;; Do nothing.
187	)
188	((null encoding)
189	;; Do nothing.
190	)
191	((memq encoding '(x-uuencode x-uue))
058635a9	192	(require 'mm-uu)
c113de23 GM	193	(funcall mm-uu-decode-function (point-min) (point-max)))
c113de23 GM	194	((eq encoding 'x-binhex)
058635a9	195	(require 'mm-uu)
c113de23 GM	196	(funcall mm-uu-binhex-decode-function (point-min) (point-max)))
	197	((functionp encoding)
	198	(funcall encoding (point-min) (point-max)))
	199	(t
	200	(message "Unknown encoding %s; defaulting to 8bit" encoding)))
	201	(error
	202	(message "Error while decoding: %s" error)
	203	nil))
	204	(when (and
	205	(memq encoding '(base64 x-uuencode x-uue x-binhex))
	206	(equal type "text/plain"))
	207	(goto-char (point-min))
	208	(while (search-forward "\r\n" nil t)
	209	(replace-match "\n" t t)))))
	210
	211	(defun mm-decode-body (charset &optional encoding type)
	212	"Decode the current article that has been encoded with ENCODING.
	213	The characters in CHARSET should then be decoded."
	214	(if (stringp charset)
	215	(setq charset (intern (downcase charset))))
	216	(if (or (not charset)
	217	(eq 'gnus-all mail-parse-ignored-charsets)
	218	(memq 'gnus-all mail-parse-ignored-charsets)
	219	(memq charset mail-parse-ignored-charsets))
	220	(setq charset mail-parse-charset))
	221	(save-excursion
	222	(when encoding
	223	(mm-decode-content-transfer-encoding encoding type))
	224	(when (featurep 'mule)
058635a9 DL	225	(let ((coding-system (mm-charset-to-coding-system charset)))
058635a9 DL	226	(if (and (not coding-system)
c113de23 GM	227	(listp mail-parse-ignored-charsets)
c113de23 GM	228	(memq 'gnus-unknown mail-parse-ignored-charsets))
058635a9	229	(setq coding-system
c113de23	230	(mm-charset-to-coding-system mail-parse-charset)))
058635a9	231	(when (and charset coding-system
c113de23 GM	232	;; buffer-file-coding-system
	233	;;Article buffer is nil coding system
	234	;;in XEmacs
	235	(mm-multibyte-p)
058635a9 DL	236	(or (not (eq coding-system 'ascii))
	237	(setq coding-system mail-parse-charset))
	238	(not (eq coding-system 'gnus-decoded)))
	239	(mm-decode-coding-region (point-min) (point-max) coding-system))))))
c113de23 GM	240
	241	(defun mm-decode-string (string charset)
	242	"Decode STRING with CHARSET."
	243	(when (stringp charset)
	244	(setq charset (intern (downcase charset))))
	245	(when (or (not charset)
	246	(eq 'gnus-all mail-parse-ignored-charsets)
	247	(memq 'gnus-all mail-parse-ignored-charsets)
	248	(memq charset mail-parse-ignored-charsets))
	249	(setq charset mail-parse-charset))
	250	(or
	251	(when (featurep 'mule)
058635a9 DL	252	(let ((coding-system (mm-charset-to-coding-system charset)))
058635a9 DL	253	(if (and (not coding-system)
c113de23 GM	254	(listp mail-parse-ignored-charsets)
c113de23 GM	255	(memq 'gnus-unknown mail-parse-ignored-charsets))
058635a9	256	(setq coding-system
c113de23	257	(mm-charset-to-coding-system mail-parse-charset)))
058635a9	258	(when (and charset coding-system
c113de23	259	(mm-multibyte-p)
058635a9 DL	260	(or (not (eq coding-system 'ascii))
	261	(setq coding-system mail-parse-charset)))
	262	(mm-decode-coding-string string coding-system))))
c113de23 GM	263	string))
	264
	265	(provide 'mm-bodies)
	266
	267	;; mm-bodies.el ends here