lisp/gnus/mm-decode.el

   1 ;;; mm-decode.el --- Functions for decoding MIME things
   2
   3 ;; Copyright (C) 1998-2013 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;;      MORIOKA Tomohiko <morioka@jaist.ac.jp>
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software: you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation, either version 3 of the License, or
  12 ;; (at your option) any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;;; Code:
  25
  26 ;; For Emacs <22.2 and XEmacs.
  27 (eval-and-compile
  28   (unless (fboundp 'declare-function) (defmacro declare-function (&rest r))))
  29
  30 (require 'mail-parse)
  31 (require 'mm-bodies)
  32 (eval-when-compile (require 'cl))
  33
  34 (autoload 'gnus-map-function "gnus-util")
  35 (autoload 'gnus-replace-in-string "gnus-util")
  36 (autoload 'gnus-read-shell-command "gnus-util")
  37
  38 (autoload 'mm-inline-partial "mm-partial")
  39 (autoload 'mm-inline-external-body "mm-extern")
  40 (autoload 'mm-extern-cache-contents "mm-extern")
  41 (autoload 'mm-insert-inline "mm-view")
  42
  43 (autoload 'mm-archive-decoders "mm-archive")
  44 (autoload 'mm-archive-dissect-and-inline "mm-archive")
  45 (autoload 'mm-dissect-archive "mm-archive")
  46
  47 (defvar gnus-current-window-configuration)
  48
  49 (add-hook 'gnus-exit-gnus-hook 'mm-destroy-postponed-undisplay-list)
  50 (add-hook 'gnus-exit-gnus-hook 'mm-temp-files-delete)
  51
  52 (defgroup mime-display ()
  53   "Display of MIME in mail and news articles."
  54   :link '(custom-manual "(emacs-mime)Display Customization")
  55   :version "21.1"
  56   :group 'mail
  57   :group 'news
  58   :group 'multimedia)
  59
  60 (defgroup mime-security ()
  61   "MIME security in mail and news articles."
  62   :link '(custom-manual "(emacs-mime)Display Customization")
  63   :group 'mail
  64   :group 'news
  65   :group 'multimedia)
  66
  67 (defface mm-command-output
  68   '((((class color)
  69       (background dark))
  70      (:foreground "ForestGreen"))
  71     (((class color)
  72       (background light))
  73      (:foreground "red3"))
  74     (t
  75      (:italic t)))
  76   "Face used for displaying output from commands."
  77   :group 'mime-display)
  78
  79 ;;; Convenience macros.
  80
  81 (defmacro mm-handle-buffer (handle)
  82   `(nth 0 ,handle))
  83 (defmacro mm-handle-type (handle)
  84   `(nth 1 ,handle))
  85 (defsubst mm-handle-media-type (handle)
  86   (if (stringp (car handle))
  87       (car handle)
  88     (car (mm-handle-type handle))))
  89 (defsubst mm-handle-media-supertype (handle)
  90   (car (split-string (mm-handle-media-type handle) "/")))
  91 (defsubst mm-handle-media-subtype (handle)
  92   (cadr (split-string (mm-handle-media-type handle) "/")))
  93 (defmacro mm-handle-encoding (handle)
  94   `(nth 2 ,handle))
  95 (defmacro mm-handle-undisplayer (handle)
  96   `(nth 3 ,handle))
  97 (defmacro mm-handle-set-undisplayer (handle function)
  98   `(setcar (nthcdr 3 ,handle) ,function))
  99 (defmacro mm-handle-disposition (handle)
 100   `(nth 4 ,handle))
 101 (defmacro mm-handle-description (handle)
 102   `(nth 5 ,handle))
 103 (defmacro mm-handle-cache (handle)
 104   `(nth 6 ,handle))
 105 (defmacro mm-handle-set-cache (handle contents)
 106   `(setcar (nthcdr 6 ,handle) ,contents))
 107 (defmacro mm-handle-id (handle)
 108   `(nth 7 ,handle))
 109 (defmacro mm-handle-multipart-original-buffer (handle)
 110   `(get-text-property 0 'buffer (car ,handle)))
 111 (defmacro mm-handle-multipart-from (handle)
 112   `(get-text-property 0 'from (car ,handle)))
 113 (defmacro mm-handle-multipart-ctl-parameter (handle parameter)
 114   `(get-text-property 0 ,parameter (car ,handle)))
 115
 116 (defmacro mm-make-handle (&optional buffer type encoding undisplayer
 117                                     disposition description cache
 118                                     id)
 119   `(list ,buffer ,type ,encoding ,undisplayer
 120          ,disposition ,description ,cache ,id))
 121
 122 (defcustom mm-text-html-renderer
 123   (cond ((fboundp 'libxml-parse-html-region) 'shr)
 124         ((executable-find "w3m") 'gnus-w3m)
 125         ((executable-find "links") 'links)
 126         ((executable-find "lynx") 'lynx)
 127         ((locate-library "w3") 'w3)
 128         ((locate-library "html2text") 'html2text)
 129         (t nil))
 130   "Render of HTML contents.
 131 It is one of defined renderer types, or a rendering function.
 132 The defined renderer types are:
 133 `shr': use the built-in Gnus HTML renderer;
 134 `gnus-w3m': use Gnus renderer based on w3m;
 135 `w3m': use emacs-w3m;
 136 `w3m-standalone': use plain w3m;
 137 `links': use links;
 138 `lynx': use lynx;
 139 `w3': use Emacs/W3;
 140 `html2text': use html2text;
 141 nil    : use external viewer (default web browser)."
 142   :version "24.1"
 143   :type '(choice (const shr)
 144                  (const gnus-w3m)
 145                  (const w3)
 146                  (const w3m :tag "emacs-w3m")
 147                  (const w3m-standalone :tag "standalone w3m" )
 148                  (const links)
 149                  (const lynx)
 150                  (const html2text)
 151                  (const nil :tag "External viewer")
 152                  (function))
 153   :group 'mime-display)
 154
 155 (defcustom mm-inline-text-html-with-images nil
 156   "If non-nil, Gnus will allow retrieving images in HTML contents with
 157 the <img> tags.  It has no effect on Emacs/w3.  See also the
 158 documentation for the `mm-w3m-safe-url-regexp' variable."
 159   :version "22.1"
 160   :type 'boolean
 161   :group 'mime-display)
 162
 163 (defcustom mm-w3m-safe-url-regexp "\\`cid:"
 164   "Regexp matching URLs which are considered to be safe.
 165 Some HTML mails might contain a nasty trick used by spammers, using
 166 the <img> tag which is far more evil than the [Click Here!] button.
 167 It is most likely intended to check whether the ominous spam mail has
 168 reached your eyes or not, in which case the spammer knows for sure
 169 that your email address is valid.  It is done by embedding an
 170 identifier string into a URL that you might automatically retrieve
 171 when displaying the image.  The default value is \"\\\\`cid:\" which only
 172 matches parts embedded to the Multipart/Related type MIME contents and
 173 Gnus will never connect to the spammer's site arbitrarily.  You may
 174 set this variable to nil if you consider all urls to be safe."
 175   :version "22.1"
 176   :type '(choice (regexp :tag "Regexp")
 177                  (const :tag "All URLs are safe" nil))
 178   :group 'mime-display)
 179
 180 (defcustom mm-inline-text-html-with-w3m-keymap t
 181   "If non-nil, use emacs-w3m command keys in the article buffer."
 182   :version "22.1"
 183   :type 'boolean
 184   :group 'mime-display)
 185
 186 (defcustom mm-enable-external t
 187   "Indicate whether external MIME handlers should be used.
 188
 189 If t, all defined external MIME handlers are used.  If nil, files are saved by
 190 `mailcap-save-binary-file'.  If it is the symbol `ask', you are prompted
 191 before the external MIME handler is invoked."
 192   :version "22.1"
 193   :type '(choice (const :tag "Always" t)
 194                  (const :tag "Never" nil)
 195                  (const :tag "Ask" ask))
 196   :group 'mime-display)
 197
 198 (defcustom mm-inline-media-tests
 199   '(("image/p?jpeg"
 200      mm-inline-image
 201      (lambda (handle)
 202        (mm-valid-and-fit-image-p 'jpeg handle)))
 203     ("image/png"
 204      mm-inline-image
 205      (lambda (handle)
 206        (mm-valid-and-fit-image-p 'png handle)))
 207     ("image/gif"
 208      mm-inline-image
 209      (lambda (handle)
 210        (mm-valid-and-fit-image-p 'gif handle)))
 211     ("image/tiff"
 212      mm-inline-image
 213      (lambda (handle)
 214        (mm-valid-and-fit-image-p 'tiff handle)))
 215     ("image/xbm"
 216      mm-inline-image
 217      (lambda (handle)
 218        (mm-valid-and-fit-image-p 'xbm handle)))
 219     ("image/x-xbitmap"
 220      mm-inline-image
 221      (lambda (handle)
 222        (mm-valid-and-fit-image-p 'xbm handle)))
 223     ("image/xpm"
 224      mm-inline-image
 225      (lambda (handle)
 226        (mm-valid-and-fit-image-p 'xpm handle)))
 227     ("image/x-xpixmap"
 228      mm-inline-image
 229      (lambda (handle)
 230        (mm-valid-and-fit-image-p 'xpm handle)))
 231     ("image/bmp"
 232      mm-inline-image
 233      (lambda (handle)
 234        (mm-valid-and-fit-image-p 'bmp handle)))
 235     ("image/x-portable-bitmap"
 236      mm-inline-image
 237      (lambda (handle)
 238        (mm-valid-and-fit-image-p 'pbm handle)))
 239     ("text/plain" mm-inline-text identity)
 240     ("text/enriched" mm-inline-text identity)
 241     ("text/richtext" mm-inline-text identity)
 242     ("text/x-patch" mm-display-patch-inline identity)
 243     ;; In case mime.types uses x-diff (as does Debian's mime-support-3.40).
 244     ("text/x-diff" mm-display-patch-inline identity)
 245     ("application/emacs-lisp" mm-display-elisp-inline identity)
 246     ("application/x-emacs-lisp" mm-display-elisp-inline identity)
 247     ("application/x-shellscript" mm-display-shell-script-inline identity)
 248     ("application/x-sh" mm-display-shell-script-inline identity)
 249     ("text/x-sh" mm-display-shell-script-inline identity)
 250     ("application/javascript" mm-display-javascript-inline identity)
 251     ("text/dns" mm-display-dns-inline identity)
 252     ("text/x-org" mm-display-org-inline identity)
 253     ("text/html"
 254      mm-inline-text-html
 255      (lambda (handle)
 256        mm-text-html-renderer))
 257     ("text/x-vcard"
 258      mm-inline-text-vcard
 259      (lambda (handle)
 260        (or (featurep 'vcard)
 261            (locate-library "vcard"))))
 262     ("message/delivery-status" mm-inline-text identity)
 263     ("message/rfc822" mm-inline-message identity)
 264     ("message/partial" mm-inline-partial identity)
 265     ("message/external-body" mm-inline-external-body identity)
 266     ("text/.*" mm-inline-text identity)
 267     ("application/x-.?tar\\(-.*\\)?" mm-archive-dissect-and-inline identity)
 268     ("application/zip" mm-archive-dissect-and-inline identity)
 269     ("audio/wav" mm-inline-audio
 270      (lambda (handle)
 271        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 272             (device-sound-enabled-p))))
 273     ("audio/au"
 274      mm-inline-audio
 275      (lambda (handle)
 276        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 277             (device-sound-enabled-p))))
 278     ("application/pgp-signature" ignore identity)
 279     ("application/x-pkcs7-signature" ignore identity)
 280     ("application/pkcs7-signature" ignore identity)
 281     ("application/x-pkcs7-mime" ignore identity)
 282     ("application/pkcs7-mime" ignore identity)
 283     ("multipart/alternative" ignore identity)
 284     ("multipart/mixed" ignore identity)
 285     ("multipart/related" ignore identity)
 286     ("image/.*"
 287      mm-inline-image
 288      (lambda (handle)
 289        (and (mm-valid-image-format-p 'imagemagick)
 290             (mm-with-unibyte-buffer
 291               (mm-insert-part handle)
 292               (let ((image
 293                      (ignore-errors
 294                        (if (fboundp 'create-image)
 295                            (create-image (buffer-string) 'imagemagick 'data-p)
 296                          (mm-create-image-xemacs
 297                           (mm-handle-media-subtype handle))))))
 298                 (when image
 299                   (setcar (cdr handle) (list "image/imagemagick"))
 300                   (mm-image-fit-p handle)))))))
 301     ;; Disable audio and image
 302     ("audio/.*" ignore ignore)
 303     ("image/.*" ignore ignore)
 304     ;; Default to displaying as text
 305     (".*" mm-inline-text mm-readable-p))
 306   "Alist of media types/tests saying whether types can be displayed inline."
 307   :type '(repeat (list (regexp :tag "MIME type")
 308                        (function :tag "Display function")
 309                        (function :tag "Display test")))
 310   :group 'mime-display)
 311
 312 (defcustom mm-inlined-types
 313   '("image/.*" "text/.*" "message/delivery-status" "message/rfc822"
 314     "message/partial" "message/external-body" "application/emacs-lisp"
 315     "application/x-emacs-lisp"
 316     "application/pgp-signature" "application/x-pkcs7-signature"
 317     "application/pkcs7-signature" "application/x-pkcs7-mime"
 318     "application/pkcs7-mime"
 319     "application/x-gtar-compressed"
 320     "application/x-tar"
 321     "application/zip"
 322     ;; Mutt still uses this even though it has already been withdrawn.
 323     "application/pgp")
 324   "List of media types that are to be displayed inline.
 325 See also `mm-inline-media-tests', which says how to display a media
 326 type inline."
 327   :type '(repeat regexp)
 328   :group 'mime-display)
 329
 330 (defcustom mm-keep-viewer-alive-types
 331   '("application/postscript" "application/msword" "application/vnd.ms-excel"
 332     "application/pdf" "application/x-dvi")
 333   "List of media types for which the external viewer will not be killed
 334 when selecting a different article."
 335   :version "22.1"
 336   :type '(repeat regexp)
 337   :group 'mime-display)
 338
 339 (defcustom mm-automatic-display
 340   '("text/plain" "text/enriched" "text/richtext" "text/html" "text/x-verbatim"
 341     "text/x-vcard" "image/.*" "message/delivery-status" "multipart/.*"
 342     "message/rfc822" "text/x-patch" "text/dns" "application/pgp-signature"
 343     "application/emacs-lisp" "application/x-emacs-lisp"
 344     "application/x-pkcs7-signature"
 345     "application/pkcs7-signature" "application/x-pkcs7-mime"
 346     "application/pkcs7-mime"
 347     ;; Mutt still uses this even though it has already been withdrawn.
 348     "application/pgp\\'"
 349      "text/x-org")
 350   "A list of MIME types to be displayed automatically."
 351   :type '(repeat regexp)
 352   :group 'mime-display)
 353
 354 (defcustom mm-attachment-override-types '("text/x-vcard"
 355                                           "application/pkcs7-mime"
 356                                           "application/x-pkcs7-mime"
 357                                           "application/pkcs7-signature"
 358                                           "application/x-pkcs7-signature")
 359   "Types to have \"attachment\" ignored if they can be displayed inline."
 360   :type '(repeat regexp)
 361   :group 'mime-display)
 362
 363 (defcustom mm-inline-override-types nil
 364   "Types to be treated as attachments even if they can be displayed inline."
 365   :type '(repeat regexp)
 366   :group 'mime-display)
 367
 368 (defcustom mm-automatic-external-display nil
 369   "List of MIME type regexps that will be displayed externally automatically."
 370   :type '(repeat regexp)
 371   :group 'mime-display)
 372
 373 (defcustom mm-discouraged-alternatives nil
 374   "List of MIME types that are discouraged when viewing multipart/alternative.
 375 Viewing agents are supposed to view the last possible part of a message,
 376 as that is supposed to be the richest.  However, users may prefer other
 377 types instead, and this list says what types are most unwanted.  If,
 378 for instance, text/html parts are very unwanted, and text/richtext are
 379 somewhat unwanted, then the value of this variable should be set
 380 to:
 381
 382  (\"text/html\" \"text/richtext\")
 383
 384 Adding \"image/.*\" might also be useful.  Spammers use it as the
 385 preferred part of multipart/alternative messages.  See also
 386 `gnus-buttonized-mime-types', to which adding \"multipart/alternative\"
 387 enables you to choose manually one of two types those mails include."
 388   :type '(repeat regexp) ;; See `mm-preferred-alternative-precedence'.
 389   :group 'mime-display)
 390
 391 (defcustom mm-tmp-directory
 392   (if (fboundp 'temp-directory)
 393       (temp-directory)
 394     (if (boundp 'temporary-file-directory)
 395         temporary-file-directory
 396       "/tmp/"))
 397   "Where mm will store its temporary files."
 398   :type 'directory
 399   :group 'mime-display)
 400
 401 (defcustom mm-inline-large-images nil
 402   "If t, then all images fit in the buffer.
 403 If 'resize, try to resize the images so they fit."
 404   :type '(radio
 405           (const :tag "Inline large images as they are." t)
 406           (const :tag "Resize large images." resize)
 407           (const :tag "Do not inline large images." nil))
 408   :group 'mime-display)
 409
 410 (defcustom mm-file-name-rewrite-functions
 411   '(mm-file-name-delete-control mm-file-name-delete-gotchas)
 412   "List of functions used for rewriting file names of MIME parts.
 413 Each function takes a file name as input and returns a file name.
 414
 415 Ready-made functions include `mm-file-name-delete-control',
 416 `mm-file-name-delete-gotchas' (you should not remove these two
 417 functions), `mm-file-name-delete-whitespace',
 418 `mm-file-name-trim-whitespace', `mm-file-name-collapse-whitespace',
 419 `mm-file-name-replace-whitespace', `capitalize', `downcase',
 420 `upcase', and `upcase-initials'."
 421   :type '(list (set :inline t
 422                     (const mm-file-name-delete-control)
 423                     (const mm-file-name-delete-gotchas)
 424                     (const mm-file-name-delete-whitespace)
 425                     (const mm-file-name-trim-whitespace)
 426                     (const mm-file-name-collapse-whitespace)
 427                     (const mm-file-name-replace-whitespace)
 428                     (const capitalize)
 429                     (const downcase)
 430                     (const upcase)
 431                     (const upcase-initials)
 432                (repeat :inline t
 433                        :tag "Function"
 434                        function)))
 435   :version "23.1" ;; No Gnus
 436   :group 'mime-display)
 437
 438
 439 (defvar mm-path-name-rewrite-functions nil
 440   "*List of functions for rewriting the full file names of MIME parts.
 441 This is used when viewing parts externally, and is meant for
 442 transforming the absolute name so that non-compliant programs can find
 443 the file where it's saved.
 444
 445 Each function takes a file name as input and returns a file name.")
 446
 447 (defvar mm-file-name-replace-whitespace nil
 448   "String used for replacing whitespace characters; default is `\"_\"'.")
 449
 450 (defcustom mm-default-directory nil
 451   "The default directory where mm will save files.
 452 If not set, `default-directory' will be used."
 453   :type '(choice directory (const :tag "Default" nil))
 454   :group 'mime-display)
 455
 456 (defcustom mm-attachment-file-modes 384
 457   "Set the mode bits of saved attachments to this integer."
 458   :version "22.1"
 459   :type 'integer
 460   :group 'mime-display)
 461
 462 (defcustom mm-external-terminal-program "xterm"
 463   "The program to start an external terminal."
 464   :version "22.1"
 465   :type 'string
 466   :group 'mime-display)
 467
 468 ;;; Internal variables.
 469
 470 (defvar mm-last-shell-command "")
 471 (defvar mm-content-id-alist nil)
 472 (defvar mm-postponed-undisplay-list nil)
 473 (defvar mm-inhibit-auto-detect-attachment nil)
 474 (defvar mm-temp-files-to-be-deleted nil
 475   "List of temporary files scheduled to be deleted.")
 476 (defvar mm-temp-files-cache-file (concat ".mm-temp-files-" (user-login-name))
 477   "Name of a file that caches a list of temporary files to be deleted.
 478 The file will be saved in the directory `mm-tmp-directory'.")
 479
 480 ;; According to RFC2046, in particular, in a digest, the default
 481 ;; Content-Type value for a body part is changed from "text/plain" to
 482 ;; "message/rfc822".
 483 (defvar mm-dissect-default-type "text/plain")
 484
 485 (autoload 'mml2015-verify "mml2015")
 486 (autoload 'mml2015-verify-test "mml2015")
 487 (autoload 'mml-smime-verify "mml-smime")
 488 (autoload 'mml-smime-verify-test "mml-smime")
 489
 490 (defvar mm-verify-function-alist
 491   '(("application/pgp-signature" mml2015-verify "PGP" mml2015-verify-test)
 492     ("application/x-gnus-pgp-signature" mm-uu-pgp-signed-extract-1 "PGP"
 493      mm-uu-pgp-signed-test)
 494     ("application/pkcs7-signature" mml-smime-verify "S/MIME"
 495      mml-smime-verify-test)
 496     ("application/x-pkcs7-signature" mml-smime-verify "S/MIME"
 497      mml-smime-verify-test)))
 498
 499 (defcustom mm-verify-option 'never
 500   "Option of verifying signed parts.
 501 `never', not verify; `always', always verify;
 502 `known', only verify known protocols.  Otherwise, ask user.
 503
 504 When set to `always' or `known', you should add
 505 \"multipart/signed\" to `gnus-buttonized-mime-types' to see
 506 result of the verification."
 507   :version "22.1"
 508   :type '(choice (item always)
 509                  (item never)
 510                  (item :tag "only known protocols" known)
 511                  (item :tag "ask" nil))
 512   :group 'mime-security)
 513
 514 (autoload 'mml2015-decrypt "mml2015")
 515 (autoload 'mml2015-decrypt-test "mml2015")
 516
 517 (defvar mm-decrypt-function-alist
 518   '(("application/pgp-encrypted" mml2015-decrypt "PGP" mml2015-decrypt-test)
 519     ("application/x-gnus-pgp-encrypted" mm-uu-pgp-encrypted-extract-1 "PGP"
 520      mm-uu-pgp-encrypted-test)))
 521
 522 (defcustom mm-decrypt-option nil
 523   "Option of decrypting encrypted parts.
 524 `never', not decrypt; `always', always decrypt;
 525 `known', only decrypt known protocols.  Otherwise, ask user."
 526   :version "22.1"
 527   :type '(choice (item always)
 528                  (item never)
 529                  (item :tag "only known protocols" known)
 530                  (item :tag "ask" nil))
 531   :group 'mime-security)
 532
 533 (defvar mm-viewer-completion-map
 534   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 535     (set-keymap-parent map minibuffer-local-completion-map)
 536     ;; Should we bind other key to minibuffer-complete-word?
 537     (define-key map " " 'self-insert-command)
 538     map)
 539   "Keymap for input viewer with completion.")
 540
 541 (defvar mm-viewer-completion-map
 542   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 543     (set-keymap-parent map minibuffer-local-completion-map)
 544     ;; Should we bind other key to minibuffer-complete-word?
 545     (define-key map " " 'self-insert-command)
 546     map)
 547   "Keymap for input viewer with completion.")
 548
 549 ;;; The functions.
 550
 551 (defun mm-alist-to-plist (alist)
 552   "Convert association list ALIST into the equivalent property-list form.
 553 The plist is returned.  This converts from
 554
 555 \((a . 1) (b . 2) (c . 3))
 556
 557 into
 558
 559 \(a 1 b 2 c 3)
 560
 561 The original alist is not modified.  See also `destructive-alist-to-plist'."
 562   (let (plist)
 563     (while alist
 564       (let ((el (car alist)))
 565         (setq plist (cons (cdr el) (cons (car el) plist))))
 566       (setq alist (cdr alist)))
 567     (nreverse plist)))
 568
 569 (defun mm-keep-viewer-alive-p (handle)
 570   "Say whether external viewer for HANDLE should stay alive."
 571   (let ((types mm-keep-viewer-alive-types)
 572         (type (mm-handle-media-type handle))
 573         ty)
 574     (catch 'found
 575       (while (setq ty (pop types))
 576         (when (string-match ty type)
 577           (throw 'found t))))))
 578
 579 (defun mm-handle-set-external-undisplayer (handle function)
 580   "Set the undisplayer for HANDLE to FUNCTION.
 581 Postpone undisplaying of viewers for types in
 582 `mm-keep-viewer-alive-types'."
 583   (if (mm-keep-viewer-alive-p handle)
 584       (let ((new-handle (copy-sequence handle)))
 585         (mm-handle-set-undisplayer new-handle function)
 586         (mm-handle-set-undisplayer handle nil)
 587         (push new-handle mm-postponed-undisplay-list))
 588     (mm-handle-set-undisplayer handle function)))
 589
 590 (defun mm-destroy-postponed-undisplay-list ()
 591   (when mm-postponed-undisplay-list
 592     (message "Destroying external MIME viewers")
 593     (mm-destroy-parts mm-postponed-undisplay-list)))
 594
 595 (defun mm-temp-files-delete ()
 596   "Delete temporary files and those parent directories.
 597 Note that the deletion may fail if a program is catching hold of a file
 598 under Windows or Cygwin.  In that case, it schedules the deletion of
 599 files left at the next time."
 600   (let* ((coding-system-for-read mm-universal-coding-system)
 601          (coding-system-for-write mm-universal-coding-system)
 602          (cache-file (expand-file-name mm-temp-files-cache-file
 603                                        mm-tmp-directory))
 604          (cache (when (file-exists-p cache-file)
 605                   (mm-with-multibyte-buffer
 606                     (insert-file-contents cache-file)
 607                     (split-string (buffer-string) "\n" t))))
 608          fails)
 609     (dolist (temp (append cache mm-temp-files-to-be-deleted))
 610       (when (and (file-exists-p temp)
 611                  (if (file-directory-p temp)
 612                      ;; A parent directory left at the previous time.
 613                      (progn
 614                        (ignore-errors (delete-directory temp))
 615                        (file-exists-p temp))
 616                    ;; Delete a temporary file and its parent directory.
 617                    (ignore-errors (delete-file temp))
 618                    (or (file-exists-p temp)
 619                        (progn
 620                          (setq temp (file-name-directory temp))
 621                          (ignore-errors (delete-directory temp))
 622                          (file-exists-p temp)))))
 623         (push temp fails)))
 624     (if fails
 625         ;; Schedule the deletion of the files left at the next time.
 626         (progn
 627           (write-region (concat (mapconcat 'identity (nreverse fails) "\n")
 628                                 "\n")
 629                         nil cache-file nil 'silent)
 630           (set-file-modes cache-file #o600))
 631       (when (file-exists-p cache-file)
 632         (ignore-errors (delete-file cache-file))))
 633     (setq mm-temp-files-to-be-deleted nil)))
 634
 635 (autoload 'message-fetch-field "message")
 636
 637 (defun mm-dissect-buffer (&optional no-strict-mime loose-mime from)
 638   "Dissect the current buffer and return a list of MIME handles.
 639 If NO-STRICT-MIME, don't require the message to have a
 640 MIME-Version header before proceeding."
 641   (save-excursion
 642     (let (ct ctl type subtype cte cd description id result)
 643       (save-restriction
 644         (mail-narrow-to-head)
 645         (when (or no-strict-mime
 646                   loose-mime
 647                   (mail-fetch-field "mime-version"))
 648           (setq ct (mail-fetch-field "content-type")
 649                 ctl (and ct (mail-header-parse-content-type ct))
 650                 cte (mail-fetch-field "content-transfer-encoding")
 651                 cd (or (mail-fetch-field "content-disposition")
 652                        (when (and ctl
 653                                   (eq 'mm-inline-text
 654                                       (cadr (mm-assoc-string-match
 655                                              mm-inline-media-tests
 656                                              (car ctl)))))
 657                          "inline"))
 658                 ;; Newlines in description should be stripped so as
 659                 ;; not to break the MIME tag into two or more lines.
 660                 description (message-fetch-field "content-description")
 661                 id (mail-fetch-field "content-id"))
 662           (unless from
 663             (setq from (mail-fetch-field "from")))
 664           ;; FIXME: In some circumstances, this code is running within
 665           ;; an unibyte macro.  mail-extract-address-components
 666           ;; creates unibyte buffers. This `if', though not a perfect
 667           ;; solution, avoids most of them.
 668           (if from
 669               (setq from (cadr (mail-extract-address-components from))))
 670           (if description
 671               (setq description (mail-decode-encoded-word-string
 672                                  description)))))
 673       (if (or (not ctl)
 674               (not (string-match "/" (car ctl))))
 675           (mm-dissect-singlepart
 676            (list mm-dissect-default-type)
 677            (and cte (intern (downcase (mail-header-strip cte))))
 678            no-strict-mime
 679            (and cd (mail-header-parse-content-disposition cd))
 680            description)
 681         (setq type (split-string (car ctl) "/"))
 682         (setq subtype (cadr type)
 683               type (car type))
 684         (setq
 685          result
 686          (cond
 687           ((equal type "multipart")
 688            (let ((mm-dissect-default-type (if (equal subtype "digest")
 689                                               "message/rfc822"
 690                                             "text/plain"))
 691                  (start (cdr (assq 'start (cdr ctl)))))
 692              (add-text-properties 0 (length (car ctl))
 693                                   (mm-alist-to-plist (cdr ctl)) (car ctl))
 694
 695              ;; what really needs to be done here is a way to link a
 696              ;; MIME handle back to it's parent MIME handle (in a multilevel
 697              ;; MIME article).  That would probably require changing
 698              ;; the mm-handle API so we simply store the multipart buffer
 699              ;; name as a text property of the "multipart/whatever" string.
 700              (add-text-properties 0 (length (car ctl))
 701                                   (list 'buffer (mm-copy-to-buffer)
 702                                         'from from
 703                                         'start start)
 704                                   (car ctl))
 705              (cons (car ctl) (mm-dissect-multipart ctl from))))
 706           (t
 707            (mm-possibly-verify-or-decrypt
 708             (mm-dissect-singlepart
 709              ctl
 710              (and cte (intern (downcase (mail-header-strip cte))))
 711              no-strict-mime
 712              (and cd (mail-header-parse-content-disposition cd))
 713              description id)
 714             ctl from))))
 715         (when id
 716           (when (string-match " *<\\(.*\\)> *" id)
 717             (setq id (match-string 1 id)))
 718           (push (cons id result) mm-content-id-alist))
 719         result))))
 720
 721 (defun mm-dissect-singlepart (ctl cte &optional force cdl description id)
 722   (when (or force
 723             (if (equal "text/plain" (car ctl))
 724                 (assoc 'format ctl)
 725               t))
 726     ;; Guess what the type of application/octet-stream parts should
 727     ;; really be.
 728     (let ((filename (cdr (assq 'filename (cdr cdl)))))
 729       (when (and (not mm-inhibit-auto-detect-attachment)
 730                  (equal (car ctl) "application/octet-stream")
 731                  filename
 732                  (string-match "\\.\\([^.]+\\)$" filename))
 733         (let ((new-type (mailcap-extension-to-mime (match-string 1 filename))))
 734           (when new-type
 735             (setcar ctl new-type)))))
 736     (let ((handle
 737            (mm-make-handle
 738             (mm-copy-to-buffer) ctl cte nil cdl description nil id))
 739           (decoder (assoc (car ctl) (mm-archive-decoders))))
 740       (if (and decoder
 741                ;; Do automatic decoding
 742                (cadr decoder)
 743                (executable-find (caddr decoder)))
 744           (mm-dissect-archive handle)
 745         handle))))
 746
 747 (defun mm-dissect-multipart (ctl from)
 748   (goto-char (point-min))
 749   (let* ((boundary (concat "\n--" (mail-content-type-get ctl 'boundary)))
 750          (close-delimiter (concat (regexp-quote boundary) "--[ \t]*$"))
 751          start parts
 752          (end (save-excursion
 753                 (goto-char (point-max))
 754                 (if (re-search-backward close-delimiter nil t)
 755                     (match-beginning 0)
 756                   (point-max))))
 757          (mm-inhibit-auto-detect-attachment
 758           (equal (car ctl) "multipart/encrypted")))
 759     (setq boundary (concat (regexp-quote boundary) "[ \t]*$"))
 760     (while (and (< (point) end) (re-search-forward boundary end t))
 761       (goto-char (match-beginning 0))
 762       (when start
 763         (save-excursion
 764           (save-restriction
 765             (narrow-to-region start (point))
 766             (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 767       (end-of-line 2)
 768       (or (looking-at boundary)
 769           (forward-line 1))
 770       (setq start (point)))
 771     (when (and start (< start end))
 772       (save-excursion
 773         (save-restriction
 774           (narrow-to-region start end)
 775           (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 776     (mm-possibly-verify-or-decrypt (nreverse parts) ctl from)))
 777
 778 (defun mm-copy-to-buffer ()
 779   "Copy the contents of the current buffer to a fresh buffer."
 780   (let ((obuf (current-buffer))
 781         (mb (mm-multibyte-p))
 782         beg)
 783     (goto-char (point-min))
 784     (search-forward-regexp "^\n" nil t)
 785     (setq beg (point))
 786     (with-current-buffer
 787           (generate-new-buffer " *mm*")
 788       ;; Preserve the data's unibyteness (for url-insert-file-contents).
 789       (mm-set-buffer-multibyte mb)
 790       (insert-buffer-substring obuf beg)
 791       (current-buffer))))
 792
 793 (defun mm-display-parts (handle &optional no-default)
 794   (if (stringp (car handle))
 795       (mapcar 'mm-display-parts (cdr handle))
 796     (if (bufferp (car handle))
 797         (save-restriction
 798           (narrow-to-region (point) (point))
 799           (mm-display-part handle)
 800           (goto-char (point-max)))
 801       (mapcar 'mm-display-parts handle))))
 802
 803 (autoload 'mailcap-parse-mailcaps "mailcap")
 804 (autoload 'mailcap-mime-info "mailcap")
 805
 806 (defun mm-display-part (handle &optional no-default force)
 807   "Display the MIME part represented by HANDLE.
 808 Returns nil if the part is removed; inline if displayed inline;
 809 external if displayed external."
 810   (save-excursion
 811     (mailcap-parse-mailcaps)
 812     (if (and (not force)
 813              (mm-handle-displayed-p handle))
 814         (mm-remove-part handle)
 815       (let* ((ehandle (if (equal (mm-handle-media-type handle)
 816                                  "message/external-body")
 817                           (progn
 818                             (unless (mm-handle-cache handle)
 819                               (mm-extern-cache-contents handle))
 820                             (mm-handle-cache handle))
 821                         handle))
 822              (type (mm-handle-media-type ehandle))
 823              (method (mailcap-mime-info type))
 824              (filename (or (mail-content-type-get
 825                             (mm-handle-disposition handle) 'filename)
 826                            (mail-content-type-get
 827                             (mm-handle-type handle) 'name)
 828                            "<file>"))
 829              (external mm-enable-external)
 830              (decoder (assoc (car (mm-handle-type handle))
 831                              (mm-archive-decoders))))
 832         (cond
 833          ((and decoder
 834                (executable-find (caddr decoder)))
 835           (mm-archive-dissect-and-inline handle)
 836           'inline)
 837          ((and (mm-inlinable-p ehandle)
 838                (mm-inlined-p ehandle))
 839           (forward-line 1)
 840           (mm-display-inline handle)
 841           'inline)
 842          ((or method
 843               (not no-default))
 844           (if (and (not method)
 845                    (equal "text" (car (split-string type "/"))))
 846               (progn
 847                 (forward-line 1)
 848                 (mm-insert-inline handle (mm-get-part handle))
 849                 'inline)
 850             (setq external
 851                   (and method         ;; If nil, we always use "save".
 852                        (stringp method) ;; 'mailcap-save-binary-file
 853                        (or (eq mm-enable-external t)
 854                            (and (eq mm-enable-external 'ask)
 855                                 (y-or-n-p
 856                                  (concat
 857                                   "Display part (" type
 858                                   ") using external program"
 859                                   ;; Can non-string method ever happen?
 860                                   (if (stringp method)
 861                                       (concat
 862                                        " \"" (format method filename) "\"")
 863                                     "")
 864                                   "? "))))))
 865             (if external
 866                 (mm-display-external
 867                  handle (or method 'mailcap-save-binary-file))
 868               (mm-display-external
 869                handle 'mailcap-save-binary-file)))))))))
 870
 871 (declare-function gnus-configure-windows "gnus-win" (setting &optional force))
 872 (defvar mailcap-mime-extensions)        ; mailcap-mime-info autoloads
 873 (declare-function term-mode "term" ())
 874 (declare-function term-char-mode "term" ())
 875
 876 (defun mm-display-external (handle method)
 877   "Display HANDLE using METHOD."
 878   (let ((outbuf (current-buffer)))
 879     (mm-with-unibyte-buffer
 880       (if (functionp method)
 881           (let ((cur (current-buffer)))
 882             (if (eq method 'mailcap-save-binary-file)
 883                 (progn
 884                   (set-buffer (generate-new-buffer " *mm*"))
 885                   (setq method nil))
 886               (mm-insert-part handle)
 887               (mm-add-meta-html-tag handle)
 888               (let ((win (get-buffer-window cur t)))
 889                 (when win
 890                   (select-window win)))
 891               (switch-to-buffer (generate-new-buffer " *mm*")))
 892             (buffer-disable-undo)
 893             (mm-set-buffer-file-coding-system mm-binary-coding-system)
 894             (insert-buffer-substring cur)
 895             (goto-char (point-min))
 896             (when method
 897               (message "Viewing with %s" method))
 898             (let ((mm (current-buffer))
 899                   (non-viewer (assq 'non-viewer
 900                                     (mailcap-mime-info
 901                                      (mm-handle-media-type handle) t))))
 902               (unwind-protect
 903                   (if method
 904                       (funcall method)
 905                     (mm-save-part handle))
 906                 (when (and (not non-viewer)
 907                            method)
 908                   (mm-handle-set-undisplayer handle mm)))))
 909         ;; The function is a string to be executed.
 910         (mm-insert-part handle)
 911         (mm-add-meta-html-tag handle)
 912         (let* ((dir (mm-make-temp-file
 913                      (expand-file-name "emm." mm-tmp-directory) 'dir))
 914                (filename (or
 915                           (mail-content-type-get
 916                            (mm-handle-disposition handle) 'filename)
 917                           (mail-content-type-get
 918                            (mm-handle-type handle) 'name)))
 919                (mime-info (mailcap-mime-info
 920                            (mm-handle-media-type handle) t))
 921                (needsterm (or (assoc "needsterm" mime-info)
 922                               (assoc "needsterminal" mime-info)))
 923                (copiousoutput (assoc "copiousoutput" mime-info))
 924                file buffer)
 925           ;; We create a private sub-directory where we store our files.
 926           (set-file-modes dir #o700)
 927           (if filename
 928               (setq file (expand-file-name
 929                           (gnus-map-function mm-file-name-rewrite-functions
 930                                              (file-name-nondirectory filename))
 931                           dir))
 932             ;; Use nametemplate (defined in RFC1524) if it is specified
 933             ;; in mailcap.
 934             (let ((suffix (cdr (assoc "nametemplate" mime-info))))
 935               (if (and suffix
 936                        (string-match "\\`%s\\(\\..+\\)\\'" suffix))
 937                   (setq suffix (match-string 1 suffix))
 938                 ;; Otherwise, use a suffix according to
 939                 ;; `mailcap-mime-extensions'.
 940                 (setq suffix (car (rassoc (mm-handle-media-type handle)
 941                                           mailcap-mime-extensions))))
 942               (setq file (mm-make-temp-file (expand-file-name "mm." dir)
 943                                             nil suffix))))
 944           (let ((coding-system-for-write mm-binary-coding-system))
 945             (write-region (point-min) (point-max) file nil 'nomesg))
 946           ;; The file is deleted after the viewer exists.  If the users edits
 947           ;; the file, changes will be lost.  Set file to read-only to make it
 948           ;; clear.
 949           (set-file-modes file #o400)
 950           (message "Viewing with %s" method)
 951           (cond
 952            (needsterm
 953             (let ((command (mm-mailcap-command
 954                             method file (mm-handle-type handle))))
 955               (unwind-protect
 956                   (if window-system
 957                       (set-process-sentinel
 958                        (start-process "*display*" nil
 959                                       mm-external-terminal-program
 960                                       "-e" shell-file-name
 961                                       shell-command-switch command)
 962                        `(lambda (process state)
 963                           (if (eq 'exit (process-status process))
 964                               (run-at-time
 965                                60.0 nil
 966                                (lambda ()
 967                                  (ignore-errors (delete-file ,file))
 968                                  (ignore-errors (delete-directory
 969                                                  ,(file-name-directory
 970                                                    file))))))))
 971                     (require 'term)
 972                     (require 'gnus-win)
 973                     (set-buffer
 974                      (setq buffer
 975                            (make-term "display"
 976                                       shell-file-name
 977                                       nil
 978                                       shell-command-switch command)))
 979                     (term-mode)
 980                     (term-char-mode)
 981                     (set-process-sentinel
 982                      (get-buffer-process buffer)
 983                      `(lambda (process state)
 984                         (when (eq 'exit (process-status process))
 985                           (ignore-errors (delete-file ,file))
 986                           (ignore-errors
 987                             (delete-directory ,(file-name-directory file)))
 988                           (gnus-configure-windows
 989                            ',gnus-current-window-configuration))))
 990                     (gnus-configure-windows 'display-term))
 991                 (mm-handle-set-external-undisplayer handle (cons file buffer))
 992                 (add-to-list 'mm-temp-files-to-be-deleted file t))
 993               (message "Displaying %s..." command))
 994             'external)
 995            (copiousoutput
 996             (with-current-buffer outbuf
 997               (forward-line 1)
 998               (mm-insert-inline
 999                handle
1000                (unwind-protect
1001                    (progn
1002                      (call-process shell-file-name nil
1003                                    (setq buffer
1004                                          (generate-new-buffer " *mm*"))
1005                                    nil
1006                                    shell-command-switch
1007                                    (mm-mailcap-command
1008                                     method file (mm-handle-type handle)))
1009                      (if (buffer-live-p buffer)
1010                          (with-current-buffer buffer
1011                            (buffer-string))))
1012                  (progn
1013                    (ignore-errors (delete-file file))
1014                    (ignore-errors (delete-directory
1015                                    (file-name-directory file)))
1016                    (ignore-errors (kill-buffer buffer))))))
1017             'inline)
1018            (t
1019             ;; Deleting the temp file should be postponed for some wrappers,
1020             ;; shell scripts, and so on, which might exit right after having
1021             ;; started a viewer command as a background job.
1022             (let ((command (mm-mailcap-command
1023                             method file (mm-handle-type handle))))
1024               (unwind-protect
1025                   (let ((process-connection-type nil))
1026                     (start-process "*display*"
1027                                    (setq buffer
1028                                          (generate-new-buffer " *mm*"))
1029                                    shell-file-name
1030                                    shell-command-switch command)
1031                     (set-process-sentinel
1032                      (get-buffer-process buffer)
1033                      (lexical-let ((outbuf outbuf)
1034                                    (file file)
1035                                    (buffer buffer)
1036                                    (command command)
1037                                    (handle handle))
1038                        (lambda (process state)
1039                          (when (eq (process-status process) 'exit)
1040                            (run-at-time
1041                             60.0 nil
1042                             (lambda ()
1043                               (ignore-errors (delete-file file))
1044                               (ignore-errors (delete-directory
1045                                               (file-name-directory file)))))
1046                            (when (buffer-live-p outbuf)
1047                              (with-current-buffer outbuf
1048                                (let ((buffer-read-only nil)
1049                                      (point (point)))
1050                                  (forward-line 2)
1051                                  (let ((start (point)))
1052                                    (mm-insert-inline
1053                                     handle (with-current-buffer buffer
1054                                              (buffer-string)))
1055                                    (put-text-property start (point)
1056                                                       'face 'mm-command-output))
1057                                  (goto-char point))))
1058                            (when (buffer-live-p buffer)
1059                              (kill-buffer buffer)))
1060                          (message "Displaying %s...done" command)))))
1061                 (mm-handle-set-external-undisplayer
1062                  handle (cons file buffer))
1063                 (add-to-list 'mm-temp-files-to-be-deleted file t))
1064               (message "Displaying %s..." command))
1065             'external)))))))
1066
1067 (defun mm-mailcap-command (method file type-list)
1068   (let ((ctl (cdr type-list))
1069         (beg 0)
1070         (uses-stdin t)
1071         out sub total)
1072     (while (string-match "%{\\([^}]+\\)}\\|'%s'\\|\"%s\"\\|%s\\|%t\\|%%"
1073                          method beg)
1074       (push (substring method beg (match-beginning 0)) out)
1075       (setq beg (match-end 0)
1076             total (match-string 0 method)
1077             sub (match-string 1 method))
1078       (cond
1079        ((string= total "%%")
1080         (push "%" out))
1081        ((or (string= total "%s")
1082             ;; We do our own quoting.
1083             (string= total "'%s'")
1084             (string= total "\"%s\""))
1085         (setq uses-stdin nil)
1086         (push (shell-quote-argument
1087                (gnus-map-function mm-path-name-rewrite-functions file)) out))
1088        ((string= total "%t")
1089         (push (shell-quote-argument (car type-list)) out))
1090        (t
1091         (push (shell-quote-argument (or (cdr (assq (intern sub) ctl)) "")) out))))
1092     (push (substring method beg (length method)) out)
1093     (when uses-stdin
1094       (push "<" out)
1095       (push (shell-quote-argument
1096              (gnus-map-function mm-path-name-rewrite-functions file))
1097             out))
1098     (mapconcat 'identity (nreverse out) "")))
1099
1100 (defun mm-remove-parts (handles)
1101   "Remove the displayed MIME parts represented by HANDLES."
1102   (if (and (listp handles)
1103            (bufferp (car handles)))
1104       (mm-remove-part handles)
1105     (let (handle)
1106       (while (setq handle (pop handles))
1107         (cond
1108          ((stringp handle)
1109           (when (buffer-live-p (get-text-property 0 'buffer handle))
1110             (kill-buffer (get-text-property 0 'buffer handle))))
1111          ((and (listp handle)
1112                (stringp (car handle)))
1113           (mm-remove-parts (cdr handle)))
1114          (t
1115           (mm-remove-part handle)))))))
1116
1117 (defun mm-destroy-parts (handles)
1118   "Remove the displayed MIME parts represented by HANDLES."
1119   (if (and (listp handles)
1120            (bufferp (car handles)))
1121       (mm-destroy-part handles)
1122     (let (handle)
1123       (while (setq handle (pop handles))
1124         (cond
1125          ((stringp handle)
1126           (when (buffer-live-p (get-text-property 0 'buffer handle))
1127             (kill-buffer (get-text-property 0 'buffer handle))))
1128          ((and (listp handle)
1129                (stringp (car handle)))
1130           (mm-destroy-parts handle))
1131          (t
1132           (mm-destroy-part handle)))))))
1133
1134 (defun mm-remove-part (handle)
1135   "Remove the displayed MIME part represented by HANDLE."
1136   (when (listp handle)
1137     (let ((object (mm-handle-undisplayer handle)))
1138       (ignore-errors
1139         (cond
1140          ;; Internally displayed part.
1141          ((mm-annotationp object)
1142           (if (featurep 'xemacs)
1143               (delete-annotation object)))
1144          ((or (functionp object)
1145               (and (listp object)
1146                    (eq (car object) 'lambda)))
1147           (funcall object))
1148          ;; Externally displayed part.
1149          ((consp object)
1150           (condition-case ()
1151               (while (get-buffer-process (cdr object))
1152                 (interrupt-process (get-buffer-process (cdr object)))
1153                 (message "Waiting for external displayer to die...")
1154                 (sit-for 1))
1155             (quit)
1156             (error))
1157           (ignore-errors (and (cdr object) (kill-buffer (cdr object))))
1158           (message "Waiting for external displayer to die...done")
1159           (ignore-errors (delete-file (car object)))
1160           (ignore-errors (delete-directory (file-name-directory
1161                                             (car object)))))
1162          ((bufferp object)
1163           (when (buffer-live-p object)
1164             (kill-buffer object)))))
1165       (mm-handle-set-undisplayer handle nil))))
1166
1167 (defun mm-display-inline (handle)
1168   (let* ((type (mm-handle-media-type handle))
1169          (function (cadr (mm-assoc-string-match mm-inline-media-tests type))))
1170     (funcall function handle)
1171     (goto-char (point-min))))
1172
1173 (defun mm-assoc-string-match (alist type)
1174   (dolist (elem alist)
1175     (when (string-match (car elem) type)
1176       (return elem))))
1177
1178 (defun mm-automatic-display-p (handle)
1179   "Say whether the user wants HANDLE to be displayed automatically."
1180   (let ((methods mm-automatic-display)
1181         (type (mm-handle-media-type handle))
1182         method result)
1183     (while (setq method (pop methods))
1184       (when (and (not (mm-inline-override-p handle))
1185                  (string-match method type))
1186         (setq result t
1187               methods nil)))
1188     result))
1189
1190 (defun mm-inlinable-p (handle &optional type)
1191   "Say whether HANDLE can be displayed inline.
1192 TYPE is the mime-type of the object; it defaults to the one given
1193 in HANDLE."
1194   (unless type (setq type (mm-handle-media-type handle)))
1195   (let ((alist mm-inline-media-tests)
1196         test)
1197     (while alist
1198       (when (string-match (caar alist) type)
1199         (setq test (caddar alist)
1200               alist nil)
1201         (setq test (funcall test handle)))
1202       (pop alist))
1203     test))
1204
1205 (defun mm-inlined-p (handle)
1206   "Say whether the user wants HANDLE to be displayed inline."
1207   (let ((methods mm-inlined-types)
1208         (type (mm-handle-media-type handle))
1209         method result)
1210     (while (setq method (pop methods))
1211       (when (and (not (mm-inline-override-p handle))
1212                  (string-match method type))
1213         (setq result t
1214               methods nil)))
1215     result))
1216
1217 (defun mm-attachment-override-p (handle)
1218   "Say whether HANDLE should have attachment behavior overridden."
1219   (let ((types mm-attachment-override-types)
1220         (type (mm-handle-media-type handle))
1221         ty)
1222     (catch 'found
1223       (while (setq ty (pop types))
1224         (when (and (string-match ty type)
1225                    (mm-inlinable-p handle))
1226           (throw 'found t))))))
1227
1228 (defun mm-inline-override-p (handle)
1229   "Say whether HANDLE should have inline behavior overridden."
1230   (let ((types mm-inline-override-types)
1231         (type (mm-handle-media-type handle))
1232         ty)
1233     (catch 'found
1234       (while (setq ty (pop types))
1235         (when (string-match ty type)
1236           (throw 'found t))))))
1237
1238 (defun mm-automatic-external-display-p (type)
1239   "Return the user-defined method for TYPE."
1240   (let ((methods mm-automatic-external-display)
1241         method result)
1242     (while (setq method (pop methods))
1243       (when (string-match method type)
1244         (setq result t
1245               methods nil)))
1246     result))
1247
1248 (defun mm-destroy-part (handle)
1249   "Destroy the data structures connected to HANDLE."
1250   (when (listp handle)
1251     (mm-remove-part handle)
1252     (when (buffer-live-p (mm-handle-buffer handle))
1253       (kill-buffer (mm-handle-buffer handle)))))
1254
1255 (defun mm-handle-displayed-p (handle)
1256   "Say whether HANDLE is displayed or not."
1257   (mm-handle-undisplayer handle))
1258
1259 ;;;
1260 ;;; Functions for outputting parts
1261 ;;;
1262
1263 (defmacro mm-with-part (handle &rest forms)
1264   "Run FORMS in the temp buffer containing the contents of HANDLE."
1265   ;; The handle-buffer's content is a sequence of bytes, not a sequence of
1266   ;; chars, so the buffer should be unibyte.  It may happen that the
1267   ;; handle-buffer is multibyte for some reason, in which case now is a good
1268   ;; time to adjust it, since we know at this point that it should
1269   ;; be unibyte.
1270   `(let* ((handle ,handle))
1271      (when (and (mm-handle-buffer handle)
1272                 (buffer-name (mm-handle-buffer handle)))
1273        (with-temp-buffer
1274          (mm-disable-multibyte)
1275          (insert-buffer-substring (mm-handle-buffer handle))
1276          (mm-decode-content-transfer-encoding
1277           (mm-handle-encoding handle)
1278           (mm-handle-media-type handle))
1279          ,@forms))))
1280 (put 'mm-with-part 'lisp-indent-function 1)
1281 (put 'mm-with-part 'edebug-form-spec '(body))
1282
1283 (defun mm-get-part (handle &optional no-cache)
1284   "Return the contents of HANDLE as a string.
1285 If NO-CACHE is non-nil, cached contents of a message/external-body part
1286 are ignored."
1287   (if (and (not no-cache)
1288            (equal (mm-handle-media-type handle) "message/external-body"))
1289       (progn
1290         (unless (mm-handle-cache handle)
1291           (mm-extern-cache-contents handle))
1292         (with-current-buffer (mm-handle-buffer (mm-handle-cache handle))
1293           (buffer-string)))
1294     (mm-with-part handle
1295       (buffer-string))))
1296
1297 (defun mm-insert-part (handle &optional no-cache)
1298   "Insert the contents of HANDLE in the current buffer.
1299 If NO-CACHE is non-nil, cached contents of a message/external-body part
1300 are ignored."
1301   (let ((text (cond ((eq (mail-content-type-get (mm-handle-type handle)
1302                                                 'charset)
1303                          'gnus-decoded)
1304                      (with-current-buffer (mm-handle-buffer handle)
1305                        (buffer-string)))
1306                     ((mm-multibyte-p)
1307                      (mm-string-to-multibyte (mm-get-part handle no-cache)))
1308                     (t
1309                      (mm-get-part handle no-cache)))))
1310     (save-restriction
1311       (widen)
1312       (goto-char
1313        (prog1
1314            (point)
1315          (if (and (eq (get-char-property (max (point-min) (1- (point))) 'face)
1316                       'mm-uu-extract)
1317                   (eq (get-char-property 0 'face text) 'mm-uu-extract))
1318              ;; Separate the extracted parts that have the same faces.
1319              (insert "\n" text)
1320            (insert text)))))))
1321
1322 (defun mm-file-name-delete-whitespace (file-name)
1323   "Remove all whitespace characters from FILE-NAME."
1324   (while (string-match "\\s-+" file-name)
1325     (setq file-name (replace-match "" t t file-name)))
1326   file-name)
1327
1328 (defun mm-file-name-trim-whitespace (file-name)
1329   "Remove leading and trailing whitespace characters from FILE-NAME."
1330   (when (string-match "\\`\\s-+" file-name)
1331     (setq file-name (substring file-name (match-end 0))))
1332   (when (string-match "\\s-+\\'" file-name)
1333     (setq file-name (substring file-name 0 (match-beginning 0))))
1334   file-name)
1335
1336 (defun mm-file-name-collapse-whitespace (file-name)
1337   "Collapse multiple whitespace characters in FILE-NAME."
1338   (while (string-match "\\s-\\s-+" file-name)
1339     (setq file-name (replace-match " " t t file-name)))
1340   file-name)
1341
1342 (defun mm-file-name-replace-whitespace (file-name)
1343   "Replace whitespace characters in FILE-NAME with underscores.
1344 Set the option `mm-file-name-replace-whitespace' to any other
1345 string if you do not like underscores."
1346   (let ((s (or mm-file-name-replace-whitespace "_")))
1347     (while (string-match "\\s-" file-name)
1348       (setq file-name (replace-match s t t file-name))))
1349   file-name)
1350
1351 (defun mm-file-name-delete-control (filename)
1352   "Delete control characters from FILENAME."
1353   (gnus-replace-in-string filename "[\x00-\x1f\x7f]" ""))
1354
1355 (defun mm-file-name-delete-gotchas (filename)
1356   "Delete shell gotchas from FILENAME."
1357   (setq filename (gnus-replace-in-string filename "[<>|]" ""))
1358   (gnus-replace-in-string filename "^[.-]+" ""))
1359
1360 (defun mm-save-part (handle &optional prompt)
1361   "Write HANDLE to a file.
1362 PROMPT overrides the default one used to ask user for a file name."
1363   (let ((filename (or (mail-content-type-get
1364                        (mm-handle-disposition handle) 'filename)
1365                       (mail-content-type-get
1366                        (mm-handle-type handle) 'name)))
1367         file)
1368     (when filename
1369       (setq filename (gnus-map-function mm-file-name-rewrite-functions
1370                                         (file-name-nondirectory filename))))
1371     (while
1372         (progn
1373           (setq file
1374                 (read-file-name
1375                  (or prompt
1376                      (format "Save MIME part to (default %s): "
1377                              (or filename "")))
1378                  (or mm-default-directory default-directory)
1379                  (expand-file-name (or filename "")
1380                                    (or mm-default-directory default-directory))))
1381           (cond ((or (not file) (equal file ""))
1382                  (message "Please enter a file name")
1383                  t)
1384                 ((and (file-directory-p file)
1385                       (not filename))
1386                  (message "Please enter a non-directory file name")
1387                  t)
1388                 (t nil)))
1389       (sit-for 2)
1390       (discard-input))
1391     (if (file-directory-p file)
1392         (setq file (expand-file-name filename file))
1393       (setq file (expand-file-name
1394                   file (or mm-default-directory default-directory))))
1395     (setq mm-default-directory (file-name-directory file))
1396     (and (or (not (file-exists-p file))
1397              (yes-or-no-p (format "File %s already exists; overwrite? "
1398                                   file)))
1399          (progn
1400            (mm-save-part-to-file handle file)
1401            file))))
1402
1403 (defun mm-add-meta-html-tag (handle &optional charset force-charset)
1404   "Add meta html tag to specify CHARSET of HANDLE in the current buffer.
1405 CHARSET defaults to the one HANDLE specifies.  Existing meta tag that
1406 specifies charset will not be modified unless FORCE-CHARSET is non-nil.
1407 Return t if meta tag is added or replaced."
1408   (when (equal (mm-handle-media-type handle) "text/html")
1409     (when (or charset
1410               (setq charset (mail-content-type-get (mm-handle-type handle)
1411                                                    'charset)))
1412       (setq charset (format "\
1413 <meta http-equiv=\"Content-Type\" content=\"text/html; charset=%s\">" charset))
1414       (let ((case-fold-search t))
1415         (goto-char (point-min))
1416         (if (re-search-forward "\
1417 <meta\\s-+http-equiv=[\"']?content-type[\"']?\\s-+content=[\"']\
1418 text/\\(\\sw+\\)\\(?:\;\\s-*charset=\\(.+\\)\\)?[\"'][^>]*>" nil t)
1419             (if (and (not force-charset)
1420                      (match-beginning 2)
1421                      (string-match "\\`html\\'" (match-string 1)))
1422                 ;; Don't modify existing meta tag.
1423                 nil
1424               ;; Replace it with the one specifying charset.
1425               (replace-match charset)
1426               t)
1427           (if (re-search-forward "<head>\\s-*" nil t)
1428               (insert charset "\n")
1429             (re-search-forward "<html\\(?:\\s-+[^>]+\\|\\s-*\\)>\\s-*" nil t)
1430             (insert "<head>\n" charset "\n</head>\n"))
1431           t)))))
1432
1433 (defun mm-save-part-to-file (handle file)
1434   (mm-with-unibyte-buffer
1435     (mm-insert-part handle)
1436     (mm-add-meta-html-tag handle)
1437     (let ((current-file-modes (default-file-modes)))
1438       (set-default-file-modes mm-attachment-file-modes)
1439       (unwind-protect
1440           ;; Don't re-compress .gz & al.  Arguably we should make
1441           ;; `file-name-handler-alist' nil, but that would chop
1442           ;; ange-ftp, which is reasonable to use here.
1443           (mm-write-region (point-min) (point-max) file nil nil nil 'binary t)
1444         (set-default-file-modes current-file-modes)))))
1445
1446 (defun mm-pipe-part (handle &optional cmd)
1447   "Pipe HANDLE to a process.
1448 Use CMD as the process."
1449   (let ((name (mail-content-type-get (mm-handle-type handle) 'name))
1450         (command (or cmd
1451                      (gnus-read-shell-command
1452                       "Shell command on MIME part: " mm-last-shell-command))))
1453     (mm-with-unibyte-buffer
1454       (mm-insert-part handle)
1455       (mm-add-meta-html-tag handle)
1456       (let ((coding-system-for-write 'binary))
1457         (shell-command-on-region (point-min) (point-max) command nil)))))
1458
1459 (autoload 'gnus-completing-read "gnus-util")
1460
1461 (defun mm-interactively-view-part (handle)
1462   "Display HANDLE using METHOD."
1463   (let* ((type (mm-handle-media-type handle))
1464          (methods
1465           (mapcar (lambda (i) (cdr (assoc 'viewer i)))
1466                   (mailcap-mime-info type 'all)))
1467          (method (let ((minibuffer-local-completion-map
1468                         mm-viewer-completion-map))
1469                    (completing-read "Viewer: " methods))))
1470     (when (string= method "")
1471       (error "No method given"))
1472     (if (string-match "^[^% \t]+$" method)
1473         (setq method (concat method " %s")))
1474     (mm-display-external handle method)))
1475
1476 (defun mm-preferred-alternative (handles &optional preferred)
1477   "Say which of HANDLES are preferred."
1478   (let ((prec (if preferred (list preferred)
1479                 (mm-preferred-alternative-precedence handles)))
1480         p h result type handle)
1481     (while (setq p (pop prec))
1482       (setq h handles)
1483       (while h
1484         (setq handle (car h))
1485         (setq type (mm-handle-media-type handle))
1486         (when (and (equal p type)
1487                    (mm-automatic-display-p handle)
1488                    (or (stringp (car handle))
1489                        (not (mm-handle-disposition handle))
1490                        (equal (car (mm-handle-disposition handle))
1491                               "inline")))
1492           (setq result handle
1493                 h nil
1494                 prec nil))
1495         (pop h)))
1496     result))
1497
1498 (defun mm-preferred-alternative-precedence (handles)
1499   "Return the precedence based on HANDLES and `mm-discouraged-alternatives'."
1500   (setq handles (reverse handles))
1501   (dolist (disc (reverse mm-discouraged-alternatives))
1502     (dolist (handle (copy-sequence handles))
1503       (when (string-match disc (mm-handle-media-type handle))
1504         (setq handles (nconc (delete handle handles) (list handle))))))
1505   ;; Remove empty parts.
1506   (dolist (handle (copy-sequence handles))
1507     (when (and (bufferp (mm-handle-buffer handle))
1508                (not (with-current-buffer (mm-handle-buffer handle)
1509                       (goto-char (point-min))
1510                       (re-search-forward "[^ \t\n]" nil t))))
1511       (setq handles (nconc (delete handle handles) (list handle)))))
1512   (mapcar #'mm-handle-media-type handles))
1513
1514 (defun mm-get-content-id (id)
1515   "Return the handle(s) referred to by ID."
1516   (cdr (assoc id mm-content-id-alist)))
1517
1518 (defconst mm-image-type-regexps
1519   '(("/\\*.*XPM.\\*/" . xpm)
1520     ("P[1-6]" . pbm)
1521     ("GIF8" . gif)
1522     ("\377\330" . jpeg)
1523     ("\211PNG\r\n" . png)
1524     ("#define" . xbm)
1525     ("\\(MM\0\\*\\)\\|\\(II\\*\0\\)" . tiff)
1526     ("%!PS" . postscript))
1527   "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
1528 When the first bytes of an image file match REGEXP, it is assumed to
1529 be of image type IMAGE-TYPE.")
1530
1531 ;; Steal from image.el. image-type-from-data suffers multi-line matching bug.
1532 (defun mm-image-type-from-buffer ()
1533   "Determine the image type from data in the current buffer.
1534 Value is a symbol specifying the image type or nil if type cannot
1535 be determined."
1536   (let ((types mm-image-type-regexps)
1537         type)
1538     (goto-char (point-min))
1539     (while (and types (null type))
1540       (let ((regexp (car (car types)))
1541             (image-type (cdr (car types))))
1542         (when (looking-at regexp)
1543           (setq type image-type))
1544         (setq types (cdr types))))
1545     type))
1546
1547 (defun mm-get-image (handle)
1548   "Return an image instance based on HANDLE."
1549   (let ((type (mm-handle-media-subtype handle))
1550         spec)
1551     ;; Allow some common translations.
1552     (setq type
1553           (cond
1554            ((equal type "x-pixmap")
1555             "xpm")
1556            ((equal type "x-xbitmap")
1557             "xbm")
1558            ((equal type "x-portable-bitmap")
1559             "pbm")
1560            (t type)))
1561     (or (mm-handle-cache handle)
1562         (mm-with-unibyte-buffer
1563           (mm-insert-part handle)
1564           (prog1
1565               (setq spec
1566                     (ignore-errors
1567                       ;; Avoid testing `make-glyph' since W3 may define
1568                       ;; a bogus version of it.
1569                       (if (fboundp 'create-image)
1570                           (create-image (buffer-string)
1571                                         (or (mm-image-type-from-buffer)
1572                                             (intern type))
1573                                         'data-p)
1574                         (mm-create-image-xemacs type))))
1575             (mm-handle-set-cache handle spec))))))
1576
1577 (defun mm-create-image-xemacs (type)
1578   (when (featurep 'xemacs)
1579     (cond
1580      ((equal type "xbm")
1581       ;; xbm images require special handling, since
1582       ;; the only way to create glyphs from these
1583       ;; (without a ton of work) is to write them
1584       ;; out to a file, and then create a file
1585       ;; specifier.
1586       (let ((file (mm-make-temp-file
1587                    (expand-file-name "emm" mm-tmp-directory)
1588                    nil ".xbm")))
1589         (unwind-protect
1590             (progn
1591               (write-region (point-min) (point-max) file)
1592               (make-glyph (list (cons 'x file))))
1593           (ignore-errors
1594             (delete-file file)))))
1595      (t
1596       (make-glyph
1597        (vector
1598         (or (mm-image-type-from-buffer)
1599             (intern type))
1600         :data (buffer-string)))))))
1601
1602 (declare-function image-size "image.c" (spec &optional pixels frame))
1603
1604 (defun mm-image-fit-p (handle)
1605   "Say whether the image in HANDLE will fit the current window."
1606   (let ((image (mm-get-image handle)))
1607     (or (not image)
1608         (if (featurep 'xemacs)
1609             ;; XEmacs's glyphs can actually tell us about their width, so
1610             ;; let's be nice and smart about them.
1611             (or mm-inline-large-images
1612                 (and (<= (glyph-width image) (window-pixel-width))
1613                      (<= (glyph-height image) (window-pixel-height))))
1614           (let* ((size (image-size image))
1615                  (w (car size))
1616                  (h (cdr size)))
1617             (or mm-inline-large-images
1618                 (and (<= h (1- (window-height))) ; Don't include mode line.
1619                      (<= w (window-width)))))))))
1620
1621 (defun mm-valid-image-format-p (format)
1622   "Say whether FORMAT can be displayed natively by Emacs."
1623   (cond
1624    ;; Handle XEmacs
1625    ((fboundp 'valid-image-instantiator-format-p)
1626     (valid-image-instantiator-format-p format))
1627    ;; Handle Emacs
1628    ((fboundp 'image-type-available-p)
1629     (and (display-graphic-p)
1630          (image-type-available-p format)))
1631    ;; Nobody else can do images yet.
1632    (t
1633     nil)))
1634
1635 (defun mm-valid-and-fit-image-p (format handle)
1636   "Say whether FORMAT can be displayed natively and HANDLE fits the window."
1637   (and (mm-valid-image-format-p format)
1638        (mm-image-fit-p handle)))
1639
1640 (defun mm-find-part-by-type (handles type &optional notp recursive)
1641   "Search in HANDLES for part with TYPE.
1642 If NOTP, returns first non-matching part.
1643 If RECURSIVE, search recursively."
1644   (let (handle)
1645     (while handles
1646       (if (and recursive (stringp (caar handles)))
1647           (if (setq handle (mm-find-part-by-type (cdar handles) type
1648                                                  notp recursive))
1649               (setq handles nil))
1650         (if (if notp
1651                 (not (equal (mm-handle-media-type (car handles)) type))
1652               (equal (mm-handle-media-type (car handles)) type))
1653             (setq handle (car handles)
1654                   handles nil)))
1655       (setq handles (cdr handles)))
1656     handle))
1657
1658 (defun mm-find-raw-part-by-type (ctl type &optional notp)
1659   (goto-char (point-min))
1660   (let* ((boundary (concat "--" (mm-handle-multipart-ctl-parameter ctl
1661                                                                    'boundary)))
1662          (close-delimiter (concat "^" (regexp-quote boundary) "--[ \t]*$"))
1663          start
1664          (end (save-excursion
1665                 (goto-char (point-max))
1666                 (if (re-search-backward close-delimiter nil t)
1667                     (match-beginning 0)
1668                   (point-max))))
1669          result)
1670     (setq boundary (concat "^" (regexp-quote boundary) "[ \t]*$"))
1671     (while (and (not result)
1672                 (re-search-forward boundary end t))
1673       (goto-char (match-beginning 0))
1674       (when start
1675         (save-excursion
1676           (save-restriction
1677             (narrow-to-region start (1- (point)))
1678             (when (let* ((ct (mail-fetch-field "content-type"))
1679                          (ctl (and ct (mail-header-parse-content-type ct))))
1680                     (if notp
1681                         (not (equal (car ctl) type))
1682                       (equal (car ctl) type)))
1683               (setq result (buffer-string))))))
1684       (forward-line 1)
1685       (setq start (point)))
1686     (when (and (not result) start)
1687       (save-excursion
1688         (save-restriction
1689           (narrow-to-region start end)
1690           (when (let* ((ct (mail-fetch-field "content-type"))
1691                        (ctl (and ct (mail-header-parse-content-type ct))))
1692                   (if notp
1693                       (not (equal (car ctl) type))
1694                     (equal (car ctl) type)))
1695             (setq result (buffer-string))))))
1696     result))
1697
1698 (defvar mm-security-handle nil)
1699
1700 (defsubst mm-set-handle-multipart-parameter (handle parameter value)
1701   ;; HANDLE could be a CTL.
1702   (when handle
1703     (put-text-property 0 (length (car handle)) parameter value
1704                        (car handle))))
1705
1706 (autoload 'mm-view-pkcs7 "mm-view")
1707
1708 (defun mm-possibly-verify-or-decrypt (parts ctl &optional from)
1709   (let ((type (car ctl))
1710         (subtype (cadr (split-string (car ctl) "/")))
1711         (mm-security-handle ctl) ;; (car CTL) is the type.
1712         protocol func functest)
1713     (cond
1714      ((or (equal type "application/x-pkcs7-mime")
1715           (equal type "application/pkcs7-mime"))
1716       (with-temp-buffer
1717         (when (and (cond
1718                     ((eq mm-decrypt-option 'never) nil)
1719                     ((eq mm-decrypt-option 'always) t)
1720                     ((eq mm-decrypt-option 'known) t)
1721                     (t (y-or-n-p
1722                         (format "Decrypt (S/MIME) part? "))))
1723                    (mm-view-pkcs7 parts from))
1724           (setq parts (mm-dissect-buffer t)))))
1725      ((equal subtype "signed")
1726       (unless (and (setq protocol
1727                          (mm-handle-multipart-ctl-parameter ctl 'protocol))
1728                    (not (equal protocol "multipart/mixed")))
1729         ;; The message is broken or draft-ietf-openpgp-multsig-01.
1730         (let ((protocols mm-verify-function-alist))
1731           (while protocols
1732             (if (and (or (not (setq functest (nth 3 (car protocols))))
1733                          (funcall functest parts ctl))
1734                      (mm-find-part-by-type parts (caar protocols) nil t))
1735                 (setq protocol (caar protocols)
1736                       protocols nil)
1737               (setq protocols (cdr protocols))))))
1738       (setq func (nth 1 (assoc protocol mm-verify-function-alist)))
1739       (when (cond
1740              ((eq mm-verify-option 'never) nil)
1741              ((eq mm-verify-option 'always) t)
1742              ((eq mm-verify-option 'known)
1743               (and func
1744                    (or (not (setq functest
1745                                   (nth 3 (assoc protocol
1746                                                 mm-verify-function-alist))))
1747                        (funcall functest parts ctl))))
1748              (t
1749               (y-or-n-p
1750                (format "Verify signed (%s) part? "
1751                        (or (nth 2 (assoc protocol mm-verify-function-alist))
1752                            (format "protocol=%s" protocol))))))
1753         (save-excursion
1754           (if func
1755               (setq parts (funcall func parts ctl))
1756             (mm-set-handle-multipart-parameter
1757              mm-security-handle 'gnus-details
1758              (format "Unknown sign protocol (%s)" protocol))))))
1759      ((equal subtype "encrypted")
1760       (unless (setq protocol
1761                     (mm-handle-multipart-ctl-parameter ctl 'protocol))
1762         ;; The message is broken.
1763         (let ((parts parts))
1764           (while parts
1765             (if (assoc (mm-handle-media-type (car parts))
1766                        mm-decrypt-function-alist)
1767                 (setq protocol (mm-handle-media-type (car parts))
1768                       parts nil)
1769               (setq parts (cdr parts))))))
1770       (setq func (nth 1 (assoc protocol mm-decrypt-function-alist)))
1771       (when (cond
1772              ((eq mm-decrypt-option 'never) nil)
1773              ((eq mm-decrypt-option 'always) t)
1774              ((eq mm-decrypt-option 'known)
1775               (and func
1776                    (or (not (setq functest
1777                                   (nth 3 (assoc protocol
1778                                                 mm-decrypt-function-alist))))
1779                        (funcall functest parts ctl))))
1780              (t
1781               (y-or-n-p
1782                (format "Decrypt (%s) part? "
1783                        (or (nth 2 (assoc protocol mm-decrypt-function-alist))
1784                            (format "protocol=%s" protocol))))))
1785         (save-excursion
1786           (if func
1787               (setq parts (funcall func parts ctl))
1788             (mm-set-handle-multipart-parameter
1789              mm-security-handle 'gnus-details
1790              (format "Unknown encrypt protocol (%s)" protocol))))))
1791      (t nil))
1792     parts))
1793
1794 (defun mm-multiple-handles (handles)
1795   (and (listp handles)
1796        (> (length handles) 1)
1797        (or (listp (car handles))
1798            (stringp (car handles)))))
1799
1800 (defun mm-complicated-handles (handles)
1801   (and (listp (car handles))
1802        (> (length handles) 1)))
1803
1804 (defun mm-merge-handles (handles1 handles2)
1805   (append
1806    (if (listp (car handles1))
1807        handles1
1808      (list handles1))
1809    (if (listp (car handles2))
1810        handles2
1811      (list handles2))))
1812
1813 (defun mm-readable-p (handle)
1814   "Say whether the content of HANDLE is readable."
1815   (and (< (with-current-buffer (mm-handle-buffer handle)
1816             (buffer-size)) 10000)
1817        (mm-with-unibyte-buffer
1818          (mm-insert-part handle)
1819          (and (eq (mm-body-7-or-8) '7bit)
1820               (not (mm-long-lines-p 76))))))
1821
1822 (declare-function libxml-parse-html-region "xml.c"
1823                   (start end &optional base-url))
1824 (declare-function shr-insert-document "shr" (dom))
1825 (defvar shr-blocked-images)
1826 (defvar gnus-inhibit-images)
1827 (autoload 'gnus-blocked-images "gnus-art")
1828
1829 (defun mm-shr (handle)
1830   ;; Require since we bind its variables.
1831   (require 'shr)
1832   (let ((article-buffer (current-buffer))
1833         (shr-content-function (lambda (id)
1834                                 (let ((handle (mm-get-content-id id)))
1835                                   (when handle
1836                                     (mm-with-part handle
1837                                       (buffer-string))))))
1838         shr-inhibit-images shr-blocked-images charset char)
1839     (if (and (boundp 'gnus-summary-buffer)
1840              (bufferp gnus-summary-buffer)
1841              (buffer-name gnus-summary-buffer))
1842         (with-current-buffer gnus-summary-buffer
1843           (setq shr-inhibit-images gnus-inhibit-images
1844                 shr-blocked-images (gnus-blocked-images)))
1845       (setq shr-inhibit-images gnus-inhibit-images
1846             shr-blocked-images (gnus-blocked-images)))
1847     (unless handle
1848       (setq handle (mm-dissect-buffer t)))
1849     (setq charset (mail-content-type-get (mm-handle-type handle) 'charset))
1850     (save-restriction
1851       (narrow-to-region (point) (point))
1852       (shr-insert-document
1853        (mm-with-part handle
1854          (insert (prog1
1855                      (if (and charset
1856                               (setq charset
1857                                     (mm-charset-to-coding-system charset
1858                                                                  nil t))
1859                               (not (eq charset 'ascii)))
1860                          (mm-decode-coding-string (buffer-string) charset)
1861                        (mm-string-as-multibyte (buffer-string)))
1862                    (erase-buffer)
1863                    (mm-enable-multibyte)))
1864          (goto-char (point-min))
1865          (setq case-fold-search t)
1866          (while (re-search-forward
1867                  "&#\\(?:x\\([89][0-9a-f]\\)\\|\\(1[2-5][0-9]\\)\\);" nil t)
1868            (when (setq char
1869                        (cdr (assq (if (match-beginning 1)
1870                                       (string-to-number (match-string 1) 16)
1871                                     (string-to-number (match-string 2)))
1872                                   mm-extra-numeric-entities)))
1873              (replace-match (char-to-string char))))
1874          ;; Remove "soft hyphens".
1875          (goto-char (point-min))
1876          (while (search-forward "" nil t)
1877            (replace-match "" t t))
1878          (libxml-parse-html-region (point-min) (point-max))))
1879       (unless (bobp)
1880         (insert "\n"))
1881       (mm-convert-shr-links)
1882       (mm-handle-set-undisplayer
1883        handle
1884        `(lambda ()
1885           (let ((inhibit-read-only t))
1886             (delete-region ,(point-min-marker)
1887                            ,(point-max-marker))))))))
1888
1889 (defvar shr-map)
1890
1891 (autoload 'widget-convert-button "wid-edit")
1892
1893 (defun mm-convert-shr-links ()
1894   (let ((start (point-min))
1895         end)
1896     (while (and start
1897                 (< start (point-max)))
1898       (when (setq start (text-property-not-all start (point-max) 'shr-url nil))
1899         (setq end (next-single-property-change start 'shr-url nil (point-max)))
1900         (widget-convert-button
1901          'url-link start end
1902          :help-echo (get-text-property start 'help-echo)
1903          :keymap shr-map
1904          (get-text-property start 'shr-url))
1905         (put-text-property start end 'local-map nil)
1906         (setq start end)))))
1907
1908 (defun mm-handle-filename (handle)
1909   "Return filename of HANDLE if any."
1910   (or (mail-content-type-get (mm-handle-type handle)
1911                              'name)
1912       (mail-content-type-get (mm-handle-disposition handle)
1913                              'filename)))
1914
1915 (provide 'mm-decode)
1916
1917 ;; Local Variables:
1918 ;; coding: utf-8
1919 ;; End:
1920
1921 ;;; mm-decode.el ends here