lisp/gnus/mm-decode.el

   1 ;;; mm-decode.el --- Functions for decoding MIME things
   2
   3 ;; Copyright (C) 1998-2015 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 (require 'mail-parse)
  27 (require 'mm-bodies)
  28 (eval-when-compile (require 'cl))
  29
  30 (autoload 'gnus-map-function "gnus-util")
  31 (autoload 'gnus-replace-in-string "gnus-util")
  32 (autoload 'gnus-read-shell-command "gnus-util")
  33
  34 (autoload 'mm-inline-partial "mm-partial")
  35 (autoload 'mm-inline-external-body "mm-extern")
  36 (autoload 'mm-extern-cache-contents "mm-extern")
  37 (autoload 'mm-insert-inline "mm-view")
  38
  39 (autoload 'mm-archive-decoders "mm-archive")
  40 (autoload 'mm-archive-dissect-and-inline "mm-archive")
  41 (autoload 'mm-dissect-archive "mm-archive")
  42
  43 (defvar gnus-current-window-configuration)
  44
  45 (add-hook 'gnus-exit-gnus-hook 'mm-destroy-postponed-undisplay-list)
  46 (add-hook 'gnus-exit-gnus-hook 'mm-temp-files-delete)
  47
  48 (defgroup mime-display ()
  49   "Display of MIME in mail and news articles."
  50   :link '(custom-manual "(emacs-mime)Display Customization")
  51   :version "21.1"
  52   :group 'mail
  53   :group 'news
  54   :group 'multimedia)
  55
  56 (defgroup mime-security ()
  57   "MIME security in mail and news articles."
  58   :link '(custom-manual "(emacs-mime)Display Customization")
  59   :group 'mail
  60   :group 'news
  61   :group 'multimedia)
  62
  63 (defface mm-command-output
  64   '((((class color)
  65       (background dark))
  66      (:foreground "ForestGreen"))
  67     (((class color)
  68       (background light))
  69      (:foreground "red3"))
  70     (t
  71      (:italic t)))
  72   "Face used for displaying output from commands."
  73   :group 'mime-display)
  74
  75 ;;; Convenience macros.
  76
  77 (defmacro mm-handle-buffer (handle)
  78   `(nth 0 ,handle))
  79 (defmacro mm-handle-type (handle)
  80   `(nth 1 ,handle))
  81 (defsubst mm-handle-media-type (handle)
  82   (if (stringp (car handle))
  83       (car handle)
  84     (car (mm-handle-type handle))))
  85 (defsubst mm-handle-media-supertype (handle)
  86   (car (split-string (mm-handle-media-type handle) "/")))
  87 (defsubst mm-handle-media-subtype (handle)
  88   (cadr (split-string (mm-handle-media-type handle) "/")))
  89 (defmacro mm-handle-encoding (handle)
  90   `(nth 2 ,handle))
  91 (defmacro mm-handle-undisplayer (handle)
  92   `(nth 3 ,handle))
  93 (defmacro mm-handle-set-undisplayer (handle function)
  94   `(setcar (nthcdr 3 ,handle) ,function))
  95 (defmacro mm-handle-disposition (handle)
  96   `(nth 4 ,handle))
  97 (defmacro mm-handle-description (handle)
  98   `(nth 5 ,handle))
  99 (defmacro mm-handle-cache (handle)
 100   `(nth 6 ,handle))
 101 (defmacro mm-handle-set-cache (handle contents)
 102   `(setcar (nthcdr 6 ,handle) ,contents))
 103 (defmacro mm-handle-id (handle)
 104   `(nth 7 ,handle))
 105 (defmacro mm-handle-multipart-original-buffer (handle)
 106   `(get-text-property 0 'buffer (car ,handle)))
 107 (defmacro mm-handle-multipart-from (handle)
 108   `(get-text-property 0 'from (car ,handle)))
 109 (defmacro mm-handle-multipart-ctl-parameter (handle parameter)
 110   `(get-text-property 0 ,parameter (car ,handle)))
 111
 112 (defmacro mm-make-handle (&optional buffer type encoding undisplayer
 113                                     disposition description cache
 114                                     id)
 115   `(list ,buffer ,type ,encoding ,undisplayer
 116          ,disposition ,description ,cache ,id))
 117
 118 (defcustom mm-text-html-renderer
 119   (cond ((fboundp 'libxml-parse-html-region) 'shr)
 120         ((executable-find "w3m") 'gnus-w3m)
 121         ((executable-find "links") 'links)
 122         ((executable-find "lynx") 'lynx)
 123         ((locate-library "html2text") 'html2text)
 124         (t nil))
 125   "Render of HTML contents.
 126 It is one of defined renderer types, or a rendering function.
 127 The defined renderer types are:
 128 `shr': use the built-in Gnus HTML renderer;
 129 `gnus-w3m': use Gnus renderer based on w3m;
 130 `w3m': use emacs-w3m;
 131 `w3m-standalone': use plain w3m;
 132 `links': use links;
 133 `lynx': use lynx;
 134 `html2text': use html2text;
 135 nil    : use external viewer (default web browser)."
 136   :version "24.1"
 137   :type '(choice (const shr)
 138                  (const gnus-w3m)
 139                  (const w3m :tag "emacs-w3m")
 140                  (const w3m-standalone :tag "standalone w3m" )
 141                  (const links)
 142                  (const lynx)
 143                  (const html2text)
 144                  (const nil :tag "External viewer")
 145                  (function))
 146   :group 'mime-display)
 147
 148 (defcustom mm-inline-text-html-with-images nil
 149   "If non-nil, Gnus will allow retrieving images in HTML that has <img> tags.
 150 See also the documentation for the `mm-w3m-safe-url-regexp'
 151 variable."
 152   :version "22.1"
 153   :type 'boolean
 154   :group 'mime-display)
 155
 156 (defcustom mm-w3m-safe-url-regexp "\\`cid:"
 157   "Regexp matching URLs which are considered to be safe.
 158 Some HTML mails might contain a nasty trick used by spammers, using
 159 the <img> tag which is far more evil than the [Click Here!] button.
 160 It is most likely intended to check whether the ominous spam mail has
 161 reached your eyes or not, in which case the spammer knows for sure
 162 that your email address is valid.  It is done by embedding an
 163 identifier string into a URL that you might automatically retrieve
 164 when displaying the image.  The default value is \"\\\\`cid:\" which only
 165 matches parts embedded to the Multipart/Related type MIME contents and
 166 Gnus will never connect to the spammer's site arbitrarily.  You may
 167 set this variable to nil if you consider all urls to be safe."
 168   :version "22.1"
 169   :type '(choice (regexp :tag "Regexp")
 170                  (const :tag "All URLs are safe" nil))
 171   :group 'mime-display)
 172
 173 (defcustom mm-inline-text-html-with-w3m-keymap t
 174   "If non-nil, use emacs-w3m command keys in the article buffer."
 175   :version "22.1"
 176   :type 'boolean
 177   :group 'mime-display)
 178
 179 (defcustom mm-enable-external t
 180   "Indicate whether external MIME handlers should be used.
 181
 182 If t, all defined external MIME handlers are used.  If nil, files are saved by
 183 `mailcap-save-binary-file'.  If it is the symbol `ask', you are prompted
 184 before the external MIME handler is invoked."
 185   :version "22.1"
 186   :type '(choice (const :tag "Always" t)
 187                  (const :tag "Never" nil)
 188                  (const :tag "Ask" ask))
 189   :group 'mime-display)
 190
 191 (defcustom mm-inline-media-tests
 192   '(("image/p?jpeg"
 193      mm-inline-image
 194      (lambda (handle)
 195        (mm-valid-and-fit-image-p 'jpeg handle)))
 196     ("image/png"
 197      mm-inline-image
 198      (lambda (handle)
 199        (mm-valid-and-fit-image-p 'png handle)))
 200     ("image/gif"
 201      mm-inline-image
 202      (lambda (handle)
 203        (mm-valid-and-fit-image-p 'gif handle)))
 204     ("image/tiff"
 205      mm-inline-image
 206      (lambda (handle)
 207        (mm-valid-and-fit-image-p 'tiff handle)))
 208     ("image/xbm"
 209      mm-inline-image
 210      (lambda (handle)
 211        (mm-valid-and-fit-image-p 'xbm handle)))
 212     ("image/x-xbitmap"
 213      mm-inline-image
 214      (lambda (handle)
 215        (mm-valid-and-fit-image-p 'xbm handle)))
 216     ("image/xpm"
 217      mm-inline-image
 218      (lambda (handle)
 219        (mm-valid-and-fit-image-p 'xpm handle)))
 220     ("image/x-xpixmap"
 221      mm-inline-image
 222      (lambda (handle)
 223        (mm-valid-and-fit-image-p 'xpm handle)))
 224     ("image/bmp"
 225      mm-inline-image
 226      (lambda (handle)
 227        (mm-valid-and-fit-image-p 'bmp handle)))
 228     ("image/x-portable-bitmap"
 229      mm-inline-image
 230      (lambda (handle)
 231        (mm-valid-and-fit-image-p 'pbm handle)))
 232     ("text/plain" mm-inline-text identity)
 233     ("text/enriched" mm-inline-text identity)
 234     ("text/richtext" mm-inline-text identity)
 235     ("text/x-patch" mm-display-patch-inline identity)
 236     ;; In case mime.types uses x-diff (as does Debian's mime-support-3.40).
 237     ("text/x-diff" mm-display-patch-inline identity)
 238     ("application/emacs-lisp" mm-display-elisp-inline identity)
 239     ("application/x-emacs-lisp" mm-display-elisp-inline identity)
 240     ("application/x-shellscript" mm-display-shell-script-inline identity)
 241     ("application/x-sh" mm-display-shell-script-inline identity)
 242     ("text/x-sh" mm-display-shell-script-inline identity)
 243     ("application/javascript" mm-display-javascript-inline identity)
 244     ("text/dns" mm-display-dns-inline identity)
 245     ("text/x-org" mm-display-org-inline identity)
 246     ("text/html"
 247      mm-inline-text-html
 248      (lambda (handle)
 249        mm-text-html-renderer))
 250     ("text/x-vcard"
 251      mm-inline-text-vcard
 252      (lambda (handle)
 253        (or (featurep 'vcard)
 254            (locate-library "vcard"))))
 255     ("message/delivery-status" mm-inline-text identity)
 256     ("message/rfc822" mm-inline-message identity)
 257     ("message/partial" mm-inline-partial identity)
 258     ("message/external-body" mm-inline-external-body identity)
 259     ("text/.*" mm-inline-text identity)
 260     ("application/x-.?tar\\(-.*\\)?" mm-archive-dissect-and-inline identity)
 261     ("application/zip" mm-archive-dissect-and-inline identity)
 262     ("audio/wav" mm-inline-audio
 263      (lambda (handle)
 264        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 265             (device-sound-enabled-p))))
 266     ("audio/au"
 267      mm-inline-audio
 268      (lambda (handle)
 269        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 270             (device-sound-enabled-p))))
 271     ("application/pgp-signature" ignore identity)
 272     ("application/x-pkcs7-signature" ignore identity)
 273     ("application/pkcs7-signature" ignore identity)
 274     ("application/x-pkcs7-mime" ignore identity)
 275     ("application/pkcs7-mime" ignore identity)
 276     ("multipart/alternative" ignore identity)
 277     ("multipart/mixed" ignore identity)
 278     ("multipart/related" ignore identity)
 279     ("image/.*"
 280      mm-inline-image
 281      (lambda (handle)
 282        (and (mm-valid-image-format-p 'imagemagick)
 283             (mm-with-unibyte-buffer
 284               (mm-insert-part handle)
 285               (let ((image
 286                      (ignore-errors
 287                        (if (fboundp 'create-image)
 288                            (create-image (buffer-string) 'imagemagick 'data-p)
 289                          (mm-create-image-xemacs
 290                           (mm-handle-media-subtype handle))))))
 291                 (when image
 292                   (setcar (cdr handle) (list "image/imagemagick"))
 293                   (mm-image-fit-p handle)))))))
 294     ;; Disable audio and image
 295     ("audio/.*" ignore ignore)
 296     ("image/.*" ignore ignore)
 297     ;; Default to displaying as text
 298     (".*" mm-inline-text mm-readable-p))
 299   "Alist of media types/tests saying whether types can be displayed inline."
 300   :type '(repeat (list (regexp :tag "MIME type")
 301                        (function :tag "Display function")
 302                        (function :tag "Display test")))
 303   :group 'mime-display)
 304
 305 (defcustom mm-inlined-types
 306   '("image/.*" "text/.*" "message/delivery-status" "message/rfc822"
 307     "message/partial" "message/external-body" "application/emacs-lisp"
 308     "application/x-emacs-lisp"
 309     "application/pgp-signature" "application/x-pkcs7-signature"
 310     "application/pkcs7-signature" "application/x-pkcs7-mime"
 311     "application/pkcs7-mime"
 312     "application/x-gtar-compressed"
 313     "application/x-tar"
 314     "application/zip"
 315     ;; Mutt still uses this even though it has already been withdrawn.
 316     "application/pgp")
 317   "List of media types that are to be displayed inline.
 318 See also `mm-inline-media-tests', which says how to display a media
 319 type inline."
 320   :type '(repeat regexp)
 321   :group 'mime-display)
 322
 323 (defcustom mm-keep-viewer-alive-types
 324   '("application/postscript" "application/msword" "application/vnd.ms-excel"
 325     "application/pdf" "application/x-dvi")
 326   "List of media types for which the external viewer will not be killed
 327 when selecting a different article."
 328   :version "22.1"
 329   :type '(repeat regexp)
 330   :group 'mime-display)
 331
 332 (defcustom mm-automatic-display
 333   '("text/plain" "text/enriched" "text/richtext" "text/html" "text/x-verbatim"
 334     "text/x-vcard" "image/.*" "message/delivery-status" "multipart/.*"
 335     "message/rfc822" "text/x-patch" "text/dns" "application/pgp-signature"
 336     "application/emacs-lisp" "application/x-emacs-lisp"
 337     "application/x-pkcs7-signature"
 338     "application/pkcs7-signature" "application/x-pkcs7-mime"
 339     "application/pkcs7-mime"
 340     ;; Mutt still uses this even though it has already been withdrawn.
 341     "application/pgp\\'"
 342      "text/x-org")
 343   "A list of MIME types to be displayed automatically."
 344   :type '(repeat regexp)
 345   :group 'mime-display)
 346
 347 (defcustom mm-attachment-override-types '("text/x-vcard"
 348                                           "application/pkcs7-mime"
 349                                           "application/x-pkcs7-mime"
 350                                           "application/pkcs7-signature"
 351                                           "application/x-pkcs7-signature")
 352   "Types to have \"attachment\" ignored if they can be displayed inline."
 353   :type '(repeat regexp)
 354   :group 'mime-display)
 355
 356 (defcustom mm-inline-override-types nil
 357   "Types to be treated as attachments even if they can be displayed inline."
 358   :type '(repeat regexp)
 359   :group 'mime-display)
 360
 361 (defcustom mm-automatic-external-display nil
 362   "List of MIME type regexps that will be displayed externally automatically."
 363   :type '(repeat regexp)
 364   :group 'mime-display)
 365
 366 (defcustom mm-discouraged-alternatives nil
 367   "List of MIME types that are discouraged when viewing multipart/alternative.
 368 Viewing agents are supposed to view the last possible part of a message,
 369 as that is supposed to be the richest.  However, users may prefer other
 370 types instead, and this list says what types are most unwanted.  If,
 371 for instance, text/html parts are very unwanted, and text/richtext are
 372 somewhat unwanted, then the value of this variable should be set
 373 to:
 374
 375  (\"text/html\" \"text/richtext\")
 376
 377 Adding \"image/.*\" might also be useful.  Spammers use it as the
 378 preferred part of multipart/alternative messages.  See also
 379 `gnus-buttonized-mime-types', to which adding \"multipart/alternative\"
 380 enables you to choose manually one of two types those mails include."
 381   :type '(repeat regexp) ;; See `mm-preferred-alternative-precedence'.
 382   :group 'mime-display)
 383
 384 (defcustom mm-tmp-directory
 385   (if (fboundp 'temp-directory)
 386       (temp-directory)
 387     (if (boundp 'temporary-file-directory)
 388         temporary-file-directory
 389       "/tmp/"))
 390   "Where mm will store its temporary files."
 391   :type 'directory
 392   :group 'mime-display)
 393
 394 (defcustom mm-inline-large-images nil
 395   "If t, then all images fit in the buffer.
 396 If 'resize, try to resize the images so they fit."
 397   :type '(radio
 398           (const :tag "Inline large images as they are." t)
 399           (const :tag "Resize large images." resize)
 400           (const :tag "Do not inline large images." nil))
 401   :group 'mime-display)
 402
 403 (defcustom mm-file-name-rewrite-functions
 404   '(mm-file-name-delete-control mm-file-name-delete-gotchas)
 405   "List of functions used for rewriting file names of MIME parts.
 406 Each function takes a file name as input and returns a file name.
 407
 408 Ready-made functions include `mm-file-name-delete-control',
 409 `mm-file-name-delete-gotchas' (you should not remove these two
 410 functions), `mm-file-name-delete-whitespace',
 411 `mm-file-name-trim-whitespace', `mm-file-name-collapse-whitespace',
 412 `mm-file-name-replace-whitespace', `capitalize', `downcase',
 413 `upcase', and `upcase-initials'."
 414   :type '(list (set :inline t
 415                     (const mm-file-name-delete-control)
 416                     (const mm-file-name-delete-gotchas)
 417                     (const mm-file-name-delete-whitespace)
 418                     (const mm-file-name-trim-whitespace)
 419                     (const mm-file-name-collapse-whitespace)
 420                     (const mm-file-name-replace-whitespace)
 421                     (const capitalize)
 422                     (const downcase)
 423                     (const upcase)
 424                     (const upcase-initials)
 425                (repeat :inline t
 426                        :tag "Function"
 427                        function)))
 428   :version "23.1" ;; No Gnus
 429   :group 'mime-display)
 430
 431
 432 (defvar mm-path-name-rewrite-functions nil
 433   "*List of functions for rewriting the full file names of MIME parts.
 434 This is used when viewing parts externally, and is meant for
 435 transforming the absolute name so that non-compliant programs can find
 436 the file where it's saved.
 437
 438 Each function takes a file name as input and returns a file name.")
 439
 440 (defvar mm-file-name-replace-whitespace nil
 441   "String used for replacing whitespace characters; default is `\"_\"'.")
 442
 443 (defcustom mm-default-directory nil
 444   "The default directory where mm will save files.
 445 If not set, `default-directory' will be used."
 446   :type '(choice directory (const :tag "Default" nil))
 447   :group 'mime-display)
 448
 449 (defcustom mm-attachment-file-modes 384
 450   "Set the mode bits of saved attachments to this integer."
 451   :version "22.1"
 452   :type 'integer
 453   :group 'mime-display)
 454
 455 (defcustom mm-external-terminal-program "xterm"
 456   "The program to start an external terminal."
 457   :version "22.1"
 458   :type 'string
 459   :group 'mime-display)
 460
 461 ;;; Internal variables.
 462
 463 (defvar mm-last-shell-command "")
 464 (defvar mm-content-id-alist nil)
 465 (defvar mm-postponed-undisplay-list nil)
 466 (defvar mm-inhibit-auto-detect-attachment nil)
 467 (defvar mm-temp-files-to-be-deleted nil
 468   "List of temporary files scheduled to be deleted.")
 469 (defvar mm-temp-files-cache-file (concat ".mm-temp-files-" (user-login-name))
 470   "Name of a file that caches a list of temporary files to be deleted.
 471 The file will be saved in the directory `mm-tmp-directory'.")
 472
 473 ;; According to RFC2046, in particular, in a digest, the default
 474 ;; Content-Type value for a body part is changed from "text/plain" to
 475 ;; "message/rfc822".
 476 (defvar mm-dissect-default-type "text/plain")
 477
 478 (autoload 'mml2015-verify "mml2015")
 479 (autoload 'mml2015-verify-test "mml2015")
 480 (autoload 'mml-smime-verify "mml-smime")
 481 (autoload 'mml-smime-verify-test "mml-smime")
 482
 483 (defvar mm-verify-function-alist
 484   '(("application/pgp-signature" mml2015-verify "PGP" mml2015-verify-test)
 485     ("application/x-gnus-pgp-signature" mm-uu-pgp-signed-extract-1 "PGP"
 486      mm-uu-pgp-signed-test)
 487     ("application/pkcs7-signature" mml-smime-verify "S/MIME"
 488      mml-smime-verify-test)
 489     ("application/x-pkcs7-signature" mml-smime-verify "S/MIME"
 490      mml-smime-verify-test)))
 491
 492 (defcustom mm-verify-option 'never
 493   "Option of verifying signed parts.
 494 `never', not verify; `always', always verify;
 495 `known', only verify known protocols.  Otherwise, ask user.
 496
 497 When set to `always' or `known', you should add
 498 \"multipart/signed\" to `gnus-buttonized-mime-types' to see
 499 result of the verification."
 500   :version "22.1"
 501   :type '(choice (item always)
 502                  (item never)
 503                  (item :tag "only known protocols" known)
 504                  (item :tag "ask" nil))
 505   :group 'mime-security)
 506
 507 (autoload 'mml2015-decrypt "mml2015")
 508 (autoload 'mml2015-decrypt-test "mml2015")
 509
 510 (defvar mm-decrypt-function-alist
 511   '(("application/pgp-encrypted" mml2015-decrypt "PGP" mml2015-decrypt-test)
 512     ("application/x-gnus-pgp-encrypted" mm-uu-pgp-encrypted-extract-1 "PGP"
 513      mm-uu-pgp-encrypted-test)))
 514
 515 (defcustom mm-decrypt-option nil
 516   "Option of decrypting encrypted parts.
 517 `never', not decrypt; `always', always decrypt;
 518 `known', only decrypt known protocols.  Otherwise, ask user."
 519   :version "22.1"
 520   :type '(choice (item always)
 521                  (item never)
 522                  (item :tag "only known protocols" known)
 523                  (item :tag "ask" nil))
 524   :group 'mime-security)
 525
 526 (defvar mm-viewer-completion-map
 527   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 528     (set-keymap-parent map minibuffer-local-completion-map)
 529     ;; Should we bind other key to minibuffer-complete-word?
 530     (define-key map " " 'self-insert-command)
 531     map)
 532   "Keymap for input viewer with completion.")
 533
 534 ;;; The functions.
 535
 536 (defun mm-alist-to-plist (alist)
 537   "Convert association list ALIST into the equivalent property-list form.
 538 The plist is returned.  This converts from
 539
 540 \((a . 1) (b . 2) (c . 3))
 541
 542 into
 543
 544 \(a 1 b 2 c 3)
 545
 546 The original alist is not modified.  See also `destructive-alist-to-plist'."
 547   (let (plist)
 548     (while alist
 549       (let ((el (car alist)))
 550         (setq plist (cons (cdr el) (cons (car el) plist))))
 551       (setq alist (cdr alist)))
 552     (nreverse plist)))
 553
 554 (defun mm-keep-viewer-alive-p (handle)
 555   "Say whether external viewer for HANDLE should stay alive."
 556   (let ((types mm-keep-viewer-alive-types)
 557         (type (mm-handle-media-type handle))
 558         ty)
 559     (catch 'found
 560       (while (setq ty (pop types))
 561         (when (string-match ty type)
 562           (throw 'found t))))))
 563
 564 (defun mm-handle-set-external-undisplayer (handle function)
 565   "Set the undisplayer for HANDLE to FUNCTION.
 566 Postpone undisplaying of viewers for types in
 567 `mm-keep-viewer-alive-types'."
 568   (if (mm-keep-viewer-alive-p handle)
 569       (let ((new-handle (copy-sequence handle)))
 570         (mm-handle-set-undisplayer new-handle function)
 571         (mm-handle-set-undisplayer handle nil)
 572         (push new-handle mm-postponed-undisplay-list))
 573     (mm-handle-set-undisplayer handle function)))
 574
 575 (defun mm-destroy-postponed-undisplay-list ()
 576   (when mm-postponed-undisplay-list
 577     (message "Destroying external MIME viewers")
 578     (mm-destroy-parts mm-postponed-undisplay-list)))
 579
 580 (defun mm-temp-files-delete ()
 581   "Delete temporary files and those parent directories.
 582 Note that the deletion may fail if a program is catching hold of a file
 583 under Windows or Cygwin.  In that case, it schedules the deletion of
 584 files left at the next time."
 585   (let* ((coding-system-for-read mm-universal-coding-system)
 586          (coding-system-for-write mm-universal-coding-system)
 587          (cache-file (expand-file-name mm-temp-files-cache-file
 588                                        mm-tmp-directory))
 589          (cache (when (file-exists-p cache-file)
 590                   (mm-with-multibyte-buffer
 591                     (insert-file-contents cache-file)
 592                     (split-string (buffer-string) "\n" t))))
 593          fails)
 594     (dolist (temp (append cache mm-temp-files-to-be-deleted))
 595       (when (and (file-exists-p temp)
 596                  (if (file-directory-p temp)
 597                      ;; A parent directory left at the previous time.
 598                      (progn
 599                        (ignore-errors (delete-directory temp))
 600                        (file-exists-p temp))
 601                    ;; Delete a temporary file and its parent directory.
 602                    (ignore-errors (delete-file temp))
 603                    (or (file-exists-p temp)
 604                        (progn
 605                          (setq temp (file-name-directory temp))
 606                          (ignore-errors (delete-directory temp))
 607                          (file-exists-p temp)))))
 608         (push temp fails)))
 609     (if fails
 610         ;; Schedule the deletion of the files left at the next time.
 611         (progn
 612           (write-region (concat (mapconcat 'identity (nreverse fails) "\n")
 613                                 "\n")
 614                         nil cache-file nil 'silent)
 615           (set-file-modes cache-file #o600))
 616       (when (file-exists-p cache-file)
 617         (ignore-errors (delete-file cache-file))))
 618     (setq mm-temp-files-to-be-deleted nil)))
 619
 620 (autoload 'message-fetch-field "message")
 621
 622 (defun mm-dissect-buffer (&optional no-strict-mime loose-mime from)
 623   "Dissect the current buffer and return a list of MIME handles.
 624 If NO-STRICT-MIME, don't require the message to have a
 625 MIME-Version header before proceeding."
 626   (save-excursion
 627     (let (ct ctl type subtype cte cd description id result)
 628       (save-restriction
 629         (mail-narrow-to-head)
 630         (when (or no-strict-mime
 631                   loose-mime
 632                   (mail-fetch-field "mime-version"))
 633           (setq ct (mail-fetch-field "content-type")
 634                 ctl (and ct (mail-header-parse-content-type ct))
 635                 cte (mail-fetch-field "content-transfer-encoding")
 636                 cd (or (mail-fetch-field "content-disposition")
 637                        (when (and ctl
 638                                   (eq 'mm-inline-text
 639                                       (cadr (mm-assoc-string-match
 640                                              mm-inline-media-tests
 641                                              (car ctl)))))
 642                          "inline"))
 643                 ;; Newlines in description should be stripped so as
 644                 ;; not to break the MIME tag into two or more lines.
 645                 description (message-fetch-field "content-description")
 646                 id (mail-fetch-field "content-id"))
 647           (unless from
 648             (setq from (mail-fetch-field "from")))
 649           ;; FIXME: In some circumstances, this code is running within
 650           ;; a unibyte macro.  mail-extract-address-components
 651           ;; creates unibyte buffers. This `if', though not a perfect
 652           ;; solution, avoids most of them.
 653           (if from
 654               (setq from (cadr (mail-extract-address-components from))))
 655           (if description
 656               (setq description (mail-decode-encoded-word-string
 657                                  description)))))
 658       (if (or (not ctl)
 659               (not (string-match "/" (car ctl))))
 660             (mm-dissect-singlepart
 661            (list mm-dissect-default-type)
 662              (and cte (intern (downcase (mail-header-strip cte))))
 663            no-strict-mime
 664            (and cd (mail-header-parse-content-disposition cd))
 665            description)
 666         (setq type (split-string (car ctl) "/"))
 667         (setq subtype (cadr type)
 668               type (car type))
 669         (setq
 670          result
 671          (cond
 672           ((equal type "multipart")
 673            (let ((mm-dissect-default-type (if (equal subtype "digest")
 674                                               "message/rfc822"
 675                                             "text/plain"))
 676                  (start (cdr (assq 'start (cdr ctl)))))
 677              (add-text-properties 0 (length (car ctl))
 678                                   (mm-alist-to-plist (cdr ctl)) (car ctl))
 679
 680              ;; what really needs to be done here is a way to link a
 681              ;; MIME handle back to it's parent MIME handle (in a multilevel
 682              ;; MIME article).  That would probably require changing
 683              ;; the mm-handle API so we simply store the multipart buffer
 684              ;; name as a text property of the "multipart/whatever" string.
 685              (add-text-properties 0 (length (car ctl))
 686                                   (list 'buffer (mm-copy-to-buffer)
 687                                         'from from
 688                                         'start start)
 689                                   (car ctl))
 690              (cons (car ctl) (mm-dissect-multipart ctl from))))
 691           (t
 692            (mm-possibly-verify-or-decrypt
 693             (mm-dissect-singlepart
 694              ctl
 695              (and cte (intern (downcase (mail-header-strip cte))))
 696              no-strict-mime
 697              (and cd (mail-header-parse-content-disposition cd))
 698              description id)
 699             ctl from))))
 700         (when id
 701           (when (string-match " *<\\(.*\\)> *" id)
 702             (setq id (match-string 1 id)))
 703           (push (cons id result) mm-content-id-alist))
 704         result))))
 705
 706 (defun mm-dissect-singlepart (ctl cte &optional force cdl description id)
 707   (when (or force
 708             (if (equal "text/plain" (car ctl))
 709                 (assoc 'format ctl)
 710               t))
 711     ;; Guess what the type of application/octet-stream parts should
 712     ;; really be.
 713     (let ((filename (cdr (assq 'filename (cdr cdl)))))
 714       (when (and (not mm-inhibit-auto-detect-attachment)
 715                  (equal (car ctl) "application/octet-stream")
 716                  filename
 717                  (string-match "\\.\\([^.]+\\)$" filename))
 718         (let ((new-type (mailcap-extension-to-mime (match-string 1 filename))))
 719           (when new-type
 720             (setcar ctl new-type)))))
 721     (let ((handle
 722            (mm-make-handle
 723             (mm-copy-to-buffer) ctl cte nil cdl description nil id))
 724           (decoder (assoc (car ctl) (mm-archive-decoders))))
 725       (if (and decoder
 726                ;; Do automatic decoding
 727                (cadr decoder)
 728                (executable-find (caddr decoder)))
 729           (mm-dissect-archive handle)
 730         handle))))
 731
 732 (defun mm-dissect-multipart (ctl from)
 733   (goto-char (point-min))
 734   (let* ((boundary (concat "\n--" (mail-content-type-get ctl 'boundary)))
 735          (close-delimiter (concat (regexp-quote boundary) "--[ \t]*$"))
 736          start parts
 737          (end (save-excursion
 738                 (goto-char (point-max))
 739                 (if (re-search-backward close-delimiter nil t)
 740                     (match-beginning 0)
 741                   (point-max))))
 742          (mm-inhibit-auto-detect-attachment
 743           (equal (car ctl) "multipart/encrypted")))
 744     (setq boundary (concat (regexp-quote boundary) "[ \t]*$"))
 745     (while (and (< (point) end) (re-search-forward boundary end t))
 746       (goto-char (match-beginning 0))
 747       (when start
 748         (save-excursion
 749           (save-restriction
 750             (narrow-to-region start (point))
 751             (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 752       (end-of-line 2)
 753       (or (looking-at boundary)
 754           (forward-line 1))
 755       (setq start (point)))
 756     (when (and start (< start end))
 757       (save-excursion
 758         (save-restriction
 759           (narrow-to-region start end)
 760           (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 761     (mm-possibly-verify-or-decrypt (nreverse parts) ctl from)))
 762
 763 (defun mm-copy-to-buffer ()
 764   "Copy the contents of the current buffer to a fresh buffer."
 765   (let ((obuf (current-buffer))
 766         (mb (mm-multibyte-p))
 767         beg)
 768     (goto-char (point-min))
 769     (search-forward-regexp "^\n" nil t)
 770     (setq beg (point))
 771     (with-current-buffer
 772           (generate-new-buffer " *mm*")
 773       ;; Preserve the data's unibyteness (for url-insert-file-contents).
 774       (mm-set-buffer-multibyte mb)
 775       (insert-buffer-substring obuf beg)
 776       (current-buffer))))
 777
 778 (defun mm-display-parts (handle &optional no-default)
 779   (if (stringp (car handle))
 780       (mapcar 'mm-display-parts (cdr handle))
 781     (if (bufferp (car handle))
 782         (save-restriction
 783           (narrow-to-region (point) (point))
 784           (mm-display-part handle)
 785           (goto-char (point-max)))
 786       (mapcar 'mm-display-parts handle))))
 787
 788 (autoload 'mailcap-parse-mailcaps "mailcap")
 789 (autoload 'mailcap-mime-info "mailcap")
 790
 791 (defun mm-display-part (handle &optional no-default force)
 792   "Display the MIME part represented by HANDLE.
 793 Returns nil if the part is removed; inline if displayed inline;
 794 external if displayed external."
 795   (save-excursion
 796     (mailcap-parse-mailcaps)
 797     (if (and (not force)
 798              (mm-handle-displayed-p handle))
 799         (mm-remove-part handle)
 800       (let* ((ehandle (if (equal (mm-handle-media-type handle)
 801                                  "message/external-body")
 802                           (progn
 803                             (unless (mm-handle-cache handle)
 804                               (mm-extern-cache-contents handle))
 805                             (mm-handle-cache handle))
 806                         handle))
 807              (type (mm-handle-media-type ehandle))
 808              (method (mailcap-mime-info type))
 809              (filename (or (mail-content-type-get
 810                             (mm-handle-disposition handle) 'filename)
 811                            (mail-content-type-get
 812                             (mm-handle-type handle) 'name)
 813                            "<file>"))
 814              (external mm-enable-external)
 815              (decoder (assoc (car (mm-handle-type handle))
 816                              (mm-archive-decoders))))
 817         (cond
 818          ((and decoder
 819                (executable-find (caddr decoder)))
 820           (mm-archive-dissect-and-inline handle)
 821           'inline)
 822          ((and (mm-inlinable-p ehandle)
 823                (mm-inlined-p ehandle))
 824           (mm-display-inline handle)
 825           'inline)
 826          ((or method
 827               (not no-default))
 828           (if (and (not method)
 829                    (equal "text" (car (split-string type "/"))))
 830               (progn
 831                 (forward-line 1)
 832                 (mm-insert-inline handle (mm-get-part handle))
 833                 'inline)
 834             (setq external
 835                   (and method         ;; If nil, we always use "save".
 836                        (or (eq mm-enable-external t)
 837                            (and (eq mm-enable-external 'ask)
 838                                 (y-or-n-p
 839                                  (concat
 840                                   "Display part (" type
 841                                   ") "
 842                                   (if (stringp method)
 843                                       (concat
 844                                        "using external program \""
 845                                        (format method filename) "\"")
 846                                     (format
 847                                      "by calling `%s' on the contents)" method))
 848                                   "? "))))))
 849             (if external
 850                 (mm-display-external
 851                  handle (or method 'mailcap-save-binary-file))
 852               (mm-display-external
 853                handle 'mailcap-save-binary-file)))))))))
 854
 855 (declare-function gnus-configure-windows "gnus-win" (setting &optional force))
 856 (defvar mailcap-mime-extensions)        ; mailcap-mime-info autoloads
 857 (declare-function term-mode "term" ())
 858 (declare-function term-char-mode "term" ())
 859
 860 (defun mm-display-external (handle method)
 861   "Display HANDLE using METHOD."
 862   (let ((outbuf (current-buffer)))
 863     (mm-with-unibyte-buffer
 864       (if (functionp method)
 865           (let ((cur (current-buffer)))
 866             (if (eq method 'mailcap-save-binary-file)
 867                 (progn
 868                   (set-buffer (generate-new-buffer " *mm*"))
 869                   (setq method nil))
 870               (mm-insert-part handle)
 871               (mm-add-meta-html-tag handle)
 872               (let ((win (get-buffer-window cur t)))
 873                 (when win
 874                   (select-window win)))
 875               (switch-to-buffer (generate-new-buffer " *mm*")))
 876             (buffer-disable-undo)
 877             (mm-set-buffer-file-coding-system mm-binary-coding-system)
 878             (insert-buffer-substring cur)
 879             (goto-char (point-min))
 880             (when method
 881               (message "Viewing with %s" method))
 882             (let ((mm (current-buffer))
 883                   (non-viewer (assq 'non-viewer
 884                                     (mailcap-mime-info
 885                                      (mm-handle-media-type handle) t))))
 886               (unwind-protect
 887                   (if method
 888                       (progn
 889                         (when (and (boundp 'gnus-summary-buffer)
 890                                    (bufferp gnus-summary-buffer)
 891                                    (buffer-name gnus-summary-buffer))
 892                           ;; So that we pop back to the right place, sortof.
 893                           (switch-to-buffer gnus-summary-buffer)
 894                           (switch-to-buffer mm))
 895                         (delete-other-windows)
 896                         (funcall method))
 897                     (mm-save-part handle))
 898                 (when (and (not non-viewer)
 899                            method)
 900                   (mm-handle-set-undisplayer handle mm)))))
 901         ;; The function is a string to be executed.
 902         (mm-insert-part handle)
 903         (mm-add-meta-html-tag handle)
 904         (let* ((dir (mm-make-temp-file
 905                      (expand-file-name "emm." mm-tmp-directory) 'dir))
 906                (filename (or
 907                           (mail-content-type-get
 908                            (mm-handle-disposition handle) 'filename)
 909                           (mail-content-type-get
 910                            (mm-handle-type handle) 'name)))
 911                (mime-info (mailcap-mime-info
 912                            (mm-handle-media-type handle) t))
 913                (needsterm (or (assoc "needsterm" mime-info)
 914                               (assoc "needsterminal" mime-info)))
 915                (copiousoutput (assoc "copiousoutput" mime-info))
 916                file buffer)
 917           ;; We create a private sub-directory where we store our files.
 918           (set-file-modes dir #o700)
 919           (if filename
 920               (setq file (expand-file-name
 921                           (gnus-map-function mm-file-name-rewrite-functions
 922                                              (file-name-nondirectory filename))
 923                           dir))
 924             ;; Use nametemplate (defined in RFC1524) if it is specified
 925             ;; in mailcap.
 926             (let ((suffix (cdr (assoc "nametemplate" mime-info))))
 927               (if (and suffix
 928                        (string-match "\\`%s\\(\\..+\\)\\'" suffix))
 929                   (setq suffix (match-string 1 suffix))
 930                 ;; Otherwise, use a suffix according to
 931                 ;; `mailcap-mime-extensions'.
 932                 (setq suffix (car (rassoc (mm-handle-media-type handle)
 933                                           mailcap-mime-extensions))))
 934               (setq file (mm-make-temp-file (expand-file-name "mm." dir)
 935                                             nil suffix))))
 936           (let ((coding-system-for-write mm-binary-coding-system))
 937             (write-region (point-min) (point-max) file nil 'nomesg))
 938           ;; The file is deleted after the viewer exists.  If the users edits
 939           ;; the file, changes will be lost.  Set file to read-only to make it
 940           ;; clear.
 941           (set-file-modes file #o400)
 942           (message "Viewing with %s" method)
 943           (cond
 944            (needsterm
 945             (let ((command (mm-mailcap-command
 946                             method file (mm-handle-type handle))))
 947               (unwind-protect
 948                   (if window-system
 949                       (set-process-sentinel
 950                        (start-process "*display*" nil
 951                                       mm-external-terminal-program
 952                                       "-e" shell-file-name
 953                                       shell-command-switch command)
 954                        `(lambda (process state)
 955                           (if (eq 'exit (process-status process))
 956                               (run-at-time
 957                                60.0 nil
 958                                (lambda ()
 959                                  (ignore-errors (delete-file ,file))
 960                                  (ignore-errors (delete-directory
 961                                                  ,(file-name-directory
 962                                                    file))))))))
 963                     (require 'term)
 964                     (require 'gnus-win)
 965                     (set-buffer
 966                      (setq buffer
 967                            (make-term "display"
 968                                       shell-file-name
 969                                       nil
 970                                       shell-command-switch command)))
 971                     (term-mode)
 972                     (term-char-mode)
 973                     (set-process-sentinel
 974                      (get-buffer-process buffer)
 975                      `(lambda (process state)
 976                         (when (eq 'exit (process-status process))
 977                           (ignore-errors (delete-file ,file))
 978                           (ignore-errors
 979                             (delete-directory ,(file-name-directory file)))
 980                           (gnus-configure-windows
 981                            ',gnus-current-window-configuration))))
 982                     (gnus-configure-windows 'display-term))
 983                 (mm-handle-set-external-undisplayer handle (cons file buffer))
 984                 (add-to-list 'mm-temp-files-to-be-deleted file t))
 985               (message "Displaying %s..." command))
 986             'external)
 987            (copiousoutput
 988             (with-current-buffer outbuf
 989               (forward-line 1)
 990               (mm-insert-inline
 991                handle
 992                (unwind-protect
 993                    (progn
 994                      (call-process shell-file-name nil
 995                                    (setq buffer
 996                                          (generate-new-buffer " *mm*"))
 997                                    nil
 998                                    shell-command-switch
 999                                    (mm-mailcap-command
1000                                     method file (mm-handle-type handle)))
1001                      (if (buffer-live-p buffer)
1002                          (with-current-buffer buffer
1003                            (buffer-string))))
1004                  (progn
1005                    (ignore-errors (delete-file file))
1006                    (ignore-errors (delete-directory
1007                                    (file-name-directory file)))
1008                    (ignore-errors (kill-buffer buffer))))))
1009             'inline)
1010            (t
1011             ;; Deleting the temp file should be postponed for some wrappers,
1012             ;; shell scripts, and so on, which might exit right after having
1013             ;; started a viewer command as a background job.
1014             (let ((command (mm-mailcap-command
1015                             method file (mm-handle-type handle))))
1016               (unwind-protect
1017                   (let ((process-connection-type nil))
1018                     (start-process "*display*"
1019                                    (setq buffer
1020                                          (generate-new-buffer " *mm*"))
1021                                    shell-file-name
1022                                    shell-command-switch command)
1023                     (set-process-sentinel
1024                      (get-buffer-process buffer)
1025                      (lexical-let ((outbuf outbuf)
1026                                    (file file)
1027                                    (buffer buffer)
1028                                    (command command)
1029                                    (handle handle))
1030                        (lambda (process state)
1031                          (when (eq (process-status process) 'exit)
1032                            (run-at-time
1033                             60.0 nil
1034                             (lambda ()
1035                               (ignore-errors (delete-file file))
1036                               (ignore-errors (delete-directory
1037                                               (file-name-directory file)))))
1038                            (when (buffer-live-p outbuf)
1039                              (with-current-buffer outbuf
1040                                (let ((buffer-read-only nil)
1041                                      (point (point)))
1042                                  (forward-line 2)
1043                                  (let ((start (point)))
1044                                    (mm-insert-inline
1045                                     handle (with-current-buffer buffer
1046                                              (buffer-string)))
1047                                    (put-text-property start (point)
1048                                                       'face 'mm-command-output))
1049                                  (goto-char point))))
1050                            (when (buffer-live-p buffer)
1051                              (kill-buffer buffer)))
1052                          (message "Displaying %s...done" command)))))
1053                 (mm-handle-set-external-undisplayer
1054                  handle (cons file buffer))
1055                 (add-to-list 'mm-temp-files-to-be-deleted file t))
1056               (message "Displaying %s..." command))
1057             'external)))))))
1058
1059 (defun mm-mailcap-command (method file type-list)
1060   (let ((ctl (cdr type-list))
1061         (beg 0)
1062         (uses-stdin t)
1063         out sub total)
1064     (while (string-match "%{\\([^}]+\\)}\\|'%s'\\|\"%s\"\\|%s\\|%t\\|%%"
1065                          method beg)
1066       (push (substring method beg (match-beginning 0)) out)
1067       (setq beg (match-end 0)
1068             total (match-string 0 method)
1069             sub (match-string 1 method))
1070       (cond
1071        ((string= total "%%")
1072         (push "%" out))
1073        ((or (string= total "%s")
1074             ;; We do our own quoting.
1075             (string= total "'%s'")
1076             (string= total "\"%s\""))
1077         (setq uses-stdin nil)
1078         (push (shell-quote-argument
1079                (gnus-map-function mm-path-name-rewrite-functions file)) out))
1080        ((string= total "%t")
1081         (push (shell-quote-argument (car type-list)) out))
1082        (t
1083         (push (shell-quote-argument (or (cdr (assq (intern sub) ctl)) "")) out))))
1084     (push (substring method beg (length method)) out)
1085     (when uses-stdin
1086       (push "<" out)
1087       (push (shell-quote-argument
1088              (gnus-map-function mm-path-name-rewrite-functions file))
1089             out))
1090     (mapconcat 'identity (nreverse out) "")))
1091
1092 (defun mm-remove-parts (handles)
1093   "Remove the displayed MIME parts represented by HANDLES."
1094   (if (and (listp handles)
1095            (bufferp (car handles)))
1096       (mm-remove-part handles)
1097     (let (handle)
1098       (while (setq handle (pop handles))
1099         (cond
1100          ((stringp handle)
1101           (when (buffer-live-p (get-text-property 0 'buffer handle))
1102             (kill-buffer (get-text-property 0 'buffer handle))))
1103          ((and (listp handle)
1104                (stringp (car handle)))
1105           (mm-remove-parts (cdr handle)))
1106          (t
1107           (mm-remove-part handle)))))))
1108
1109 (defun mm-destroy-parts (handles)
1110   "Remove the displayed MIME parts represented by HANDLES."
1111   (if (and (listp handles)
1112            (bufferp (car handles)))
1113       (mm-destroy-part handles)
1114     (let (handle)
1115       (while (setq handle (pop handles))
1116         (cond
1117          ((stringp handle)
1118           (when (buffer-live-p (get-text-property 0 'buffer handle))
1119             (kill-buffer (get-text-property 0 'buffer handle))))
1120          ((and (listp handle)
1121                (stringp (car handle)))
1122           (mm-destroy-parts handle))
1123          (t
1124           (mm-destroy-part handle)))))))
1125
1126 (defun mm-remove-part (handle)
1127   "Remove the displayed MIME part represented by HANDLE."
1128   (when (listp handle)
1129     (let ((object (mm-handle-undisplayer handle)))
1130       (ignore-errors
1131         (cond
1132          ;; Internally displayed part.
1133          ((mm-annotationp object)
1134           (if (featurep 'xemacs)
1135               (delete-annotation object)))
1136          ((or (functionp object)
1137               (and (listp object)
1138                    (eq (car object) 'lambda)))
1139           (funcall object))
1140          ;; Externally displayed part.
1141          ((consp object)
1142           (condition-case ()
1143               (while (get-buffer-process (cdr object))
1144                 (interrupt-process (get-buffer-process (cdr object)))
1145                 (message "Waiting for external displayer to die...")
1146                 (sit-for 1))
1147             (quit)
1148             (error))
1149           (ignore-errors (and (cdr object) (kill-buffer (cdr object))))
1150           (message "Waiting for external displayer to die...done")
1151           (ignore-errors (delete-file (car object)))
1152           (ignore-errors (delete-directory (file-name-directory
1153                                             (car object)))))
1154          ((bufferp object)
1155           (when (buffer-live-p object)
1156             (kill-buffer object)))))
1157       (mm-handle-set-undisplayer handle nil))))
1158
1159 (defun mm-display-inline (handle)
1160   (let* ((type (mm-handle-media-type handle))
1161          (function (cadr (mm-assoc-string-match mm-inline-media-tests type))))
1162     (funcall function handle)
1163     (goto-char (point-min))))
1164
1165 (defun mm-assoc-string-match (alist type)
1166   (dolist (elem alist)
1167     (when (string-match (car elem) type)
1168       (return elem))))
1169
1170 (defun mm-automatic-display-p (handle)
1171   "Say whether the user wants HANDLE to be displayed automatically."
1172   (let ((methods mm-automatic-display)
1173         (type (mm-handle-media-type handle))
1174         method result)
1175     (while (setq method (pop methods))
1176       (when (and (not (mm-inline-override-p handle))
1177                  (string-match method type))
1178         (setq result t
1179               methods nil)))
1180     result))
1181
1182 (defun mm-inlinable-p (handle &optional type)
1183   "Say whether HANDLE can be displayed inline.
1184 TYPE is the mime-type of the object; it defaults to the one given
1185 in HANDLE."
1186   (unless type (setq type (mm-handle-media-type handle)))
1187   (let ((alist mm-inline-media-tests)
1188         test)
1189     (while alist
1190       (when (string-match (caar alist) type)
1191         (setq test (caddar alist)
1192               alist nil)
1193         (setq test (funcall test handle)))
1194       (pop alist))
1195     test))
1196
1197 (defun mm-inlined-p (handle)
1198   "Say whether the user wants HANDLE to be displayed inline."
1199   (let ((methods mm-inlined-types)
1200         (type (mm-handle-media-type handle))
1201         method result)
1202     (while (setq method (pop methods))
1203       (when (and (not (mm-inline-override-p handle))
1204                  (string-match method type))
1205         (setq result t
1206               methods nil)))
1207     result))
1208
1209 (defun mm-attachment-override-p (handle)
1210   "Say whether HANDLE should have attachment behavior overridden."
1211   (let ((types mm-attachment-override-types)
1212         (type (mm-handle-media-type handle))
1213         ty)
1214     (catch 'found
1215       (while (setq ty (pop types))
1216         (when (and (string-match ty type)
1217                    (mm-inlinable-p handle))
1218           (throw 'found t))))))
1219
1220 (defun mm-inline-override-p (handle)
1221   "Say whether HANDLE should have inline behavior overridden."
1222   (let ((types mm-inline-override-types)
1223         (type (mm-handle-media-type handle))
1224         ty)
1225     (catch 'found
1226       (while (setq ty (pop types))
1227         (when (string-match ty type)
1228           (throw 'found t))))))
1229
1230 (defun mm-automatic-external-display-p (type)
1231   "Return the user-defined method for TYPE."
1232   (let ((methods mm-automatic-external-display)
1233         method result)
1234     (while (setq method (pop methods))
1235       (when (string-match method type)
1236         (setq result t
1237               methods nil)))
1238     result))
1239
1240 (defun mm-destroy-part (handle)
1241   "Destroy the data structures connected to HANDLE."
1242   (when (listp handle)
1243     (mm-remove-part handle)
1244     (when (buffer-live-p (mm-handle-buffer handle))
1245       (kill-buffer (mm-handle-buffer handle)))))
1246
1247 (defun mm-handle-displayed-p (handle)
1248   "Say whether HANDLE is displayed or not."
1249   (mm-handle-undisplayer handle))
1250
1251 ;;;
1252 ;;; Functions for outputting parts
1253 ;;;
1254
1255 (defmacro mm-with-part (handle &rest forms)
1256   "Run FORMS in the temp buffer containing the contents of HANDLE."
1257   ;; The handle-buffer's content is a sequence of bytes, not a sequence of
1258   ;; chars, so the buffer should be unibyte.  It may happen that the
1259   ;; handle-buffer is multibyte for some reason, in which case now is a good
1260   ;; time to adjust it, since we know at this point that it should
1261   ;; be unibyte.
1262   `(let* ((handle ,handle))
1263      (when (and (mm-handle-buffer handle)
1264                 (buffer-name (mm-handle-buffer handle)))
1265        (with-temp-buffer
1266          (mm-disable-multibyte)
1267          (insert-buffer-substring (mm-handle-buffer handle))
1268          (mm-decode-content-transfer-encoding
1269           (mm-handle-encoding handle)
1270           (mm-handle-media-type handle))
1271          ,@forms))))
1272 (put 'mm-with-part 'lisp-indent-function 1)
1273 (put 'mm-with-part 'edebug-form-spec '(body))
1274
1275 (defun mm-get-part (handle &optional no-cache)
1276   "Return the contents of HANDLE as a string.
1277 If NO-CACHE is non-nil, cached contents of a message/external-body part
1278 are ignored."
1279   (if (and (not no-cache)
1280            (equal (mm-handle-media-type handle) "message/external-body"))
1281       (progn
1282         (unless (mm-handle-cache handle)
1283           (mm-extern-cache-contents handle))
1284         (with-current-buffer (mm-handle-buffer (mm-handle-cache handle))
1285           (buffer-string)))
1286     (mm-with-part handle
1287       (buffer-string))))
1288
1289 (defun mm-insert-part (handle &optional no-cache)
1290   "Insert the contents of HANDLE in the current buffer.
1291 If NO-CACHE is non-nil, cached contents of a message/external-body part
1292 are ignored."
1293   (let ((text (cond ((eq (mail-content-type-get (mm-handle-type handle)
1294                                                 'charset)
1295                          'gnus-decoded)
1296                      (with-current-buffer (mm-handle-buffer handle)
1297                        (buffer-string)))
1298                     ((mm-multibyte-p)
1299                      (mm-string-to-multibyte (mm-get-part handle no-cache)))
1300                     (t
1301                      (mm-get-part handle no-cache)))))
1302     (save-restriction
1303       (widen)
1304       (goto-char
1305        (prog1
1306            (point)
1307          (if (and (eq (get-char-property (max (point-min) (1- (point))) 'face)
1308                       'mm-uu-extract)
1309                   (eq (get-char-property 0 'face text) 'mm-uu-extract))
1310              ;; Separate the extracted parts that have the same faces.
1311              (insert "\n" text)
1312            (insert text)))))))
1313
1314 (defun mm-file-name-delete-whitespace (file-name)
1315   "Remove all whitespace characters from FILE-NAME."
1316   (while (string-match "\\s-+" file-name)
1317     (setq file-name (replace-match "" t t file-name)))
1318   file-name)
1319
1320 (defun mm-file-name-trim-whitespace (file-name)
1321   "Remove leading and trailing whitespace characters from FILE-NAME."
1322   (when (string-match "\\`\\s-+" file-name)
1323     (setq file-name (substring file-name (match-end 0))))
1324   (when (string-match "\\s-+\\'" file-name)
1325     (setq file-name (substring file-name 0 (match-beginning 0))))
1326   file-name)
1327
1328 (defun mm-file-name-collapse-whitespace (file-name)
1329   "Collapse multiple whitespace characters in FILE-NAME."
1330   (while (string-match "\\s-\\s-+" file-name)
1331     (setq file-name (replace-match " " t t file-name)))
1332   file-name)
1333
1334 (defun mm-file-name-replace-whitespace (file-name)
1335   "Replace whitespace characters in FILE-NAME with underscores.
1336 Set the option `mm-file-name-replace-whitespace' to any other
1337 string if you do not like underscores."
1338   (let ((s (or mm-file-name-replace-whitespace "_")))
1339     (while (string-match "\\s-" file-name)
1340       (setq file-name (replace-match s t t file-name))))
1341   file-name)
1342
1343 (defun mm-file-name-delete-control (filename)
1344   "Delete control characters from FILENAME."
1345   (gnus-replace-in-string filename "[\x00-\x1f\x7f]" ""))
1346
1347 (defun mm-file-name-delete-gotchas (filename)
1348   "Delete shell gotchas from FILENAME."
1349   (setq filename (gnus-replace-in-string filename "[<>|]" ""))
1350   (gnus-replace-in-string filename "^[.-]+" ""))
1351
1352 (defun mm-save-part (handle &optional prompt)
1353   "Write HANDLE to a file.
1354 PROMPT overrides the default one used to ask user for a file name."
1355   (let ((filename (or (mail-content-type-get
1356                        (mm-handle-disposition handle) 'filename)
1357                       (mail-content-type-get
1358                        (mm-handle-type handle) 'name)))
1359         file)
1360     (when filename
1361       (setq filename (gnus-map-function mm-file-name-rewrite-functions
1362                                         (file-name-nondirectory filename))))
1363     (while
1364         (progn
1365           (setq file
1366                 (read-file-name
1367                  (or prompt
1368                      (format "Save MIME part to (default %s): "
1369                              (or filename "")))
1370                  (or mm-default-directory default-directory)
1371                  (expand-file-name (or filename "")
1372                                    (or mm-default-directory default-directory))))
1373           (cond ((or (not file) (equal file ""))
1374                  (message "Please enter a file name")
1375                  t)
1376                 ((and (file-directory-p file)
1377                       (not filename))
1378                  (message "Please enter a non-directory file name")
1379                  t)
1380                 (t nil)))
1381       (sit-for 2)
1382       (discard-input))
1383     (if (file-directory-p file)
1384         (setq file (expand-file-name filename file))
1385       (setq file (expand-file-name
1386                   file (or mm-default-directory default-directory))))
1387     (setq mm-default-directory (file-name-directory file))
1388     (and (or (not (file-exists-p file))
1389              (yes-or-no-p (format "File %s already exists; overwrite? "
1390                                   file)))
1391          (progn
1392            (mm-save-part-to-file handle file)
1393            file))))
1394
1395 (defun mm-add-meta-html-tag (handle &optional charset force-charset)
1396   "Add meta html tag to specify CHARSET of HANDLE in the current buffer.
1397 CHARSET defaults to the one HANDLE specifies.  Existing meta tag that
1398 specifies charset will not be modified unless FORCE-CHARSET is non-nil.
1399 Return t if meta tag is added or replaced."
1400   (when (equal (mm-handle-media-type handle) "text/html")
1401     (when (or charset
1402               (setq charset (mail-content-type-get (mm-handle-type handle)
1403                                                    'charset)))
1404       (setq charset (format "\
1405 <meta http-equiv=\"Content-Type\" content=\"text/html; charset=%s\">" charset))
1406       (let ((case-fold-search t))
1407         (goto-char (point-min))
1408         (if (re-search-forward "\
1409 <meta\\s-+http-equiv=[\"']?content-type[\"']?\\s-+content=[\"']\
1410 text/\\(\\sw+\\)\\(?:\;\\s-*charset=\\([^\"'>]+\\)\\)?[^>]*>" nil t)
1411             (if (and (not force-charset)
1412                      (match-beginning 2)
1413                      (string-match "\\`html\\'" (match-string 1)))
1414                 ;; Don't modify existing meta tag.
1415                 nil
1416               ;; Replace it with the one specifying charset.
1417               (replace-match charset)
1418               t)
1419           (if (re-search-forward "<head>\\s-*" nil t)
1420               (insert charset "\n")
1421             (re-search-forward "<html\\(?:\\s-+[^>]+\\|\\s-*\\)>\\s-*" nil t)
1422             (insert "<head>\n" charset "\n</head>\n"))
1423           t)))))
1424
1425 (defun mm-save-part-to-file (handle file)
1426   (mm-with-unibyte-buffer
1427     (mm-insert-part handle)
1428     (mm-add-meta-html-tag handle)
1429     (let ((current-file-modes (default-file-modes)))
1430       (set-default-file-modes mm-attachment-file-modes)
1431       (unwind-protect
1432           ;; Don't re-compress .gz & al.  Arguably we should make
1433           ;; `file-name-handler-alist' nil, but that would chop
1434           ;; ange-ftp, which is reasonable to use here.
1435           (mm-write-region (point-min) (point-max) file nil nil nil 'binary t)
1436         (set-default-file-modes current-file-modes)))))
1437
1438 (defun mm-pipe-part (handle &optional cmd)
1439   "Pipe HANDLE to a process.
1440 Use CMD as the process."
1441   (let ((name (mail-content-type-get (mm-handle-type handle) 'name))
1442         (command (or cmd
1443                      (gnus-read-shell-command
1444                       "Shell command on MIME part: " mm-last-shell-command))))
1445     (mm-with-unibyte-buffer
1446       (mm-insert-part handle)
1447       (mm-add-meta-html-tag handle)
1448       (let ((coding-system-for-write 'binary))
1449         (shell-command-on-region (point-min) (point-max) command nil)))))
1450
1451 (autoload 'gnus-completing-read "gnus-util")
1452
1453 (defun mm-interactively-view-part (handle)
1454   "Display HANDLE using METHOD."
1455   (let* ((type (mm-handle-media-type handle))
1456          (methods
1457           (mapcar (lambda (i) (cdr (assoc 'viewer i)))
1458                   (mailcap-mime-info type 'all)))
1459          (method (let ((minibuffer-local-completion-map
1460                         mm-viewer-completion-map))
1461                    (completing-read "Viewer: " methods))))
1462     (when (string= method "")
1463       (error "No method given"))
1464     (if (string-match "^[^% \t]+$" method)
1465         (setq method (concat method " %s")))
1466     (mm-display-external handle method)))
1467
1468 (defun mm-preferred-alternative (handles &optional preferred)
1469   "Say which of HANDLES are preferred."
1470   (let ((prec (if preferred (list preferred)
1471                 (mm-preferred-alternative-precedence handles)))
1472         p h result type handle)
1473     (while (setq p (pop prec))
1474       (setq h handles)
1475       (while h
1476         (setq handle (car h))
1477         (setq type (mm-handle-media-type handle))
1478         (when (and (equal p type)
1479                    (mm-automatic-display-p handle)
1480                    (or (stringp (car handle))
1481                        (not (mm-handle-disposition handle))
1482                        (equal (car (mm-handle-disposition handle))
1483                               "inline")))
1484           (setq result handle
1485                 h nil
1486                 prec nil))
1487         (pop h)))
1488     result))
1489
1490 (defun mm-preferred-alternative-precedence (handles)
1491   "Return the precedence based on HANDLES and `mm-discouraged-alternatives'."
1492   (setq handles (reverse handles))
1493   (dolist (disc (reverse mm-discouraged-alternatives))
1494     (dolist (handle (copy-sequence handles))
1495       (when (string-match disc (mm-handle-media-type handle))
1496         (setq handles (nconc (delete handle handles) (list handle))))))
1497   ;; Remove empty parts.
1498   (dolist (handle (copy-sequence handles))
1499     (when (and (bufferp (mm-handle-buffer handle))
1500                (not (with-current-buffer (mm-handle-buffer handle)
1501                       (goto-char (point-min))
1502                       (re-search-forward "[^ \t\n]" nil t))))
1503       (setq handles (nconc (delete handle handles) (list handle)))))
1504   (mapcar #'mm-handle-media-type handles))
1505
1506 (defun mm-get-content-id (id)
1507   "Return the handle(s) referred to by ID."
1508   (cdr (assoc id mm-content-id-alist)))
1509
1510 (defconst mm-image-type-regexps
1511   '(("/\\*.*XPM.\\*/" . xpm)
1512     ("P[1-6]" . pbm)
1513     ("GIF8" . gif)
1514     ("\377\330" . jpeg)
1515     ("\211PNG\r\n" . png)
1516     ("#define" . xbm)
1517     ("\\(MM\0\\*\\)\\|\\(II\\*\0\\)" . tiff)
1518     ("%!PS" . postscript))
1519   "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
1520 When the first bytes of an image file match REGEXP, it is assumed to
1521 be of image type IMAGE-TYPE.")
1522
1523 ;; Steal from image.el. image-type-from-data suffers multi-line matching bug.
1524 (defun mm-image-type-from-buffer ()
1525   "Determine the image type from data in the current buffer.
1526 Value is a symbol specifying the image type or nil if type cannot
1527 be determined."
1528   (let ((types mm-image-type-regexps)
1529         type)
1530     (goto-char (point-min))
1531     (while (and types (null type))
1532       (let ((regexp (car (car types)))
1533             (image-type (cdr (car types))))
1534         (when (looking-at regexp)
1535           (setq type image-type))
1536         (setq types (cdr types))))
1537     type))
1538
1539 (defun mm-get-image (handle)
1540   "Return an image instance based on HANDLE."
1541   (let ((type (mm-handle-media-subtype handle))
1542         spec)
1543     ;; Allow some common translations.
1544     (setq type
1545           (cond
1546            ((equal type "x-pixmap")
1547             "xpm")
1548            ((equal type "x-xbitmap")
1549             "xbm")
1550            ((equal type "x-portable-bitmap")
1551             "pbm")
1552            (t type)))
1553     (or (mm-handle-cache handle)
1554         (mm-with-unibyte-buffer
1555           (mm-insert-part handle)
1556           (prog1
1557               (setq spec
1558                     (ignore-errors
1559                       ;; Avoid testing `make-glyph' since W3 may define
1560                       ;; a bogus version of it.
1561                       (if (fboundp 'create-image)
1562                           (create-image (buffer-string)
1563                                         (or (mm-image-type-from-buffer)
1564                                             (intern type))
1565                                         'data-p)
1566                         (mm-create-image-xemacs type))))
1567             (mm-handle-set-cache handle spec))))))
1568
1569 (defun mm-create-image-xemacs (type)
1570   (when (featurep 'xemacs)
1571     (cond
1572      ((equal type "xbm")
1573       ;; xbm images require special handling, since
1574       ;; the only way to create glyphs from these
1575       ;; (without a ton of work) is to write them
1576       ;; out to a file, and then create a file
1577       ;; specifier.
1578       (let ((file (mm-make-temp-file
1579                    (expand-file-name "emm" mm-tmp-directory)
1580                    nil ".xbm")))
1581         (unwind-protect
1582             (progn
1583               (write-region (point-min) (point-max) file)
1584               (make-glyph (list (cons 'x file))))
1585           (ignore-errors
1586             (delete-file file)))))
1587      (t
1588       (make-glyph
1589        (vector
1590         (or (mm-image-type-from-buffer)
1591             (intern type))
1592         :data (buffer-string)))))))
1593
1594 (declare-function image-size "image.c" (spec &optional pixels frame))
1595
1596 (defun mm-image-fit-p (handle)
1597   "Say whether the image in HANDLE will fit the current window."
1598   (let ((image (mm-get-image handle)))
1599     (or (not image)
1600         (if (featurep 'xemacs)
1601             ;; XEmacs's glyphs can actually tell us about their width, so
1602             ;; let's be nice and smart about them.
1603             (or mm-inline-large-images
1604                 (and (<= (glyph-width image) (window-pixel-width))
1605                      (<= (glyph-height image) (window-pixel-height))))
1606           (let* ((size (image-size image))
1607                  (w (car size))
1608                  (h (cdr size)))
1609             (or mm-inline-large-images
1610                 (and (<= h (1- (window-height))) ; Don't include mode line.
1611                      (<= w (window-width)))))))))
1612
1613 (defun mm-valid-image-format-p (format)
1614   "Say whether FORMAT can be displayed natively by Emacs."
1615   (cond
1616    ;; Handle XEmacs
1617    ((fboundp 'valid-image-instantiator-format-p)
1618     (valid-image-instantiator-format-p format))
1619    ;; Handle Emacs
1620    ((fboundp 'image-type-available-p)
1621     (and (display-graphic-p)
1622          (image-type-available-p format)))
1623    ;; Nobody else can do images yet.
1624    (t
1625     nil)))
1626
1627 (defun mm-valid-and-fit-image-p (format handle)
1628   "Say whether FORMAT can be displayed natively and HANDLE fits the window."
1629   (and (mm-valid-image-format-p format)
1630        (mm-image-fit-p handle)))
1631
1632 (defun mm-find-part-by-type (handles type &optional notp recursive)
1633   "Search in HANDLES for part with TYPE.
1634 If NOTP, returns first non-matching part.
1635 If RECURSIVE, search recursively."
1636   (let (handle)
1637     (while handles
1638       (if (and recursive (stringp (caar handles)))
1639           (if (setq handle (mm-find-part-by-type (cdar handles) type
1640                                                  notp recursive))
1641               (setq handles nil))
1642         (if (if notp
1643                 (not (equal (mm-handle-media-type (car handles)) type))
1644               (equal (mm-handle-media-type (car handles)) type))
1645             (setq handle (car handles)
1646                   handles nil)))
1647       (setq handles (cdr handles)))
1648     handle))
1649
1650 (defun mm-find-raw-part-by-type (ctl type &optional notp)
1651   (goto-char (point-min))
1652   (let* ((boundary (concat "--" (mm-handle-multipart-ctl-parameter ctl
1653                                                                    'boundary)))
1654          (close-delimiter (concat "^" (regexp-quote boundary) "--[ \t]*$"))
1655          start
1656          (end (save-excursion
1657                 (goto-char (point-max))
1658                 (if (re-search-backward close-delimiter nil t)
1659                     (match-beginning 0)
1660                   (point-max))))
1661          result)
1662     (setq boundary (concat "^" (regexp-quote boundary) "[ \t]*$"))
1663     (while (and (not result)
1664                 (re-search-forward boundary end t))
1665       (goto-char (match-beginning 0))
1666       (when start
1667         (save-excursion
1668           (save-restriction
1669             (narrow-to-region start (1- (point)))
1670             (when (let* ((ct (mail-fetch-field "content-type"))
1671                          (ctl (and ct (mail-header-parse-content-type ct))))
1672                     (if notp
1673                         (not (equal (car ctl) type))
1674                       (equal (car ctl) type)))
1675               (setq result (buffer-string))))))
1676       (forward-line 1)
1677       (setq start (point)))
1678     (when (and (not result) start)
1679       (save-excursion
1680         (save-restriction
1681           (narrow-to-region start end)
1682           (when (let* ((ct (mail-fetch-field "content-type"))
1683                        (ctl (and ct (mail-header-parse-content-type ct))))
1684                   (if notp
1685                       (not (equal (car ctl) type))
1686                     (equal (car ctl) type)))
1687             (setq result (buffer-string))))))
1688     result))
1689
1690 (defvar mm-security-handle nil)
1691
1692 (defsubst mm-set-handle-multipart-parameter (handle parameter value)
1693   ;; HANDLE could be a CTL.
1694   (when handle
1695     (put-text-property 0 (length (car handle)) parameter value
1696                        (car handle))))
1697
1698 (autoload 'mm-view-pkcs7 "mm-view")
1699
1700 (defun mm-possibly-verify-or-decrypt (parts ctl &optional from)
1701   (let ((type (car ctl))
1702         (subtype (cadr (split-string (car ctl) "/")))
1703         (mm-security-handle ctl) ;; (car CTL) is the type.
1704         protocol func functest)
1705     (cond
1706      ((or (equal type "application/x-pkcs7-mime")
1707           (equal type "application/pkcs7-mime"))
1708       (with-temp-buffer
1709         (when (and (cond
1710                     ((eq mm-decrypt-option 'never) nil)
1711                     ((eq mm-decrypt-option 'always) t)
1712                     ((eq mm-decrypt-option 'known) t)
1713                     (t (y-or-n-p
1714                         (format "Decrypt (S/MIME) part? "))))
1715                    (mm-view-pkcs7 parts from))
1716           (setq parts (mm-dissect-buffer t)))))
1717      ((equal subtype "signed")
1718       (unless (and (setq protocol
1719                          (mm-handle-multipart-ctl-parameter ctl 'protocol))
1720                    (not (equal protocol "multipart/mixed")))
1721         ;; The message is broken or draft-ietf-openpgp-multsig-01.
1722         (let ((protocols mm-verify-function-alist))
1723           (while protocols
1724             (if (and (or (not (setq functest (nth 3 (car protocols))))
1725                          (funcall functest parts ctl))
1726                      (mm-find-part-by-type parts (caar protocols) nil t))
1727                 (setq protocol (caar protocols)
1728                       protocols nil)
1729               (setq protocols (cdr protocols))))))
1730       (setq func (nth 1 (assoc protocol mm-verify-function-alist)))
1731       (when (cond
1732              ((eq mm-verify-option 'never) nil)
1733              ((eq mm-verify-option 'always) t)
1734              ((eq mm-verify-option 'known)
1735               (and func
1736                    (or (not (setq functest
1737                                   (nth 3 (assoc protocol
1738                                                 mm-verify-function-alist))))
1739                        (funcall functest parts ctl))))
1740              (t
1741               (y-or-n-p
1742                (format "Verify signed (%s) part? "
1743                        (or (nth 2 (assoc protocol mm-verify-function-alist))
1744                            (format "protocol=%s" protocol))))))
1745         (save-excursion
1746           (if func
1747               (setq parts (funcall func parts ctl))
1748             (mm-set-handle-multipart-parameter
1749              mm-security-handle 'gnus-details
1750              (format "Unknown sign protocol (%s)" protocol))))))
1751      ((equal subtype "encrypted")
1752       (unless (setq protocol
1753                     (mm-handle-multipart-ctl-parameter ctl 'protocol))
1754         ;; The message is broken.
1755         (let ((parts parts))
1756           (while parts
1757             (if (assoc (mm-handle-media-type (car parts))
1758                        mm-decrypt-function-alist)
1759                 (setq protocol (mm-handle-media-type (car parts))
1760                       parts nil)
1761               (setq parts (cdr parts))))))
1762       (setq func (nth 1 (assoc protocol mm-decrypt-function-alist)))
1763       (when (cond
1764              ((eq mm-decrypt-option 'never) nil)
1765              ((eq mm-decrypt-option 'always) t)
1766              ((eq mm-decrypt-option 'known)
1767               (and func
1768                    (or (not (setq functest
1769                                   (nth 3 (assoc protocol
1770                                                 mm-decrypt-function-alist))))
1771                        (funcall functest parts ctl))))
1772              (t
1773               (y-or-n-p
1774                (format "Decrypt (%s) part? "
1775                        (or (nth 2 (assoc protocol mm-decrypt-function-alist))
1776                            (format "protocol=%s" protocol))))))
1777         (save-excursion
1778           (if func
1779               (setq parts (funcall func parts ctl))
1780             (mm-set-handle-multipart-parameter
1781              mm-security-handle 'gnus-details
1782              (format "Unknown encrypt protocol (%s)" protocol))))))
1783      (t nil))
1784     parts))
1785
1786 (defun mm-multiple-handles (handles)
1787   (and (listp handles)
1788        (> (length handles) 1)
1789        (or (listp (car handles))
1790            (stringp (car handles)))))
1791
1792 (defun mm-complicated-handles (handles)
1793   (and (listp (car handles))
1794        (> (length handles) 1)))
1795
1796 (defun mm-merge-handles (handles1 handles2)
1797   (append
1798    (if (listp (car handles1))
1799        handles1
1800      (list handles1))
1801    (if (listp (car handles2))
1802        handles2
1803      (list handles2))))
1804
1805 (defun mm-readable-p (handle)
1806   "Say whether the content of HANDLE is readable."
1807   (and (< (with-current-buffer (mm-handle-buffer handle)
1808             (buffer-size)) 10000)
1809        (mm-with-unibyte-buffer
1810          (mm-insert-part handle)
1811          (and (eq (mm-body-7-or-8) '7bit)
1812               (not (mm-long-lines-p 76))))))
1813
1814 (declare-function libxml-parse-html-region "xml.c"
1815                   (start end &optional base-url))
1816 (declare-function shr-insert-document "shr" (dom))
1817 (defvar shr-blocked-images)
1818 (defvar gnus-inhibit-images)
1819 (autoload 'gnus-blocked-images "gnus-art")
1820
1821 (defun mm-shr (handle)
1822   ;; Require since we bind its variables.
1823   (require 'shr)
1824   (let ((article-buffer (current-buffer))
1825         (shr-width fill-column)
1826         (shr-content-function (lambda (id)
1827                                 (let ((handle (mm-get-content-id id)))
1828                                   (when handle
1829                                     (mm-with-part handle
1830                                       (buffer-string))))))
1831         shr-inhibit-images shr-blocked-images charset char)
1832     (if (and (boundp 'gnus-summary-buffer)
1833              (bufferp gnus-summary-buffer)
1834              (buffer-name gnus-summary-buffer))
1835         (with-current-buffer gnus-summary-buffer
1836           (setq shr-inhibit-images gnus-inhibit-images
1837                 shr-blocked-images (gnus-blocked-images)))
1838       (setq shr-inhibit-images gnus-inhibit-images
1839             shr-blocked-images (gnus-blocked-images)))
1840     (unless handle
1841       (setq handle (mm-dissect-buffer t)))
1842     (setq charset (mail-content-type-get (mm-handle-type handle) 'charset))
1843     (save-restriction
1844       (narrow-to-region (point) (point))
1845       (shr-insert-document
1846        (mm-with-part handle
1847          (insert (prog1
1848                      (if (and charset
1849                               (setq charset
1850                                     (mm-charset-to-coding-system charset
1851                                                                  nil t))
1852                               (not (eq charset 'ascii)))
1853                          (mm-decode-coding-string (buffer-string) charset)
1854                        (mm-string-as-multibyte (buffer-string)))
1855                    (erase-buffer)
1856                    (mm-enable-multibyte)))
1857          (goto-char (point-min))
1858          (setq case-fold-search t)
1859          (while (re-search-forward
1860                  "&#\\(?:x\\([89][0-9a-f]\\)\\|\\(1[2-5][0-9]\\)\\);" nil t)
1861            (when (setq char
1862                        (cdr (assq (if (match-beginning 1)
1863                                       (string-to-number (match-string 1) 16)
1864                                     (string-to-number (match-string 2)))
1865                                   mm-extra-numeric-entities)))
1866              (replace-match (char-to-string char))))
1867          ;; Remove "soft hyphens".
1868          (goto-char (point-min))
1869          (while (search-forward "" nil t)
1870            (replace-match "" t t))
1871          (libxml-parse-html-region (point-min) (point-max))))
1872       (unless (bobp)
1873         (insert "\n"))
1874       (mm-convert-shr-links)
1875       (mm-handle-set-undisplayer
1876        handle
1877        `(lambda ()
1878           (let ((inhibit-read-only t))
1879             (delete-region ,(copy-marker (point-min) t)
1880                            ,(point-max-marker))))))))
1881
1882 (defvar shr-map)
1883
1884 (autoload 'widget-convert-button "wid-edit")
1885
1886 (defun mm-convert-shr-links ()
1887   (let ((start (point-min))
1888         end)
1889     (while (and start
1890                 (< start (point-max)))
1891       (when (setq start (text-property-not-all start (point-max) 'shr-url nil))
1892         (setq end (next-single-property-change start 'shr-url nil (point-max)))
1893         (widget-convert-button
1894          'url-link start end
1895          :help-echo (get-text-property start 'help-echo)
1896          :keymap shr-map
1897          (get-text-property start 'shr-url))
1898         (put-text-property start end 'local-map nil)
1899         (setq start end)))))
1900
1901 (defun mm-handle-filename (handle)
1902   "Return filename of HANDLE if any."
1903   (or (mail-content-type-get (mm-handle-type handle)
1904                              'name)
1905       (mail-content-type-get (mm-handle-disposition handle)
1906                              'filename)))
1907
1908 (provide 'mm-decode)
1909
1910 ;; Local Variables:
1911 ;; coding: utf-8
1912 ;; End:
1913
1914 ;;; mm-decode.el ends here