2001-07-25 11:00:00 ShengHuo ZHU <zsh@cs.rochester.edu>

[gnus] / lisp / gnus-art.el

;;; gnus-art.el --- article mode commands for Gnus
;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001
;;        Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news

;; 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-when-compile (require 'cl))

(require 'gnus)
(require 'gnus-sum)
(require 'gnus-spec)
(require 'gnus-int)
(require 'mm-bodies)
(require 'mail-parse)
(require 'mm-decode)
(require 'mm-view)
(require 'wid-edit)
(require 'mm-uu)

(autoload 'gnus-msg-mail "gnus-msg" nil t)
(autoload 'gnus-button-mailto "gnus-msg")
(autoload 'gnus-button-reply "gnus-msg" nil t)

(defgroup gnus-article nil
  "Article display."
  :link '(custom-manual "(gnus)The Article Buffer")
  :group 'gnus)

(defgroup gnus-article-treat nil
  "Treating article parts."
  :link '(custom-manual "(gnus)Article Hiding")
  :group 'gnus-article)

(defgroup gnus-article-hiding nil
  "Hiding article parts."
  :link '(custom-manual "(gnus)Article Hiding")
  :group 'gnus-article)

(defgroup gnus-article-highlight nil
  "Article highlighting."
  :link '(custom-manual "(gnus)Article Highlighting")
  :group 'gnus-article
  :group 'gnus-visual)

(defgroup gnus-article-signature nil
  "Article signatures."
  :link '(custom-manual "(gnus)Article Signature")
  :group 'gnus-article)

(defgroup gnus-article-headers nil
  "Article headers."
  :link '(custom-manual "(gnus)Hiding Headers")
  :group 'gnus-article)

(defgroup gnus-article-washing nil
  "Special commands on articles."
  :link '(custom-manual "(gnus)Article Washing")
  :group 'gnus-article)

(defgroup gnus-article-emphasis nil
  "Fontisizing articles."
  :link '(custom-manual "(gnus)Article Fontisizing")
  :group 'gnus-article)

(defgroup gnus-article-saving nil
  "Saving articles."
  :link '(custom-manual "(gnus)Saving Articles")
  :group 'gnus-article)

(defgroup gnus-article-mime nil
  "Worshiping the MIME wonder."
  :link '(custom-manual "(gnus)Using MIME")
  :group 'gnus-article)

(defgroup gnus-article-buttons nil
  "Pushable buttons in the article buffer."
  :link '(custom-manual "(gnus)Article Buttons")
  :group 'gnus-article)

(defgroup gnus-article-various nil
  "Other article options."
  :link '(custom-manual "(gnus)Misc Article")
  :group 'gnus-article)

(defcustom gnus-ignored-headers
  '("^Path:" "^Expires:" "^Date-Received:" "^References:" "^Xref:" "^Lines:"
    "^Relay-Version:" "^Message-ID:" "^Approved:" "^Sender:" "^Received:"
    "^X-UIDL:" "^MIME-Version:" "^Return-Path:" "^In-Reply-To:"
    "^Content-Type:" "^Content-Transfer-Encoding:" "^X-WebTV-Signature:"
    "^X-MimeOLE:" "^X-MSMail-Priority:" "^X-Priority:" "^X-Loop:"
    "^X-Authentication-Warning:" "^X-MIME-Autoconverted:" "^X-Face:"
    "^X-Attribution:" "^X-Originating-IP:" "^Delivered-To:"
    "^NNTP-[-A-Za-z]+:" "^Distribution:" "^X-no-archive:" "^X-Trace:"
    "^X-Complaints-To:" "^X-NNTP-Posting-Host:" "^X-Orig.*:"
    "^Abuse-Reports-To:" "^Cache-Post-Path:" "^X-Article-Creation-Date:"
    "^X-Poster:" "^X-Mail2News-Path:" "^X-Server-Date:" "^X-Cache:"
    "^Originator:" "^X-Problems-To:" "^X-Auth-User:" "^X-Post-Time:"
    "^X-Admin:" "^X-UID:" "^Resent-[-A-Za-z]+:" "^X-Mailing-List:"
    "^Precedence:" "^Original-[-A-Za-z]+:" "^X-filename:" "^X-Orcpt:"
    "^Old-Received:" "^X-Pgp" "^X-Auth:" "^X-From-Line:"
    "^X-Gnus-Article-Number:" "^X-Majordomo:" "^X-Url:" "^X-Sender:"
    "^MBOX-Line" "^Priority:" "^X400-[-A-Za-z]+:"
    "^Status:" "^X-Gnus-Mail-Source:" "^Cancel-Lock:"
    "^X-FTN" "^X-EXP32-SerialNo:" "^Encoding:" "^Importance:"
    "^Autoforwarded:" "^Original-Encoded-Information-Types:" "^X-Ya-Pop3:"
    "^X-Face-Version:" "^X-Vms-To:" "^X-ML-NAME:" "^X-ML-COUNT:"
    "^Mailing-List:" "^X-finfo:" "^X-md5sum:" "^X-md5sum-Origin:"
    "^X-Sun-Charset:" "^X-Accept-Language:" "^X-Envelope-Sender:"
    "^List-[A-Za-z]+:" "^X-Listprocessor-Version:"
    "^X-Received:" "^X-Distribute:" "^X-Sequence:" "^X-Juno-Line-Breaks:"
    "^X-Notes-Item:" "^X-MS-TNEF-Correlator:" "^x-uunet-gateway:"
    "^X-Received:" "^Content-length:" "X-precedence:"
    "^X-Authenticated-User:" "^X-Comment" "^X-Report:" "^X-Abuse-Info:"
    "^X-HTTP-Proxy:" "^X-Mydeja-Info:" "^X-Copyright" "^X-No-Markup:"
    "^X-Abuse-Info:")
  "*All headers that start with this regexp will be hidden.
This variable can also be a list of regexps of headers to be ignored.
If `gnus-visible-headers' is non-nil, this variable will be ignored."
  :type '(choice :custom-show nil
                 regexp
                 (repeat regexp))
  :group 'gnus-article-hiding)

(defcustom gnus-visible-headers
  "^From:\\|^Newsgroups:\\|^Subject:\\|^Date:\\|^Followup-To:\\|^Reply-To:\\|^Organization:\\|^Summary:\\|^Keywords:\\|^To:\\|^[BGF]?Cc:\\|^Posted-To:\\|^Mail-Copies-To:\\|^Mail-Followup-To:\\|^Apparently-To:\\|^Gnus-Warning:\\|^Resent-From:\\|^X-Sent:"
  "*All headers that do not match this regexp will be hidden.
This variable can also be a list of regexp of headers to remain visible.
If this variable is non-nil, `gnus-ignored-headers' will be ignored."
  :type '(repeat :value-to-internal (lambda (widget value)
                                      (custom-split-regexp-maybe value))
                 :match (lambda (widget value)
                          (or (stringp value)
                              (widget-editable-list-match widget value)))
                 regexp)
  :group 'gnus-article-hiding)

(defcustom gnus-sorted-header-list
  '("^From:" "^Subject:" "^Summary:" "^Keywords:" "^Newsgroups:"
    "^Followup-To:" "^To:" "^Cc:" "^Date:" "^Organization:")
  "*This variable is a list of regular expressions.
If it is non-nil, headers that match the regular expressions will
be placed first in the article buffer in the sequence specified by
this list."
  :type '(repeat regexp)
  :group 'gnus-article-hiding)

(defcustom gnus-boring-article-headers '(empty followup-to reply-to)
  "Headers that are only to be displayed if they have interesting data.
Possible values in this list are:

  'empty       Headers with no content.
  'newsgroups  Newsgroup identical to Gnus group.
  'to-address  To identical to To-address.
  'followup-to Followup-to identical to Newsgroups.
  'reply-to    Reply-to identical to From.
  'date        Date less than four days old.
  'long-to     To and/or Cc longer than 1024 characters.
  'many-to     Multiple To and/or Cc."
  :type '(set (const :tag "Headers with no content." empty)
              (const :tag "Newsgroups identical to Gnus group." newsgroups)
              (const :tag "To identical to To-address." to-address)
              (const :tag "Followup-to identical to Newsgroups." followup-to)
              (const :tag "Reply-to identical to From." reply-to)
              (const :tag "Date less than four days old." date)
              (const :tag "To and/or Cc longer than 1024 characters." long-to)
              (const :tag "Multiple To and/or Cc headers." many-to))
  :group 'gnus-article-hiding)

(defcustom gnus-signature-separator '("^-- $" "^-- *$")
  "Regexp matching signature separator.
This can also be a list of regexps.  In that case, it will be checked
from head to tail looking for a separator.  Searches will be done from
the end of the buffer."
  :type '(repeat string)
  :group 'gnus-article-signature)

(defcustom gnus-signature-limit nil
  "Provide a limit to what is considered a signature.
If it is a number, no signature may not be longer (in characters) than
that number.  If it is a floating point number, no signature may be
longer (in lines) than that number.  If it is a function, the function
will be called without any parameters, and if it returns nil, there is
no signature in the buffer.  If it is a string, it will be used as a
regexp.  If it matches, the text in question is not a signature."
  :type '(choice (integer :value 200)
                 (number :value 4.0)
                 (function :value fun)
                 (regexp :value ".*"))
  :group 'gnus-article-signature)

(defcustom gnus-hidden-properties '(invisible t intangible t)
  "Property list to use for hiding text."
  :type 'sexp
  :group 'gnus-article-hiding)

;; Fixme: This isn't the right thing for mixed graphical and and
;; non-graphical frames in a session.
;; gnus-xmas.el overrides this for XEmacs.
(defcustom gnus-article-x-face-command
  (if (and (fboundp 'image-type-available-p)
           (image-type-available-p 'xbm))
      'gnus-article-display-xface
    (if gnus-article-compface-xbm
        "{ echo '/* Width=48, Height=48 */'; uncompface; } | display -"
      "{ echo '/* Width=48, Height=48 */'; uncompface; } | icontopbm | \
display -"))
  "*String or function to be executed to display an X-Face header.
If it is a string, the command will be executed in a sub-shell
asynchronously.  The compressed face will be piped to this command."
  :type '(choice string
                 (function-item gnus-article-display-xface)
                 function)
  :version "21.1"
  :group 'gnus-article-washing)

(defcustom gnus-article-x-face-too-ugly nil
  "Regexp matching posters whose face shouldn't be shown automatically."
  :type '(choice regexp (const nil))
  :group 'gnus-article-washing)

(defcustom gnus-article-banner-alist nil
  "Banner alist for stripping.
For example,
     ((egroups . \"^[ \\t\\n]*-------------------+\\\\( \\\\(e\\\\|Yahoo! \\\\)Groups Sponsor -+\\\\)?....\\n\\\\(.+\\n\\\\)+\"))"
  :version "21.1"
  :type '(repeat (cons symbol regexp))
  :group 'gnus-article-washing)

(gnus-define-group-parameter
 banner
 :variable-document
 "Alist of regexps (to match group names) and banner."
 :variable-group gnus-article-washing
 :parameter-type
 '(choice :tag "Banner"
          :value nil
          (const :tag "Remove signature" signature)
          (symbol :tag "Item in `gnus-article-banner-alist'" none)
          regexp
          (const :tag "None" nil))
 :parameter-document
 "If non-nil, specify how to remove `banners' from articles.

Symbol `signature' means to remove signatures delimited by
`gnus-signature-separator'.  Any other symbol is used to look up a
regular expression to match the banner in `gnus-article-banner-alist'.
A string is used as a regular expression to match the banner
directly.")

(defcustom gnus-emphasis-alist
  (let ((format
         "\\(\\s-\\|^\\|[-\"]\\|\\s(\\)\\(%s\\(\\w+\\(\\s-+\\w+\\)*[.,]?\\)%s\\)\\(\\s-\\|[-,;:\"]\\s-\\|[?!.]+\\s-\\|\\s)\\)")
        (types
         '(("_" "_" underline)
           ("/" "/" italic)
           ("\\*" "\\*" bold)
           ("_/" "/_" underline-italic)
           ("_\\*" "\\*_" underline-bold)
           ("\\*/" "/\\*" bold-italic)
           ("_\\*/" "/\\*_" underline-bold-italic))))
    `(("\\(\\s-\\|^\\)\\(_\\(\\(\\w\\|_[^_]\\)+\\)_\\)\\(\\s-\\|[?!.,;]\\)"
       2 3 gnus-emphasis-underline)
      ,@(mapcar
         (lambda (spec)
           (list
            (format format (car spec) (cadr spec))
            2 3 (intern (format "gnus-emphasis-%s" (nth 2 spec)))))
         types)))
  "*Alist that says how to fontify certain phrases.
Each item looks like this:

  (\"_\\\\(\\\\w+\\\\)_\" 0 1 'underline)

The first element is a regular expression to be matched.  The second
is a number that says what regular expression grouping used to find
the entire emphasized word.  The third is a number that says what
regexp grouping should be displayed and highlighted.  The fourth
is the face used for highlighting."
  :type '(repeat (list :value ("" 0 0 default)
                       regexp
                       (integer :tag "Match group")
                       (integer :tag "Emphasize group")
                       face))
  :group 'gnus-article-emphasis)

(defcustom gnus-emphasize-whitespace-regexp "^[ \t]+\\|[ \t]*\n"
  "A regexp to describe whitespace which should not be emphasized.
Typical values are \"^[ \\t]+\\\\|[ \\t]*\\n\" and \"[ \\t]+\\\\|[ \\t]*\\n\".
The former avoids underlining of leading and trailing whitespace,
and the latter avoids underlining any whitespace at all."
  :version "21.1"
  :group 'gnus-article-emphasis
  :type 'regexp)

(defface gnus-emphasis-bold '((t (:bold t)))
  "Face used for displaying strong emphasized text (*word*)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-italic '((t (:italic t)))
  "Face used for displaying italic emphasized text (/word/)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-underline '((t (:underline t)))
  "Face used for displaying underlined emphasized text (_word_)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-underline-bold '((t (:bold t :underline t)))
  "Face used for displaying underlined bold emphasized text (_*word*_)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-underline-italic '((t (:italic t :underline t)))
  "Face used for displaying underlined italic emphasized text (_/word/_)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-bold-italic '((t (:bold t :italic t)))
  "Face used for displaying bold italic emphasized text (/*word*/)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-underline-bold-italic
  '((t (:bold t :italic t :underline t)))
  "Face used for displaying underlined bold italic emphasized text.
Esample: (_/*word*/_)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-highlight-words
  '((t (:background "black" :foreground "yellow")))
  "Face used for displaying highlighted words."
  :group 'gnus-article-emphasis)

(defcustom gnus-article-time-format "%a, %b %d %Y %T %Z"
  "Format for display of Date headers in article bodies.
See `format-time-string' for the possible values.

The variable can also be function, which should return a complete Date
header.  The function is called with one argument, the time, which can
be fed to `format-time-string'."
  :type '(choice string symbol)
  :link '(custom-manual "(gnus)Article Date")
  :group 'gnus-article-washing)

(eval-and-compile
  (autoload 'mail-extract-address-components "mail-extr"))

(defcustom gnus-save-all-headers t
  "*If non-nil, don't remove any headers before saving."
  :group 'gnus-article-saving
  :type 'boolean)

(defcustom gnus-prompt-before-saving 'always
  "*This variable says how much prompting is to be done when saving articles.
If it is nil, no prompting will be done, and the articles will be
saved to the default files.  If this variable is `always', each and
every article that is saved will be preceded by a prompt, even when
saving large batches of articles.  If this variable is neither nil not
`always', there the user will be prompted once for a file name for
each invocation of the saving commands."
  :group 'gnus-article-saving
  :type '(choice (item always)
                 (item :tag "never" nil)
                 (sexp :tag "once" :format "%t\n" :value t)))

(defcustom gnus-saved-headers gnus-visible-headers
  "Headers to keep if `gnus-save-all-headers' is nil.
If `gnus-save-all-headers' is non-nil, this variable will be ignored.
If that variable is nil, however, all headers that match this regexp
will be kept while the rest will be deleted before saving."
  :group 'gnus-article-saving
  :type 'regexp)

(defcustom gnus-default-article-saver 'gnus-summary-save-in-rmail
  "A function to save articles in your favourite format.
The function must be interactively callable (in other words, it must
be an Emacs command).

Gnus provides the following functions:

* gnus-summary-save-in-rmail (Rmail format)
* gnus-summary-save-in-mail (Unix mail format)
* gnus-summary-save-in-folder (MH folder)
* gnus-summary-save-in-file (article format)
* gnus-summary-save-in-vm (use VM's folder format)
* gnus-summary-write-to-file (article format -- overwrite)."
  :group 'gnus-article-saving
  :type '(radio (function-item gnus-summary-save-in-rmail)
                (function-item gnus-summary-save-in-mail)
                (function-item gnus-summary-save-in-folder)
                (function-item gnus-summary-save-in-file)
                (function-item gnus-summary-save-in-vm)
                (function-item gnus-summary-write-to-file)))

(defcustom gnus-rmail-save-name 'gnus-plain-save-name
  "A function generating a file name to save articles in Rmail format.
The function is called with NEWSGROUP, HEADERS, and optional LAST-FILE."
  :group 'gnus-article-saving
  :type 'function)

(defcustom gnus-mail-save-name 'gnus-plain-save-name
  "A function generating a file name to save articles in Unix mail format.
The function is called with NEWSGROUP, HEADERS, and optional LAST-FILE."
  :group 'gnus-article-saving
  :type 'function)

(defcustom gnus-folder-save-name 'gnus-folder-save-name
  "A function generating a file name to save articles in MH folder.
The function is called with NEWSGROUP, HEADERS, and optional LAST-FOLDER."
  :group 'gnus-article-saving
  :type 'function)

(defcustom gnus-file-save-name 'gnus-numeric-save-name
  "A function generating a file name to save articles in article format.
The function is called with NEWSGROUP, HEADERS, and optional
LAST-FILE."
  :group 'gnus-article-saving
  :type 'function)

(defcustom gnus-split-methods
  '((gnus-article-archive-name)
    (gnus-article-nndoc-name))
  "*Variable used to suggest where articles are to be saved.
For instance, if you would like to save articles related to Gnus in
the file \"gnus-stuff\", and articles related to VM in \"vm-stuff\",
you could set this variable to something like:

 '((\"^Subject:.*gnus\\|^Newsgroups:.*gnus\" \"gnus-stuff\")
   (\"^Subject:.*vm\\|^Xref:.*vm\" \"vm-stuff\"))

This variable is an alist where the where the key is the match and the
value is a list of possible files to save in if the match is non-nil.

If the match is a string, it is used as a regexp match on the
article.  If the match is a symbol, that symbol will be funcalled
from the buffer of the article to be saved with the newsgroup as the
parameter.  If it is a list, it will be evaled in the same buffer.

If this form or function returns a string, this string will be used as
a possible file name; and if it returns a non-nil list, that list will
be used as possible file names."
  :group 'gnus-article-saving
  :type '(repeat (choice (list :value (fun) function)
                         (cons :value ("" "") regexp (repeat string))
                         (sexp :value nil))))

(defcustom gnus-page-delimiter "^\^L"
  "*Regexp describing what to use as article page delimiters.
The default value is \"^\^L\", which is a form linefeed at the
beginning of a line."
  :type 'regexp
  :group 'gnus-article-various)

(defcustom gnus-article-mode-line-format "Gnus: %g [%w] %S%m"
  "*The format specification for the article mode line.
See `gnus-summary-mode-line-format' for a closer description.

The following additional specs are available:

%w  The article washing status.
%m  The number of MIME parts in the article."
  :type 'string
  :group 'gnus-article-various)

(defcustom gnus-article-mode-hook nil
  "*A hook for Gnus article mode."
  :type 'hook
  :group 'gnus-article-various)

(when (featurep 'xemacs)
  ;; Extracted from gnus-xmas-define in order to preserve user settings
  (when (fboundp 'turn-off-scroll-in-place)
    (add-hook 'gnus-article-mode-hook 'turn-off-scroll-in-place))
  ;; Extracted from gnus-xmas-redefine in order to preserve user settings
  (add-hook 'gnus-article-mode-hook 'gnus-xmas-article-menu-add))

(defcustom gnus-article-menu-hook nil
  "*Hook run after the creation of the article mode menu."
  :type 'hook
  :group 'gnus-article-various)

(defcustom gnus-article-prepare-hook nil
  "*A hook called after an article has been prepared in the article buffer."
  :type 'hook
  :group 'gnus-article-various)

(defcustom gnus-article-hide-pgp-hook nil
  "*A hook called after successfully hiding a PGP signature."
  :type 'hook
  :group 'gnus-article-various)

(defcustom gnus-article-button-face 'bold
  "Face used for highlighting buttons in the article buffer.

An article button is a piece of text that you can activate by pressing
`RET' or `mouse-2' above it."
  :type 'face
  :group 'gnus-article-buttons)

(defcustom gnus-article-mouse-face 'highlight
  "Face used for mouse highlighting in the article buffer.

Article buttons will be displayed in this face when the cursor is
above them."
  :type 'face
  :group 'gnus-article-buttons)

(defcustom gnus-signature-face 'gnus-signature-face
  "Face used for highlighting a signature in the article buffer.
Obsolete; use the face `gnus-signature-face' for customizations instead."
  :type 'face
  :group 'gnus-article-highlight
  :group 'gnus-article-signature)

(defface gnus-signature-face
  '((t
     (:italic t)))
  "Face used for highlighting a signature in the article buffer."
  :group 'gnus-article-highlight
  :group 'gnus-article-signature)

(defface gnus-header-from-face
  '((((class color)
      (background dark))
     (:foreground "spring green"))
    (((class color)
      (background light))
     (:foreground "red3"))
    (t
     (:italic t)))
  "Face used for displaying from headers."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)

(defface gnus-header-subject-face
  '((((class color)
      (background dark))
     (:foreground "SeaGreen3"))
    (((class color)
      (background light))
     (:foreground "red4"))
    (t
     (:bold t :italic t)))
  "Face used for displaying subject headers."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)

(defface gnus-header-newsgroups-face
  '((((class color)
      (background dark))
     (:foreground "yellow" :italic t))
    (((class color)
      (background light))
     (:foreground "MidnightBlue" :italic t))
    (t
     (:italic t)))
  "Face used for displaying newsgroups headers."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)

(defface gnus-header-name-face
  '((((class color)
      (background dark))
     (:foreground "SeaGreen"))
    (((class color)
      (background light))
     (:foreground "maroon"))
    (t
     (:bold t)))
  "Face used for displaying header names."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)

(defface gnus-header-content-face
  '((((class color)
      (background dark))
     (:foreground "forest green" :italic t))
    (((class color)
      (background light))
     (:foreground "indianred4" :italic t))
    (t
     (:italic t)))  "Face used for displaying header content."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)

(defcustom gnus-header-face-alist
  '(("From" nil gnus-header-from-face)
    ("Subject" nil gnus-header-subject-face)
    ("Newsgroups:.*," nil gnus-header-newsgroups-face)
    ("" gnus-header-name-face gnus-header-content-face))
  "*Controls highlighting of article header.

An alist of the form (HEADER NAME CONTENT).

HEADER is a regular expression which should match the name of an
header header and NAME and CONTENT are either face names or nil.

The name of each header field will be displayed using the face
specified by the first element in the list where HEADER match the
header name and NAME is non-nil.  Similarly, the content will be
displayed by the first non-nil matching CONTENT face."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight
  :type '(repeat (list (regexp :tag "Header")
                       (choice :tag "Name"
                               (item :tag "skip" nil)
                               (face :value default))
                       (choice :tag "Content"
                               (item :tag "skip" nil)
                               (face :value default)))))

(defcustom gnus-article-decode-hook
  '(article-decode-charset article-decode-encoded-words)
  "*Hook run to decode charsets in articles."
  :group 'gnus-article-headers
  :type 'hook)

(defcustom gnus-display-mime-function 'gnus-display-mime
  "Function to display MIME articles."
  :group 'gnus-article-mime
  :type 'function)

(defvar gnus-decode-header-function 'mail-decode-encoded-word-region
  "Function used to decode headers.")

(defvar gnus-article-dumbquotes-map
  '(("\200" "EUR")
    ("\202" ",")
    ("\203" "f")
    ("\204" ",,")
    ("\205" "...")
    ("\213" "<")
    ("\214" "OE")
    ("\221" "`")
    ("\222" "'")
    ("\223" "``")
    ("\224" "\"")
    ("\225" "*")
    ("\226" "-")
    ("\227" "--")
    ("\231" "(TM)")
    ("\233" ">")
    ("\234" "oe")
    ("\264" "'"))
  "Table for MS-to-Latin1 translation.")

(defcustom gnus-ignored-mime-types nil
  "List of MIME types that should be ignored by Gnus."
  :version "21.1"
  :group 'gnus-article-mime
  :type '(repeat regexp))

(defcustom gnus-unbuttonized-mime-types '(".*/.*")
  "List of MIME types that should not be given buttons when rendered inline."
  :version "21.1"
  :group 'gnus-article-mime
  :type '(repeat regexp))

(defcustom gnus-article-mime-part-function nil
  "Function called with a MIME handle as the argument.
This is meant for people who want to do something automatic based
on parts -- for instance, adding Vcard info to a database."
  :group 'gnus-article-mime
  :type 'function)

(defcustom gnus-mime-multipart-functions nil
  "An alist of MIME types to functions to display them."
  :version "21.1"
  :group 'gnus-article-mime
  :type 'alist)

(defcustom gnus-article-date-lapsed-new-header nil
  "Whether the X-Sent and Date headers can coexist.
When using `gnus-treat-date-lapsed', the \"X-Sent:\" header will
either replace the old \"Date:\" header (if this variable is nil), or
be added below it (otherwise)."
  :version "21.1"
  :group 'gnus-article-headers
  :type 'boolean)

(defcustom gnus-article-mime-match-handle-function 'undisplayed-alternative
  "Function called with a MIME handle as the argument.
This is meant for people who want to view first matched part.
For `undisplayed-alternative' (default), the first undisplayed
part or alternative part is used.  For `undisplayed', the first
undisplayed part is used.  For a function, the first part which
the function return `t' is used.  For `nil', the first part is
used."
  :version "21.1"
  :group 'gnus-article-mime
  :type '(choice
          (item :tag "first" :value nil)
          (item :tag "undisplayed" :value undisplayed)
          (item :tag "undisplayed or alternative"
                :value undisplayed-alternative)
          (function)))

(defcustom gnus-mime-action-alist
  '(("save to file" . gnus-mime-save-part)
    ("save and strip" . gnus-mime-save-part-and-strip)
    ("display as text" . gnus-mime-inline-part)
    ("view the part" . gnus-mime-view-part)
    ("pipe to command" . gnus-mime-pipe-part)
    ("toggle display" . gnus-article-press-button)
    ("toggle display" . gnus-article-view-part-as-charset)
    ("view as type" . gnus-mime-view-part-as-type)
    ("internalize type" . gnus-mime-internalize-part)
    ("externalize type" . gnus-mime-externalize-part))
  "An alist of actions that run on the MIME attachment."
  :group 'gnus-article-mime
  :type '(repeat (cons (string :tag "name")
                       (function))))

(defcustom gnus-mime-action-alist
  '(("save to file" . gnus-mime-save-part)
    ("display as text" . gnus-mime-inline-part)
    ("view the part" . gnus-mime-view-part)
    ("pipe to command" . gnus-mime-pipe-part)
    ("toggle display" . gnus-article-press-button)
    ("view as type" . gnus-mime-view-part-as-type)
    ("internalize type" . gnus-mime-internalize-part)
    ("externalize type" . gnus-mime-externalize-part))
  "An alist of actions that run on the MIME attachment."
  :version "21.1"
  :group 'gnus-article-mime
  :type '(repeat (cons (string :tag "name")
                       (function))))

;;;
;;; The treatment variables
;;;

(defvar gnus-part-display-hook nil
  "Hook called on parts that are to receive treatment.")

(defvar gnus-article-treat-custom
  '(choice (const :tag "Off" nil)
           (const :tag "On" t)
           (const :tag "Header" head)
           (const :tag "Last" last)
           (integer :tag "Less")
           (repeat :tag "Groups" regexp)
           (sexp :tag "Predicate")))

(defvar gnus-article-treat-head-custom
  '(choice (const :tag "Off" nil)
           (const :tag "Header" head)))

(defvar gnus-article-treat-types '("text/plain")
  "Parts to treat.")

(defvar gnus-inhibit-treatment nil
  "Whether to inhibit treatment.")

(defcustom gnus-treat-highlight-signature '(or last (typep "text/x-vcard"))
  "Highlight the signature.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)
(put 'gnus-treat-highlight-signature 'highlight t)

(defcustom gnus-treat-buttonize 100000
  "Add buttons.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)
(put 'gnus-treat-buttonize 'highlight t)

(defcustom gnus-treat-buttonize-head 'head
  "Add buttons to the head.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-buttonize-head 'highlight t)

(defcustom gnus-treat-emphasize
  (and (or window-system
           (featurep 'xemacs)
           (>= (string-to-number emacs-version) 21))
       50000)
  "Emphasize text.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)
(put 'gnus-treat-emphasize 'highlight t)

(defcustom gnus-treat-strip-cr nil
  "Remove carriage returns.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-leading-whitespace nil
  "Remove leading whitespace in headers.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-headers 'head
  "Hide headers.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-hide-boring-headers nil
  "Hide boring headers.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-hide-signature nil
  "Hide the signature.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-fill-article nil
  "Fill the article.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-citation nil
  "Hide cited text.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-citation-maybe nil
  "Hide cited text.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-citation-maybe nil
  "Hide cited text.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-list-identifiers 'head
  "Strip list identifiers from `gnus-list-identifiers`.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-pgp t
  "Strip PGP signatures.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-pem nil
  "Strip PEM signatures.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-banner t
  "Strip banners from articles.
The banner to be stripped is specified in the `banner' group parameter.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-highlight-headers 'head
  "Highlight the headers.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-highlight-headers 'highlight t)

(defcustom gnus-treat-highlight-citation t
  "Highlight cited text.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)
(put 'gnus-treat-highlight-citation 'highlight t)

(defcustom gnus-treat-date-ut nil
  "Display the Date in UT (GMT).
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-local nil
  "Display the Date in the local timezone.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-english nil
  "Display the Date in a format that can be read aloud in English.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-lapsed nil
  "Display the Date header in a way that says how much time has elapsed.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-original nil
  "Display the date in the original timezone.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-iso8601 nil
  "Display the date in the ISO8601 format.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-date-user-defined nil
  "Display the date in a user-defined format.
The format is defined by the `gnus-article-time-format' variable.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-strip-headers-in-body t
  "Strip the X-No-Archive header line from the beginning of the body.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-trailing-blank-lines nil
  "Strip trailing blank lines.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-leading-blank-lines nil
  "Strip leading blank lines.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-multiple-blank-lines nil
  "Strip multiple blank lines.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-overstrike t
  "Treat overstrike highlighting.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)
(put 'gnus-treat-overstrike 'highlight t)

(defcustom gnus-treat-display-xface
  (and (or (and (fboundp 'image-type-available-p)
                (image-type-available-p 'xbm)
                (string-match "^0x" (shell-command-to-string "uncompface")))
           (and (featurep 'xemacs) (featurep 'xface)))
       'head)
  "Display X-Face headers.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :version "21.1"
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-display-xface 'highlight t)

(defcustom gnus-treat-display-smileys
  (if (or (and (featurep 'xemacs)
               (featurep 'xpm))
          (and (fboundp 'image-type-available-p)
               (image-type-available-p 'pbm)))
      t nil)
  "Display smileys.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :version "21.1"
  :type gnus-article-treat-custom)
(put 'gnus-treat-display-smileys 'highlight t)

(defcustom gnus-treat-display-picons (if (featurep 'xemacs) 'head nil)
  "Display picons.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-display-picons 'highlight t)

(defcustom gnus-treat-capitalize-sentences nil
  "Capitalize sentence-starting words.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-fill-long-lines nil
  "Fill long lines.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-play-sounds nil
  "Play sounds.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-translate nil
  "Translate articles from one language to another.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :version "21.1"
  :group 'gnus-article-treat
  :type gnus-article-treat-custom)

(defcustom gnus-treat-x-pgp-sig nil
  "Verify X-PGP-Sig.
To automatically treat X-PGP-Sig, set it to head.
Valid values are nil, t, `head', `last', an integer or a predicate.
See the manual for details."
  :group 'gnus-article-treat
  :group 'mime-security
  :type gnus-article-treat-custom)

(defvar gnus-article-encrypt-protocol-alist
  '(("PGP" . mml2015-self-encrypt)))

;; Set to nil if more than one protocol added to
;; gnus-article-encrypt-protocol-alist.
(defcustom gnus-article-encrypt-protocol "PGP"
  "The protocol used for encrypt articles.
It is a string, such as \"PGP\". If nil, ask user."
  :type 'string
  :group 'mime-security)

;;; Internal variables

(defvar gnus-english-month-names
  '("January" "February" "March" "April" "May" "June" "July" "August"
    "September" "October" "November" "December"))

(defvar article-goto-body-goes-to-point-min-p nil)
(defvar gnus-article-wash-types nil)
(defvar gnus-article-emphasis-alist nil)

(defvar gnus-article-mime-handle-alist-1 nil)
(defvar gnus-treatment-function-alist
  '((gnus-treat-x-pgp-sig gnus-article-verify-x-pgp-sig)
    (gnus-treat-strip-banner gnus-article-strip-banner)
    (gnus-treat-strip-headers-in-body gnus-article-strip-headers-in-body)
    (gnus-treat-highlight-signature gnus-article-highlight-signature)
    (gnus-treat-buttonize gnus-article-add-buttons)
    (gnus-treat-fill-article gnus-article-fill-cited-article)
    (gnus-treat-fill-long-lines gnus-article-fill-long-lines)
    (gnus-treat-strip-cr gnus-article-remove-cr)
    (gnus-treat-emphasize gnus-article-emphasize)
    (gnus-treat-display-xface gnus-article-display-x-face)
    (gnus-treat-date-ut gnus-article-date-ut)
    (gnus-treat-date-local gnus-article-date-local)
    (gnus-treat-date-english gnus-article-date-english)
    (gnus-treat-date-lapsed gnus-article-date-lapsed)
    (gnus-treat-date-original gnus-article-date-original)
    (gnus-treat-date-user-defined gnus-article-date-user)
    (gnus-treat-date-iso8601 gnus-article-date-iso8601)
    (gnus-treat-hide-headers gnus-article-maybe-hide-headers)
    (gnus-treat-hide-boring-headers gnus-article-hide-boring-headers)
    (gnus-treat-hide-signature gnus-article-hide-signature)
    (gnus-treat-hide-citation gnus-article-hide-citation)
    (gnus-treat-hide-citation-maybe gnus-article-hide-citation-maybe)
    (gnus-treat-strip-list-identifiers gnus-article-hide-list-identifiers)
    (gnus-treat-leading-whitespace gnus-article-remove-leading-whitespace)
    (gnus-treat-strip-pgp gnus-article-hide-pgp)
    (gnus-treat-strip-pem gnus-article-hide-pem)
    (gnus-treat-highlight-headers gnus-article-highlight-headers)
    (gnus-treat-highlight-citation gnus-article-highlight-citation)
    (gnus-treat-highlight-signature gnus-article-highlight-signature)
    (gnus-treat-strip-trailing-blank-lines
     gnus-article-remove-trailing-blank-lines)
    (gnus-treat-strip-leading-blank-lines
     gnus-article-strip-leading-blank-lines)
    (gnus-treat-strip-multiple-blank-lines
     gnus-article-strip-multiple-blank-lines)
    (gnus-treat-overstrike gnus-article-treat-overstrike)
    (gnus-treat-buttonize-head gnus-article-add-buttons-to-head)
    (gnus-treat-display-smileys gnus-smiley-display)
    (gnus-treat-capitalize-sentences gnus-article-capitalize-sentences)
    (gnus-treat-display-picons gnus-article-display-picons)
    (gnus-treat-play-sounds gnus-earcon-display)))

(defvar gnus-article-mime-handle-alist nil)
(defvar article-lapsed-timer nil)
(defvar gnus-article-current-summary nil)

(defvar gnus-article-mode-syntax-table
  (let ((table (copy-syntax-table text-mode-syntax-table)))
    ;; This causes the citation match run O(2^n).
    ;; (modify-syntax-entry ?- "w" table)
    (modify-syntax-entry ?> ")" table)
    (modify-syntax-entry ?< "(" table)
    table)
  "Syntax table used in article mode buffers.
Initialized from `text-mode-syntax-table.")

(defvar gnus-save-article-buffer nil)

(defvar gnus-article-mode-line-format-alist
  (nconc '((?w (gnus-article-wash-status) ?s)
           (?m (gnus-article-mime-part-status) ?s))
         gnus-summary-mode-line-format-alist))

(defvar gnus-number-of-articles-to-be-saved nil)

(defvar gnus-inhibit-hiding nil)

(defsubst gnus-article-hide-text (b e props)
  "Set text PROPS on the B to E region, extending `intangible' 1 past B."
  (gnus-add-text-properties-when 'article-type nil b e props)
  (when (memq 'intangible props)
    (put-text-property
     (max (1- b) (point-min))
     b 'intangible (cddr (memq 'intangible props)))))

(defsubst gnus-article-unhide-text (b e)
  "Remove hidden text properties from region between B and E."
  (remove-text-properties b e gnus-hidden-properties)
  (when (memq 'intangible gnus-hidden-properties)
    (put-text-property (max (1- b) (point-min))
                       b 'intangible nil)))

(defun gnus-article-hide-text-type (b e type)
  "Hide text of TYPE between B and E."
  (push type gnus-article-wash-types)
  (gnus-article-hide-text
   b e (cons 'article-type (cons type gnus-hidden-properties))))

(defun gnus-article-unhide-text-type (b e type)
  "Unhide text of TYPE between B and E."
  (setq gnus-article-wash-types
        (delq type gnus-article-wash-types))
  (remove-text-properties
   b e (cons 'article-type (cons type gnus-hidden-properties)))
  (when (memq 'intangible gnus-hidden-properties)
    (put-text-property (max (1- b) (point-min))
                       b 'intangible nil)))

(defun gnus-article-hide-text-of-type (type)
  "Hide text of TYPE in the current buffer."
  (save-excursion
    (let ((b (point-min))
          (e (point-max)))
      (while (setq b (text-property-any b e 'article-type type))
        (add-text-properties b (incf b) gnus-hidden-properties)))))

(defun gnus-article-delete-text-of-type (type)
  "Delete text of TYPE in the current buffer."
  (save-excursion
    (let ((b (point-min)))
      (while (setq b (text-property-any b (point-max) 'article-type type))
        (delete-region
         b (or (text-property-not-all b (point-max) 'article-type type)
               (point-max)))))))

(defun gnus-article-delete-invisible-text ()
  "Delete all invisible text in the current buffer."
  (save-excursion
    (let ((b (point-min)))
      (while (setq b (text-property-any b (point-max) 'invisible t))
        (delete-region
         b (or (text-property-not-all b (point-max) 'invisible t)
               (point-max)))))))

(defun gnus-article-text-type-exists-p (type)
  "Say whether any text of type TYPE exists in the buffer."
  (text-property-any (point-min) (point-max) 'article-type type))

(defsubst gnus-article-header-rank ()
  "Give the rank of the string HEADER as given by `gnus-sorted-header-list'."
  (let ((list gnus-sorted-header-list)
        (i 0))
    (while list
      (when (looking-at (car list))
        (setq list nil))
      (setq list (cdr list))
      (incf i))
    i))

(defun article-hide-headers (&optional arg delete)
  "Hide unwanted headers and possibly sort them as well."
  (interactive)
  ;; This function might be inhibited.
  (unless gnus-inhibit-hiding
    (save-excursion
      (save-restriction
        (let ((buffer-read-only nil)
              (case-fold-search t)
              (max (1+ (length gnus-sorted-header-list)))
              (ignored (when (not gnus-visible-headers)
                         (cond ((stringp gnus-ignored-headers)
                                gnus-ignored-headers)
                               ((listp gnus-ignored-headers)
                                (mapconcat 'identity gnus-ignored-headers
                                           "\\|")))))
              (visible
               (cond ((stringp gnus-visible-headers)
                      gnus-visible-headers)
                     ((and gnus-visible-headers
                           (listp gnus-visible-headers))
                      (mapconcat 'identity gnus-visible-headers "\\|"))))
              (inhibit-point-motion-hooks t)
              beg)
          ;; First we narrow to just the headers.
          (article-narrow-to-head)
          ;; Hide any "From " lines at the beginning of (mail) articles.
          (while (looking-at "From ")
            (forward-line 1))
          (unless (bobp)
            (delete-region (point-min) (point)))
          ;; Then treat the rest of the header lines.
          ;; Then we use the two regular expressions
          ;; `gnus-ignored-headers' and `gnus-visible-headers' to
          ;; select which header lines is to remain visible in the
          ;; article buffer.
          (while (re-search-forward "^[^ \t:]*:" nil t)
            (beginning-of-line)
            ;; Mark the rank of the header.
            (put-text-property
             (point) (1+ (point)) 'message-rank
             (if (or (and visible (looking-at visible))
                     (and ignored
                          (not (looking-at ignored))))
                 (gnus-article-header-rank)
               (+ 2 max)))
            (forward-line 1))
          (message-sort-headers-1)
          (when (setq beg (text-property-any
                           (point-min) (point-max) 'message-rank (+ 2 max)))
            ;; We delete the unwanted headers.
            (push 'headers gnus-article-wash-types)
            (add-text-properties (point-min) (+ 5 (point-min))
                                 '(article-type headers dummy-invisible t))
            (delete-region beg (point-max))))))))

(defun article-hide-boring-headers (&optional arg)
  "Toggle hiding of headers that aren't very interesting.
If given a negative prefix, always show; if given a positive prefix,
always hide."
  (interactive (gnus-article-hidden-arg))
  (when (and (not (gnus-article-check-hidden-text 'boring-headers arg))
             (not gnus-show-all-headers))
    (save-excursion
      (save-restriction
        (let ((buffer-read-only nil)
              (list gnus-boring-article-headers)
              (inhibit-point-motion-hooks t)
              elem)
          (article-narrow-to-head)
          (while list
            (setq elem (pop list))
            (goto-char (point-min))
            (cond
             ;; Hide empty headers.
             ((eq elem 'empty)
              (while (re-search-forward "^[^: \t]+:[ \t]*\n[^ \t]" nil t)
                (forward-line -1)
                (gnus-article-hide-text-type
                 (progn (beginning-of-line) (point))
                 (progn
                   (end-of-line)
                   (if (re-search-forward "^[^ \t]" nil t)
                       (match-beginning 0)
                     (point-max)))
                 'boring-headers)))
             ;; Hide boring Newsgroups header.
             ((eq elem 'newsgroups)
              (when (gnus-string-equal
                     (gnus-fetch-field "newsgroups")
                     (gnus-group-real-name
                      (if (boundp 'gnus-newsgroup-name)
                          gnus-newsgroup-name
                        "")))
                (gnus-article-hide-header "newsgroups")))
             ((eq elem 'to-address)
              (let ((to (message-fetch-field "to"))
                    (to-address
                     (gnus-parameter-to-address
                      (if (boundp 'gnus-newsgroup-name)
                          gnus-newsgroup-name ""))))
                (when (and to to-address
                           (ignore-errors
                             (gnus-string-equal
                              ;; only one address in To
                              (nth 1 (mail-extract-address-components to))
                              to-address)))
                  (gnus-article-hide-header "to"))))
             ((eq elem 'followup-to)
              (when (gnus-string-equal
                     (message-fetch-field "followup-to")
                     (message-fetch-field "newsgroups"))
                (gnus-article-hide-header "followup-to")))
             ((eq elem 'reply-to)
              (let ((from (message-fetch-field "from"))
                    (reply-to (message-fetch-field "reply-to")))
                (when (and
                       from reply-to
                       (ignore-errors
                         (gnus-string-equal
                          (nth 1 (mail-extract-address-components from))
                          (nth 1 (mail-extract-address-components reply-to)))))
                  (gnus-article-hide-header "reply-to"))))
             ((eq elem 'date)
              (let ((date (message-fetch-field "date")))
                (when (and date
                           (< (days-between (current-time-string) date)
                              4))
                  (gnus-article-hide-header "date"))))
             ((eq elem 'long-to)
              (let ((to (message-fetch-field "to"))
                    (cc (message-fetch-field "cc")))
                (when (> (length to) 1024)
                  (gnus-article-hide-header "to"))
                (when (> (length cc) 1024)
                  (gnus-article-hide-header "cc"))))
             ((eq elem 'many-to)
              (let ((to-count 0)
                    (cc-count 0))
                (goto-char (point-min))
                (while (re-search-forward "^to:" nil t)
                  (setq to-count (1+ to-count)))
                (when (> to-count 1)
                  (while (> to-count 0)
                    (goto-char (point-min))
                    (save-restriction
                      (re-search-forward "^to:" nil nil to-count)
                      (forward-line -1)
                      (narrow-to-region (point) (point-max))
                      (gnus-article-hide-header "to"))
                    (setq to-count (1- to-count))))
                (goto-char (point-min))
                (while (re-search-forward "^cc:" nil t)
                  (setq cc-count (1+ cc-count)))
                (when (> cc-count 1)
                  (while (> cc-count 0)
                    (goto-char (point-min))
                    (save-restriction
                      (re-search-forward "^cc:" nil nil cc-count)
                      (forward-line -1)
                      (narrow-to-region (point) (point-max))
                      (gnus-article-hide-header "cc"))
                    (setq cc-count (1- cc-count)))))))))))))

(defun gnus-article-hide-header (header)
  (save-excursion
    (goto-char (point-min))
    (when (re-search-forward (concat "^" header ":") nil t)
      (gnus-article-hide-text-type
       (progn (beginning-of-line) (point))
       (progn
         (end-of-line)
         (if (re-search-forward "^[^ \t]" nil t)
             (match-beginning 0)
           (point-max)))
       'boring-headers))))

(defvar gnus-article-normalized-header-length 40
  "Length of normalized headers.")

(defun article-normalize-headers ()
  "Make all header lines 40 characters long."
  (interactive)
  (let ((buffer-read-only nil)
        column)
    (save-excursion
      (save-restriction
        (article-narrow-to-head)
        (while (not (eobp))
          (cond
           ((< (setq column (- (gnus-point-at-eol) (point)))
               gnus-article-normalized-header-length)
            (end-of-line)
            (insert (make-string
                     (- gnus-article-normalized-header-length column)
                     ? )))
           ((> column gnus-article-normalized-header-length)
            (gnus-put-text-property
             (progn
               (forward-char gnus-article-normalized-header-length)
               (point))
             (gnus-point-at-eol)
             'invisible t))
           (t
            ;; Do nothing.
            ))
          (forward-line 1))))))

(defun article-treat-dumbquotes ()
  "Translate M****s*** sm*rtq**t*s into proper text.
Note that this function guesses whether a character is a sm*rtq**t* or
not, so it should only be used interactively.

Sm*rtq**t*s are M****s***'s unilateral extension to the character map
in an attempt to provide more quoting characters.  If you see
something like \\222 or \\264 where you're expecting some kind of
apostrophe or quotation mark, then try this wash."
  (interactive)
  (article-translate-strings gnus-article-dumbquotes-map))

(defun article-translate-characters (from to)
  "Translate all characters in the body of the article according to FROM and TO.
FROM is a string of characters to translate from; to is a string of
characters to translate to."
  (save-excursion
    (when (article-goto-body)
      (let ((buffer-read-only nil)
            (x (make-string 225 ?x))
            (i -1))
        (while (< (incf i) (length x))
          (aset x i i))
        (setq i 0)
        (while (< i (length from))
          (aset x (aref from i) (aref to i))
          (incf i))
        (translate-region (point) (point-max) x)))))

(defun article-translate-strings (map)
  "Translate all string in the body of the article according to MAP.
MAP is an alist where the elements are on the form (\"from\" \"to\")."
  (save-excursion
    (when (article-goto-body)
      (let ((buffer-read-only nil)
            elem)
        (while (setq elem (pop map))
          (save-excursion
            (while (search-forward (car elem) nil t)
              (replace-match (cadr elem)))))))))

(defun article-treat-overstrike ()
  "Translate overstrikes into bold text."
  (interactive)
  (save-excursion
    (when (article-goto-body)
      (let ((buffer-read-only nil))
        (while (search-forward "\b" nil t)
          (let ((next (char-after))
                (previous (char-after (- (point) 2))))
            ;; We do the boldification/underlining by hiding the
            ;; overstrikes and putting the proper text property
            ;; on the letters.
            (cond
             ((eq next previous)
              (gnus-article-hide-text-type (- (point) 2) (point) 'overstrike)
              (put-text-property (point) (1+ (point)) 'face 'bold))
             ((eq next ?_)
              (gnus-article-hide-text-type
               (1- (point)) (1+ (point)) 'overstrike)
              (put-text-property
               (- (point) 2) (1- (point)) 'face 'underline))
             ((eq previous ?_)
              (gnus-article-hide-text-type (- (point) 2) (point) 'overstrike)
              (put-text-property
               (point) (1+ (point)) 'face 'underline)))))))))

(defun article-fill-long-lines ()
  "Fill lines that are wider than the window width."
  (interactive)
  (save-excursion
    (let ((buffer-read-only nil)
          (width (window-width (get-buffer-window (current-buffer)))))
      (save-restriction
        (article-goto-body)
        (let ((adaptive-fill-mode nil)) ;Why?  -sm
          (while (not (eobp))
            (end-of-line)
            (when (>= (current-column) (min fill-column width))
              (narrow-to-region (point) (gnus-point-at-bol))
              (fill-paragraph nil)
              (goto-char (point-max))
              (widen))
            (forward-line 1)))))))

(defun article-capitalize-sentences ()
  "Capitalize the first word in each sentence."
  (interactive)
  (save-excursion
    (let ((buffer-read-only nil)
          (paragraph-start "^[\n\^L]"))
      (article-goto-body)
      (while (not (eobp))
        (capitalize-word 1)
        (forward-sentence)))))

(defun article-remove-cr ()
  "Remove trailing CRs and then translate remaining CRs into LFs."
  (interactive)
  (save-excursion
    (let ((buffer-read-only nil))
      (goto-char (point-min))
      (while (re-search-forward "\r+$" nil t)
        (replace-match "" t t))
      (goto-char (point-min))
      (while (search-forward "\r" nil t)
        (replace-match "\n" t t)))))

(defun article-remove-trailing-blank-lines ()
  "Remove all trailing blank lines from the article."
  (interactive)
  (save-excursion
    (let ((buffer-read-only nil))
      (goto-char (point-max))
      (delete-region
       (point)
       (progn
         (while (and (not (bobp))
                     (looking-at "^[ \t]*$")
                     (not (gnus-annotation-in-region-p
                           (point) (gnus-point-at-eol))))
           (forward-line -1))
         (forward-line 1)
         (point))))))

(defun article-display-x-face (&optional force)
  "Look for an X-Face header and display it if present."
  (interactive (list 'force))
  (save-excursion
    ;; Delete the old process, if any.
    (when (process-status "article-x-face")
      (delete-process "article-x-face"))
    (let ((inhibit-point-motion-hooks t)
          x-faces
          (case-fold-search t)
          from last)
      (save-restriction
        (article-narrow-to-head)
        (when (and buffer-read-only ;; When type `W f'
                   (progn
                     (goto-char (point-min))
                     (not (re-search-forward "^X-Face:[\t ]*" nil t)))
                   (gnus-buffer-live-p gnus-original-article-buffer))
          (with-current-buffer gnus-original-article-buffer
            (save-restriction
              (article-narrow-to-head)
              (while (re-search-forward "^X-Face:" nil t)
                (setq x-faces
                      (concat
                       (or x-faces "")
                       (buffer-substring
                        (match-beginning 0)
                        (1- (re-search-forward
                             "^\\($\\|[^ \t]\\)" nil t))))))))
          (if x-faces
              (let (point start bface eface buffer-read-only)
                (goto-char (point-max))
                (forward-line -1)
                (setq bface (get-text-property (gnus-point-at-bol) 'face)
                      eface (get-text-property (1- (gnus-point-at-eol)) 'face))
                (goto-char (point-max))
                (setq point (point))
                (insert x-faces)
                (goto-char point)
                (while (looking-at "\\([^:]+\\): *")
                  (put-text-property (match-beginning 1) (1+ (match-end 1))
                                     'face bface)
                  (setq start (match-end 0))
                  (forward-line 1)
                  (while (looking-at "[\t ]")
                    (forward-line 1))
                  (put-text-property start (point)
                                     'face eface)))))
        (goto-char (point-min))
        (setq from (message-fetch-field "from"))
        (goto-char (point-min))
        (while (and gnus-article-x-face-command
                    (not last)
                    (or force
                        ;; Check whether this face is censored.
                        (not gnus-article-x-face-too-ugly)
                        (and gnus-article-x-face-too-ugly from
                             (not (string-match gnus-article-x-face-too-ugly
                                                from))))
                    ;; Has to be present.
                    (re-search-forward "^X-Face:[\t ]*" nil t))
          ;; This used to try to do multiple faces (`while' instead of
          ;; `when' above), but (a) sending multiple EOFs to xv doesn't
          ;; work (b) it can crash some versions of Emacs (c) are
          ;; multiple faces really something to encourage?
          (when (stringp gnus-article-x-face-command)
            (setq last t))
          ;; We now have the area of the buffer where the X-Face is stored.
          (save-excursion
            (let ((beg (point))
                  (end (1- (re-search-forward "^\\($\\|[^ \t]\\)" nil t))))
              ;; We display the face.
              (if (symbolp gnus-article-x-face-command)
                  ;; The command is a lisp function, so we call it.
                  (if (gnus-functionp gnus-article-x-face-command)
                      (funcall gnus-article-x-face-command beg end)
                    (error "%s is not a function" gnus-article-x-face-command))
                ;; The command is a string, so we interpret the command
                ;; as a, well, command, and fork it off.
                (let ((process-connection-type nil))
                  (process-kill-without-query
                   (start-process
                    "article-x-face" nil shell-file-name shell-command-switch
                    gnus-article-x-face-command))
                  (process-send-region "article-x-face" beg end)
                  (process-send-eof "article-x-face"))))))))))

(defun article-decode-mime-words ()
  "Decode all MIME-encoded words in the article."
  (interactive)
  (save-excursion
    (set-buffer gnus-article-buffer)
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only
          (mail-parse-charset gnus-newsgroup-charset)
          (mail-parse-ignored-charsets
           (save-excursion (set-buffer gnus-summary-buffer)
                           gnus-newsgroup-ignored-charsets)))
      (mail-decode-encoded-word-region (point-min) (point-max)))))

(defun article-decode-charset (&optional prompt)
  "Decode charset-encoded text in the article.
If PROMPT (the prefix), prompt for a coding system to use."
  (interactive "P")
  (let ((inhibit-point-motion-hooks t) (case-fold-search t)
        buffer-read-only
        (mail-parse-charset gnus-newsgroup-charset)
        (mail-parse-ignored-charsets
         (save-excursion (condition-case nil
                             (set-buffer gnus-summary-buffer)
                           (error))
                         gnus-newsgroup-ignored-charsets))
        ct cte ctl charset format)
  (save-excursion
    (save-restriction
      (article-narrow-to-head)
      (setq ct (message-fetch-field "Content-Type" t)
            cte (message-fetch-field "Content-Transfer-Encoding" t)
            ctl (and ct (ignore-errors
                          (mail-header-parse-content-type ct)))
            charset (cond
                     (prompt
                      (mm-read-coding-system "Charset to decode: "))
                     (ctl
                      (mail-content-type-get ctl 'charset)))
            format (and ctl (mail-content-type-get ctl 'format)))
      (when cte
        (setq cte (mail-header-strip cte)))
      (if (and ctl (not (string-match "/" (car ctl))))
          (setq ctl nil))
      (goto-char (point-max)))
    (forward-line 1)
    (save-restriction
      (narrow-to-region (point) (point-max))
      (when (and (eq mail-parse-charset 'gnus-decoded)
                 (eq (mm-body-7-or-8) '8bit))
        ;; The text code could have been decoded.
        (setq charset mail-parse-charset))
      (when (and (or (not ctl)
                     (equal (car ctl) "text/plain"))
                 (not format)) ;; article with format will decode later.
        (mm-decode-body
         charset (and cte (intern (downcase
                                   (gnus-strip-whitespace cte))))
         (car ctl)))))))

(defun article-decode-encoded-words ()
  "Remove encoded-word encoding from headers."
  (let ((inhibit-point-motion-hooks t)
        (mail-parse-charset gnus-newsgroup-charset)
        (mail-parse-ignored-charsets
         (save-excursion (condition-case nil
                             (set-buffer gnus-summary-buffer)
                           (error))
                         gnus-newsgroup-ignored-charsets))
        buffer-read-only)
    (save-restriction
      (article-narrow-to-head)
      (funcall gnus-decode-header-function (point-min) (point-max)))))

(defun article-de-quoted-unreadable (&optional force read-charset)
  "Translate a quoted-printable-encoded article.
If FORCE, decode the article whether it is marked as quoted-printable
or not.
If READ-CHARSET, ask for a coding system."
  (interactive (list 'force current-prefix-arg))
  (save-excursion
    (let ((buffer-read-only nil) type charset)
      (if (gnus-buffer-live-p gnus-original-article-buffer)
          (with-current-buffer gnus-original-article-buffer
            (setq type
                  (gnus-fetch-field "content-transfer-encoding"))
            (let* ((ct (gnus-fetch-field "content-type"))
                   (ctl (and ct
                             (ignore-errors
                               (mail-header-parse-content-type ct)))))
              (setq charset (and ctl
                                 (mail-content-type-get ctl 'charset)))
              (if (stringp charset)
                  (setq charset (intern (downcase charset)))))))
      (if read-charset
          (setq charset (mm-read-coding-system "Charset: " charset)))
      (unless charset
        (setq charset gnus-newsgroup-charset))
      (when (or force
                (and type (let ((case-fold-search t))
                            (string-match "quoted-printable" type))))
        (article-goto-body)
        (quoted-printable-decode-region
         (point) (point-max) (mm-charset-to-coding-system charset))))))

(defun article-de-base64-unreadable (&optional force read-charset)
  "Translate a base64 article.
If FORCE, decode the article whether it is marked as base64 not.
If READ-CHARSET, ask for a coding system."
  (interactive (list 'force current-prefix-arg))
  (save-excursion
    (let ((buffer-read-only nil) type charset)
      (if (gnus-buffer-live-p gnus-original-article-buffer)
          (with-current-buffer gnus-original-article-buffer
            (setq type
                  (gnus-fetch-field "content-transfer-encoding"))
            (let* ((ct (gnus-fetch-field "content-type"))
                   (ctl (and ct
                             (ignore-errors
                               (mail-header-parse-content-type ct)))))
              (setq charset (and ctl
                                 (mail-content-type-get ctl 'charset)))
              (if (stringp charset)
                  (setq charset (intern (downcase charset)))))))
      (if read-charset
          (setq charset (mm-read-coding-system "Charset: " charset)))
      (unless charset
        (setq charset gnus-newsgroup-charset))
      (when (or force
                (and type (let ((case-fold-search t))
                            (string-match "base64" type))))
        (article-goto-body)
        (save-restriction
          (narrow-to-region (point) (point-max))
          (base64-decode-region (point-min) (point-max))
          (mm-decode-coding-region
           (point-min) (point-max) (mm-charset-to-coding-system charset)))))))

(eval-when-compile
  (require 'rfc1843))

(defun article-decode-HZ ()
  "Translate a HZ-encoded article."
  (interactive)
  (require 'rfc1843)
  (save-excursion
    (let ((buffer-read-only nil))
      (rfc1843-decode-region (point-min) (point-max)))))

(defun article-wash-html (&optional read-charset)
  "Format an html article.
If READ-CHARSET, ask for a coding system."
  (interactive "P")
  (save-excursion
    (let ((buffer-read-only nil)
          charset)
      (if (gnus-buffer-live-p gnus-original-article-buffer)
          (with-current-buffer gnus-original-article-buffer
            (let* ((ct (gnus-fetch-field "content-type"))
                   (ctl (and ct
                             (ignore-errors
                               (mail-header-parse-content-type ct)))))
              (setq charset (and ctl
                                 (mail-content-type-get ctl 'charset)))
              (if (stringp charset)
                  (setq charset (intern (downcase charset)))))))
      (if read-charset
          (setq charset (mm-read-coding-system "Charset: " charset)))
      (unless charset
        (setq charset gnus-newsgroup-charset))
      (article-goto-body)
      (save-window-excursion
        (save-restriction
          (narrow-to-region (point) (point-max))
          (mm-setup-w3)
          (let ((w3-strict-width (window-width))
                (url-standalone-mode t))
            (condition-case var
                (w3-region (point-min) (point-max))
              (error))))))))

(defun article-hide-list-identifiers ()
  "Remove list identifies from the Subject header.
The `gnus-list-identifiers' variable specifies what to do."
  (interactive)
  (let ((inhibit-point-motion-hooks t)
        (regexp (if (consp gnus-list-identifiers)
                    (mapconcat 'identity gnus-list-identifiers " *\\|")
                  gnus-list-identifiers))
        buffer-read-only)
    (when regexp
      (save-excursion
        (save-restriction
          (article-narrow-to-head)
          (goto-char (point-min))
          (while (re-search-forward
                  (concat "^Subject: +\\(R[Ee]: +\\)*\\(" regexp " *\\)")
                  nil t)
            (delete-region (match-beginning 2) (match-end 0))
            (beginning-of-line))
          (when (re-search-forward
                 "^Subject: +\\(\\(R[Ee]: +\\)+\\)R[Ee]: +" nil t)
            (delete-region (match-beginning 1) (match-end 1))))))))

(defun article-hide-pgp ()
  "Remove any PGP headers and signatures in the current article."
  (interactive)
  (save-excursion
    (save-restriction
      (let ((inhibit-point-motion-hooks t)
            buffer-read-only beg end)
        (article-goto-body)
        ;; Hide the "header".
        (when (re-search-forward "^-----BEGIN PGP SIGNED MESSAGE-----\n" nil t)
          (push 'pgp gnus-article-wash-types)
          (delete-region (match-beginning 0) (match-end 0))
          ;; Remove armor headers (rfc2440 6.2)
          (delete-region (point) (or (re-search-forward "^[ \t]*\n" nil t)
                                     (point)))
          (setq beg (point))
          ;; Hide the actual signature.
          (and (search-forward "\n-----BEGIN PGP SIGNATURE-----\n" nil t)
               (setq end (1+ (match-beginning 0)))
               (delete-region
                end
                (if (search-forward "\n-----END PGP SIGNATURE-----\n" nil t)
                    (match-end 0)
                  ;; Perhaps we shouldn't hide to the end of the buffer
                  ;; if there is no end to the signature?
                  (point-max))))
          ;; Hide "- " PGP quotation markers.
          (when (and beg end)
            (narrow-to-region beg end)
            (goto-char (point-min))
            (while (re-search-forward "^- " nil t)
              (delete-region
               (match-beginning 0) (match-end 0)))
            (widen))
          (gnus-run-hooks 'gnus-article-hide-pgp-hook))))))

(defun article-hide-pem (&optional arg)
  "Toggle hiding of any PEM headers and signatures in the current article.
If given a negative prefix, always show; if given a positive prefix,
always hide."
  (interactive (gnus-article-hidden-arg))
  (unless (gnus-article-check-hidden-text 'pem arg)
    (save-excursion
      (let (buffer-read-only end)
        (goto-char (point-min))
        ;; Hide the horrendously ugly "header".
        (when (and (search-forward
                    "\n-----BEGIN PRIVACY-ENHANCED MESSAGE-----\n"
                    nil t)
                   (setq end (1+ (match-beginning 0))))
          (push 'pem gnus-article-wash-types)
          (gnus-article-hide-text-type
           end
           (if (search-forward "\n\n" nil t)
               (match-end 0)
             (point-max))
           'pem)
          ;; Hide the trailer as well
          (when (search-forward "\n-----END PRIVACY-ENHANCED MESSAGE-----\n"
                                nil t)
            (gnus-article-hide-text-type
             (match-beginning 0) (match-end 0) 'pem)))))))

(defun article-strip-banner ()
  "Strip the banner specified by the `banner' group parameter."
  (interactive)
  (save-excursion
    (save-restriction
      (let ((inhibit-point-motion-hooks t)
            (banner (gnus-parameter-banner gnus-newsgroup-name))
            (gnus-signature-limit nil)
            buffer-read-only beg end)
        (when banner
          (article-goto-body)
          (cond
           ((eq banner 'signature)
            (when (gnus-article-narrow-to-signature)
              (widen)
              (forward-line -1)
              (delete-region (point) (point-max))))
           ((symbolp banner)
            (if (setq banner (cdr (assq banner gnus-article-banner-alist)))
                (while (re-search-forward banner nil t)
                  (delete-region (match-beginning 0) (match-end 0)))))
           ((stringp banner)
            (while (re-search-forward banner nil t)
              (delete-region (match-beginning 0) (match-end 0))))))))))

(defun article-babel ()
  "Translate article using an online translation service."
  (interactive)
  (require 'babel)
  (save-excursion
    (set-buffer gnus-article-buffer)
    (when (article-goto-body)
      (let* ((buffer-read-only nil)
             (start (point))
             (end (point-max))
             (orig (buffer-substring start end))
             (trans (babel-as-string orig)))
        (save-restriction
          (narrow-to-region start end)
          (delete-region start end)
          (insert trans))))))

(defun article-hide-signature (&optional arg)
  "Hide the signature in the current article.
If given a negative prefix, always show; if given a positive prefix,
always hide."
  (interactive (gnus-article-hidden-arg))
  (unless (gnus-article-check-hidden-text 'signature arg)
    (save-excursion
      (save-restriction
        (let ((buffer-read-only nil))
          (when (gnus-article-narrow-to-signature)
            (gnus-article-hide-text-type
             (point-min) (point-max) 'signature)))))))

(defun article-strip-headers-in-body ()
  "Strip offensive headers from bodies."
  (interactive)
  (save-excursion
    (article-goto-body)
    (let ((case-fold-search t))
      (when (looking-at "x-no-archive:")
        (gnus-delete-line)))))

(defun article-strip-leading-blank-lines ()
  "Remove all blank lines from the beginning of the article."
  (interactive)
  (save-excursion
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only)
      (when (article-goto-body)
        (while (and (not (eobp))
                    (looking-at "[ \t]*$"))
          (gnus-delete-line))))))

(defun article-narrow-to-head ()
  "Narrow the buffer to the head of the message.
Point is left at the beginning of the narrowed-to region."
  (narrow-to-region
   (goto-char (point-min))
   (if (search-forward "\n\n" nil 1)
       (1- (point))
     (point-max)))
  (goto-char (point-min)))

(defun article-goto-body ()
  "Place point at the start of the body."
  (goto-char (point-min))
  (cond
   ;; This variable is only bound when dealing with separate
   ;; MIME body parts.
   (article-goto-body-goes-to-point-min-p
    t)
   ((search-forward "\n\n" nil t)
    t)
   (t
    (goto-char (point-max))
    nil)))

(defun article-strip-multiple-blank-lines ()
  "Replace consecutive blank lines with one empty line."
  (interactive)
  (save-excursion
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only)
      ;; First make all blank lines empty.
      (article-goto-body)
      (while (re-search-forward "^[ \t]+$" nil t)
        (unless (gnus-annotation-in-region-p
                 (match-beginning 0) (match-end 0))
          (replace-match "" nil t)))
      ;; Then replace multiple empty lines with a single empty line.
      (article-goto-body)
      (while (re-search-forward "\n\n\\(\n+\\)" nil t)
        (unless (gnus-annotation-in-region-p
                 (match-beginning 0) (match-end 0))
          (delete-region (match-beginning 1) (match-end 1)))))))

(defun article-strip-leading-space ()
  "Remove all white space from the beginning of the lines in the article."
  (interactive)
  (save-excursion
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only)
      (article-goto-body)
      (while (re-search-forward "^[ \t]+" nil t)
        (replace-match "" t t)))))

(defun article-strip-trailing-space ()
  "Remove all white space from the end of the lines in the article."
  (interactive)
  (save-excursion
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only)
      (article-goto-body)
      (while (re-search-forward "[ \t]+$" nil t)
        (replace-match "" t t)))))

(defun article-strip-blank-lines ()
  "Strip leading, trailing and multiple blank lines."
  (interactive)
  (article-strip-leading-blank-lines)
  (article-remove-trailing-blank-lines)
  (article-strip-multiple-blank-lines))

(defun article-strip-all-blank-lines ()
  "Strip all blank lines."
  (interactive)
  (save-excursion
    (let ((inhibit-point-motion-hooks t)
          buffer-read-only)
      (article-goto-body)
      (while (re-search-forward "^[ \t]*\n" nil t)
        (replace-match "" t t)))))

(defun gnus-article-narrow-to-signature ()
  "Narrow to the signature; return t if a signature is found, else nil."
  (let ((inhibit-point-motion-hooks t))
    (when (gnus-article-search-signature)
      (forward-line 1)
      ;; Check whether we have some limits to what we consider
      ;; to be a signature.
      (let ((limits (if (listp gnus-signature-limit) gnus-signature-limit
                      (list gnus-signature-limit)))
            limit limited)
        (while (setq limit (pop limits))
          (if (or (and (integerp limit)
                       (< (- (point-max) (point)) limit))
                  (and (floatp limit)
                       (< (count-lines (point) (point-max)) limit))
                  (and (gnus-functionp limit)
                       (funcall limit))
                  (and (stringp limit)
                       (not (re-search-forward limit nil t))))
              ()                        ; This limit did not succeed.
            (setq limited t
                  limits nil)))
        (unless limited
          (narrow-to-region (point) (point-max))
          t)))))

(defun gnus-article-search-signature ()
  "Search the current buffer for the signature separator.
Put point at the beginning of the signature separator."
  (let ((cur (point)))
    (goto-char (point-max))
    (if (if (stringp gnus-signature-separator)
            (re-search-backward gnus-signature-separator nil t)
          (let ((seps gnus-signature-separator))
            (while (and seps
                        (not (re-search-backward (car seps) nil t)))
              (pop seps))
            seps))
        t
      (goto-char cur)
      nil)))

(defun gnus-article-hidden-arg ()
  "Return the current prefix arg as a number, or 0 if no prefix."
  (list (if current-prefix-arg
            (prefix-numeric-value current-prefix-arg)
          0)))

(defun gnus-article-check-hidden-text (type arg)
  "Return nil if hiding is necessary.
Arg can be nil or a number.  Nil and positive means hide, negative
means show, 0 means toggle."
  (save-excursion
    (save-restriction
      (let ((hide (gnus-article-hidden-text-p type)))
        (cond
         ((or (null arg)
              (> arg 0))
          nil)
         ((< arg 0)
          (gnus-article-show-hidden-text type)
          t)
         (t
          (if (eq hide 'hidden)
              (progn
                (gnus-article-show-hidden-text type)
                t)
            nil)))))))

(defun gnus-article-hidden-text-p (type)
  "Say whether the current buffer contains hidden text of type TYPE."
  (let ((pos (text-property-any (point-min) (point-max) 'article-type type)))
    (while (and pos
                (not (get-text-property pos 'invisible))
                (not (get-text-property pos 'dummy-invisible)))
      (setq pos
            (text-property-any (1+ pos) (point-max) 'article-type type)))
    (if pos
        'hidden
      nil)))

(defun gnus-article-show-hidden-text (type &optional dummy)
  "Show all hidden text of type TYPE.
Originally it is hide instead of DUMMY."
  (let ((buffer-read-only nil)
        (inhibit-point-motion-hooks t))
    (gnus-remove-text-properties-when
     'article-type type
     (point-min) (point-max)
     (cons 'article-type (cons type
                               gnus-hidden-properties)))))

(defconst article-time-units
  `((year . ,(* 365.25 24 60 60))
    (week . ,(* 7 24 60 60))
    (day . ,(* 24 60 60))
    (hour . ,(* 60 60))
    (minute . 60)
    (second . 1))
  "Mapping from time units to seconds.")

(defun article-date-ut (&optional type highlight header)
  "Convert DATE date to universal time in the current article.
If TYPE is `local', convert to local time; if it is `lapsed', output
how much time has lapsed since DATE.  For `lapsed', the value of
`gnus-article-date-lapsed-new-header' says whether the \"X-Sent:\" header
should replace the \"Date:\" one, or should be added below it."
  (interactive (list 'ut t))
  (let* ((header (or header
                     (message-fetch-field "date")
                     ""))
         (tdate-regexp "^Date:[ \t]\\|^X-Sent:[ \t]")
         (date-regexp
          (cond
           ((not gnus-article-date-lapsed-new-header)
            tdate-regexp)
           ((eq type 'lapsed)
            "^X-Sent:[ \t]")
           (t
            "^Date:[ \t]")))
         (date (if (vectorp header) (mail-header-date header)
                 header))
         (inhibit-point-motion-hooks t)
         pos
         bface eface)
    (save-excursion
      (save-restriction
        (article-narrow-to-head)
        (when (re-search-forward tdate-regexp nil t)
          (setq bface (get-text-property (gnus-point-at-bol) 'face)
                date (or (get-text-property (gnus-point-at-bol)
                                            'original-date)
                         date)
                eface (get-text-property (1- (gnus-point-at-eol)) 'face))
          (forward-line 1))
        (when (and date (not (string= date "")))
          (goto-char (point-min))
          (let ((buffer-read-only nil))
            ;; Delete any old Date headers.
            (while (re-search-forward date-regexp nil t)
              (if pos
                  (delete-region (progn (beginning-of-line) (point))
                                 (progn (forward-line 1) (point)))
                (delete-region (progn (beginning-of-line) (point))
                               (progn (end-of-line) (point)))
                (setq pos (point))))
            (when (and (not pos) (re-search-forward tdate-regexp nil t))
              (forward-line 1))
            (if pos (goto-char pos))
            (insert (article-make-date-line date (or type 'ut)))
            (when (not pos)
              (insert "\n")
              (forward-line -1))
            ;; Do highlighting.
            (beginning-of-line)
            (when (looking-at "\\([^:]+\\): *\\(.*\\)$")
              (put-text-property (match-beginning 1) (1+ (match-end 1))
                                 'original-date date)
              (put-text-property (match-beginning 1) (1+ (match-end 1))
                                 'face bface)
              (put-text-property (match-beginning 2) (match-end 2)
                                 'face eface))))))))

(defun article-make-date-line (date type)
  "Return a DATE line of TYPE."
  (unless (memq type '(local ut original user iso8601 lapsed english))
    (error "Unknown conversion type: %s" type))
  (condition-case ()
      (let ((time (date-to-time date)))
        (cond
         ;; Convert to the local timezone.
         ((eq type 'local)
          (let ((tz (car (current-time-zone time))))
            (format "Date: %s %s%02d%02d" (current-time-string time)
                    (if (> tz 0) "+" "-") (/ (abs tz) 3600)
                    (/ (% (abs tz) 3600) 60))))
         ;; Convert to Universal Time.
         ((eq type 'ut)
          (concat "Date: "
                  (current-time-string
                   (let* ((e (parse-time-string date))
                          (tm (apply 'encode-time e))
                          (ms (car tm))
                          (ls (- (cadr tm) (car (current-time-zone time)))))
                     (cond ((< ls 0) (list (1- ms) (+ ls 65536)))
                           ((> ls 65535) (list (1+ ms) (- ls 65536)))
                           (t (list ms ls)))))
                  " UT"))
         ;; Get the original date from the article.
         ((eq type 'original)
          (concat "Date: " (if (string-match "\n+$" date)
                               (substring date 0 (match-beginning 0))
                             date)))
         ;; Let the user define the format.
         ((eq type 'user)
          (if (gnus-functionp gnus-article-time-format)
              (funcall gnus-article-time-format time)
            (concat
             "Date: "
             (format-time-string gnus-article-time-format time))))
         ;; ISO 8601.
         ((eq type 'iso8601)
          (let ((tz (car (current-time-zone time))))
            (concat
             "Date: "
             (format-time-string "%Y%m%dT%H%M%S" time)
             (format "%s%02d%02d"
                     (if (> tz 0) "+" "-") (/ (abs tz) 3600)
                     (/ (% (abs tz) 3600) 60)))))
         ;; Do an X-Sent lapsed format.
         ((eq type 'lapsed)
          ;; If the date is seriously mangled, the timezone functions are
          ;; liable to bug out, so we ignore all errors.
          (let* ((now (current-time))
                 (real-time (subtract-time now time))
                 (real-sec (and real-time
                                (+ (* (float (car real-time)) 65536)
                                   (cadr real-time))))
                 (sec (and real-time (abs real-sec)))
                 num prev)
            (cond
             ((null real-time)
              "X-Sent: Unknown")
             ((zerop sec)
              "X-Sent: Now")
             (t
              (concat
               "X-Sent: "
               ;; This is a bit convoluted, but basically we go
               ;; through the time units for years, weeks, etc,
               ;; and divide things to see whether that results
               ;; in positive answers.
               (mapconcat
                (lambda (unit)
                  (if (zerop (setq num (ffloor (/ sec (cdr unit)))))
                      ;; The (remaining) seconds are too few to
                      ;; be divided into this time unit.
                      ""
                    ;; It's big enough, so we output it.
                    (setq sec (- sec (* num (cdr unit))))
                    (prog1
                        (concat (if prev ", " "") (int-to-string
                                                   (floor num))
                                " " (symbol-name (car unit))
                                (if (> num 1) "s" ""))
                      (setq prev t))))
                article-time-units "")
               ;; If dates are odd, then it might appear like the
               ;; article was sent in the future.
               (if (> real-sec 0)
                   " ago"
                 " in the future"))))))
         ;; Display the date in proper English
         ((eq type 'english)
          (let ((dtime (decode-time time)))
            (concat
             "Date: the "
             (number-to-string (nth 3 dtime))
             (let ((digit (% (nth 3 dtime) 10)))
               (cond
                ((memq (nth 3 dtime) '(11 12 13)) "th")
                ((= digit 1) "st")
                ((= digit 2) "nd")
                ((= digit 3) "rd")
                (t "th")))
             " of "
             (nth (1- (nth 4 dtime)) gnus-english-month-names)
             " "
             (number-to-string (nth 5 dtime))
             " at "
             (format "%02d" (nth 2 dtime))
             ":"
             (format "%02d" (nth 1 dtime)))))))
        (error
         (format "Date: %s (from Oort)" date))))

(defun article-date-local (&optional highlight)
  "Convert the current article date to the local timezone."
  (interactive (list t))
  (article-date-ut 'local highlight))

(defun article-date-english (&optional highlight)
  "Convert the current article date to something that is proper English."
  (interactive (list t))
  (article-date-ut 'english highlight))

(defun article-date-original (&optional highlight)
  "Convert the current article date to what it was originally.
This is only useful if you have used some other date conversion
function and want to see what the date was before converting."
  (interactive (list t))
  (article-date-ut 'original highlight))

(defun article-date-lapsed (&optional highlight)
  "Convert the current article date to time lapsed since it was sent."
  (interactive (list t))
  (article-date-ut 'lapsed highlight))

(defun article-update-date-lapsed ()
  "Function to be run from a timer to update the lapsed time line."
  (let (deactivate-mark)
    (save-excursion
      (ignore-errors
        (walk-windows
         (lambda (w)
           (set-buffer (window-buffer w))
           (when (eq major-mode 'gnus-article-mode)
             (goto-char (point-min))
             (when (re-search-forward "^X-Sent:" nil t)
               (article-date-lapsed t))))
         nil 'visible)))))

(defun gnus-start-date-timer (&optional n)
  "Start a timer to update the X-Sent header in the article buffers.
The numerical prefix says how frequently (in seconds) the function
is to run."
  (interactive "p")
  (unless n
    (setq n 1))
  (gnus-stop-date-timer)
  (setq article-lapsed-timer
        (nnheader-run-at-time 1 n 'article-update-date-lapsed)))

(defun gnus-stop-date-timer ()
  "Stop the X-Sent timer."
  (interactive)
  (when article-lapsed-timer
    (nnheader-cancel-timer article-lapsed-timer)
    (setq article-lapsed-timer nil)))

(defun article-date-user (&optional highlight)
  "Convert the current article date to the user-defined format.
This format is defined by the `gnus-article-time-format' variable."
  (interactive (list t))
  (article-date-ut 'user highlight))

(defun article-date-iso8601 (&optional highlight)
  "Convert the current article date to ISO8601."
  (interactive (list t))
  (article-date-ut 'iso8601 highlight))

(defun article-show-all ()
  "Show all hidden text in the article buffer."
  (interactive)
  (save-excursion
    (let ((buffer-read-only nil))
      (gnus-article-unhide-text (point-min) (point-max)))))

(defun article-remove-leading-whitespace ()
  "Remove excessive whitespace from all headers."
  (interactive)
  (save-excursion
    (save-restriction
      (let ((buffer-read-only nil))
        (article-narrow-to-head)
        (goto-char (point-min))
        (while (re-search-forward "^[^ :]+: \\([ \t]+\\)" nil t)
          (delete-region (match-beginning 1) (match-end 1)))))))

(defun article-emphasize (&optional arg)
  "Emphasize text according to `gnus-emphasis-alist'."
  (interactive (gnus-article-hidden-arg))
  (unless (gnus-article-check-hidden-text 'emphasis arg)
    (save-excursion
      (let ((alist (or
                    (condition-case nil
                        (with-current-buffer gnus-summary-buffer
                          gnus-article-emphasis-alist)
                      (error))
                    gnus-emphasis-alist))
            (buffer-read-only nil)
            (props (append '(article-type emphasis)
                           gnus-hidden-properties))
            regexp elem beg invisible visible face)
        (article-goto-body)
        (setq beg (point))
        (while (setq elem (pop alist))
          (goto-char beg)
          (setq regexp (car elem)
                invisible (nth 1 elem)
                visible (nth 2 elem)
                face (nth 3 elem))
          (while (re-search-forward regexp nil t)
            (when (and (match-beginning visible) (match-beginning invisible))
              (push 'emphasis gnus-article-wash-types)
              (gnus-article-hide-text
               (match-beginning invisible) (match-end invisible) props)
              (gnus-article-unhide-text-type
               (match-beginning visible) (match-end visible) 'emphasis)
              (gnus-put-text-property-excluding-newlines
               (match-beginning visible) (match-end visible) 'face face)
              (goto-char (match-end invisible)))))))))

(defun gnus-article-setup-highlight-words (&optional highlight-words)
  "Setup newsgroup emphasis alist."
  (unless gnus-article-emphasis-alist
    (let ((name (and gnus-newsgroup-name
                     (gnus-group-real-name gnus-newsgroup-name))))
      (make-local-variable 'gnus-article-emphasis-alist)
      (setq gnus-article-emphasis-alist
            (nconc
             (let ((alist gnus-group-highlight-words-alist) elem highlight)
               (while (setq elem (pop alist))
                 (when (and name (string-match (car elem) name))
                   (setq alist nil
                         highlight (copy-sequence (cdr elem)))))
               highlight)
             (copy-sequence highlight-words)
             (if gnus-newsgroup-name
                 (copy-sequence (gnus-group-find-parameter
                                 gnus-newsgroup-name 'highlight-words t)))
             gnus-emphasis-alist)))))

(eval-when-compile
  (defvar gnus-summary-article-menu)
  (defvar gnus-summary-post-menu))

;;; Saving functions.

(defun gnus-article-save (save-buffer file &optional num)
  "Save the currently selected article."
  (unless gnus-save-all-headers
    ;; Remove headers according to `gnus-saved-headers'.
    (let ((gnus-visible-headers
           (or gnus-saved-headers gnus-visible-headers))
          (gnus-article-buffer save-buffer))
      (save-excursion
        (set-buffer save-buffer)
        (article-hide-headers 1 t))))
  (save-window-excursion
    (if (not gnus-default-article-saver)
        (error "No default saver is defined")
      ;; !!! Magic!  The saving functions all save
      ;; `gnus-save-article-buffer' (or so they think), but we
      ;; bind that variable to our save-buffer.
      (set-buffer gnus-article-buffer)
      (let* ((gnus-save-article-buffer save-buffer)
             (filename
              (cond
               ((not gnus-prompt-before-saving) 'default)
               ((eq gnus-prompt-before-saving 'always) nil)
               (t file)))
             (gnus-number-of-articles-to-be-saved
              (when (eq gnus-prompt-before-saving t)
                num)))                  ; Magic
        (set-buffer gnus-article-current-summary)
        (funcall gnus-default-article-saver filename)))))

(defun gnus-read-save-file-name (prompt &optional filename
                                        function group headers variable)
  (let ((default-name
          (funcall function group headers (symbol-value variable)))
        result)
    (setq result
          (expand-file-name
           (cond
            ((eq filename 'default)
             default-name)
            ((eq filename t)
             default-name)
            (filename filename)
            (t
             (let* ((split-name (gnus-get-split-value gnus-split-methods))
                    (prompt
                     (format prompt
                             (if (and gnus-number-of-articles-to-be-saved
                                      (> gnus-number-of-articles-to-be-saved 1))
                                 (format "these %d articles"
                                         gnus-number-of-articles-to-be-saved)
                               "this article")))
                    (file
                     ;; Let the split methods have their say.
                     (cond
                      ;; No split name was found.
                      ((null split-name)
                       (read-file-name
                        (concat prompt " (default "
                                (file-name-nondirectory default-name) ") ")
                        (file-name-directory default-name)
                        default-name))
                      ;; A single group name is returned.
                      ((stringp split-name)
                       (setq default-name
                             (funcall function split-name headers
                                      (symbol-value variable)))
                       (read-file-name
                        (concat prompt " (default "
                                (file-name-nondirectory default-name) ") ")
                        (file-name-directory default-name)
                        default-name))
                      ;; A single split name was found
                      ((= 1 (length split-name))
                       (let* ((name (expand-file-name
                                     (car split-name)
                                     gnus-article-save-directory))
                              (dir (cond ((file-directory-p name)
                                          (file-name-as-directory name))
                                         ((file-exists-p name) name)
                                         (t gnus-article-save-directory))))
                         (read-file-name
                          (concat prompt " (default " name ") ")
                          dir name)))
                      ;; A list of splits was found.
                      (t
                       (setq split-name (nreverse split-name))
                       (let (result)
                         (let ((file-name-history
                                (nconc split-name file-name-history)))
                           (setq result
                                 (expand-file-name
                                  (read-file-name
                                   (concat prompt " (`M-p' for defaults) ")
                                   gnus-article-save-directory
                                   (car split-name))
                                  gnus-article-save-directory)))
                         (car (push result file-name-history)))))))
               ;; Create the directory.
               (gnus-make-directory (file-name-directory file))
      ;; If we have read a directory, we append the default file name.
               (when (file-directory-p file)
                 (setq file (expand-file-name (file-name-nondirectory
                                               default-name)
                                              (file-name-as-directory file))))
               ;; Possibly translate some characters.
               (nnheader-translate-file-chars file))))))
    (gnus-make-directory (file-name-directory result))
    (set variable result)))

(defun gnus-article-archive-name (group)
  "Return the first instance of an \"Archive-name\" in the current buffer."
  (let ((case-fold-search t))
    (when (re-search-forward "archive-name: *\\([^ \n\t]+\\)[ \t]*$" nil t)
      (nnheader-concat gnus-article-save-directory
                       (match-string 1)))))

(defun gnus-article-nndoc-name (group)
  "If GROUP is an nndoc group, return the name of the parent group."
  (when (eq (car (gnus-find-method-for-group group)) 'nndoc)
    (gnus-group-get-parameter group 'save-article-group)))

(defun gnus-summary-save-in-rmail (&optional filename)
  "Append this article to Rmail file.
Optional argument FILENAME specifies file name.
Directory to save to is default to `gnus-article-save-directory'."
  (setq filename (gnus-read-save-file-name
                  "Save %s in rmail file:" filename
                  gnus-rmail-save-name gnus-newsgroup-name
                  gnus-current-headers 'gnus-newsgroup-last-rmail))
  (gnus-eval-in-buffer-window gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (gnus-output-to-rmail filename))))
  filename)

(defun gnus-summary-save-in-mail (&optional filename)
  "Append this article to Unix mail file.
Optional argument FILENAME specifies file name.
Directory to save to is default to `gnus-article-save-directory'."
  (setq filename (gnus-read-save-file-name
                  "Save %s in Unix mail file:" filename
                  gnus-mail-save-name gnus-newsgroup-name
                  gnus-current-headers 'gnus-newsgroup-last-mail))
  (gnus-eval-in-buffer-window gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (if (and (file-readable-p filename)
                 (mail-file-babyl-p filename))
            (rmail-output-to-rmail-file filename t)
          (gnus-output-to-mail filename)))))
  filename)

(defun gnus-summary-save-in-file (&optional filename overwrite)
  "Append this article to file.
Optional argument FILENAME specifies file name.
Directory to save to is default to `gnus-article-save-directory'."
  (setq filename (gnus-read-save-file-name
                  "Save %s in file:" filename
                  gnus-file-save-name gnus-newsgroup-name
                  gnus-current-headers 'gnus-newsgroup-last-file))
  (gnus-eval-in-buffer-window gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (when (and overwrite
                   (file-exists-p filename))
          (delete-file filename))
        (gnus-output-to-file filename))))
  filename)

(defun gnus-summary-write-to-file (&optional filename)
  "Write this article to a file.
Optional argument FILENAME specifies file name.
The directory to save in defaults to `gnus-article-save-directory'."
  (gnus-summary-save-in-file nil t))

(defun gnus-summary-save-body-in-file (&optional filename)
  "Append this article body to a file.
Optional argument FILENAME specifies file name.
The directory to save in defaults to `gnus-article-save-directory'."
  (setq filename (gnus-read-save-file-name
                  "Save %s body in file:" filename
                  gnus-file-save-name gnus-newsgroup-name
                  gnus-current-headers 'gnus-newsgroup-last-file))
  (gnus-eval-in-buffer-window gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (when (article-goto-body)
          (narrow-to-region (point) (point-max)))
        (gnus-output-to-file filename))))
  filename)

(defun gnus-summary-save-in-pipe (&optional command)
  "Pipe this article to subprocess."
  (setq command
        (cond ((and (eq command 'default)
                    gnus-last-shell-command)
               gnus-last-shell-command)
              ((stringp command)
               command)
              (t (read-string
                  (format
                   "Shell command on %s: "
                   (if (and gnus-number-of-articles-to-be-saved
                            (> gnus-number-of-articles-to-be-saved 1))
                       (format "these %d articles"
                               gnus-number-of-articles-to-be-saved)
                     "this article"))
                  gnus-last-shell-command))))
  (when (string-equal command "")
    (if gnus-last-shell-command
        (setq command gnus-last-shell-command)
      (error "A command is required")))
  (gnus-eval-in-buffer-window gnus-article-buffer
    (save-restriction
      (widen)
      (shell-command-on-region (point-min) (point-max) command nil)))
  (setq gnus-last-shell-command command))

;;; Article file names when saving.

(defun gnus-capitalize-newsgroup (newsgroup)
  "Capitalize NEWSGROUP name."
  (when (not (zerop (length newsgroup)))
    (concat (char-to-string (upcase (aref newsgroup 0)))
            (substring newsgroup 1))))

(defun gnus-Numeric-save-name (newsgroup headers &optional last-file)
  "Generate file name from NEWSGROUP, HEADERS, and optional LAST-FILE.
If variable `gnus-use-long-file-name' is non-nil, it is ~/News/News.group/num.
Otherwise, it is like ~/News/news/group/num."
  (let ((default
          (expand-file-name
           (concat (if (gnus-use-long-file-name 'not-save)
                       (gnus-capitalize-newsgroup newsgroup)
                     (gnus-newsgroup-directory-form newsgroup))
                   "/" (int-to-string (mail-header-number headers)))
           gnus-article-save-directory)))
    (if (and last-file
             (string-equal (file-name-directory default)
                           (file-name-directory last-file))
             (string-match "^[0-9]+$" (file-name-nondirectory last-file)))
        default
      (or last-file default))))

(defun gnus-numeric-save-name (newsgroup headers &optional last-file)
  "Generate file name from NEWSGROUP, HEADERS, and optional LAST-FILE.
If variable `gnus-use-long-file-name' is non-nil, it is
~/News/news.group/num.  Otherwise, it is like ~/News/news/group/num."
  (let ((default
          (expand-file-name
           (concat (if (gnus-use-long-file-name 'not-save)
                       newsgroup
                     (gnus-newsgroup-directory-form newsgroup))
                   "/" (int-to-string (mail-header-number headers)))
           gnus-article-save-directory)))
    (if (and last-file
             (string-equal (file-name-directory default)
                           (file-name-directory last-file))
             (string-match "^[0-9]+$" (file-name-nondirectory last-file)))
        default
      (or last-file default))))

(defun gnus-plain-save-name (newsgroup headers &optional last-file)
  "Generate file name from NEWSGROUP, HEADERS, and optional LAST-FILE.
If variable `gnus-use-long-file-name' is non-nil, it is
~/News/news.group.  Otherwise, it is like ~/News/news/group/news."
  (or last-file
      (expand-file-name
       (if (gnus-use-long-file-name 'not-save)
           newsgroup
         (file-relative-name
          (expand-file-name "news" (gnus-newsgroup-directory-form newsgroup))
          default-directory))
       gnus-article-save-directory)))

(defun gnus-sender-save-name (newsgroup headers &optional last-file)
  "Generate file name from sender."
  (let ((from (mail-header-from headers)))
    (expand-file-name
     (if (and from (string-match "\\([^ <]+\\)@" from))
         (match-string 1 from)
       "nobody")
     gnus-article-save-directory)))

(defun article-verify-x-pgp-sig ()
  "Verify X-PGP-Sig."
  (interactive)
  (if (gnus-buffer-live-p gnus-original-article-buffer)
      (let ((sig (with-current-buffer gnus-original-article-buffer
                   (gnus-fetch-field "X-PGP-Sig")))
            items info headers)
        (when (and sig
                   mml2015-use
                   (mml2015-clear-verify-function))
          (with-temp-buffer
            (insert-buffer gnus-original-article-buffer)
            (setq items (split-string sig))
            (message-narrow-to-head)