;;; rfc2047.el --- functions for encoding and decoding rfc2047 messages
-;; Copyright (C) 1998, 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
+
+;; Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004,
+;; 2005 Free Software Foundation, Inc.
;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; MORIOKA Tomohiko <morioka@jaist.ac.jp>
;; 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.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
(require 'qp)
(require 'mm-util)
+(require 'ietf-drums)
;; Fixme: Avoid this (used for mail-parse-charset) mm dependence on gnus.
(require 'mail-prsvr)
(require 'base64)
'(("Newsgroups" . nil)
("Followup-To" . nil)
("Message-ID" . nil)
- ("\\(Resent-\\)?\\(From\\|Cc\\|To\\|Bcc\\|Reply-To\\|Sender\
+ ("\\(Resent-\\)?\\(From\\|Cc\\|To\\|Bcc\\|\\(In-\\)?Reply-To\\|Sender\
\\|Mail-Followup-To\\|Mail-Copies-To\\|Approved\\)" . address-mime)
(t . mime))
"*Header/encoding method alist.
Valid encodings are nil, `Q' and `B'. These indicate binary (no) encoding,
quoted-printable and base64 respectively.")
-(defvar rfc2047-encoding-function-alist
- '((Q . rfc2047-q-encode-region)
- (B . rfc2047-b-encode-region)
- (nil . ignore))
+(defvar rfc2047-encode-function-alist
+ '((Q . rfc2047-q-encode-string)
+ (B . rfc2047-b-encode-string)
+ (nil . identity))
"Alist of RFC2047 encodings to encoding functions.")
+(defvar rfc2047-encode-encoded-words t
+ "Whether encoded words should be encoded again.")
+
;;;
;;; Functions for encoding RFC2047 messages
;;;
(rfc2047-narrow-to-field)
(if (not (rfc2047-encodable-p))
(prog1
- (if (and (eq (mm-body-7-or-8) '8bit)
- (mm-multibyte-p)
- (mm-coding-system-p
- (car message-posting-charset)))
- ;; 8 bit must be decoded.
- (mm-encode-coding-region
- (point-min) (point-max)
- (mm-charset-to-coding-system
- (car message-posting-charset))))
+ (if (and (eq (mm-body-7-or-8) '8bit)
+ (mm-multibyte-p)
+ (mm-coding-system-p
+ (car message-posting-charset)))
+ ;; 8 bit must be decoded.
+ (mm-encode-coding-region
+ (point-min) (point-max)
+ (mm-charset-to-coding-system
+ (car message-posting-charset))))
;; No encoding necessary, but folding is nice
- (rfc2047-fold-region
- (save-excursion
- (goto-char (point-min))
- (skip-chars-forward "^:")
- (when (looking-at ": ")
- (forward-char 2))
- (point))
- (point-max)))
+ (when nil
+ (rfc2047-fold-region
+ (save-excursion
+ (goto-char (point-min))
+ (skip-chars-forward "^:")
+ (when (looking-at ": ")
+ (forward-char 2))
+ (point))
+ (point-max))))
;; We found something that may perhaps be encoded.
(setq method nil
alist rfc2047-header-encoding-alist)
(eq (car elem) t))
(setq alist nil
method (cdr elem))))
- (goto-char (point-min))
(re-search-forward "^[^:]+: *" nil t)
(cond
((eq method 'address-mime)
(require 'message) ; for message-posting-charset
(let ((charsets
(mm-find-mime-charset-region (point-min) (point-max))))
- (and charsets
- (not (equal charsets (list (car message-posting-charset)))))))
+ (goto-char (point-min))
+ (or (and rfc2047-encode-encoded-words
+ (prog1
+ (search-forward "=?" nil t)
+ (goto-char (point-min))))
+ (and charsets
+ (not (equal charsets (list (car message-posting-charset))))))))
;; Use this syntax table when parsing into regions that may need
;; encoding. Double quotes are string delimiters, backslash is
table))))
(modify-syntax-entry ?\\ "\\" table)
(modify-syntax-entry ?\" "\"" table)
- (modify-syntax-entry ?\( "." table)
- (modify-syntax-entry ?\) "." table)
+ (modify-syntax-entry ?\( "(" table)
+ (modify-syntax-entry ?\) ")" table)
(modify-syntax-entry ?\< "." table)
(modify-syntax-entry ?\> "." table)
(modify-syntax-entry ?\[ "." table)
Dynamically bind `rfc2047-encoding-type' to change that."
(save-restriction
(narrow-to-region b e)
- (if (eq 'mime rfc2047-encoding-type)
- ;; Simple case. Treat as single word after any initial ASCII
- ;; part and before any tailing ASCII part. The leading ASCII
- ;; is relevant for instance in Subject headers with `Re:' for
- ;; interoperability with non-MIME clients, and we might as
- ;; well avoid the tail too.
- (progn
- (goto-char (point-min))
- ;; Does it need encoding?
- (skip-chars-forward "\000-\177")
- (unless (eobp)
- (skip-chars-backward "^ \n") ; beginning of space-delimited word
- (rfc2047-encode (point) (progn
- (goto-char e)
- (skip-chars-backward "\000-\177")
- (skip-chars-forward "^ \n")
- ;; end of space-delimited word
- (point)))))
- ;; `address-mime' case -- take care of quoted words, comments.
- (with-syntax-table rfc2047-syntax-table
- (let ((start) ; start of current token
- end ; end of current token
- ;; Whether there's an encoded word before the current
- ;; token, either immediately or separated by space.
- last-encoded)
+ (let ((encodable-regexp (if rfc2047-encode-encoded-words
+ "[^\000-\177]+\\|=\\?"
+ "[^\000-\177]+"))
+ start ; start of current token
+ end begin csyntax
+ ;; Whether there's an encoded word before the current token,
+ ;; either immediately or separated by space.
+ last-encoded
+ (orig-text (buffer-substring-no-properties b e)))
+ (if (eq 'mime rfc2047-encoding-type)
+ ;; Simple case. Continuous words in which all those contain
+ ;; non-ASCII characters are encoded collectively. Encoding
+ ;; ASCII words, including `Re:' used in Subject headers, is
+ ;; avoided for interoperability with non-MIME clients and
+ ;; for making it easy to find keywords.
+ (progn
+ (goto-char (point-min))
+ (while (progn (skip-chars-forward " \t\n")
+ (not (eobp)))
+ (setq start (point))
+ (while (and (looking-at "[ \t\n]*\\([^ \t\n]+\\)")
+ (progn
+ (setq end (match-end 0))
+ (re-search-forward encodable-regexp end t)))
+ (goto-char end))
+ (if (> (point) start)
+ (rfc2047-encode start (point))
+ (goto-char end))))
+ ;; `address-mime' case -- take care of quoted words, comments.
+ (with-syntax-table rfc2047-syntax-table
(goto-char (point-min))
- (condition-case nil ; in case of unbalanced quotes
+ (condition-case err ; in case of unbalanced quotes
;; Look for rfc2822-style: sequences of atoms, quoted
;; strings, specials, whitespace. (Specials mustn't be
;; encoded.)
(while (not (eobp))
- (setq start (point))
;; Skip whitespace.
- (unless (= 0 (skip-chars-forward " \t\n"))
- (setq start (point)))
+ (skip-chars-forward " \t\n")
+ (setq start (point))
(cond
((not (char-after))) ; eob
;; else token start
- ((eq ?\" (char-syntax (char-after)))
+ ((eq ?\" (setq csyntax (char-syntax (char-after))))
;; Quoted word.
(forward-sexp)
(setq end (point))
;; Does it need encoding?
(goto-char start)
- (skip-chars-forward "\000-\177" end)
- (if (= end (point))
- (setq last-encoded nil)
- ;; It needs encoding. Strip the quotes first,
- ;; since encoded words can't occur in quotes.
- (goto-char end)
- (delete-backward-char 1)
- (goto-char start)
- (delete-char 1)
- (when last-encoded
- ;; There was a preceding quoted word. We need
- ;; to include any separating whitespace in this
- ;; word to avoid it getting lost.
- (skip-chars-backward " \t")
- ;; A space is needed between the encoded words.
- (insert ? )
- (setq start (point)
- end (1+ end)))
- ;; Adjust the end position for the deleted quotes.
- (rfc2047-encode start (- end 2))
- (setq last-encoded t))) ; record that it was encoded
- ((eq ?. (char-syntax (char-after)))
+ (if (re-search-forward encodable-regexp end 'move)
+ ;; It needs encoding. Strip the quotes first,
+ ;; since encoded words can't occur in quotes.
+ (progn
+ (goto-char end)
+ (delete-backward-char 1)
+ (goto-char start)
+ (delete-char 1)
+ (when last-encoded
+ ;; There was a preceding quoted word. We need
+ ;; to include any separating whitespace in this
+ ;; word to avoid it getting lost.
+ (skip-chars-backward " \t")
+ ;; A space is needed between the encoded words.
+ (insert ? )
+ (setq start (point)
+ end (1+ end)))
+ ;; Adjust the end position for the deleted quotes.
+ (rfc2047-encode start (- end 2))
+ (setq last-encoded t)) ; record that it was encoded
+ (setq last-encoded nil)))
+ ((eq ?. csyntax)
;; Skip other delimiters, but record that they've
;; potentially separated quoted words.
(forward-char)
(setq last-encoded nil))
+ ((eq ?\) csyntax)
+ (error "Unbalanced parentheses"))
+ ((eq ?\( csyntax)
+ ;; Look for the end of parentheses.
+ (forward-list)
+ ;; Encode text as an unstructured field.
+ (let ((rfc2047-encoding-type 'mime))
+ (rfc2047-encode-region (1+ start) (1- (point))))
+ (skip-chars-forward ")"))
(t ; normal token/whitespace sequence
;; Find the end.
- (forward-word 1)
- (skip-chars-backward " \t")
+ ;; Skip one ASCII word, or encode continuous words
+ ;; in which all those contain non-ASCII characters.
+ (setq end nil)
+ (while (not (or end (eobp)))
+ (when (looking-at "[\000-\177]+")
+ (setq begin (point)
+ end (match-end 0))
+ (when (progn
+ (while (and (or (re-search-forward
+ "[ \t\n]\\|\\Sw" end 'move)
+ (setq end nil))
+ (eq ?\\ (char-syntax (char-before))))
+ ;; Skip backslash-quoted characters.
+ (forward-char))
+ end)
+ (setq end (match-beginning 0))
+ (if rfc2047-encode-encoded-words
+ (progn
+ (goto-char begin)
+ (when (search-forward "=?" end 'move)
+ (goto-char (match-beginning 0))
+ (setq end nil)))
+ (goto-char end))))
+ ;; Where the value nil of `end' means there may be
+ ;; text to have to be encoded following the point.
+ ;; Otherwise, the point reached to the end of ASCII
+ ;; words separated by whitespace or a special char.
+ (unless end
+ (when (looking-at encodable-regexp)
+ (goto-char (setq begin (match-end 0)))
+ (while (and (looking-at "[ \t\n]+\\([^ \t\n]+\\)")
+ (setq end (match-end 0))
+ (progn
+ (while (re-search-forward
+ encodable-regexp end t))
+ (< begin (point)))
+ (goto-char begin)
+ (or (not (re-search-forward "\\Sw" end t))
+ (progn
+ (goto-char (match-beginning 0))
+ nil)))
+ (goto-char end))
+ (when (looking-at "[^ \t\n]+")
+ (setq end (match-end 0))
+ (if (re-search-forward "\\Sw+" end t)
+ ;; There are special characters better
+ ;; to be encoded so that MTAs may parse
+ ;; them safely.
+ (cond ((= end (point)))
+ ((looking-at (concat "\\sw*\\("
+ encodable-regexp
+ "\\)"))
+ (setq end nil))
+ (t
+ (goto-char (1- (match-end 0)))
+ (unless (= (point) (match-beginning 0))
+ ;; Separate encodable text and
+ ;; delimiter.
+ (insert " "))))
+ (goto-char end)
+ (skip-chars-forward " \t\n")
+ (if (and (looking-at "[^ \t\n]+")
+ (string-match encodable-regexp
+ (match-string 0)))
+ (setq end nil)
+ (goto-char end)))))))
+ (skip-chars-backward " \t\n")
(setq end (point))
- ;; Deal with encoding and leading space as for
- ;; quoted words.
(goto-char start)
- (skip-chars-forward "\000-\177" end)
- (if (= end (point))
- (setq last-encoded nil)
- (when last-encoded
- (goto-char start)
- (skip-chars-backward " \t")
- (insert ? )
- (setq start (point)
- end (1+ end)))
- (rfc2047-encode start end)
- (setq last-encoded t)))))
+ (if (re-search-forward encodable-regexp end 'move)
+ (progn
+ (unless (memq (char-before start) '(nil ?\t ? ))
+ (if (progn
+ (goto-char start)
+ (skip-chars-backward "^ \t\n")
+ (and (looking-at "\\Sw+")
+ (= (match-end 0) start)))
+ ;; Also encode bogus delimiters.
+ (setq start (point))
+ ;; Separate encodable text and delimiter.
+ (goto-char start)
+ (insert " ")
+ (setq start (1+ start)
+ end (1+ end))))
+ (rfc2047-encode start end)
+ (setq last-encoded t))
+ (setq last-encoded nil)))))
(error
- (error "Invalid data for rfc2047 encoding: %s"
- (buffer-substring b e)))))))
- (rfc2047-fold-region b (point))))
+ (if (or debug-on-quit debug-on-error)
+ (signal (car err) (cdr err))
+ (error "Invalid data for rfc2047 encoding: %s"
+ (mm-replace-in-string orig-text "[ \t\n]+" " "))))))))
+ (rfc2047-fold-region b (point))
+ (goto-char (point-max))))
(defun rfc2047-encode-string (string)
"Encode words in STRING.
By default, the string is treated as containing addresses (see
`rfc2047-encoding-type')."
- (with-temp-buffer
+ (mm-with-multibyte-buffer
(insert string)
(rfc2047-encode-region (point-min) (point-max))
(buffer-string)))
+(defvar rfc2047-encode-max-chars 76
+ "Maximum characters of each header line that contain encoded-words.
+If it is nil, encoded-words will not be folded. Too small value may
+cause an error. Don't change this for no particular reason.")
+
+(defun rfc2047-encode-1 (column string cs encoder start crest tail
+ &optional eword)
+ "Subroutine used by `rfc2047-encode'."
+ (cond ((string-equal string "")
+ (or eword ""))
+ ((not rfc2047-encode-max-chars)
+ (concat start
+ (funcall encoder (if cs
+ (mm-encode-coding-string string cs)
+ string))
+ "?="))
+ ((>= column rfc2047-encode-max-chars)
+ (when eword
+ (cond ((string-match "\n[ \t]+\\'" eword)
+ ;; Reomove a superfluous empty line.
+ (setq eword (substring eword 0 (match-beginning 0))))
+ ((string-match "(+\\'" eword)
+ ;; Break the line before the open parenthesis.
+ (setq crest (concat crest (match-string 0 eword))
+ eword (substring eword 0 (match-beginning 0))))))
+ (rfc2047-encode-1 (length crest) string cs encoder start " " tail
+ (concat eword "\n" crest)))
+ (t
+ (let ((index 0)
+ (limit (1- (length string)))
+ (prev "")
+ next len)
+ (while (and prev
+ (<= index limit))
+ (setq next (concat start
+ (funcall encoder
+ (if cs
+ (mm-encode-coding-string
+ (substring string 0 (1+ index))
+ cs)
+ (substring string 0 (1+ index))))
+ "?=")
+ len (+ column (length next)))
+ (if (> len rfc2047-encode-max-chars)
+ (setq next prev
+ prev nil)
+ (if (or (< index limit)
+ (<= (+ len (or (string-match "\n" tail)
+ (length tail)))
+ rfc2047-encode-max-chars))
+ (setq prev next
+ index (1+ index))
+ (if (string-match "\\`)+" tail)
+ ;; Break the line after the close parenthesis.
+ (setq tail (concat (substring tail 0 (match-end 0))
+ "\n "
+ (substring tail (match-end 0)))
+ prev next
+ index (1+ index))
+ (setq next prev
+ prev nil)))))
+ (if (> index limit)
+ (concat eword next tail)
+ (if (= 0 index)
+ (if (and eword
+ (string-match "(+\\'" eword))
+ (setq crest (concat crest (match-string 0 eword))
+ eword (substring eword 0 (match-beginning 0)))
+ (setq eword (concat eword next)))
+ (setq crest " "
+ eword (concat eword next)))
+ (when (string-match "\n[ \t]+\\'" eword)
+ ;; Reomove a superfluous empty line.
+ (setq eword (substring eword 0 (match-beginning 0))))
+ (rfc2047-encode-1 (length crest) (substring string index)
+ cs encoder start " " tail
+ (concat eword "\n" crest)))))))
+
(defun rfc2047-encode (b e)
"Encode the word(s) in the region B to E.
-By default, the region is treated as containing addresses (see
-`rfc2047-encoding-type')."
- (let* ((mime-charset (mm-find-mime-charset-region b e))
- (cs (if (> (length mime-charset) 1)
- ;; Fixme: Instead of this, try to break region into
- ;; parts that can be encoded separately.
- (error "Can't rfc2047-encode `%s'"
- (buffer-substring b e))
- (setq mime-charset (car mime-charset))
- (mm-charset-to-coding-system mime-charset)))
- ;; Fixme: Better, calculate the number of non-ASCII
- ;; characters, at least for 8-bit charsets.
- (encoding (or (cdr (assq mime-charset
+Point moves to the end of the region."
+ (let ((mime-charset (or (mm-find-mime-charset-region b e) (list 'us-ascii)))
+ cs encoding tail crest eword)
+ (cond ((> (length mime-charset) 1)
+ (error "Can't rfc2047-encode `%s'"
+ (buffer-substring-no-properties b e)))
+ ((= (length mime-charset) 1)
+ (setq mime-charset (car mime-charset)
+ cs (mm-charset-to-coding-system mime-charset))
+ (unless (and (mm-multibyte-p)
+ (mm-coding-system-p cs))
+ (setq cs nil))
+ (save-restriction
+ (narrow-to-region b e)
+ (setq encoding
+ (or (cdr (assq mime-charset
rfc2047-charset-encoding-alist))
;; For the charsets that don't have a preferred
;; encoding, choose the one that's shorter.
- (save-restriction
- (narrow-to-region b e)
- (if (eq (rfc2047-qp-or-base64) 'base64)
- 'B
- 'Q))))
- (start (concat
- "=?" (downcase (symbol-name mime-charset)) "?"
- (upcase (symbol-name encoding)) "?"))
- (factor (case mime-charset
- ((iso-8859-5 iso-8859-7 iso-8859-8 koi8-r) 1)
- ((big5 gb2312 euc-kr) 2)
- (utf-8 4)
- (t 8)))
- (pre (- b (save-restriction
- (widen)
- (point-at-bol))))
- ;; encoded-words must not be longer than 75 characters,
- ;; including charset, encoding etc. This leaves us with
- ;; 75 - (length start) - 2 - 2 characters. The last 2 is for
- ;; possible base64 padding. In the worst case (iso-2022-*)
- ;; each character expands to 8 bytes which is expanded by a
- ;; factor of 4/3 by base64 encoding.
- (length (floor (- 75 (length start) 4) (* factor (/ 4.0 3.0))))
- ;; Limit line length to 76 characters.
- (length1 (max 1 (floor (- 76 (length start) 4 pre)
- (* factor (/ 4.0 3.0)))))
- (first t))
- (if mime-charset
- (save-restriction
- (narrow-to-region b e)
- (when (eq encoding 'B)
- ;; break into lines before encoding
- (goto-char (point-min))
- (while (not (eobp))
- (if first
- (progn
- (goto-char (min (point-max) (+ length1 (point))))
- (setq first nil))
- (goto-char (min (point-max) (+ length (point)))))
- (unless (eobp)
- (insert ?\n)))
- (setq first t))
- (if (and (mm-multibyte-p)
- (mm-coding-system-p cs))
- (mm-encode-coding-region (point-min) (point-max) cs))
- (funcall (cdr (assq encoding rfc2047-encoding-function-alist))
- (point-min) (point-max))
- (goto-char (point-min))
- (while (not (eobp))
- (unless first
- (insert ? ))
- (setq first nil)
- (insert start)
- (end-of-line)
- (insert "?=")
- (forward-line 1))))))
+ (if (eq (rfc2047-qp-or-base64) 'base64)
+ 'B
+ 'Q)))
+ (widen)
+ (goto-char e)
+ (skip-chars-forward "^ \t\n")
+ ;; `tail' may contain a close parenthesis.
+ (setq tail (buffer-substring-no-properties e (point)))
+ (goto-char b)
+ (setq b (point-marker)
+ e (set-marker (make-marker) e))
+ (rfc2047-fold-region (point-at-bol) b)
+ (goto-char b)
+ (skip-chars-backward "^ \t\n")
+ (unless (= 0 (skip-chars-backward " \t"))
+ ;; `crest' may contain whitespace and an open parenthesis.
+ (setq crest (buffer-substring-no-properties (point) b)))
+ (setq eword (rfc2047-encode-1
+ (- b (point-at-bol))
+ (mm-replace-in-string
+ (buffer-substring-no-properties b e)
+ "\n\\([ \t]?\\)" "\\1")
+ cs
+ (or (cdr (assq encoding
+ rfc2047-encode-function-alist))
+ 'identity)
+ (concat "=?" (downcase (symbol-name mime-charset))
+ "?" (upcase (symbol-name encoding)) "?")
+ (or crest " ")
+ tail))
+ (delete-region (if (eq (aref eword 0) ?\n)
+ (if (bolp)
+ ;; The line was folded before encoding.
+ (1- (point))
+ (point))
+ (goto-char b))
+ (+ e (length tail)))
+ ;; `eword' contains `crest' and `tail'.
+ (insert eword)
+ (set-marker b nil)
+ (set-marker e nil)
+ (unless (or (/= 0 (length tail))
+ (eobp)
+ (looking-at "[ \t\n)]"))
+ (insert " "))))
+ (t
+ (goto-char e)))))
(defun rfc2047-fold-field ()
"Fold the current header field."
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
+ (skip-chars-backward " \t")
(if (looking-at "[ \t]")
(insert ?\n)
(insert "\n "))
(forward-char 1))
((memq (char-after) '(? ?\t))
(skip-chars-forward " \t")
- (if first
- ;; Don't break just after the header name.
- (setq first nil)
- (setq break (1- (point)))))
+ (unless first ;; Don't break just after the header name.
+ (setq break (point))))
((not break)
(if (not (looking-at "=\\?[^=]"))
(if (eq (char-after) ?=)
(setq qword-break (point)))
(skip-chars-forward "^ \t\n\r")))
(t
- (skip-chars-forward "^ \t\n\r"))))
+ (skip-chars-forward "^ \t\n\r")))
+ (setq first nil))
(when (and (or break qword-break)
(> (- (point) bol) 76))
(goto-char (or break qword-break))
(setq break nil
qword-break nil)
- (if (looking-at "[ \t]")
- (insert ?\n)
- (insert "\n "))
+ (if (or (> 0 (skip-chars-backward " \t"))
+ (looking-at "[ \t]"))
+ (insert ?\n)
+ (insert "\n "))
(setq bol (1- (point)))
;; Don't break before the first non-LWSP characters.
(skip-chars-forward " \t")
(setq eol (point-at-eol))
(forward-line 1)))))
-(defun rfc2047-b-encode-region (b e)
- "Base64-encode the header contained in region B to E."
- (save-restriction
- (narrow-to-region (goto-char b) e)
- (while (not (eobp))
- (base64-encode-region (point) (progn (end-of-line) (point)) t)
- (if (and (bolp) (eolp))
- (delete-backward-char 1))
- (forward-line))))
-
-(defun rfc2047-q-encode-region (b e)
- "Quoted-printable-encode the header in region B to E."
- (save-excursion
- (save-restriction
- (narrow-to-region (goto-char b) e)
- (let ((bol (save-restriction
- (widen)
- (point-at-bol))))
- (quoted-printable-encode-region
- b e nil
- ;; = (\075), _ (\137), ? (\077) are used in the encoded word.
- ;; Avoid using 8bit characters.
- ;; This list excludes `especials' (see the RFC2047 syntax),
- ;; meaning that some characters in non-structured fields will
- ;; get encoded when they con't need to be. The following is
- ;; what it used to be.
-;;; ;; Equivalent to "^\000-\007\011\013\015-\037\200-\377=_?"
-;;; "\010\012\014\040-\074\076\100-\136\140-\177")
- "-\b\n\f !#-'*+0-9A-Z\\^`-~\d")
- (subst-char-in-region (point-min) (point-max) ? ?_)
- ;; The size of QP encapsulation is about 20, so set limit to
- ;; 56=76-20.
- (unless (< (- (point-max) (point-min)) 56)
- ;; Don't break if it could fit in one line.
- ;; Let rfc2047-encode-region break it later.
- (goto-char (1+ (point-min)))
- (while (and (not (bobp)) (not (eobp)))
- (goto-char (min (point-max) (+ 56 bol)))
- (search-backward "=" (- (point) 2) t)
- (unless (or (bobp) (eobp))
- (insert ?\n)
- (setq bol (point)))))))))
+(defun rfc2047-b-encode-string (string)
+ "Base64-encode the header contained in STRING."
+ (base64-encode-string string t))
+
+(defun rfc2047-q-encode-string (string)
+ "Quoted-printable-encode the header in STRING."
+ (mm-with-unibyte-buffer
+ (insert string)
+ (quoted-printable-encode-region
+ (point-min) (point-max) nil
+ ;; = (\075), _ (\137), ? (\077) are used in the encoded word.
+ ;; Avoid using 8bit characters.
+ ;; This list excludes `especials' (see the RFC2047 syntax),
+ ;; meaning that some characters in non-structured fields will
+ ;; get encoded when they con't need to be. The following is
+ ;; what it used to be.
+ ;;; ;; Equivalent to "^\000-\007\011\013\015-\037\200-\377=_?"
+ ;;; "\010\012\014\040-\074\076\100-\136\140-\177")
+ "-\b\n\f !#-'*+0-9A-Z\\^`-~\d")
+ (subst-char-in-region (point-min) (point-max) ? ?_)
+ (buffer-string)))
+
+(defun rfc2047-encode-parameter (param value)
+ "Return and PARAM=VALUE string encoded in the RFC2047-like style.
+This is a replacement for the `rfc2231-encode-string' function.
+
+When attaching files as MIME parts, we should use the RFC2231 encoding
+to specify the file names containing non-ASCII characters. However,
+many mail softwares don't support it in practice and recipients won't
+be able to extract files with correct names. Instead, the RFC2047-like
+encoding is acceptable generally. This function provides the very
+RFC2047-like encoding, resigning to such a regrettable trend. To use
+it, put the following line in your ~/.gnus.el file:
+
+\(defalias 'mail-header-encode-parameter 'rfc2047-encode-parameter)
+"
+ (let* ((rfc2047-encoding-type 'mime)
+ (rfc2047-encode-max-chars nil)
+ (string (rfc2047-encode-string value)))
+ (if (string-match (concat "[" ietf-drums-tspecials "]") string)
+ (format "%s=%S" param string)
+ (concat param "=" string))))
;;;
;;; Functions for decoding RFC2047 messages
"=\\?\\([^][\000-\040()<>@,\;:*\\\"/?.=]+\\)\\(?:\\*[^?]+\\)?\
\\?\\(B\\|Q\\)\\?\\([!->@-~ ]*\\)\\?="))
+(defvar rfc2047-quote-decoded-words-containing-tspecials nil
+ "If non-nil, quote decoded words containing special characters.")
+
+(defvar rfc2047-allow-incomplete-encoded-text t
+ "*Non-nil means allow incomplete encoded-text in successive encoded-words.
+Dividing of encoded-text in the place other than character boundaries
+violates RFC2047 section 5, while we have a capability to decode it.
+If it is non-nil, the decoder will decode B- or Q-encoding in each
+encoded-word, concatenate them, and decode it by charset. Otherwise,
+the decoder will fully decode each encoded-word before concatenating
+them.")
+
+(defun rfc2047-charset-to-coding-system (charset)
+ "Return coding-system corresponding to MIME CHARSET.
+If your Emacs implementation can't decode CHARSET, return nil."
+ (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))
+ (let ((cs (mm-coding-system-p (mm-charset-to-coding-system charset))))
+ (cond ((eq cs 'ascii)
+ (setq cs (or (mm-charset-to-coding-system mail-parse-charset)
+ 'raw-text)))
+ (cs)
+ ((and charset
+ (listp mail-parse-ignored-charsets)
+ (memq 'gnus-unknown mail-parse-ignored-charsets))
+ (setq cs (mm-charset-to-coding-system mail-parse-charset))))
+ (if (eq cs 'ascii)
+ 'raw-text
+ cs)))
+
+(defun rfc2047-decode-encoded-words (words)
+ "Decode successive encoded-words in WORDS and return a decoded string.
+Each element of WORDS looks like (CHARSET ENCODING ENCODED-TEXT
+ENCODED-WORD)."
+ (let (word charset cs encoding text rest)
+ (while words
+ (setq word (pop words))
+ (if (and (or (setq cs (rfc2047-charset-to-coding-system
+ (setq charset (car word))))
+ (progn
+ (message "Unknown charset: %s" charset)
+ nil))
+ (condition-case code
+ (cond ((char-equal ?B (nth 1 word))
+ (setq text (base64-decode-string
+ (rfc2047-pad-base64 (nth 2 word)))))
+ ((char-equal ?Q (nth 1 word))
+ (setq text (quoted-printable-decode-string
+ (mm-subst-char-in-string
+ ?_ ? (nth 2 word) t)))))
+ (error
+ (message "%s" (error-message-string code))
+ nil)))
+ (if (and rfc2047-allow-incomplete-encoded-text
+ (eq cs (caar rest)))
+ ;; Concatenate text of which the charset is the same.
+ (setcdr (car rest) (concat (cdar rest) text))
+ (push (cons cs text) rest))
+ ;; Don't decode encoded-word.
+ (push (cons nil (nth 3 word)) rest)))
+ (while rest
+ (setq words (concat
+ (or (and (setq cs (caar rest))
+ (condition-case code
+ (mm-decode-coding-string (cdar rest) cs)
+ (error
+ (message "%s" (error-message-string code))
+ nil)))
+ (concat (when (cdr rest) " ")
+ (cdar rest)
+ (when (and words
+ (not (eq (string-to-char words) ? )))
+ " ")))
+ words)
+ rest (cdr rest)))
+ words))
+
;; Fixme: This should decode in place, not cons intermediate strings.
;; Also check whether it needs to worry about delimiting fields like
;; encoding.
"Decode MIME-encoded words in region between START and END."
(interactive "r")
(let ((case-fold-search t)
- b e)
+ (eword-regexp (eval-when-compile
+ ;; Ignore whitespace between encoded-words.
+ (concat "[\n\t ]*\\(" rfc2047-encoded-word-regexp
+ "\\)")))
+ b e match words)
(save-excursion
(save-restriction
(narrow-to-region start end)
- (goto-char (point-min))
- ;; Remove whitespace between encoded words.
- (while (re-search-forward
- (eval-when-compile
- (concat "\\(" rfc2047-encoded-word-regexp "\\)"
- "\\(\n?[ \t]\\)+"
- "\\(" rfc2047-encoded-word-regexp "\\)"))
- nil t)
- (delete-region (goto-char (match-end 1)) (match-beginning 6)))
- ;; Decode the encoded words.
- (setq b (goto-char (point-min)))
- (while (re-search-forward rfc2047-encoded-word-regexp nil t)
- (setq e (match-beginning 0))
- (insert (rfc2047-parse-and-decode
- (prog1
- (match-string 0)
- (delete-region (match-beginning 0) (match-end 0)))))
- ;; Remove newlines between decoded words, though such things
- ;; essentially must not be there.
+ (goto-char (setq b start))
+ ;; Look for the encoded-words.
+ (while (setq match (re-search-forward eword-regexp nil t))
+ (setq e (match-beginning 1)
+ end (match-end 0)
+ words nil)
+ (while match
+ (push (list (match-string 2) ;; charset
+ (char-after (match-beginning 3)) ;; encoding
+ (match-string 4) ;; encoded-text
+ (match-string 1)) ;; encoded-word
+ words)
+ ;; Look for the subsequent encoded-words.
+ (when (setq match (looking-at eword-regexp))
+ (goto-char (setq end (match-end 0)))))
+ ;; Replace the encoded-words with the decoded one.
+ (delete-region e end)
+ (insert (rfc2047-decode-encoded-words (nreverse words)))
(save-restriction
(narrow-to-region e (point))
(goto-char e)
+ ;; Remove newlines between decoded words, though such
+ ;; things essentially must not be there.
(while (re-search-forward "[\n\r]+" nil t)
(replace-match " "))
+ ;; Quote decoded words if there are special characters
+ ;; which might violate RFC2822.
+ (when (and rfc2047-quote-decoded-words-containing-tspecials
+ (let ((regexp (car (rassq
+ 'address-mime
+ rfc2047-header-encoding-alist))))
+ (when regexp
+ (save-restriction
+ (widen)
+ (beginning-of-line)
+ (while (and (memq (char-after) '(? ?\t))
+ (zerop (forward-line -1))))
+ (looking-at regexp)))))
+ (let (quoted)
+ (goto-char e)
+ (skip-chars-forward " \t")
+ (setq start (point))
+ (setq quoted (eq (char-after) ?\"))
+ (goto-char (point-max))
+ (skip-chars-backward " \t")
+ (if (setq quoted (and quoted
+ (> (point) (1+ start))
+ (eq (char-before) ?\")))
+ (progn
+ (backward-char)
+ (setq start (1+ start)
+ end (point-marker)))
+ (setq end (point-marker)))
+ (goto-char start)
+ (while (search-forward "\"" end t)
+ (when (prog2
+ (backward-char)
+ (zerop (% (skip-chars-backward "\\\\") 2))
+ (goto-char (match-beginning 0)))
+ (insert "\\"))
+ (forward-char))
+ (when (and (not quoted)
+ (progn
+ (goto-char start)
+ (re-search-forward
+ (concat "[" ietf-drums-tspecials "]")
+ end t)))
+ (goto-char start)
+ (insert "\"")
+ (goto-char end)
+ (insert "\""))
+ (set-marker end nil)))
(goto-char (point-max)))
(when (and (mm-multibyte-p)
mail-parse-charset
(mm-decode-coding-string string mail-parse-charset))
(mm-string-as-multibyte string)))))
-(defun rfc2047-parse-and-decode (word)
- "Decode WORD and return it if it is an encoded word.
-Return WORD if it is not not an encoded word or if the charset isn't
-decodable."
- (if (not (string-match rfc2047-encoded-word-regexp word))
- word
- (or
- (condition-case nil
- (rfc2047-decode
- (match-string 1 word)
- (string-to-char (match-string 2 word))
- (match-string 3 word))
- (error word))
- word))) ; un-decodable
-
(defun rfc2047-pad-base64 (string)
"Pad STRING to quartets."
;; Be more liberal to accept buggy base64 strings. If
(2 (concat string "=="))
(3 (concat string "=")))))
-(defun rfc2047-decode (charset encoding string)
- "Decode STRING from the given MIME CHARSET in the given ENCODING.
-Valid ENCODINGs are the characters \"B\" and \"Q\".
-If your Emacs implementation can't decode CHARSET, return nil."
- (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))
- (let ((cs (mm-charset-to-coding-system charset)))
- (if (and (not cs) charset
- (listp mail-parse-ignored-charsets)
- (memq 'gnus-unknown mail-parse-ignored-charsets))
- (setq cs (mm-charset-to-coding-system mail-parse-charset)))
- (when cs
- (when (and (eq cs 'ascii)
- mail-parse-charset)
- (setq cs mail-parse-charset))
- (mm-decode-coding-string
- (cond
- ((char-equal ?B encoding)
- (base64-decode-string
- (rfc2047-pad-base64 string)))
- ((char-equal ?Q encoding)
- (quoted-printable-decode-string
- (mm-subst-char-in-string ?_ ? string t)))
- (t (error "Invalid encoding: %c" encoding)))
- cs))))
-
(provide 'rfc2047)
+;;; arch-tag: a07fe3d4-22b5-4c4a-bd89-b1f82d5d36f6
;;; rfc2047.el ends here
projects / gnus / blobdiff