lisp/mail/undigest.el

   1 ;;; undigest.el --- digest-cracking support for the RMAIL mail reader
   2
   3 ;; Copyright (C) 1985-1986, 1994, 1996, 2001-2015 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Maintainer: emacs-devel@gnu.org
   7 ;; Keywords: mail
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; See Internet RFC 934 and RFC 1153.
  27 ;; Also limited support for MIME digest encapsulation.
  28
  29 ;;; Code:
  30
  31 (require 'rmail)
  32
  33 (defcustom rmail-forward-separator-regex
  34   "^----.*\\([Ff]orwarded\\|[Oo]riginal\\).*[Mm]essage"
  35   "Regexp to match the string that introduces forwarded messages.
  36 This is not a header, but a string contained in the body of the message.
  37 You may need to customize it for local needs."
  38   :type 'regexp
  39   :group 'rmail-headers)
  40
  41 \f
  42 (defconst rmail-digest-methods
  43   '(rmail-digest-parse-mime
  44     rmail-digest-parse-rfc1153strict
  45     rmail-digest-parse-rfc1153sloppy
  46     rmail-digest-parse-rfc934)
  47   "List of digest parsing functions, first tried first.
  48
  49 These functions operate on the current narrowing, and take no argument.
  50 A function returns nil if it cannot parse the digest.  If it can, it
  51 returns a list of cons pairs containing the start and end positions of
  52 each undigestified message as markers.")
  53
  54 (defun rmail-digest-parse-mime ()
  55   (goto-char (point-min))
  56   (when (let ((head-end (progn (search-forward "\n\n" nil t) (point))))
  57           (goto-char (point-min))
  58           (and head-end                 ; FIXME always true
  59                (re-search-forward
  60                 (concat
  61                  "^Content-type: multipart/digest;"
  62                  "\\s-* boundary=\"?\\([^\";\n]+\\)[\";\n]") head-end t)
  63                (search-forward (match-string 1) nil t)))
  64     ;; Ok, prolog separator found
  65     (let ((start (make-marker))
  66           (end (make-marker))
  67           (separator (concat "\n--" (match-string 0) "\n\n"))
  68           result)
  69       (while (search-forward separator nil t)
  70         (move-marker start (match-beginning 0))
  71         (move-marker end (match-end 0))
  72         (add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
  73       ;; Return the list of marker pairs
  74       (nreverse result))))
  75
  76 (defun rmail-digest-parse-rfc1153strict ()
  77   "Parse following strictly the method defined in RFC 1153.
  78 See rmail-digest-methods."
  79  (rmail-digest-rfc1153
  80   "^-\\{70\\}\n\n"
  81   "^\n-\\{30\\}\n\n"
  82   "^\n-\\{30\\}\n\nEnd of .* Digest.*\n\\*\\{15,\\}\n+\'"))
  83
  84 (defun rmail-digest-parse-rfc1153sloppy ()
  85   "Parse using the method defined in RFC 1153, allowing for some sloppiness.
  86 See rmail-digest-methods."
  87  (rmail-digest-rfc1153
  88   "^-\\{55,\\}\n\n"
  89   "^\n-\\{27,\\}\n\n"
  90   ;; GNU Mailman knowingly (see comment at line 353 of ToDigest.py in
  91   ;; Mailman source) produces non-conformant rfc 1153 digests, in that
  92   ;; the trailer contains a "digest footer" like this:
  93   ;; _______________________________________________
  94   ;; <one or more lines of list blurb>
  95   ;;
  96   ;; End of Foo Digest...
  97   ;; **************************************
  98   "^\nEnd of"))
  99
 100 (defun rmail-digest-rfc1153 (prolog-sep message-sep trailer-sep)
 101   (goto-char (point-min))
 102   (when (re-search-forward prolog-sep nil t)
 103     ;; Ok, prolog separator found
 104     (let ((start (make-marker))
 105           (end (make-marker))
 106           separator result)
 107       (move-marker start (match-beginning 0))
 108       (move-marker end (match-end 0))
 109       (setq result (list (cons (copy-marker start) (copy-marker end t))))
 110       (when (re-search-forward message-sep nil t)
 111         ;; Ok, at least one message separator found
 112         (setq separator (match-string 0))
 113         (when (re-search-forward trailer-sep nil t)
 114           ;; Wonderful, we found a trailer, too.  Now, go on splitting
 115           ;; the digest into separate rmail messages
 116           (goto-char (cdar result))
 117           (while (search-forward separator nil t)
 118             (move-marker start (match-beginning 0))
 119             (move-marker end (match-end 0))
 120             (add-to-list 'result
 121                          (cons (copy-marker start) (copy-marker end t))))
 122           ;; Undo masking of separators inside digestified messages
 123           (goto-char (point-min))
 124           (while (search-forward
 125                   (replace-regexp-in-string "\n-" "\n " separator) nil t)
 126             (replace-match separator))
 127           ;; Return the list of marker pairs
 128           (nreverse result))))))
 129
 130 (defun rmail-digest-parse-rfc934 ()
 131   (goto-char (point-min))
 132   (when (re-search-forward "^\n?-[^ ].*\n\n?" nil t)
 133     ;; Message separator found
 134     (let ((start (make-marker))
 135           (end (make-marker))
 136           (separator (match-string 0))
 137           result)
 138       (goto-char (point-min))
 139       (while (search-forward separator nil t)
 140         (move-marker start (match-beginning 0))
 141         (move-marker end (match-end 0))
 142         (add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
 143       ;; Undo masking of separators inside digestified messages
 144       (goto-char (point-min))
 145       (while (search-forward "\n- -" nil t)
 146         (replace-match "\n-"))
 147       ;; Return the list of marker pairs
 148       (nreverse result))))
 149
 150 (declare-function rmail-update-summary "rmailsum" (&rest ignore))
 151
 152 ;;;###autoload
 153 (defun undigestify-rmail-message ()
 154   "Break up a digest message into its constituent messages.
 155 Leaves original message, deleted, before the undigestified messages."
 156   (interactive)
 157   (set-buffer rmail-buffer)
 158   (let ((buff (current-buffer))
 159         (current rmail-current-message)
 160         (msgbeg (rmail-msgbeg rmail-current-message))
 161         (msgend (rmail-msgend rmail-current-message)))
 162     (if (rmail-buffers-swapped-p) (set-buffer rmail-view-buffer))
 163     (widen)
 164     (let ((error t)
 165           (buffer-read-only nil))
 166       (goto-char msgend)
 167       (let ((msg-copy (buffer-substring-no-properties msgbeg msgend)))
 168         (narrow-to-region (point) (point))
 169         (insert "\n" msg-copy))
 170       (goto-char (point-min))
 171       (unwind-protect
 172           (progn
 173             (let ((fill-prefix "")
 174                   (case-fold-search t)
 175                   digest-name fun-list sep-list start end)
 176               (setq digest-name (mail-strip-quoted-names
 177                                  (save-restriction
 178                                    (search-forward "\n\n" nil 'move)
 179                                    (narrow-to-region (point-min) (point))
 180                                    (or (mail-fetch-field "Reply-To")
 181                                        (mail-fetch-field "To")
 182                                        (mail-fetch-field "Apparently-To")
 183                                        (mail-fetch-field "From")))))
 184               (unless digest-name
 185                 (error "Message is not a digest--bad header"))
 186               (setq fun-list rmail-digest-methods)
 187               (while (and fun-list
 188                           (null (setq sep-list (funcall (car fun-list)))))
 189                 (setq fun-list (cdr fun-list)))
 190               (unless sep-list
 191                 (error "Message is not a digest--no messages found"))
 192               ;; Split the digest into separate rmail messages.
 193               (while sep-list
 194                 (setq start (caar sep-list)
 195                       end (cdar sep-list))
 196                 (delete-region start end)
 197                 (goto-char start)
 198                 (search-forward "\n\n" (caar (cdr sep-list)) 'move)
 199                 (save-restriction
 200                   (narrow-to-region end (point))
 201                   (goto-char (point-min))
 202                   (insert "\nFrom rmail@localhost  " (current-time-string) "\n")
 203                   (save-excursion
 204                     (forward-line -1)
 205                     (rmail-add-mbox-headers))
 206                   (unless (mail-fetch-field "To")
 207                     (insert "To: " digest-name "\n")))
 208                 (set-marker start nil)
 209                 (set-marker end nil)
 210                 (setq sep-list (cdr sep-list))))
 211             (setq error nil)
 212             (message "Message successfully undigestified")
 213             (set-buffer buff)
 214             (rmail-swap-buffers-maybe)
 215             (goto-char (point-max))
 216             ;; FIXME use rmail-count-new-messages.
 217             (rmail-set-message-counters)
 218             (set-buffer-modified-p t)
 219             (rmail-show-message current)
 220             (rmail-delete-forward)
 221             (if (rmail-summary-exists)
 222                 (rmail-select-summary (rmail-update-summary))))
 223         (when error
 224           (delete-region (point-min) (point-max))
 225           (set-buffer buff)
 226           (rmail-show-message current))))))
 227 \f
 228 ;;;###autoload
 229 (defun unforward-rmail-message ()
 230   "Extract a forwarded message from the containing message.
 231 This puts the forwarded message into a separate rmail message following
 232 the containing message.  This command is only useful when messages are
 233 forwarded with `rmail-enable-mime-composing' set to nil."
 234   (interactive)
 235   (set-buffer rmail-buffer)
 236   (let ((buff (current-buffer))
 237         (current rmail-current-message)
 238         (beg (rmail-msgbeg rmail-current-message))
 239         (msgend (rmail-msgend rmail-current-message))
 240         (error t))
 241     (unwind-protect
 242         (progn
 243           (if (rmail-buffers-swapped-p) (set-buffer rmail-view-buffer))
 244           (widen)
 245           (goto-char beg)
 246           (search-forward "\n\n" msgend)
 247           (narrow-to-region beg (point))
 248           (let ((old-fwd-from (mail-fetch-field "Forwarded-From" nil nil t))
 249                 (old-fwd-date (mail-fetch-field "Forwarded-Date" nil nil t))
 250                 (fwd-from (mail-fetch-field "From"))
 251                 (fwd-date (mail-fetch-field "Date"))
 252                 (buffer-read-only nil)
 253                 prefix forward-msg end)
 254             (widen)
 255             (narrow-to-region beg msgend)
 256             (cond ((re-search-forward rmail-forward-separator-regex nil t)
 257                    (forward-line 1)
 258                    (skip-chars-forward "\n")
 259                    (setq beg (point))
 260                    (setq end (if (re-search-forward "^----.*[^- \t\n]" nil t)
 261                                  (match-beginning 0) (point-max)))
 262                    (setq forward-msg
 263                          (replace-regexp-in-string
 264                           "^- -" "-" (buffer-substring beg end))))
 265                   ((and (re-search-forward "^\\(> ?\\)[a-zA-Z-]+: .*\n" nil t)
 266                         (setq beg (match-beginning 0))
 267                         (setq prefix (match-string-no-properties 1))
 268                         (goto-char beg)
 269                         (looking-at (concat "\\(" prefix ".+\n\\)*"
 270                                             prefix "Date: ."))
 271                         (looking-at (concat "\\(" prefix ".+\n\\)*"
 272                                             prefix "From: .+\n"
 273                                             "\\(" prefix ".+\n\\)*"
 274                                             "\\(> ?\\)?\n" prefix)))
 275                    (re-search-forward "^[^>\n]" nil 'move)
 276                    (backward-char)
 277                    (skip-chars-backward " \t\n")
 278                    (forward-line 1)
 279                    (setq end (point))
 280                    (setq forward-msg
 281                          (replace-regexp-in-string
 282                           (if (string= prefix ">") "^>" "> ?")
 283                           "" (buffer-substring beg end))))
 284                   (t
 285                    (error "No forwarded message found")))
 286             (widen)
 287             (goto-char msgend)
 288             ;; Insert a fake From line.
 289             ;; FIXME we could construct one using the From and Date headers
 290             ;; of the forwarded message - is it worth it?
 291             (insert "\n\nFrom rmail@localhost  " (current-time-string) "\n")
 292             (setq beg (point))          ; start of header
 293             (while old-fwd-from
 294               (insert "Forwarded-From: " (car old-fwd-from) "\n")
 295               (insert "Forwarded-Date: " (car old-fwd-date) "\n")
 296               (setq old-fwd-from (cdr old-fwd-from))
 297               (setq old-fwd-date (cdr old-fwd-date)))
 298             (insert "Forwarded-From: " fwd-from "\n")
 299             (insert "Forwarded-Date: " fwd-date "\n")
 300             (insert forward-msg "\n")
 301             (goto-char beg)
 302             (re-search-forward "\n$" nil 'move) ; end of header
 303             (narrow-to-region beg (point))
 304             (goto-char (point-min))
 305             (while (not (eobp))
 306               (unless (looking-at "^[a-zA-Z-]+: ")
 307                 (insert "\t"))
 308               (forward-line))
 309             (widen)
 310             (goto-char beg)
 311             (forward-line -1)
 312             (rmail-add-mbox-headers))           ; marks as unseen
 313           (setq error nil)
 314           (set-buffer buff)
 315           (rmail-swap-buffers-maybe)
 316           (goto-char (point-max))
 317           ;; FIXME use rmail-count-new-messages.
 318           (rmail-set-message-counters)
 319           (set-buffer-modified-p t)
 320           (rmail-show-message current)
 321           (if (rmail-summary-exists)
 322               (rmail-select-summary (rmail-update-summary))))
 323       (when error
 324         (set-buffer buff)
 325         (rmail-show-message current)))))
 326
 327 (provide 'undigest)
 328
 329 ;; Local Variables:
 330 ;; generated-autoload-file: "rmail.el"
 331 ;; End:
 332
 333 ;;; undigest.el ends here