[gnus] / lisp / gnus-art.el

;;; gnus-art.el --- article mode commands for Gnus

;; Copyright (C) 1996-2015 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 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(eval-when-compile
  (require 'cl))
(defvar tool-bar-map)
(defvar w3m-minor-mode-map)

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

(autoload 'gnus-msg-mail "gnus-msg" nil t)
(autoload 'gnus-button-mailto "gnus-msg")
(autoload 'gnus-button-reply "gnus-msg" nil t)
(autoload 'parse-time-string "parse-time" nil nil)
(autoload 'ansi-color-apply-on-region "ansi-color")
(autoload 'mm-url-insert-file-contents-external "mm-url")
(autoload 'mm-extern-cache-contents "mm-extern")

(defgroup gnus-article nil
  "Article display."
  :link '(custom-manual "(gnus)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
  (mapcar
   (lambda (header)
     (concat "^" header ":"))
   '("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" "X-From_" "X-Accept-Language" "Errors-To"
     "X-BeenThere" "X-Mailman-Version" "List-Help" "List-Post"
     "List-Subscribe" "List-Id" "List-Unsubscribe" "List-Archive"
     "X-Content-length" "X-Posting-Agent" "Original-Received"
     "X-Request-PGP" "X-Fingerprint" "X-WRIEnvto" "X-WRIEnvfrom"
     "X-Virus-Scanned" "X-Delivery-Agent" "Posted-Date" "X-Gateway"
     "X-Local-Origin" "X-Local-Destination" "X-UserInfo1"
     "X-Received-Date" "X-Hashcash" "Face" "X-DMCA-Notifications"
     "X-Abuse-and-DMCA-Info" "X-Postfilter" "X-Gpg-.*" "X-Disclaimer"
     "Envelope-To" "X-Spam-Score" "System-Type" "X-Injected-Via-Gmane"
     "X-Gmane-NNTP-Posting-Host" "Jabber-ID" "Archived-At"
     "Envelope-Sender" "Envelope-Recipients"))
  "*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 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:"
  "*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 '(choice
          (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)
          (const :tag "Use gnus-ignored-headers" nil)
          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.
  'to-list     To identical to To-list.
  'cc-list     CC identical to To-list.
  '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 "To identical to To-list." to-list)
              (const :tag "CC identical to To-list." cc-list)
              (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-article-skip-boring nil
  "Skip over text that is not worth reading.
By default, if you set this t, then Gnus will display citations and
signatures, but will never scroll down to show you a page consisting
only of boring text.  Boring text is controlled by
`gnus-article-boring-faces'."
  :version "22.1"
  :type 'boolean
  :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 '(choice :format "%{%t%}: %[Value Menu%]\n%v"
                 (regexp)
                 (repeat :tag "List of regexp" regexp))
  :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.

This can also be a list of the above values."
  :type '(choice (const nil)
                 (integer :value 200)
                 (number :value 4.0)
                 function
                 (regexp :value ".*"))
  :group 'gnus-article-signature)

(defcustom gnus-hidden-properties
  (if (featurep 'xemacs)
      ;; `intangible' is evil, but I keep it here in case it's useful.
      '(invisible t intangible t)
    ;; Emacs's command loop moves point out of invisible text anyway, so
    ;; `intangible' is clearly not needed there.
    '(invisible 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 non-graphical
;; frames in a session.
(defcustom gnus-article-x-face-command
  (if (featurep 'xemacs)
      (if (or (gnus-image-type-available-p 'xface)
              (gnus-image-type-available-p 'pbm))
          'gnus-display-x-face-in-from
        "{ echo \
'/* Format_version=1, Width=48, Height=48, Depth=1, Valid_bits_per_item=16 */'\
; uncompface; } | icontopbm | ee -")
    (if (gnus-image-type-available-p 'pbm)
        'gnus-display-x-face-in-from
      "{ echo \
'/* Format_version=1, Width=48, Height=48, Depth=1, Valid_bits_per_item=16 */'\
; 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-display-x-face-in-from)
                 function)
  :version "21.1"
  :group 'gnus-picon
  :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-article-address-banner-alist nil
  "Alist of mail addresses and banners.
Each element has the form (ADDRESS . BANNER), where ADDRESS is a regexp
to match a mail address in the From: header, BANNER is one of a symbol
`signature', an item in `gnus-article-banner-alist', a regexp and nil.
If ADDRESS matches author's mail address, it will remove things like
advertisements.  For example:

\((\"@yoo-hoo\\\\.co\\\\.jp\\\\'\" . \"\\n_+\\nDo You Yoo-hoo!\\\\?\\n.*\\n.*\\n\"))
"
  :type '(repeat
          (cons
           (regexp :tag "Address")
           (choice :tag "Banner" :value nil
                   (const :tag "Remove signature" signature)
                   (symbol :tag "Item in `gnus-article-banner-alist'" none)
                   regexp
                   (const :tag "None" nil))))
  :version "22.1"
  :group 'gnus-article-washing)

(defmacro gnus-emphasis-custom-with-format (&rest body)
  `(let ((format "\
\\(\\s-\\|^\\|\\=\\|[-\"]\\|\\s(\\)\\(%s\\(\\w+\\(\\s-+\\w+\\)*[.,]?\\)%s\\)\
\\(\\([-,.;:!?\"]\\|\\s)\\)+\\s-\\|[?!.]\\s-\\|\\s)\\|\\s-\\)"))
     ,@body))

(defun gnus-emphasis-custom-value-to-external (value)
  (gnus-emphasis-custom-with-format
   (if (consp (car value))
       (list (format format (car (car value)) (cdr (car value)))
             2
             (if (nth 1 value) 2 3)
             (nth 2 value))
     value)))

(defun gnus-emphasis-custom-value-to-internal (value)
  (gnus-emphasis-custom-with-format
   (let ((regexp (concat "\\`"
                         (format (regexp-quote format)
                                 "\\([^()]+\\)" "\\([^()]+\\)")
                         "\\'"))
         pattern)
     (if (string-match regexp (setq pattern (car value)))
         (list (cons (match-string 1 pattern) (match-string 2 pattern))
               (= (nth 2 value) 2)
               (nth 3 value))
       value))))

(defcustom gnus-emphasis-alist
  (let ((types
         '(("\\*" "\\*" bold nil 2)
           ("_" "_" underline)
           ("/" "/" italic)
           ("_/" "/_" underline-italic)
           ("_\\*" "\\*_" underline-bold)
           ("\\*/" "/\\*" bold-italic)
           ("_\\*/" "/\\*_" underline-bold-italic))))
    (nconc
     (gnus-emphasis-custom-with-format
      (mapcar (lambda (spec)
                (list (format format (car spec) (cadr spec))
                      (or (nth 3 spec) 2)
                      (or (nth 4 spec) 3)
                      (intern (format "gnus-emphasis-%s" (nth 2 spec)))))
              types))
     '(;; I've never seen anyone use this strikethru convention whereas I've
       ;; several times seen it triggered by normal text.  --Stef
       ;; Miles suggests that this form is sometimes used but for italics,
       ;; so maybe we should map it to `italic'.
       ;; ("\\(\\s-\\|^\\)\\(-\\(\\(\\w\\|-[^-]\\)+\\)-\\)\\(\\s-\\|[?!.,;]\\)"
       ;; 2 3 gnus-emphasis-strikethru)
       ("\\(\\s-\\|^\\)\\(_\\(\\(\\w\\|_[^_]\\)+\\)_\\)\\(\\s-\\|[?!.,;]\\)"
        2 3 gnus-emphasis-underline))))
  "*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
    (menu-choice
     :format "%[Customizing Style%]\n%v"
     :indent 2
     (group :tag "Default"
            :value ("" 0 0 default)
            :value-create
            (lambda (widget)
              (let ((value (widget-get
                            (cadr (widget-get (widget-get widget :parent)
                                              :args))
                            :value)))
                (if (not (eq (nth 2 value) 'default))
                    (widget-put
                     widget
                     :value
                     (gnus-emphasis-custom-value-to-external value))))
              (widget-group-value-create widget))
            regexp
            (integer :format "Match group: %v")
            (integer :format "Emphasize group: %v")
            face)
     (group :tag "Simple"
            :value (("_" . "_") nil default)
            (cons :format "%v"
                  (regexp :format "Start regexp: %v")
                  (regexp :format "End regexp: %v"))
            (boolean :format "Show start and end patterns: %[%v%]\n"
                     :on " On " :off " Off ")
            face)))
  :get (lambda (symbol)
         (mapcar 'gnus-emphasis-custom-value-to-internal
                 (default-value symbol)))
  :set (lambda (symbol value)
         (set-default symbol (mapcar 'gnus-emphasis-custom-value-to-external
                                     value)))
  :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.
Example: (_/*word*/_)."
  :group 'gnus-article-emphasis)

(defface gnus-emphasis-strikethru (if (featurep 'xemacs)
                                      '((t (:strikethru t)))
                                    '((t (:strike-through t))))
  "Face used for displaying strike-through text (-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, %d %b %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 function)
  :link '(custom-manual "(gnus)Article Date")
  :group 'gnus-article-washing)

(defcustom gnus-save-all-headers t
  "*If non-nil, don't remove any headers before saving.
This will be overridden by the `:headers' property that the symbol of
the saver function, which is specified by `gnus-default-article-saver',
might have."
  :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.  This and
`gnus-save-all-headers' will be overridden by the `:headers' property
that the symbol of the saver function, which is specified by
`gnus-default-article-saver', might have."
  :group 'gnus-article-saving
  :type 'regexp)

;; Note that "Rmail format" is mbox since Emacs 23, but Babyl before.
(defcustom gnus-default-article-saver 'gnus-summary-save-in-rmail
  "A function to save articles in your favorite format.
The function will be called by way of the `gnus-summary-save-article'
command, and friends such as `gnus-summary-save-article-rmail'.

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-body-in-file (article body)
* gnus-summary-save-in-vm (use VM's folder format)
* gnus-summary-write-to-file (article format -- overwrite)
* gnus-summary-write-body-to-file (article body -- overwrite)
* gnus-summary-save-in-pipe (article format)

The symbol of each function may have the following properties:

* :decode
The value non-nil means save decoded articles.  This is meaningful
only with `gnus-summary-save-in-file', `gnus-summary-save-body-in-file',
`gnus-summary-write-to-file', `gnus-summary-write-body-to-file', and
`gnus-summary-save-in-pipe'.

* :function
The value specifies an alternative function which appends, not
overwrites, articles to a file.  This implies that when saving many
articles at a time, `gnus-prompt-before-saving' is bound to t and all
articles are saved in a single file.  This is meaningful only with
`gnus-summary-write-to-file' and `gnus-summary-write-body-to-file'.

* :headers
The value specifies the symbol of a variable of which the value
specifies headers to be saved.  If it is omitted,
`gnus-save-all-headers' and `gnus-saved-headers' control what
headers should be saved."
  :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-body-in-file)
                (function-item gnus-summary-save-in-vm)
                (function-item gnus-summary-write-to-file)
                (function-item gnus-summary-write-body-to-file)
                (function-item gnus-summary-save-in-pipe)
                (function)))

(defcustom gnus-article-save-coding-system
  (or (and (mm-coding-system-p 'utf-8) 'utf-8)
      (and (mm-coding-system-p 'iso-2022-7bit) 'iso-2022-7bit)
      (and (mm-coding-system-p 'emacs-mule) 'emacs-mule)
      (and (mm-coding-system-p 'escape-quoted) 'escape-quoted))
  "Coding system used to save decoded articles to a file.

The recommended coding systems are `utf-8', `iso-2022-7bit' and so on,
which can safely encode any characters in text.  This is used by the
commands including:

* gnus-summary-save-article-file
* gnus-summary-save-article-body-file
* gnus-summary-write-article-file
* gnus-summary-write-article-body-file

and the functions to which you may set `gnus-default-article-saver':

* gnus-summary-save-in-file
* gnus-summary-save-body-in-file
* gnus-summary-write-to-file
* gnus-summary-write-body-to-file

Those commands and functions save just text displayed in the article
buffer to a file if the value of this variable is non-nil.  Note that
buttonized MIME parts will be lost in a saved file in that case.
Otherwise, raw articles will be saved."
  :group 'gnus-article-saving
  :type `(choice
          :format "%{%t%}:\n %[Value Menu%] %v"
          (const :tag "Save raw articles" nil)
          ,@(delq nil
                  (mapcar
                   (lambda (arg) (if (mm-coding-system-p (nth 3 arg)) arg))
                   '((const :tag "UTF-8" utf-8)
                     (const :tag "iso-2022-7bit" iso-2022-7bit)
                     (const :tag "Emacs internal" emacs-mule)
                     (const :tag "escape-quoted" escape-quoted))))
          (symbol :tag "Coding system")))

(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 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 evalled 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 %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."
  :version "24.1"
  :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-copy-article-ignored-headers nil
  "List of headers to be removed when copying an article.
Each element is a regular expression."
  :version "23.1" ;; No Gnus
  :type '(repeat regexp)
  :group 'gnus-article-various)

(make-obsolete-variable 'gnus-article-hide-pgp-hook nil
                        "Gnus 5.10 (Emacs 22.1)")

(defface gnus-button
  '((t (:weight bold)))
  "Face used for highlighting a button in the article buffer."
  :group 'gnus-article-buttons)

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

(defface gnus-signature
  '((t
     (:italic t)))
  "Face used for highlighting a signature in the article buffer."
  :group 'gnus-article-highlight
  :group 'gnus-article-signature)
;; backward-compatibility alias
(put 'gnus-signature-face 'face-alias 'gnus-signature)
(put 'gnus-signature-face 'obsolete-face "22.1")

(defface gnus-header-from
  '((((class color)
      (background dark))
     (:foreground "PaleGreen1"))
    (((class color)
      (background light))
     (:foreground "red3"))
    (t
     (:italic t)))
  "Face used for displaying from headers."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)
;; backward-compatibility alias
(put 'gnus-header-from-face 'face-alias 'gnus-header-from)
(put 'gnus-header-from-face 'obsolete-face "22.1")

(defface gnus-header-subject
  '((((class color)
      (background dark))
     (:foreground "SeaGreen1"))
    (((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)
;; backward-compatibility alias
(put 'gnus-header-subject-face 'face-alias 'gnus-header-subject)
(put 'gnus-header-subject-face 'obsolete-face "22.1")

(defface gnus-header-newsgroups
  '((((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.
In the default setup this face is only used for crossposted
articles."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)
;; backward-compatibility alias
(put 'gnus-header-newsgroups-face 'face-alias 'gnus-header-newsgroups)
(put 'gnus-header-newsgroups-face 'obsolete-face "22.1")

(defface gnus-header-name
  '((((class color)
      (background dark))
     (:foreground "SpringGreen2"))
    (((class color)
      (background light))
     (:foreground "maroon"))
    (t
     (:bold t)))
  "Face used for displaying header names."
  :group 'gnus-article-headers
  :group 'gnus-article-highlight)
;; backward-compatibility alias
(put 'gnus-header-name-face 'face-alias 'gnus-header-name)
(put 'gnus-header-name-face 'obsolete-face "22.1")

(defface gnus-header-content
  '((((class color)
      (background dark))
     (:foreground "SpringGreen1" :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)
;; backward-compatibility alias
(put 'gnus-header-content-face 'face-alias 'gnus-header-content)
(put 'gnus-header-content-face 'obsolete-face "22.1")

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

An alist of the form (HEADER NAME CONTENT).

HEADER is a regular expression which should match the name of a
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 matches
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-face-properties-alist (if (featurep 'xemacs)
                                          '((xface . (:face gnus-x-face)))
                                        '((pbm . (:face gnus-x-face))
                                          (png . nil)))
  "Alist of image types and properties applied to Face and X-Face images.
Here are examples:

;; Specify the altitude of Face images in the From header.
\(setq gnus-face-properties-alist
      '((pbm . (:face gnus-x-face :ascent 80))
        (png . (:ascent 80))))

;; Show Face images as pressed buttons.
\(setq gnus-face-properties-alist
      '((pbm . (:face gnus-x-face :relief -2))
        (png . (:relief -2))))

See the manual for the valid properties for various image types.
Currently, `pbm' is used for X-Face images and `png' is used for Face
images in Emacs.  Only the `:face' property is effective on the `xface'
image type in XEmacs if it is built with the libcompface library."
  :version "23.1" ;; No Gnus
  :group 'gnus-article-headers
  :type '(repeat (cons :format "%v" (symbol :tag "Image type") plist)))

(defcustom gnus-article-decode-hook
  '(article-decode-charset article-decode-encoded-words
                           article-decode-group-name article-decode-idna-rhs)
  "*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-decode-address-function 'mail-decode-encoded-address-region
  "Function used to decode addresses.")

(defvar gnus-article-dumbquotes-map
  '((?\200 "EUR")
    (?\202 ",")
    (?\203 "f")
    (?\204 ",,")
    (?\205 "...")
    (?\213 "<")
    (?\214 "OE")
    (?\221 "`")
    (?\222 "'")
    (?\223 "``")
    (?\224 "\"")
    (?\225 "*")
    (?\226 "-")
    (?\227 "--")
    (?\230 "~")
    (?\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.
See also `gnus-buttonized-mime-types' which may override this variable.
This variable is only used when `gnus-inhibit-mime-unbuttonizing' is nil."
  :version "21.1"
  :group 'gnus-article-mime
  :type '(repeat regexp))

(defcustom gnus-buttonized-mime-types nil
  "List of MIME types that should be given buttons when rendered inline.
If set, this variable overrides `gnus-unbuttonized-mime-types'.
To see e.g. security buttons you could set this to
`(\"multipart/signed\")'.  You could also add \"multipart/alternative\" to
this list to display radio buttons that allow you to choose one of two
media types those mails include.  See also `mm-discouraged-alternatives'.
This variable is only used when `gnus-inhibit-mime-unbuttonizing' is nil."
  :version "22.1"
  :group 'gnus-article-mime
  :type '(repeat regexp))

(defcustom gnus-inhibit-mime-unbuttonizing nil
  "If non-nil, all MIME parts get buttons.
When nil (the default value), then some MIME parts do not get buttons,
as described by the variables `gnus-buttonized-mime-types' and
`gnus-unbuttonized-mime-types'."
  :version "22.1"
  :group 'gnus-article-mime
  :type 'boolean)

(defcustom gnus-body-boundary-delimiter "_"
  "String used to delimit header and body.
This variable is used by `gnus-article-treat-body-boundary' which can
be controlled by `gnus-treat-body-boundary'."
  :version "22.1"
  :group 'gnus-article-various
  :type '(choice (item :tag "None" :value nil)
                 string))

(defcustom gnus-picon-databases '("/usr/lib/picon" "/usr/local/faces"
                                  "/usr/share/picons")
  "Defines the location of the faces database.
For information on obtaining this database of pretty pictures, please
see http://www.cs.indiana.edu/picons/ftp/index.html"
  :version "22.1"
  :type '(repeat directory)
  :link '(url-link :tag "download"
                   "http://www.cs.indiana.edu/picons/ftp/index.html")
  :link '(custom-manual "(gnus)Picons")
  :group 'gnus-picon)

(defun gnus-picons-installed-p ()
  "Say whether picons are installed on your machine."
  (let ((installed nil))
    (dolist (database gnus-picon-databases)
      (when (file-exists-p database)
        (setq installed t)))
    installed))

(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 '(choice (const nil)
                 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 '(repeat (cons :format "%v" (string :tag "MIME type") function)))

(defcustom gnus-article-date-headers '(combined-lapsed)
  "A list of Date header formats to display.
Valid formats are `ut' (universal time), `local' (local time
zone), `english' (readable English), `lapsed' (elapsed time),
`combined-lapsed' (both the original date and the elapsed time),
`original' (the original date header), `iso8601' (ISO8601
format), and `user-defined' (a user-defined format defined by the
`gnus-article-time-format' variable).

You have as many date headers as you want in the article buffer.
Some of these headers are updated automatically.  See
`gnus-article-update-date-headers' for details."
  :version "24.1"
  :group 'gnus-article-headers
  :type '(set
          (const :tag "Universal time (UT)" ut)
          (const :tag "Local time zone" local)
          (const :tag "Readable English" english)
          (const :tag "Elapsed time" lapsed)
          (const :tag "Original and elapsed time" combined-lapsed)
          (const :tag "Original date header" original)
          (const :tag "ISO8601 format" iso8601)
          (const :tag "User-defined" user-defined)))

(defcustom gnus-article-update-date-headers nil
  "A number that says how often to update the date header (in seconds).
If nil, don't update it at all."
  :version "24.1"
  :group 'gnus-article-headers
  :type '(choice
          (item :tag "Don't update" :value nil)
          integer))

(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)
    ("replace with file" . gnus-mime-replace-part)
    ("delete part" . gnus-mime-delete-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)
    ("toggle display" . gnus-article-view-part-as-charset)
    ("view as type" . gnus-mime-view-part-as-type)
    ("view internally" . gnus-mime-view-part-internally)
    ("view externally" . gnus-mime-view-part-externally))
  "An alist of actions that run on the MIME attachment."
  :group 'gnus-article-mime
  :type '(repeat (cons (string :tag "name")
                       (function))))

(defcustom gnus-auto-select-part 1
  "Advance to next MIME part when deleting or stripping parts.

When 0, point will be placed on the same part as before.  When
positive (negative), move point forward (backwards) this many
parts.  When nil, redisplay article."
  :version "23.1" ;; No Gnus
  :group 'gnus-article-mime
  :type '(choice (const nil :tag "Redisplay article.")
                 (const 1 :tag "Next part.")
                 (const 0 :tag "Current part.")
                 integer))

;;;
;;; 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 "First" first)
           (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" "text/x-verbatim"
                                   "text/x-patch" "text/html")
  "Part types eligible for treatment.")

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

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

(defcustom gnus-treat-buttonize '(and 100000 (typep "text/plain"))
  "Add buttons.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-buttonize-head 'highlight t)

(defcustom gnus-treat-date 'head
  "Display dates according to the `gnus-article-date-headers' variable.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "24.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-emphasize 50000
  "Emphasize text.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-unsplit-urls nil
  "Remove newlines from within URLs.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-leading-whitespace nil
  "Remove leading whitespace in headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-headers 'head
  "Hide headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-head-custom)

(defcustom gnus-treat-hide-boring-headers nil
  "Hide boring headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-head-custom)

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

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

(defcustom gnus-treat-hide-citation nil
  "Hide cited text.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'.

See `gnus-article-highlight-citation' for variables used to
control what it hides."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-hide-citation-maybe nil
  "Hide cited text according to certain conditions.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'.

See `gnus-cite-hide-percentage' and `gnus-cite-hide-absolute' for
how to control what it hides."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "21.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(gnus-define-group-parameter
 list-identifier
 :variable-document
 "Alist of regexps and correspondent identifiers."
 :variable-group gnus-article-washing
 :parameter-type
 '(choice :tag "Identifier"
          :value nil
          (symbol :tag "Item in `gnus-list-identifiers'" none)
          regexp
          (const :tag "None" nil))
 :parameter-document
 "If non-nil, specify how to remove `identifiers' from articles' subject.

Any symbol is used to look up a regular expression to match the
banner in `gnus-list-identifiers'.  A string is used as a regular
expression to match the identifier directly.")

(make-obsolete-variable 'gnus-treat-strip-pgp nil
                        "Gnus 5.10 (Emacs 22.1)")

(defcustom gnus-treat-strip-pem nil
  "Strip PEM signatures.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-highlight-headers 'head
  "Highlight the headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)
(put 'gnus-treat-highlight-citation 'highlight t)

(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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "21.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-trailing-blank-lines nil
  "Strip trailing blank lines.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'.

When set to t, it also strips trailing blanks in all MIME parts.
Consider to use `last' instead."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-leading-blank-lines nil
  "Strip leading blank lines.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'.

When set to t, it also strips trailing blanks in all MIME parts."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-strip-multiple-blank-lines nil
  "Strip multiple blank lines.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-unfold-headers 'head
  "Unfold folded header lines.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-article-unfold-long-headers nil
  "If non-nil, allow unfolding headers even if the header is long.
If it is a regexp, only long headers matching this regexp are unfolded.
If it is t, all long headers are unfolded.

This variable has no effect if `gnus-treat-unfold-headers' is nil."
  :version "23.1" ;; No Gnus
  :group 'gnus-article-treat
  :type '(choice (const nil)
                 (const :tag "all" t)
                 (regexp)))

(defcustom gnus-treat-fold-headers nil
  "Fold headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-fold-newsgroups 'head
  "Fold the Newsgroups and Followup-To headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-overstrike t
  "Treat overstrike highlighting.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)
(put 'gnus-treat-overstrike 'highlight t)

(defcustom gnus-treat-ansi-sequences (if (locate-library "ansi-color") t)
  "Treat ANSI SGR control sequences.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(make-obsolete-variable 'gnus-treat-display-xface
                        'gnus-treat-display-x-face "Emacs 22.1")

(defcustom gnus-treat-display-x-face
  (and (not noninteractive)
       (gnus-image-type-available-p 'xbm)
       (if (featurep 'xemacs)
           (featurep 'xface)
         (condition-case nil
             (and (string-match "^0x" (shell-command-to-string "uncompface"))
                  (executable-find "icontopbm"))
           ;; shell-command-to-string may signal an error, e.g. if
           ;; shell-file-name is not found.
           (error nil)))
       'head)
  "Display X-Face headers.
Valid values are nil and `head'.
See Info node `(gnus)Customizing Articles' and Info node
`(gnus)X-Face' for details."
  :group 'gnus-article-treat
  :version "21.1"
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)X-Face")
  :type gnus-article-treat-head-custom
  :set (lambda (symbol value)
         (set-default
          symbol
          (cond ((or (boundp symbol) (get symbol 'saved-value))
                 value)
                ((boundp 'gnus-treat-display-xface)
                 (message "\
** gnus-treat-display-xface is an obsolete variable;\
 use gnus-treat-display-x-face instead")
                 (default-value 'gnus-treat-display-xface))
                ((get 'gnus-treat-display-xface 'saved-value)
                 (message "\
** gnus-treat-display-xface is an obsolete variable;\
 use gnus-treat-display-x-face instead")
                 (eval (car (get 'gnus-treat-display-xface 'saved-value))))
                (t
                 value)))))
(put 'gnus-treat-display-x-face 'highlight t)

(defcustom gnus-treat-display-face
  (and (not noninteractive)
       (gnus-image-type-available-p 'png)
       'head)
  "Display Face headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Face' for details."
  :group 'gnus-article-treat
  :version "22.1"
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)X-Face")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-display-face 'highlight t)

(defcustom gnus-treat-display-smileys (gnus-image-type-available-p 'xpm)
  "Display smileys.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Smileys' for details."
  :group 'gnus-article-treat
  :version "21.1"
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Smileys")
  :type gnus-article-treat-custom)
(put 'gnus-treat-display-smileys 'highlight t)

(defcustom gnus-treat-from-picon
  (if (and (gnus-image-type-available-p 'xpm)
           (gnus-picons-installed-p))
      'head nil)
  "Display picons in the From header.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Picons' for details."
  :version "22.1"
  :group 'gnus-article-treat
  :group 'gnus-picon
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Picons")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-from-picon 'highlight t)

(defcustom gnus-treat-mail-picon
  (if (and (gnus-image-type-available-p 'xpm)
           (gnus-picons-installed-p))
      'head nil)
  "Display picons in To and Cc headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Picons' for details."
  :version "22.1"
  :group 'gnus-article-treat
  :group 'gnus-picon
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Picons")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-mail-picon 'highlight t)

(defcustom gnus-treat-newsgroups-picon
  (if (and (gnus-image-type-available-p 'xpm)
           (gnus-picons-installed-p))
      'head nil)
  "Display picons in the Newsgroups and Followup-To headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Picons' for details."
  :version "22.1"
  :group 'gnus-article-treat
  :group 'gnus-picon
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Picons")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-newsgroups-picon 'highlight t)

(defcustom gnus-treat-from-gravatar nil
  "Display gravatars in the From header.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Gravatars' for details."
  :version "24.1"
  :group 'gnus-article-treat
  :group 'gnus-gravatar
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Gravatars")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-from-gravatar 'highlight t)

(defcustom gnus-treat-mail-gravatar nil
  "Display gravatars in To and Cc headers.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles' and Info
node `(gnus)Gravatars' for details."
  :version "24.1"
  :group 'gnus-article-treat
  :group 'gnus-gravatar
  :link '(custom-manual "(gnus)Customizing Articles")
  :link '(custom-manual "(gnus)Gravatars")
  :type gnus-article-treat-head-custom)
(put 'gnus-treat-mail-gravatar 'highlight t)

(defcustom gnus-treat-body-boundary
  (if (or gnus-treat-newsgroups-picon
          gnus-treat-mail-picon
          gnus-treat-from-picon
          gnus-treat-from-gravatar
          gnus-treat-mail-gravatar)
      ;; If there's much decoration, the user might prefer a boundary.
      'head
    nil)
  "Draw a boundary at the end of the headers.
Valid values are nil and `head'.
See Info node `(gnus)Customizing Articles' for details."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-head-custom)

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

(defcustom gnus-treat-wash-html nil
  "Format as HTML.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :type gnus-article-treat-custom)

(defcustom gnus-treat-fill-long-lines '(typep "text/plain")
  "Fill long lines.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "24.1"
  :group 'gnus-article-treat
  :link '(custom-manual "(gnus)Customizing Articles")
  :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', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "22.1"
  :group 'gnus-article-treat
  :group 'mime-security
  :link '(custom-manual "(gnus)Customizing Articles")
  :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."
  :version "22.1"
  :type 'string
  :group 'mime-security)

(defvar idna-program)

(defcustom gnus-use-idna (and (condition-case nil (require 'idna) (file-error))
                              (mm-coding-system-p 'utf-8)
                              idna-program
                              (executable-find idna-program))
  "Whether IDNA decoding of headers is used when viewing messages.
This requires GNU Libidn, and by default only enabled if it is found."
  :version "22.1"
  :group 'gnus-article-headers
  :type 'boolean)

(defcustom gnus-article-over-scroll nil
  "If non-nil, allow scrolling the article buffer even when there no more text."
  :version "22.1"
  :group 'gnus-article
  :type 'boolean)

(defcustom gnus-inhibit-images nil
  "Non-nil means inhibit displaying of images inline in the article body."
  :version "24.1"
  :group 'gnus-article
  :type 'boolean)

(defcustom gnus-blocked-images 'gnus-block-private-groups
  "Images that have URLs matching this regexp will be blocked.
This can also be a function to be evaluated.  If so, it will be
called with the group name as the parameter, and should return a
regexp."
  :version "24.1"
  :group 'gnus-art
  :type '(choice regexp function))

;;; 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-image-alist nil)

(defvar gnus-article-mime-handle-alist-1 nil)
(defvar gnus-treatment-function-alist
  '((gnus-treat-strip-cr gnus-article-remove-cr)
    (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-cited-long-lines)
    (gnus-treat-unsplit-urls gnus-article-unsplit-urls)
    (gnus-treat-display-x-face gnus-article-display-x-face)
    (gnus-treat-display-face gnus-article-display-face)
    (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-strip-list-identifiers gnus-article-hide-list-identifiers)
    (gnus-treat-leading-whitespace gnus-article-remove-leading-whitespace)
    (gnus-treat-from-picon gnus-treat-from-picon)
    (gnus-treat-mail-picon gnus-treat-mail-picon)
    (gnus-treat-newsgroups-picon gnus-treat-newsgroups-picon)
    (gnus-treat-strip-pem gnus-article-hide-pem)
    (gnus-treat-date gnus-article-treat-date)
    (gnus-treat-from-gravatar gnus-treat-from-gravatar)
    (gnus-treat-mail-gravatar gnus-treat-mail-gravatar)
    (gnus-treat-highlight-headers gnus-article-highlight-headers)
    (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-ansi-sequences gnus-article-treat-ansi-sequences)
    (gnus-treat-unfold-headers gnus-article-treat-unfold-headers)
    (gnus-treat-fold-newsgroups gnus-article-treat-fold-newsgroups)
    (gnus-treat-fold-headers gnus-article-treat-fold-headers)
    (gnus-treat-buttonize-head gnus-article-add-buttons-to-head)
    (gnus-treat-display-smileys gnus-treat-smiley)
    (gnus-treat-capitalize-sentences gnus-article-capitalize-sentences)
    (gnus-treat-wash-html gnus-article-wash-html)
    (gnus-treat-emphasize gnus-article-emphasize)
    (gnus-treat-hide-citation gnus-article-hide-citation)
    (gnus-treat-hide-citation-maybe gnus-article-hide-citation-maybe)
    (gnus-treat-highlight-citation gnus-article-highlight-citation)
    (gnus-treat-body-boundary gnus-article-treat-body-boundary)))

(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)
    ;; make M-. in article buffers work for `foo' strings
    (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-number-of-articles-to-be-saved nil)

(defvar gnus-inhibit-hiding nil)

(defvar gnus-article-edit-mode nil)

;;; Macros for dealing with the article buffer.

(defmacro gnus-with-article-headers (&rest forms)
  `(with-current-buffer gnus-article-buffer
     (save-restriction
       (let ((inhibit-read-only t)
             (inhibit-point-motion-hooks t)
             (case-fold-search t))
         (article-narrow-to-head)
         ,@forms))))

(put 'gnus-with-article-headers 'lisp-indent-function 0)
(put 'gnus-with-article-headers 'edebug-form-spec '(body))

(defmacro gnus-with-article-buffer (&rest forms)
  `(when (buffer-live-p (get-buffer gnus-article-buffer))
     (with-current-buffer gnus-article-buffer
       (let ((inhibit-read-only t))
         ,@forms))))

(put 'gnus-with-article-buffer 'lisp-indent-function 0)
(put 'gnus-with-article-buffer 'edebug-form-spec '(body))

(defun gnus-article-goto-header (header)
  "Go to HEADER, which is a regular expression."
  (re-search-forward (concat "^\\(" header "\\):") nil t))

(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."
  (gnus-add-wash-type type)
  (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."
  (gnus-delete-wash-type type)
  (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-delete-text-of-type (type)
  "Delete text of TYPE in the current buffer."
  (save-excursion
    (let ((b (point-min)))
      (if (eq type 'multipart)
          ;; Remove MIME buttons associated with multipart/alternative parts.
          (progn
            (goto-char b)
            (while (if (get-text-property (point) 'gnus-part)
                       (setq b (point))
                     (when (setq b (next-single-property-change (point)
                                                                'gnus-part))
                       (goto-char b)
                       t))
              (end-of-line)
              (skip-chars-forward "\n")
              (when (eq (get-text-property b 'article-type) 'multipart)
                (delete-region b (point)))))
        (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)))))))

(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 1))
    (while list
      (if (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
    (let ((inhibit-read-only t)
          (case-fold-search t)
          (max (1+ (length gnus-sorted-header-list)))
          (inhibit-point-motion-hooks t)
          (cur (current-buffer))
          ignored visible beg)
      (save-excursion
        ;; `gnus-ignored-headers' and `gnus-visible-headers' may be
        ;; group parameters, so we should go to the summary buffer.
        (when (prog1
                  (condition-case nil
                      (progn (set-buffer gnus-summary-buffer) t)
                    (error nil))
                (setq 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
                                                "\\|")))))
          (set-buffer cur))
        (save-restriction
          ;; 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.
            (gnus-add-wash-type 'headers)
            (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 ((inhibit-read-only t)
              (inhibit-point-motion-hooks t))
          (article-narrow-to-head)
          (dolist (elem gnus-boring-article-headers)
            (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
                 (point-at-bol)
                 (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 'to-list)
              (let ((to (message-fetch-field "to"))
                    (to-list
                     (gnus-parameter-to-list
                      (if (boundp 'gnus-newsgroup-name)
                          gnus-newsgroup-name ""))))
                (when (and to to-list
                           (ignore-errors
                             (gnus-string-equal
                              ;; only one address in To
                              (nth 1 (mail-extract-address-components to))
                              to-list)))
                  (gnus-article-hide-header "to"))))
             ((eq elem 'cc-list)
              (let ((cc (message-fetch-field "cc"))
                    (to-list
                     (gnus-parameter-to-list
                      (if (boundp 'gnus-newsgroup-name)
                          gnus-newsgroup-name ""))))
                (when (and cc to-list
                           (ignore-errors
                             (gnus-string-equal
                              ;; only one address in CC
                              (nth 1 (mail-extract-address-components cc))
                              to-list)))
                  (gnus-article-hide-header "cc"))))
             ((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)
              (if (gnus-group-find-parameter
                   gnus-newsgroup-name 'broken-reply-to)
                  (gnus-article-hide-header "reply-to")
                (let ((from (message-fetch-field "from"))
                      (reply-to (message-fetch-field "reply-to")))
                  (when
                      (and
                       from reply-to
                       (ignore-errors
                         (equal
                          (sort (mapcar
                                 (lambda (x) (downcase (cadr x)))
                                 (mail-extract-address-components from t))
                                'string<)
                          (sort (mapcar
                                 (lambda (x) (downcase (cadr x)))
                                 (mail-extract-address-components reply-to t))
                                'string<))))
                    (gnus-article-hide-header "reply-to")))))
             ((eq elem 'date)
              (let ((date (with-current-buffer gnus-original-article-buffer
                            ;; If date in `gnus-article-buffer' is localized
                            ;; (`gnus-treat-date-user-defined'),
                            ;; `days-between' might fail.
                            (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
       (point-at-bol)
       (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 ((inhibit-read-only t)
        column)
    (save-excursion
      (save-restriction
        (article-narrow-to-head)
        (while (not (eobp))
          (cond
           ((< (setq column (- (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))
             (point-at-eol)
             'invisible t))
           (t
            ;; Do nothing.
            ))
          (forward-line 1))))))

(defun article-treat-dumbquotes ()
  "Translate M****s*** sm*rtq**t*s and other symbols 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
iso-8859-1 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))

(defvar org-entities)

(defun article-treat-non-ascii ()
  "Translate many Unicode characters into their ASCII equivalents."
  (interactive)
  (require 'org-entities)
  (let ((table (make-char-table (if (featurep 'xemacs) 'generic))))
    (dolist (elem org-entities)
      (when (and (listp elem)
                 (= (length (nth 6 elem)) 1))
        (if (featurep 'xemacs)
            (put-char-table (aref (nth 6 elem) 0) (nth 4 elem) table)
          (set-char-table-range table (aref (nth 6 elem) 0) (nth 4 elem)))))
    (save-excursion
      (when (article-goto-body)
        (let ((inhibit-read-only t)
              replace props)
          (while (not (eobp))
            (if (not (setq replace (if (featurep 'xemacs)
                                       (get-char-table (following-char) table)
                                     (aref table (following-char)))))
                (forward-char 1)
              (if (prog1
                      (setq props (text-properties-at (point)))
                    (delete-char 1))
                  (add-text-properties (point) (progn (insert replace) (point))
                                       props)
                (insert replace)))))))))

(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 ((inhibit-read-only t))
        (dolist (elem map)
          (let ((from (car elem))
                (to (cadr elem)))
            (save-excursion
              (if (stringp from)
                  (while (search-forward from nil t)
                    (replace-match to))
                (while (not (eobp))
                  (if (eq (following-char) from)
                      (progn
                        (delete-char 1)
                        (insert to))
                    (forward-char 1)))))))))))

(defun article-treat-overstrike ()
  "Translate overstrikes into bold text."
  (interactive)
  (save-excursion
    (when (article-goto-body)
      (let ((inhibit-read-only t))
        (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-treat-ansi-sequences ()
  "Translate ANSI SGR control sequences into overlays or extents."
  (interactive)
  (save-excursion
    (when (article-goto-body)
      (let ((inhibit-read-only t))
        (ansi-color-apply-on-region (point) (point-max))))))

(defun gnus-article-treat-unfold-headers ()
  "Unfold folded message headers.
Only the headers that fit into the current window width will be
unfolded."
  (interactive)
  (gnus-with-article-headers
    (let (length)
      (while (not (eobp))
        (save-restriction
          (mail-header-narrow-to-field)
          (let* ((header (buffer-string))
                 (unfoldable
                  (or (equal gnus-article-unfold-long-headers t)
                      (and (stringp gnus-article-unfold-long-headers)
                           (string-match gnus-article-unfold-long-headers
                                         header)))))
            (with-temp-buffer
              (insert header)
              (goto-char (point-min))
              (while (re-search-forward "\n[\t ]" nil t)
                (replace-match " " t t)))
            (setq length (- (point-max) (point-min) 1))
            (when (or unfoldable
                      (< length (window-width)))
              (while (re-search-forward "\n[\t ]" nil t)
                (replace-match " " t t))))
          (goto-char (point-max)))))))

(defun gnus-article-treat-fold-headers ()
  "Fold message headers."
  (interactive)
  (gnus-with-article-headers
    (while (not (eobp))
      (save-restriction
        (mail-header-narrow-to-field)
        (mail-header-fold-field)
        (goto-char (point-max))))))

(defun gnus-treat-smiley ()
  "Toggle display of textual emoticons (\"smileys\") as small graphical icons."
  (interactive)
  (gnus-with-article-buffer
    (if (memq 'smiley gnus-article-wash-types)
        (gnus-delete-images 'smiley)
      (article-goto-body)
      (let ((images (smiley-region (point) (point-max))))
        (when images
          (gnus-add-wash-type 'smiley)
          (dolist (image images)
            (gnus-add-image 'smiley image)))))))

(defun gnus-article-remove-images ()
  "Remove all images from the article buffer."
  (interactive)
  (gnus-with-article-buffer
    (save-restriction
      (widen)
      (dolist (elem gnus-article-image-alist)
        (gnus-delete-images (car elem))))))

(autoload 'w3m-toggle-inline-images "w3m")

(defun gnus-article-show-images ()
  "Show any images that are in the HTML-rendered article buffer.
This only works if the article in question is HTML."
  (interactive)
  (gnus-with-article-buffer
    (save-restriction
      (widen)
      (if (eq mm-text-html-renderer 'w3m)
          (let ((mm-inline-text-html-with-images nil))
            (w3m-toggle-inline-images))
        (dolist (region (gnus-find-text-property-region (point-min) (point-max)
                                                        'image-displayer))
          (destructuring-bind (start end function) region
            (funcall function (get-text-property start 'image-url)
                     start end)))))))

(defun gnus-article-treat-fold-newsgroups ()
  "Unfold folded message headers.
Only the headers that fit into the current window width will be
unfolded."
  (interactive)
  (gnus-with-article-headers
    (while (gnus-article-goto-header "newsgroups\\|followup-to")
      (save-restriction
        (mail-header-narrow-to-field)
        (while (re-search-forward ", *" nil t)
          (replace-match ", " t t))
        (mail-header-fold-field)
        (goto-char (point-max))))))

(defcustom gnus-article-truncate-lines (default-value 'truncate-lines)
  "Value of `truncate-lines' in Gnus Article buffer.
Valid values are nil, t, `head', `first', `last', an integer or a
predicate.  See Info node `(gnus)Customizing Articles'."
  :version "23.1" ;; No Gnus
  :group 'gnus-article
  ;; :link '(custom-manual "(gnus)Customizing Articles")
  :type 'boolean)

(defun gnus-article-toggle-truncate-lines (&optional arg)
  "Toggle whether to fold or truncate long lines in article the buffer.
If ARG is non-nil and not a number, toggle
`gnus-article-truncate-lines' too.  If ARG is a number, truncate
long lines if and only if arg is positive."
  (interactive "P")
  (cond
   ((and (numberp arg) (> arg 0))
    (setq gnus-article-truncate-lines t))
   ((numberp arg)
    (setq gnus-article-truncate-lines nil))
   (arg
    (setq gnus-article-truncate-lines
          (not gnus-article-truncate-lines))))
  (gnus-with-article-buffer
    (cond
     ((and (numberp arg) (> arg 0))
      (setq truncate-lines nil))
     ((numberp arg)
      (setq truncate-lines t)))
    ;; In versions of Emacs 22 (CVS) before 2006-05-26,
    ;; `toggle-truncate-lines' needs an argument.
    (toggle-truncate-lines)))

(defun gnus-article-treat-body-boundary ()
  "Place a boundary line at the end of the headers."
  (interactive)
  (when (and gnus-body-boundary-delimiter
             (> (length gnus-body-boundary-delimiter) 0))
    (gnus-with-article-headers
      (goto-char (point-max))
      (let ((start (point)))
        (insert "X-Boundary: ")
        (gnus-add-text-properties start (point) '(invisible t intangible t))
       (insert (let (str (max (window-width)))
                 (if (featurep 'xemacs)
                     (setq max (1- max)))
                 (while (>= max (length str))
                    (setq str (concat str gnus-body-boundary-delimiter)))
                 (substring str 0 max))
                "\n")
        (gnus-put-text-property start (point) 'gnus-decoration 'header)))))

(defun article-fill-long-lines ()
  "Fill lines that are wider than the window width."
  (interactive)
  (save-excursion
    (let ((inhibit-read-only t)
          (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 (min (1+ (point)) (point-max))
                                (point-at-bol))
              (let ((goback (point-marker)))
                (fill-paragraph nil)
                (goto-char (marker-position goback)))
              (widen))
            (forward-line 1)))))))

(defun article-capitalize-sentences ()
  "Capitalize the first word in each sentence."
  (interactive)
  (save-excursion
    (let ((inhibit-read-only t)
          (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 ((inhibit-read-only t))
      (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 ((inhibit-read-only t))
      (goto-char (point-max))
      (delete-region
       (point)
       (progn
         (while (and (not (bobp))
                     (looking-at "^[ \t]*$")
                     (not (gnus-annotation-in-region-p
                           (point) (point-at-eol))))
           (forward-line -1))
         (forward-line 1)
         (point))))))

(defvar gnus-face-properties-alist)

(defun article-display-face (&optional force)
  "Display any Face headers in the header."
  (interactive (list 'force))
  (let ((wash-face-p buffer-read-only))
    (gnus-with-article-headers
      ;; When displaying parts, this function can be called several times on
      ;; the same article, without any intended toggle semantic (as typing `W
      ;; D d' would have). So face deletion must occur only when we come from
      ;; an interactive command, that is when the *Article* buffer is
      ;; read-only.
      (if (and wash-face-p (memq 'face gnus-article-wash-types))
          (gnus-delete-images 'face)
        (let ((from (message-fetch-field "from"))
              faces)
          (save-current-buffer
            (when (and wash-face-p
                       (gnus-buffer-live-p gnus-original-article-buffer)
                       (not (re-search-forward "^Face:[\t ]*" nil t)))
              (set-buffer gnus-original-article-buffer))
            (save-restriction
              (mail-narrow-to-head)
              (when (or force
                        ;; Check whether this face is censored.
                        (not (and gnus-article-x-face-too-ugly
                                  (or from
                                      (setq from (message-fetch-field "from")))
                                  (string-match gnus-article-x-face-too-ugly
                                                from))))
                (while (gnus-article-goto-header "Face")
                  (push (mail-header-field-value) faces)))))
          (when faces
            (goto-char (point-min))
            (let (png image)
              (unless (setq from (gnus-article-goto-header "from"))
                (insert "From:")
                (setq from (point))
                (insert " [no `from' set]\n"))
              (while faces
                (when (setq png (gnus-convert-face-to-png (pop faces)))
                  (setq image
                        (apply 'gnus-create-image png 'png t
                               (cdr (assq 'png gnus-face-properties-alist))))
                  (goto-char from)
                  (when image
                    (gnus-add-wash-type 'face)
                    (gnus-add-image 'face image)
                    (gnus-put-image image nil 'face)))))))))))

(defun article-display-x-face (&optional force)
  "Look for an X-Face header and display it if present."
  (interactive (list 'force))
  (let ((wash-face-p buffer-read-only)) ;; When type `W f'
    (gnus-with-article-headers
      ;; Delete the old process, if any.
      (when (process-status "article-x-face")
        (delete-process "article-x-face"))
      ;; See the comment in `article-display-face'.
      (if (and wash-face-p (memq 'xface gnus-article-wash-types))
          ;; We have already displayed X-Faces, so we remove them
          ;; instead.
          (gnus-delete-images 'xface)
        ;; Display X-Faces.
        (let ((from (message-fetch-field "from"))
              x-faces)
          (save-current-buffer
            (when (and wash-face-p
                       (gnus-buffer-live-p gnus-original-article-buffer)
                       (not (re-search-forward "^X-Face:[\t ]*" nil t)))
              ;; If type `W f', use gnus-original-article-buffer,
              ;; otherwise use the current buffer because displaying
              ;; RFC822 parts calls this function too.
              (set-buffer gnus-original-article-buffer))
            (save-restriction
              (mail-narrow-to-head)
              (and gnus-article-x-face-command
                   (or force
                       ;; Check whether this face is censored.
                       (not (and gnus-article-x-face-too-ugly
                                 (or from
                                     (setq from (message-fetch-field "from")))
                                 (string-match gnus-article-x-face-too-ugly
                                               from))))
                   (while (gnus-article-goto-header "X-Face")
                     (push (mail-header-field-value) x-faces)))))
          (when x-faces
            ;; We display the face.
            (cond ((functionp gnus-article-x-face-command)
                   ;; The command is a lisp function, so we call it.
                   (mapc gnus-article-x-face-command x-faces))
                  ((stringp 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))
                     (gnus-set-process-query-on-exit-flag
                      (start-process
                       "article-x-face" nil shell-file-name
                       shell-command-switch gnus-article-x-face-command)
                      nil)
                     ;; Sending multiple EOFs to xv doesn't work,
                     ;; so we only do a single external face.
                     (with-temp-buffer
                       (insert (car x-faces))
                       (process-send-region "article-x-face"
                                            (point-min) (point-max)))
                     (process-send-eof "article-x-face")))
                  (t
                   (error "`%s' set to `%s' is not a function"
                          gnus-article-x-face-command
                          'gnus-article-x-face-command)))))))))

(defun article-decode-mime-words ()
  "Decode all MIME-encoded words in the article."
  (interactive)
  (gnus-with-article-buffer
    (let ((inhibit-point-motion-hooks t)
          (mail-parse-charset gnus-newsgroup-charset)
          (mail-parse-ignored-charsets
           (with-current-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)
        (inhibit-read-only 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))
        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 (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))
        (inhibit-read-only t)
        end start)
    (goto-char (point-min))
    (when (search-forward "\n\n" nil 'move)
      (forward-line -1))
    (setq end (point))
    (while (not (bobp))
      (while (progn
               (forward-line -1)
               (and (not (bobp))
                    (memq (char-after) '(?\t ? )))))
      (setq start (point))
      (if (looking-at "\
\\(?:Resent-\\)?\\(?:From\\|Cc\\|To\\|Bcc\\|\\(?:In-\\)?Reply-To\\|Sender\
\\|Mail-Followup-To\\|Mail-Copies-To\\|Approved\\):")
          (funcall gnus-decode-address-function start end)
        (funcall gnus-decode-header-function start end))
      (goto-char (setq end start)))))

(defun article-decode-group-name ()
  "Decode group names in Newsgroups, Followup-To and Xref headers."
  (let ((inhibit-point-motion-hooks t)
        (inhibit-read-only t)
        (method (gnus-find-method-for-group gnus-newsgroup-name))
        regexp)
    (when (and (or gnus-group-name-charset-method-alist
                   gnus-group-name-charset-group-alist)
               (gnus-buffer-live-p gnus-original-article-buffer))
      (save-restriction
        (article-narrow-to-head)
        (dolist (header '("Newsgroups" "Followup-To" "Xref"))
          (with-current-buffer gnus-original-article-buffer
            (goto-char (point-min)))
          (setq regexp (concat "^" header
                               ":\\([^\n]*\\(?:\n[\t ]+[^\n]+\\)*\\)\n"))
          (while (re-search-forward regexp nil t)
            (replace-match (save-match-data
                             (gnus-decode-newsgroups
                              ;; XXX how to use data in article buffer?
                              (with-current-buffer gnus-original-article-buffer
                                (re-search-forward regexp nil t)
                                (match-string 1))
                              gnus-newsgroup-name method))
                           t t nil 1))
          (goto-char (point-min)))))))

(autoload 'idna-to-unicode "idna")

(defun article-decode-idna-rhs ()
  "Decode IDNA strings in RHS in various headers in current buffer.
The following headers are decoded: From:, To:, Cc:, Reply-To:,
Mail-Reply-To: and Mail-Followup-To:."
  (when gnus-use-idna
    (save-restriction
      (let ((inhibit-point-motion-hooks t)
            (inhibit-read-only t))
        (article-narrow-to-head)
        (goto-char (point-min))
        (while (re-search-forward "@[^ \t\n\r,>]*\\(xn--[-A-Za-z0-9.]*\\)[ \t\n\r,>]" nil t)
          (let (ace unicode)
            (when (save-match-data
                    (and (setq ace (match-string 1))
                         (save-excursion
                           (and (re-search-backward "^[^ \t]" nil t)
                                (looking-at "From\\|To\\|Cc\\|Reply-To\\|Mail-Reply-To\\|Mail-Followup-To")))
                         (setq unicode (idna-to-unicode ace))))
              (unless (string= ace unicode)
                (replace-match unicode nil nil nil 1)))))))))

(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 ((inhibit-read-only t) 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 (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 nil t))))))

(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 ((inhibit-read-only t) 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 (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 nil t)))))))

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

(defun article-decode-HZ ()
  "Translate a HZ-encoded article."
  (interactive)
  (require 'rfc1843)
  (save-excursion
    (let ((inhibit-read-only t))
      (rfc1843-decode-region (point-min) (point-max)))))

(defun article-unsplit-urls ()
  "Remove the newlines that some other mailers insert into URLs."
  (interactive)
  (save-excursion
    (let ((inhibit-read-only t))
      (goto-char (point-min))
      (while (re-search-forward
              "\\(\\(https?\\|ftp\\)://\\S-+\\) *\n\\(\\S-+\\)" nil t)
        (replace-match "\\1\\3" t)))
    (when (gmm-called-interactively-p 'any)
      (gnus-treat-article nil))))

(defun article-wash-html ()
  "Format an HTML article."
  (interactive)
  (let ((handles nil)
        (buffer-read-only nil))
    (when (gnus-buffer-live-p gnus-original-article-buffer)
      (with-current-buffer gnus-original-article-buffer
        (setq handles (mm-dissect-buffer t t))))
    (article-goto-body)
    (delete-region (point) (point-max))
    (mm-enable-multibyte)
    (mm-inline-text-html handles)))

(defvar gnus-article-browse-html-temp-list nil
  "List of temporary files created by `gnus-article-browse-html-parts'.
Internal variable.")

(defcustom gnus-article-browse-delete-temp 'ask
  "What to do with temporary files from `gnus-article-browse-html-parts'.
If nil, don't delete temporary files.  If it is t, delete them on
exit from the summary buffer.  If it is the symbol `file', query
on each file, if it is `ask' ask once when exiting from the
summary buffer."
  :group 'gnus-article
  :version "23.1" ;; No Gnus
  :type '(choice (const :tag "Don't delete" nil)
                 (const :tag "Don't ask" t)
                 (const :tag "Ask" ask)
                 (const :tag "Ask for each file" file)))

;; Cf. mm-postponed-undisplay-list / mm-destroy-postponed-undisplay-list.

(defun gnus-article-browse-delete-temp-files (&optional how)
  "Delete temp-files created by `gnus-article-browse-html-parts'."
  (when (and gnus-article-browse-html-temp-list
             (progn
               (or how (setq how gnus-article-browse-delete-temp))
               (if (eq how 'ask)
                   (let ((files (length gnus-article-browse-html-temp-list)))
                     (or (gnus-y-or-n-p
                          (if (= files 1)
                              "Delete the temporary HTML file? "
                            (format "Delete all %s temporary HTML files? "
                                    files)))
                         (setq gnus-article-browse-html-temp-list nil)))
                 how)))
    (dolist (file gnus-article-browse-html-temp-list)
      (cond ((file-directory-p file)
             (when (or (not (eq how 'file))
                       (gnus-y-or-n-p
                        (format
                         "Delete temporary HTML file(s) in directory `%s'? "
                         (file-name-as-directory file))))
               (gnus-delete-directory file)))
            ((file-exists-p file)
             (when (or (not (eq how 'file))
                       (gnus-y-or-n-p
                        (format "Delete temporary HTML file `%s'? " file)))
               (delete-file file)))))
    ;; Also remove file from the list when not deleted or if file doesn't
    ;; exist anymore.
    (setq gnus-article-browse-html-temp-list nil))
  gnus-article-browse-html-temp-list)

(defun gnus-article-browse-html-save-cid-content (cid handles directory abs)
  "Find CID content in HANDLES and save it in a file in DIRECTORY.
Return absolute file name if ABS is non-nil, otherwise relative to
the parent of DIRECTORY."
  (save-match-data
    (let (file afile)
      (catch 'found
        (dolist (handle handles)
          (cond
           ((not (listp handle)))
           ;; Exclude broken handles that `gnus-summary-enter-digest-group'
           ;; may create.
           ((not (or (bufferp (car handle)) (stringp (car handle)))))
           ((equal (mm-handle-media-supertype handle) "multipart")
            (when (setq file (gnus-article-browse-html-save-cid-content
                              cid handle directory abs))
              (throw 'found file)))
           ((equal (concat "<" cid ">") (mm-handle-id handle))
            (setq file (or (mm-handle-filename handle)
                           (concat
                            (make-temp-name "cid")
                            (car (rassoc (car (mm-handle-type handle))
                                         mailcap-mime-extensions))))
                  afile (expand-file-name file directory))
            (mm-save-part-to-file handle afile)
            (throw 'found (if abs
                              afile
                            (concat (file-name-nondirectory
                                     (directory-file-name directory))
                                    "/" file))))))))))

(defun gnus-article-browse-html-parts (list &optional header)
  "View all \"text/html\" parts from LIST.
Recurse into multiparts.  The optional HEADER that should be a decoded
message header will be added to the bodies of the \"text/html\" parts."
  ;; Internal function used by `gnus-article-browse-html-article'.
  (let (type file charset content cid-dir tmp-file showed)
    ;; Find and show the html-parts.
    (dolist (handle list)
      ;; If HTML, show it:
      (cond ((not (listp handle)))
            ((or (equal (car (setq type (mm-handle-type handle))) "text/html")
                 (and (equal (car type) "message/external-body")
                      (or header
                          (setq file (mm-handle-filename handle)))
                      (or (mm-handle-cache handle)
                          (condition-case code
                              (progn (mm-extern-cache-contents handle) t)
                            (error
                             (gnus-message 3 "%s" (error-message-string code))
                             (when (>= gnus-verbose 3) (sit-for 2))
                             nil)))
                      (progn
                        (setq handle (mm-handle-cache handle)
                              type (mm-handle-type handle))
                        (equal (car type) "text/html"))))
             (setq charset (mail-content-type-get type 'charset)
                   content (mm-get-part handle))
             (with-temp-buffer
               (if (eq charset 'gnus-decoded)
                   (mm-enable-multibyte)
                 (mm-disable-multibyte))
               (insert content)
               ;; resolve cid contents
               (let ((case-fold-search t)
                     abs st cid-file)
                 (goto-char (point-min))
                 (when (re-search-forward "<head[\t\n >]" nil t)
                   (setq st (match-end 0)
                         abs (or
                              (not (re-search-forward "</head[\t\n >]" nil t))
                              (re-search-backward "<base[\t\n >]" st t))))
                 (while (re-search-forward "\
<img[\t\n ]+\\(?:[^\t\n >]+[\t\n ]+\\)*src=\"\\(cid:\\([^\"]+\\)\\)\""
                                           nil t)
                   (unless cid-dir
                     (setq cid-dir (mm-make-temp-file "cid" t))
                     (add-to-list 'gnus-article-browse-html-temp-list cid-dir))
                   (setq file nil
                         content nil)
                   (when (setq cid-file
                               (gnus-article-browse-html-save-cid-content
                                (match-string 2)
                                (with-current-buffer gnus-article-buffer
                                  gnus-article-mime-handles)
                                cid-dir abs))
                     (when abs
                       (setq cid-file
                             (if (eq system-type 'cygwin)
                                 (concat "file:///"
                                         (substring
                                          (with-output-to-string
                                            (call-process "cygpath" nil
                                                          standard-output
                                                          nil "-m" cid-file))
                                          0 -1))
                               (concat "file://" cid-file))))
                     (replace-match cid-file nil nil nil 1))))
               (unless content (setq content (buffer-string))))
             (when (or charset header (not file))
               (setq tmp-file (mm-make-temp-file
                               ;; Do we need to care for 8.3 filenames?
                               "mm-" nil ".html")))
             ;; Add a meta html tag to specify charset and a header.
             (cond
              (header
               (let (title eheader body hcharset coding)
                 (with-temp-buffer
                   (mm-enable-multibyte)
                   (setq case-fold-search t)
                   (insert header "\n")
                   (setq title (message-fetch-field "subject"))
                   (goto-char (point-min))
                   (while (re-search-forward "\\(<\\)\\|\\(>\\)\\|\\(&\\)\\|\n"
                                             nil t)
                     (replace-match (cond ((match-beginning 1) "&lt;")
                                          ((match-beginning 2) "&gt;")
                                          ((match-beginning 3) "&amp;")
                                          (t "<br>\n"))))
                   (goto-char (point-min))
                   (while (re-search-forward "^[\t ]+" nil t)
                     (dotimes (i (prog1
                                     (current-column)
                                   (delete-region (match-beginning 0)
                                                  (match-end 0))))
                       (insert "&nbsp;")))
                   (goto-char (point-min))
                   (insert "<div align=\"left\">\n")
                   (goto-char (point-max))
                   (insert "</div>\n<hr>\n")
                   ;; We have to examine charset one by one since
                   ;; charset specified in parts might be different.
                   (if (eq charset 'gnus-decoded)
                       (setq charset 'utf-8
                             eheader (mm-encode-coding-string (buffer-string)
                                                              charset)
                             title (when title
                                     (mm-encode-coding-string title charset))
                             body (mm-encode-coding-string content charset))
                     (setq hcharset (mm-find-mime-charset-region (point-min)
                                                                 (point-max)))
                     (cond ((= (length hcharset) 1)
                            (setq hcharset (car hcharset)
                                  coding (mm-charset-to-coding-system
                                          hcharset nil t)))
                           ((> (length hcharset) 1)
                            (setq hcharset 'utf-8
                                  coding hcharset)))
                     (if coding
                         (if charset
                             (progn
                               (setq body
                                     (mm-charset-to-coding-system charset
                                                                  nil t))
                               (if (eq coding body)
                                   (setq eheader (mm-encode-coding-string
                                                  (buffer-string) coding)
                                         title (when title
                                                 (mm-encode-coding-string
                                                  title coding))
                                         body content)
                                 (setq charset 'utf-8
                                       eheader (mm-encode-coding-string
                                                (buffer-string) charset)
                                       title (when title
                                               (mm-encode-coding-string
                                                title charset))
                                       body (mm-encode-coding-string
                                             (mm-decode-coding-string
                                              content body)
                                             charset))))
                           (setq charset hcharset
                                 eheader (mm-encode-coding-string
                                          (buffer-string) coding)
                                 title (when title
                                         (mm-encode-coding-string
                                          title coding))
                                 body content))
                       (setq eheader (mm-string-as-unibyte (buffer-string))
                             body content)))
                   (erase-buffer)
                   (mm-disable-multibyte)
                   (insert body)
                   (when charset
                     (mm-add-meta-html-tag handle charset t))
                   (when title
                     (goto-char (point-min))
                     (unless (search-forward "<title>" nil t)
                       (re-search-forward "<head>\\s-*" nil t)
                       (insert "<title>" title "</title>\n")))
                   (goto-char (point-min))
                   (or (re-search-forward
                        "<body\\(?:\\s-+[^>]+\\|\\s-*\\)>\\s-*" nil t)
                       (re-search-forward
                        "</head\\(?:\\s-+[^>]+\\|\\s-*\\)>\\s-*" nil t))
                   (insert eheader)
                   (mm-write-region (point-min) (point-max)
                                    tmp-file nil nil nil 'binary t))))
              (charset
               (mm-with-unibyte-buffer
                 (insert (if (eq charset 'gnus-decoded)
                             (mm-encode-coding-string content
                                                      (setq charset 'utf-8))
                           content))
                 (if (or (mm-add-meta-html-tag handle charset)
                         (not file))
                     (mm-write-region (point-min) (point-max)
                                      tmp-file nil nil nil 'binary t)
                   (setq tmp-file nil))))
              (tmp-file
               (mm-save-part-to-file handle tmp-file)))
             (when tmp-file
               (add-to-list 'gnus-article-browse-html-temp-list tmp-file))
             (add-hook 'gnus-summary-prepare-exit-hook
                       'gnus-article-browse-delete-temp-files)
             (add-hook 'gnus-exit-gnus-hook
                       (lambda  ()
                         (gnus-article-browse-delete-temp-files t)))
             ;; FIXME: Warn if there's an <img> tag?
             (browse-url-of-file (or tmp-file (expand-file-name file)))
             (setq showed t))
            ;; If multipart, recurse
            ((equal (mm-handle-media-supertype handle) "multipart")
             (when (gnus-article-browse-html-parts handle header)
               (setq showed t)))
            ((equal (mm-handle-media-type handle) "message/rfc822")
             (mm-with-multibyte-buffer
               (mm-insert-part handle)
               (setq handle (mm-dissect-buffer t t))
               (when (and (bufferp (car handle))
                          (stringp (car (mm-handle-type handle))))
                 (setq handle (list handle)))
               (when header
                 (article-decode-encoded-words)
                 (let ((gnus-visible-headers
                        (or (get 'gnus-visible-headers 'standard-value)
                            gnus-visible-headers)))
                   (article-hide-headers))
                 (goto-char (point-min))
                 (search-forward "\n\n" nil 'move)
                 (skip-chars-backward "\t\n ")
                 (setq header (buffer-substring (point-min) (point)))))
             (when (prog1
                       (gnus-article-browse-html-parts handle header)
                     (mm-destroy-parts handle))
               (setq showed t)))))
    showed))

(defun gnus-article-browse-html-article (&optional arg)
  "View \"text/html\" parts of the current article with a WWW browser.
Inline images embedded in a message using the cid scheme, as they are
generally considered to be safe, will be processed properly.
The message header is added to the beginning of every html part unless
the prefix argument ARG is given.

Warning: Spammers use links to images (using the http scheme) in HTML
articles to verify whether you have read the message.  As
`gnus-article-browse-html-article' passes the HTML content to the
browser without eliminating these \"web bugs\" you should only
use it for mails from trusted senders.

If you always want to display HTML parts in the browser, set
`mm-text-html-renderer' to nil.

This command creates temporary files to pass HTML contents including
images if any to the browser, and deletes them when exiting the group
\(if you want)."
  ;; Cf. `mm-w3m-safe-url-regexp'
  (interactive "P")
  (if arg
      (gnus-summary-show-article)
    (let ((gnus-visible-headers (or (get 'gnus-visible-headers 'standard-value)
                                    gnus-visible-headers))
          ;; As we insert a <hr>, there's no need for the body boundary.
          (gnus-treat-body-boundary nil))
      (gnus-summary-show-article)))
  (with-current-buffer gnus-article-buffer
    (let ((header (unless arg
                    (save-restriction
                      (widen)
                      (buffer-substring-no-properties
                       (goto-char (point-min))
                       (if (search-forward "\n\n" nil t)
                           (match-beginning 0)
                         (goto-char (point-max))
                         (skip-chars-backward "\t\n ")
                         (point))))))
          parts)
      (set-buffer gnus-original-article-buffer)
      (setq parts (mm-dissect-buffer t t))
      ;; If singlepart, enforce a list.
      (when (and (bufferp (car parts))
                 (stringp (car (mm-handle-type parts))))
        (setq parts (list parts)))
      ;; Process the list
      (unless (gnus-article-browse-html-parts parts header)
        (gnus-error 3 "Mail doesn't contain a \"text/html\" part!"))
      (mm-destroy-parts parts)
      (unless arg
        (gnus-summary-show-article)))))

(defun article-hide-list-identifiers ()
  "Remove list identifiers from the Subject header.
The `gnus-list-identifiers' variable specifies what to do."
  (interactive)
  (let ((inhibit-point-motion-hooks t)
        (regexp (gnus-group-get-list-identifiers gnus-newsgroup-name))
        (inhibit-read-only t))
    (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-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 ((inhibit-read-only t) 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))))
          (gnus-add-wash-type 'pem)
          (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 banners specified by the `banner' group parameter and by
`gnus-article-address-banner-alist'."
  (interactive)
  (save-excursion
    (save-restriction
      (let ((inhibit-point-motion-hooks t))
        (when (gnus-parameter-banner gnus-newsgroup-name)
          (article-really-strip-banner
           (gnus-parameter-banner gnus-newsgroup-name)))
        (when gnus-article-address-banner-alist
          ;; Note that the From header is decoded here, so it is
          ;; required that the *-extract-address-components function
          ;; supports non-ASCII text.
          (let ((from (save-restriction
                        (widen)
                        (article-narrow-to-head)
                        (mail-fetch-field "from"))))
            (when (and from
                       (setq from
                             (cadr (funcall gnus-extract-address-components
                                            from))))
              (catch 'found
                (dolist (pair gnus-article-address-banner-alist)
                  (when (string-match (car pair) from)
                    (throw 'found
                           (article-really-strip-banner (cdr pair)))))))))))))

(defun article-really-strip-banner (banner)
  "Strip the banner specified by the argument."
  (save-excursion
    (save-restriction
      (let ((inhibit-point-motion-hooks t)
            (gnus-signature-limit nil)
            (inhibit-read-only t))
        (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)
  (gnus-with-article-buffer
    (when (article-goto-body)
      (let* ((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 ((inhibit-read-only t))
          (when (gnus-article-narrow-to-signature)
            (gnus-article-hide-text-type
             (point-min) (point-max) 'signature))))))
  (gnus-set-mode-line 'article))

(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)
          (inhibit-read-only t))
      (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))
   (cond
    ;; Absolutely no headers displayed.
    ((looking-at "\n")
     (point))
    ;; Normal headers.
    ((search-forward "\n\n" nil 1)
     (1- (point)))
    ;; Nothing but headers.
    (t
     (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)
          (inhibit-read-only t))
      ;; 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)
          (inhibit-read-only t))
      (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)
          (inhibit-read-only t))
      (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)
          (inhibit-read-only t))
      (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 (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 ((inhibit-read-only t)
        (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)))
    (gnus-delete-wash-type type)))

(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 gnus-article-forward-header ()
  "Move point to the start of the next header.
If the current header is a continuation header, this can be several
lines forward."
  (let ((ended nil))
    (while (not ended)
      (forward-line 1)
      (if (looking-at "[ \t]+[^ \t]")
          (forward-line 1)
        (setq ended t)))))

(defun article-treat-date ()
  (article-date-ut (if (gnus-buffer-live-p gnus-summary-buffer)
                       (with-current-buffer gnus-summary-buffer
                         gnus-article-date-headers)
                     gnus-article-date-headers)
                   t))

(defun article-date-ut (&optional type _highlight date-position)
  "Convert DATE date to TYPE in the current article.
The default type is `ut'.  See `gnus-article-date-headers' for
possible values."
  (interactive (list 'ut t))
  (let* ((case-fold-search t)
         (inhibit-read-only t)
         (inhibit-point-motion-hooks t)
         (visible-date (mail-fetch-field "Date"))
         pos date bface eface)
    (save-excursion
      (if date-position
          (progn
            (goto-char date-position)
            (setq date (get-text-property (point) 'original-date))
            (when (looking-at "[^:]+:[\t ]*")
              (setq bface (get-text-property (match-beginning 0) 'face)
                    eface (get-text-property (match-end 0) 'face)))
            (delete-region (point)
                           (progn
                             (gnus-article-forward-header)
                             (point)))
            (article-transform-date date type bface eface))
        (save-restriction
          (widen)
          (goto-char (point-min))
          (while (or (get-text-property (setq pos (point)) 'original-date)
                     (and (setq pos (next-single-property-change
                                     (point) 'original-date))
                          (goto-char pos)))
            (narrow-to-region pos (if (search-forward "\n\n" nil t)
                                      (1+ (match-beginning 0))
                                    (point-max)))
            (while (setq pos (text-property-not-all pos (point-max)
                                                    'gnus-date-type nil))
              (setq date (get-text-property pos 'original-date))
              (goto-char pos)
              (when (looking-at "[^:]+:[\t ]*")
                (setq bface (get-text-property (match-beginning 0) 'face)
                      eface (get-text-property (match-end 0) 'face)))
              (delete-region pos (or (text-property-any pos (point-max)
                                                        'gnus-date-type nil)
                                     (point-max))))
            (unless date ;; the 1st time
              (goto-char (point-min))
              (while (re-search-forward "^Date:[\t ]*" nil t)
                (setq date (get-text-property (match-beginning 0)
                                              'original-date)
                      bface (get-text-property (match-beginning 0) 'face)
                      eface (get-text-property (match-end 0) 'face))
                (delete-region (point-at-bol) (progn
                                                (gnus-article-forward-header)
                                                (point)))))
            (when (and (not date)
                       visible-date)
              (setq date visible-date))
            (when date
              (article-transform-date date type bface eface))
            (goto-char (point-max))
            (widen)))))))

(defun article-transform-date (date type bface eface)
  (dolist (this-type (cond
                      ((null type)
                       (list 'ut))
                      ((atom type)
                       (list type))
                      (t
                       type)))
    (goto-char
     (prog1
         (point)
       (add-text-properties
        (point)
        (progn
          (insert (article-make-date-line date (or this-type 'ut)) "\n")
          (point))
        (list 'original-date date 'gnus-date-type this-type))))
    ;; Do highlighting.
    (when (looking-at
           "\\([^:]+:\\)[\t ]*\\(\\(?:[^\t\n ]+[\t ]+\\)*[^\t\n ]+\\)?")
      (put-text-property (match-beginning 1) (match-end 1) 'face bface)
      (when (match-beginning 2)
        (put-text-property (match-beginning 2) (match-end 2) 'face eface))
      (while (and (zerop (forward-line 1))
                  (looking-at "[\t ]+\\(\\(?:[^\t\n ]+[\t ]+\\)*[^\t\n ]+\\)?"))
        (when (match-beginning 1)
          (put-text-property (match-beginning 1) (match-end 1) 'face eface))))))

(defun article-make-date-line (date type)
  "Return a DATE line of TYPE."
  (unless (memq type '(local ut original user-defined iso8601 lapsed english
                             combined-lapsed))
    (error "Unknown conversion type: %s" type))
  (condition-case ()
      (let ((time (ignore-errors (date-to-time date))))
        (cond
         ;; Convert to the local timezone.
         ((eq type 'local)
          (concat "Date: " (message-make-date time)))
         ;; Convert to Universal Time.
         ((eq type 'ut)
          (concat "Date: "
                  (substring
                   (message-make-date
                    (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)))))
                   0 -5)
                  "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-defined)
          (let ((format (or (condition-case nil
                                (with-current-buffer gnus-summary-buffer
                                  gnus-article-time-format)
                              (error nil))
                            gnus-article-time-format)))
            (if (functionp format)
                (funcall format time)
              (concat "Date: " (format-time-string 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 a lapsed format.
         ((eq type 'lapsed)
          (concat "Date: " (article-lapsed-string time)))
         ;; A combined date/lapsed format.
         ((eq type 'combined-lapsed)
          (let ((date-string (article-make-date-line date 'original))
                (segments 3)
                lapsed-string)
            (while (and
                    time
                    (setq lapsed-string
                          (concat " (" (article-lapsed-string time segments) ")"))
                    (> (+ (length date-string)
                          (length lapsed-string))
                       (+ fill-column 6))
                    (> segments 0))
              (setq segments (1- segments)))
            (if (> segments 0)
                (concat date-string lapsed-string)
              date-string)))
         ;; 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)))))))
    (foo
     (format "Date: %s (from Gnus)" date))))

(defun article-lapsed-string (time &optional max-segments)
  ;; 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)))
         (segments 0)
         num prev)
    (unless max-segments
      (setq max-segments (length article-time-units)))
    (cond
     ((null real-time)
      "Unknown")
     ((zerop sec)
      "Now")
     (t
      (concat
       ;; 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 (or (zerop (setq num (ffloor (/ sec (cdr unit)))))
                  (>= segments max-segments))
              ;; 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
                    segments (1+ segments)))))
        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"))))))

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

(defun article-update-date-lapsed ()
  "Function to be run from a timer to update the lapsed time line."
  (save-match-data
    (let ((buffer (current-buffer)))
      (ignore-errors
        (walk-windows
         (lambda (w)
           (set-buffer (window-buffer w))
           (when (derived-mode-p 'gnus-article-mode)
             (let ((old-line (count-lines (point-min) (point)))
                   (old-column (- (point) (line-beginning-position)))
                   (window-start (window-start w))
                   (pos (point-min))
                   type next end)
               (while (setq pos (text-property-not-all pos (point-max)
                                                       'gnus-date-type nil))
                 (setq next (or (next-single-property-change pos
                                                             'gnus-date-type)
                                (point-max)))
                 (setq type (get-text-property pos 'gnus-date-type))
                 (when (memq type '(lapsed combined-lapsed user-defined))
                   (article-date-ut type t pos)
                   (setq end (or (next-single-property-change pos
                                                              'gnus-date-type)
                                 (point-max)))
                   (when window-start
                     (if (/= window-start next)
                         (setq window-start nil)
                       (set-window-start w end)))
                   (setq next end))
                 (setq pos next))
               (goto-char (point-min))
               (when (> old-column 0)
                 (setq old-line (1- old-line)))
               (forward-line old-line)
               (end-of-line)
               (when (> (current-column) old-column)
                 (beginning-of-line)
                 (forward-char old-column)))))
         nil 'visible))
      (set-buffer buffer))))

(defun gnus-start-date-timer (&optional n)
  "Start a timer to update the Date headers 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
        (run-at-time 1 n 'article-update-date-lapsed)))

(defun gnus-stop-date-timer ()
  "Stop the Date 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))

(defmacro gnus-article-save-original-date (&rest forms)
  "Save the original date as a text property and evaluate FORMS."
  `(let* ((case-fold-search t)
          (start (progn
                   (goto-char (point-min))
                   (when (and (re-search-forward "^date:[\t\n ]+" nil t)
                              (not (bolp)))
                     (match-end 0))))
          (date (when (and start
                           (re-search-forward "[\t ]*\n\\(?:[^\t ]\\|\\'\\)"
                                              nil t))
                  (buffer-substring-no-properties start
                                                  (match-beginning 0)))))
     (goto-char (point-max))
     (skip-chars-backward "\n")
     (put-text-property (point-min) (point) 'original-date date)
     ,@forms
     (goto-char (point-max))
     (skip-chars-backward "\n")
     (put-text-property (point-min) (point) 'original-date date)))

;; (defun article-show-all ()
;;   "Show all hidden text in the article buffer."
;;   (interactive)
;;   (save-excursion
;;     (let ((inhibit-read-only t))
;;       (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 ((inhibit-read-only t))
        (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))
            (inhibit-read-only t)
            (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))
              (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-overlay-excluding-newlines
               (match-beginning visible) (match-end visible) 'face face)
              (gnus-add-wash-type 'emphasis)
              (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)))))

(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."
  (when (or (get gnus-default-article-saver :headers)
            (not gnus-save-all-headers))
    ;; Remove headers according to `gnus-saved-headers' or the value
    ;; of the `:headers' property that the saver function might have.
    (let ((gnus-visible-headers
           (or (symbol-value (get gnus-default-article-saver :headers))
               gnus-saved-headers gnus-visible-headers))
          ;; Ignore group parameter.  See `article-hide-headers'.
          (gnus-summary-buffer nil))
      (with-current-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
                                        dir-var)
  (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
             (when (symbol-value dir-var)
               (setq default-name (expand-file-name
                                   (file-name-nondirectory default-name)
                                   (symbol-value dir-var))))
             (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))
    (when variable
      (set variable result))
    (when dir-var
      (set dir-var (file-name-directory result)))
    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))
  (with-current-buffer gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        ;; Note that unlike gnus-summary-save-in-mail, there is no
        ;; check to see if filename is Babyl.  Rmail in Emacs 23 does
        ;; not use Babyl.
        (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))
  (with-current-buffer gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (if (and (file-readable-p filename)
                 (file-regular-p filename)
                 (mail-file-babyl-p filename))
            (gnus-output-to-rmail filename)
          (gnus-output-to-mail filename)))))
  filename)

(put 'gnus-summary-save-in-file :decode t)
(put 'gnus-summary-save-in-file :headers 'gnus-saved-headers)
(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))
  (with-current-buffer 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)

(put 'gnus-summary-write-to-file :decode t)
(put 'gnus-summary-write-to-file :function 'gnus-summary-save-in-file)
(put 'gnus-summary-write-to-file :headers 'gnus-saved-headers)
(defun gnus-summary-write-to-file (&optional filename)
  "Write this article to a file, overwriting it if the file exists.
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 in file" filename
                  gnus-file-save-name gnus-newsgroup-name
                  gnus-current-headers nil 'gnus-newsgroup-last-directory))
  (gnus-summary-save-in-file filename t))

(put 'gnus-summary-save-body-in-file :decode t)
(defun gnus-summary-save-body-in-file (&optional filename overwrite)
  "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))
  (with-current-buffer gnus-save-article-buffer
    (save-excursion
      (save-restriction
        (widen)
        (when (article-goto-body)
          (narrow-to-region (point) (point-max)))
        (when (and overwrite
                   (file-exists-p filename))
          (delete-file filename))
        (gnus-output-to-file filename))))
  filename)

(put 'gnus-summary-write-body-to-file :decode t)
(put 'gnus-summary-write-body-to-file
     :function 'gnus-summary-save-body-in-file)
(defun gnus-summary-write-body-to-file (&optional filename)
  "Write this article body to a file, overwriting it if the file exists.
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 nil 'gnus-newsgroup-last-directory))
  (gnus-summary-save-body-in-file filename t))

(put 'gnus-summary-save-in-pipe :decode t)
(put 'gnus-summary-save-in-pipe :headers 'gnus-saved-headers)
(defun gnus-summary-save-in-pipe (&optional command raw)
  "Pipe this article to subprocess COMMAND.
Valid values for COMMAND include:
  a string
    The executable command name and possibly arguments.
  nil
    You will be prompted for the command in the minibuffer.
  the symbol `default'
    It will be replaced with the command which the variable
    `gnus-summary-pipe-output-default-command' holds or the command
    last used for saving.
Non-nil value for RAW overrides `:decode' and `:headers' properties
and the raw article including all headers will be piped."
  (let ((article (gnus-summary-article-number))
        (decode (unless raw
                  (get 'gnus-summary-save-in-pipe :decode)))
        save-buffer default)
    (if article
        (if (vectorp (gnus-summary-article-header article))
            (save-current-buffer
              (gnus-summary-select-article decode decode nil article)
              (insert-buffer-substring
               (prog1
                   (if decode
                       gnus-article-buffer
                     gnus-original-article-buffer)
                 (setq save-buffer
                       (nnheader-set-temp-buffer " *Gnus Save*"))))
              ;; Remove unwanted headers.
              (when (and (not raw)
                         (or (get 'gnus-summary-save-in-pipe :headers)
                             (not gnus-save-all-headers)))
                (let ((gnus-visible-headers
                       (or (symbol-value (get 'gnus-summary-save-in-pipe
                                              :headers))
                           gnus-saved-headers gnus-visible-headers))
                      (gnus-summary-buffer nil))
                  (article-hide-headers 1 t))))
          (error "%d is not a real article" article))
      (error "No article to pipe"))
    (setq default (or gnus-summary-pipe-output-default-command
                      gnus-last-shell-command))
    (unless (stringp command)
      (setq command
            (if (and (eq command 'default) default)
                default
              (gnus-read-shell-command "Shell command on this article: "
                                       default))))
    (when (string-equal command "")
      (if default
          (setq command default)
        (error "A command is required")))
    (with-current-buffer save-buffer
      (save-restriction
        (widen)
        (shell-command-on-region (point-min) (point-max) command nil)))
    (gnus-kill-buffer save-buffer))