;;; undigest.el --- digest-cracking support for the RMAIL mail reader
;; Copyright (C) 1985-1986, 1994, 1996, 2001-2016 Free Software
;; Foundation, Inc.
;; Maintainer: emacs-devel@gnu.org
;; Keywords: mail
;; 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 3 of the License, 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. If not, see .
;;; Commentary:
;; See Internet RFC 934 and RFC 1153.
;; Also limited support for MIME digest encapsulation.
;;; Code:
(require 'rmail)
(defcustom rmail-forward-separator-regex
"^----.*\\([Ff]orwarded\\|[Oo]riginal\\).*[Mm]essage"
"Regexp to match the string that introduces forwarded messages.
This is not a header, but a string contained in the body of the message.
You may need to customize it for local needs."
:type 'regexp
:group 'rmail-headers)
(defconst rmail-digest-methods
'(rmail-digest-parse-mime
rmail-digest-parse-rfc1153strict
rmail-digest-parse-rfc1153sloppy
rmail-digest-parse-rfc934)
"List of digest parsing functions, first tried first.
These functions operate on the current narrowing, and take no argument.
A function returns nil if it cannot parse the digest. If it can, it
returns a list of cons pairs containing the start and end positions of
each undigestified message as markers.")
(defun rmail-digest-parse-mime ()
(goto-char (point-min))
(when (let ((head-end (progn (search-forward "\n\n" nil t) (point))))
(goto-char (point-min))
(and head-end ; FIXME always true
(re-search-forward
(concat
"^Content-type: multipart/digest;"
"\\s-* boundary=\"?\\([^\";\n]+\\)[\";\n]") head-end t)
(search-forward (match-string 1) nil t)))
;; Ok, prolog separator found
(let ((start (make-marker))
(end (make-marker))
(separator (concat "\n--" (match-string 0) "\n\n"))
result)
(while (search-forward separator nil t)
(move-marker start (match-beginning 0))
(move-marker end (match-end 0))
(add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
;; Return the list of marker pairs
(nreverse result))))
(defun rmail-digest-parse-rfc1153strict ()
"Parse following strictly the method defined in RFC 1153.
See rmail-digest-methods."
(rmail-digest-rfc1153
"^-\\{70\\}\n\n"
"^\n-\\{30\\}\n\n"
"^\n-\\{30\\}\n\nEnd of .* Digest.*\n\\*\\{15,\\}\n+\\'"))
(defun rmail-digest-parse-rfc1153sloppy ()
"Parse using the method defined in RFC 1153, allowing for some sloppiness.
See rmail-digest-methods."
(rmail-digest-rfc1153
"^-\\{55,\\}\n\n"
"^\n-\\{27,\\}\n\n"
;; GNU Mailman knowingly (see comment at line 353 of ToDigest.py in
;; Mailman source) produces non-conformant rfc 1153 digests, in that
;; the trailer contains a "digest footer" like this:
;; _______________________________________________
;;
;;
;; End of Foo Digest...
;; **************************************
"^\nEnd of"))
(defun rmail-digest-rfc1153 (prolog-sep message-sep trailer-sep)
(goto-char (point-min))
(when (re-search-forward prolog-sep nil t)
;; Ok, prolog separator found
(let ((start (make-marker))
(end (make-marker))
separator result)
(move-marker start (match-beginning 0))
(move-marker end (match-end 0))
(setq result (list (cons (copy-marker start) (copy-marker end t))))
(when (re-search-forward message-sep nil t)
;; Ok, at least one message separator found
(setq separator (match-string 0))
(when (re-search-forward trailer-sep nil t)
;; Wonderful, we found a trailer, too. Now, go on splitting
;; the digest into separate rmail messages
(goto-char (cdar result))
(while (search-forward separator nil t)
(move-marker start (match-beginning 0))
(move-marker end (match-end 0))
(add-to-list 'result
(cons (copy-marker start) (copy-marker end t))))
;; Undo masking of separators inside digestified messages
(goto-char (point-min))
(while (search-forward
(replace-regexp-in-string "\n-" "\n " separator) nil t)
(replace-match separator))
;; Return the list of marker pairs
(nreverse result))))))
(defun rmail-digest-parse-rfc934 ()
(goto-char (point-min))
(when (re-search-forward "^\n?-[^ ].*\n\n?" nil t)
;; Message separator found
(let ((start (make-marker))
(end (make-marker))
(separator (match-string 0))
result)
(goto-char (point-min))
(while (search-forward separator nil t)
(move-marker start (match-beginning 0))
(move-marker end (match-end 0))
(add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
;; Undo masking of separators inside digestified messages
(goto-char (point-min))
(while (search-forward "\n- -" nil t)
(replace-match "\n-"))
;; Return the list of marker pairs
(nreverse result))))
(declare-function rmail-update-summary "rmailsum" (&rest ignore))
;;;###autoload
(defun undigestify-rmail-message ()
"Break up a digest message into its constituent messages.
Leaves original message, deleted, before the undigestified messages."
(interactive)
(set-buffer rmail-buffer)
(let ((buff (current-buffer))
(current rmail-current-message)
(msgbeg (rmail-msgbeg rmail-current-message))
(msgend (rmail-msgend rmail-current-message)))
(if (rmail-buffers-swapped-p) (set-buffer rmail-view-buffer))
(widen)
(let ((error t)
(buffer-read-only nil))
(goto-char msgend)
(let ((msg-copy (buffer-substring-no-properties msgbeg msgend)))
(narrow-to-region (point) (point))
(insert "\n" msg-copy))
(goto-char (point-min))
(unwind-protect
(progn
(let ((fill-prefix "")
(case-fold-search t)
digest-name fun-list sep-list start end)
(setq digest-name (mail-strip-quoted-names
(save-restriction
(search-forward "\n\n" nil 'move)
(narrow-to-region (point-min) (point))
(or (mail-fetch-field "Reply-To")
(mail-fetch-field "To")
(mail-fetch-field "Apparently-To")
(mail-fetch-field "From")))))
(unless digest-name
(error "Message is not a digest--bad header"))
(setq fun-list rmail-digest-methods)
(while (and fun-list
(null (setq sep-list (funcall (car fun-list)))))
(setq fun-list (cdr fun-list)))
(unless sep-list
(error "Message is not a digest--no messages found"))
;; Split the digest into separate rmail messages.
(while sep-list
(setq start (caar sep-list)
end (cdar sep-list))
(delete-region start end)
(goto-char start)
(search-forward "\n\n" (caar (cdr sep-list)) 'move)
(save-restriction
(narrow-to-region end (point))
(goto-char (point-min))
(insert "\nFrom rmail@localhost " (current-time-string) "\n")
(save-excursion
(forward-line -1)
(rmail-add-mbox-headers))
(unless (mail-fetch-field "To")
(insert "To: " digest-name "\n")))
(set-marker start nil)
(set-marker end nil)
(setq sep-list (cdr sep-list))))
(setq error nil)
(message "Message successfully undigestified")
(set-buffer buff)
(rmail-swap-buffers-maybe)
(goto-char (point-max))
;; FIXME use rmail-count-new-messages.
(rmail-set-message-counters)
(set-buffer-modified-p t)
(rmail-show-message current)
(rmail-delete-forward)
(if (rmail-summary-exists)
(rmail-select-summary (rmail-update-summary))))
(when error
(delete-region (point-min) (point-max))
(set-buffer buff)
(rmail-show-message current))))))
;;;###autoload
(defun unforward-rmail-message ()
"Extract a forwarded message from the containing message.
This puts the forwarded message into a separate rmail message following
the containing message. This command is only useful when messages are
forwarded with `rmail-enable-mime-composing' set to nil."
(interactive)
(set-buffer rmail-buffer)
(let ((buff (current-buffer))
(current rmail-current-message)
(beg (rmail-msgbeg rmail-current-message))
(msgend (rmail-msgend rmail-current-message))
(error t))
(unwind-protect
(progn
(if (rmail-buffers-swapped-p) (set-buffer rmail-view-buffer))
(widen)
(goto-char beg)
(search-forward "\n\n" msgend)
(narrow-to-region beg (point))
(let ((old-fwd-from (mail-fetch-field "Forwarded-From" nil nil t))
(old-fwd-date (mail-fetch-field "Forwarded-Date" nil nil t))
(fwd-from (mail-fetch-field "From"))
(fwd-date (mail-fetch-field "Date"))
(buffer-read-only nil)
prefix forward-msg end)
(widen)
(narrow-to-region beg msgend)
(cond ((re-search-forward rmail-forward-separator-regex nil t)
(forward-line 1)
(skip-chars-forward "\n")
(setq beg (point))
(setq end (if (re-search-forward "^----.*[^- \t\n]" nil t)
(match-beginning 0) (point-max)))
(setq forward-msg
(replace-regexp-in-string
"^- -" "-" (buffer-substring beg end))))
((and (re-search-forward "^\\(> ?\\)[a-zA-Z-]+: .*\n" nil t)
(setq beg (match-beginning 0))
(setq prefix (match-string-no-properties 1))
(goto-char beg)
(looking-at (concat "\\(" prefix ".+\n\\)*"
prefix "Date: ."))
(looking-at (concat "\\(" prefix ".+\n\\)*"
prefix "From: .+\n"
"\\(" prefix ".+\n\\)*"
"\\(> ?\\)?\n" prefix)))
(re-search-forward "^[^>\n]" nil 'move)
(backward-char)
(skip-chars-backward " \t\n")
(forward-line 1)
(setq end (point))
(setq forward-msg
(replace-regexp-in-string
(if (string= prefix ">") "^>" "> ?")
"" (buffer-substring beg end))))
(t
(error "No forwarded message found")))
(widen)
(goto-char msgend)
;; Insert a fake From line.
;; FIXME we could construct one using the From and Date headers
;; of the forwarded message - is it worth it?
(insert "\n\nFrom rmail@localhost " (current-time-string) "\n")
(setq beg (point)) ; start of header
(while old-fwd-from
(insert "Forwarded-From: " (car old-fwd-from) "\n")
(insert "Forwarded-Date: " (car old-fwd-date) "\n")
(setq old-fwd-from (cdr old-fwd-from))
(setq old-fwd-date (cdr old-fwd-date)))
(insert "Forwarded-From: " fwd-from "\n")
(insert "Forwarded-Date: " fwd-date "\n")
(insert forward-msg "\n")
(goto-char beg)
(re-search-forward "\n$" nil 'move) ; end of header
(narrow-to-region beg (point))
(goto-char (point-min))
(while (not (eobp))
(unless (looking-at "^[a-zA-Z-]+: ")
(insert "\t"))
(forward-line))
(widen)
(goto-char beg)
(forward-line -1)
(rmail-add-mbox-headers)) ; marks as unseen
(setq error nil)
(set-buffer buff)
(rmail-swap-buffers-maybe)
(goto-char (point-max))
;; FIXME use rmail-count-new-messages.
(rmail-set-message-counters)
(set-buffer-modified-p t)
(rmail-show-message current)
(if (rmail-summary-exists)
(rmail-select-summary (rmail-update-summary))))
(when error
(set-buffer buff)
(rmail-show-message current)))))
(provide 'undigest)
;; Local Variables:
;; generated-autoload-file: "rmail-loaddefs.el"
;; End:
;;; undigest.el ends here