lisp/gnus/mm-decode.el

   1 ;;; mm-decode.el --- Functions for decoding MIME things
   2
   3 ;; Copyright (C) 1998-2016 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
  32 (autoload 'mm-inline-partial "mm-partial")
  33 (autoload 'mm-inline-external-body "mm-extern")
  34 (autoload 'mm-extern-cache-contents "mm-extern")
  35 (autoload 'mm-insert-inline "mm-view")
  36
  37 (autoload 'mm-archive-decoders "mm-archive")
  38 (autoload 'mm-archive-dissect-and-inline "mm-archive")
  39 (autoload 'mm-dissect-archive "mm-archive")
  40
  41 (defvar gnus-current-window-configuration)
  42
  43 (add-hook 'gnus-exit-gnus-hook 'mm-destroy-postponed-undisplay-list)
  44 (add-hook 'gnus-exit-gnus-hook 'mm-temp-files-delete)
  45
  46 (defgroup mime-display ()
  47   "Display of MIME in mail and news articles."
  48   :link '(custom-manual "(emacs-mime)Display Customization")
  49   :version "21.1"
  50   :group 'mail
  51   :group 'news
  52   :group 'multimedia)
  53
  54 (defgroup mime-security ()
  55   "MIME security in mail and news articles."
  56   :link '(custom-manual "(emacs-mime)Display Customization")
  57   :group 'mail
  58   :group 'news
  59   :group 'multimedia)
  60
  61 (defface mm-command-output
  62   '((((class color)
  63       (background dark))
  64      (:foreground "ForestGreen"))
  65     (((class color)
  66       (background light))
  67      (:foreground "red3"))
  68     (t
  69      (:italic t)))
  70   "Face used for displaying output from commands."
  71   :group 'mime-display)
  72
  73 ;;; Convenience macros.
  74
  75 (defmacro mm-handle-buffer (handle)
  76   `(nth 0 ,handle))
  77 (defmacro mm-handle-type (handle)
  78   `(nth 1 ,handle))
  79 (defsubst mm-handle-media-type (handle)
  80   (if (stringp (car handle))
  81       (car handle)
  82     (car (mm-handle-type handle))))
  83 (defsubst mm-handle-media-supertype (handle)
  84   (car (split-string (mm-handle-media-type handle) "/")))
  85 (defsubst mm-handle-media-subtype (handle)
  86   (cadr (split-string (mm-handle-media-type handle) "/")))
  87 (defmacro mm-handle-encoding (handle)
  88   `(nth 2 ,handle))
  89 (defmacro mm-handle-undisplayer (handle)
  90   `(nth 3 ,handle))
  91 (defmacro mm-handle-set-undisplayer (handle function)
  92   `(setcar (nthcdr 3 ,handle) ,function))
  93 (defmacro mm-handle-disposition (handle)
  94   `(nth 4 ,handle))
  95 (defmacro mm-handle-description (handle)
  96   `(nth 5 ,handle))
  97 (defmacro mm-handle-cache (handle)
  98   `(nth 6 ,handle))
  99 (defmacro mm-handle-set-cache (handle contents)
 100   `(setcar (nthcdr 6 ,handle) ,contents))
 101 (defmacro mm-handle-id (handle)
 102   `(nth 7 ,handle))
 103 (defmacro mm-handle-multipart-original-buffer (handle)
 104   `(get-text-property 0 'buffer (car ,handle)))
 105 (defmacro mm-handle-multipart-from (handle)
 106   `(get-text-property 0 'from (car ,handle)))
 107 (defmacro mm-handle-multipart-ctl-parameter (handle parameter)
 108   `(get-text-property 0 ,parameter (car ,handle)))
 109
 110 (defmacro mm-make-handle (&optional buffer type encoding undisplayer
 111                                     disposition description cache
 112                                     id)
 113   `(list ,buffer ,type ,encoding ,undisplayer
 114          ,disposition ,description ,cache ,id))
 115
 116 (defcustom mm-text-html-renderer
 117   (cond ((fboundp 'libxml-parse-html-region) 'shr)
 118         ((executable-find "w3m") 'gnus-w3m)
 119         ((executable-find "links") 'links)
 120         ((executable-find "lynx") 'lynx)
 121         ((locate-library "html2text") 'html2text)
 122         (t nil))
 123   "Render of HTML contents.
 124 It is one of defined renderer types, or a rendering function.
 125 The defined renderer types are:
 126 `shr': use the built-in Gnus HTML renderer;
 127 `gnus-w3m': use Gnus renderer based on w3m;
 128 `w3m': use emacs-w3m;
 129 `w3m-standalone': use plain w3m;
 130 `links': use links;
 131 `lynx': use lynx;
 132 `html2text': use html2text;
 133 nil    : use external viewer (default web browser)."
 134   :version "24.1"
 135   :type '(choice (const shr)
 136                  (const gnus-w3m)
 137                  (const w3m :tag "emacs-w3m")
 138                  (const w3m-standalone :tag "standalone w3m" )
 139                  (const links)
 140                  (const lynx)
 141                  (const html2text)
 142                  (const nil :tag "External viewer")
 143                  (function))
 144   :group 'mime-display)
 145
 146 (defcustom mm-html-inhibit-images nil
 147   "Non-nil means inhibit displaying of images inline in the article body."
 148   :version "25.1"
 149   :type 'boolean
 150   :group 'mime-display)
 151
 152 (defcustom mm-html-blocked-images ""
 153   "Regexp matching image URLs to be blocked, or nil meaning not to block.
 154 Note that cid images that are embedded in a message won't be blocked."
 155   :version "25.1"
 156   :type '(choice (const :tag "Allow all" nil)
 157                  (regexp :tag "Regular expression"))
 158   :group 'mime-display)
 159
 160 (defcustom mm-w3m-safe-url-regexp "\\`cid:"
 161   "Regexp matching URLs which are considered to be safe.
 162 Some HTML mails might contain a nasty trick used by spammers, using
 163 the <img> tag which is far more evil than the [Click Here!] button.
 164 It is most likely intended to check whether the ominous spam mail has
 165 reached your eyes or not, in which case the spammer knows for sure
 166 that your email address is valid.  It is done by embedding an
 167 identifier string into a URL that you might automatically retrieve
 168 when displaying the image.  The default value is \"\\\\`cid:\" which only
 169 matches parts embedded to the Multipart/Related type MIME contents and
 170 Gnus will never connect to the spammer's site arbitrarily.  You may
 171 set this variable to nil if you consider all urls to be safe."
 172   :version "22.1"
 173   :type '(choice (regexp :tag "Regexp")
 174                  (const :tag "All URLs are safe" nil))
 175   :group 'mime-display)
 176
 177 (defcustom mm-inline-text-html-with-w3m-keymap t
 178   "If non-nil, use emacs-w3m command keys in the article buffer."
 179   :version "22.1"
 180   :type 'boolean
 181   :group 'mime-display)
 182
 183 (defcustom mm-enable-external t
 184   "Indicate whether external MIME handlers should be used.
 185
 186 If t, all defined external MIME handlers are used.  If nil, files are saved by
 187 `mailcap-save-binary-file'.  If it is the symbol `ask', you are prompted
 188 before the external MIME handler is invoked."
 189   :version "22.1"
 190   :type '(choice (const :tag "Always" t)
 191                  (const :tag "Never" nil)
 192                  (const :tag "Ask" ask))
 193   :group 'mime-display)
 194
 195 (defcustom mm-inline-media-tests
 196   '(("image/p?jpeg"
 197      mm-inline-image
 198      (lambda (handle)
 199        (mm-valid-and-fit-image-p 'jpeg handle)))
 200     ("image/png"
 201      mm-inline-image
 202      (lambda (handle)
 203        (mm-valid-and-fit-image-p 'png handle)))
 204     ("image/gif"
 205      mm-inline-image
 206      (lambda (handle)
 207        (mm-valid-and-fit-image-p 'gif handle)))
 208     ("image/tiff"
 209      mm-inline-image
 210      (lambda (handle)
 211        (mm-valid-and-fit-image-p 'tiff handle)))
 212     ("image/xbm"
 213      mm-inline-image
 214      (lambda (handle)
 215        (mm-valid-and-fit-image-p 'xbm handle)))
 216     ("image/x-xbitmap"
 217      mm-inline-image
 218      (lambda (handle)
 219        (mm-valid-and-fit-image-p 'xbm handle)))
 220     ("image/xpm"
 221      mm-inline-image
 222      (lambda (handle)
 223        (mm-valid-and-fit-image-p 'xpm handle)))
 224     ("image/x-xpixmap"
 225      mm-inline-image
 226      (lambda (handle)
 227        (mm-valid-and-fit-image-p 'xpm handle)))
 228     ("image/bmp"
 229      mm-inline-image
 230      (lambda (handle)
 231        (mm-valid-and-fit-image-p 'bmp handle)))
 232     ("image/x-portable-bitmap"
 233      mm-inline-image
 234      (lambda (handle)
 235        (mm-valid-and-fit-image-p 'pbm handle)))
 236     ("text/plain" mm-inline-text identity)
 237     ("text/enriched" mm-inline-text identity)
 238     ("text/richtext" mm-inline-text identity)
 239     ("text/x-patch" mm-display-patch-inline identity)
 240     ;; In case mime.types uses x-diff (as does Debian's mime-support-3.40).
 241     ("text/x-diff" mm-display-patch-inline identity)
 242     ("application/emacs-lisp" mm-display-elisp-inline identity)
 243     ("application/x-emacs-lisp" mm-display-elisp-inline identity)
 244     ("application/x-shellscript" mm-display-shell-script-inline identity)
 245     ("application/x-sh" mm-display-shell-script-inline identity)
 246     ("text/x-sh" mm-display-shell-script-inline identity)
 247     ("application/javascript" mm-display-javascript-inline identity)
 248     ("text/dns" mm-display-dns-inline identity)
 249     ("text/x-org" mm-display-org-inline identity)
 250     ("text/html"
 251      mm-inline-text-html
 252      (lambda (handle)
 253        mm-text-html-renderer))
 254     ("text/x-vcard"
 255      mm-inline-text-vcard
 256      (lambda (handle)
 257        (or (featurep 'vcard)
 258            (locate-library "vcard"))))
 259     ("message/delivery-status" mm-inline-text identity)
 260     ("message/rfc822" mm-inline-message identity)
 261     ("message/partial" mm-inline-partial identity)
 262     ("message/external-body" mm-inline-external-body identity)
 263     ("text/.*" mm-inline-text identity)
 264     ("application/x-.?tar\\(-.*\\)?" mm-archive-dissect-and-inline identity)
 265     ("application/zip" mm-archive-dissect-and-inline identity)
 266     ("audio/wav" mm-inline-audio
 267      (lambda (handle)
 268        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 269             (device-sound-enabled-p))))
 270     ("audio/au"
 271      mm-inline-audio
 272      (lambda (handle)
 273        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 274             (device-sound-enabled-p))))
 275     ("application/pgp-signature" ignore identity)
 276     ("application/x-pkcs7-signature" ignore identity)
 277     ("application/pkcs7-signature" ignore identity)
 278     ("application/x-pkcs7-mime" ignore identity)
 279     ("application/pkcs7-mime" ignore identity)
 280     ("multipart/alternative" ignore identity)
 281     ("multipart/mixed" ignore identity)
 282     ("multipart/related" ignore identity)
 283     ("image/.*"
 284      mm-inline-image
 285      (lambda (handle)
 286        (and (mm-valid-image-format-p 'imagemagick)
 287             (mm-with-unibyte-buffer
 288               (mm-insert-part handle)
 289               (let ((image
 290                      (ignore-errors
 291                        (create-image (buffer-string) 'imagemagick 'data-p))))
 292                 (when image
 293                   (setcar (cdr handle) (list "image/imagemagick"))
 294                   (mm-image-fit-p handle)))))))
 295     ;; Disable audio and image
 296     ("audio/.*" ignore ignore)
 297     ("image/.*" ignore ignore)
 298     ;; Default to displaying as text
 299     (".*" mm-inline-text mm-readable-p))
 300   "Alist of media types/tests saying whether types can be displayed inline."
 301   :type '(repeat (list (regexp :tag "MIME type")
 302                        (function :tag "Display function")
 303                        (function :tag "Display test")))
 304   :group 'mime-display)
 305
 306 (defcustom mm-inlined-types
 307   '("image/.*" "text/.*" "message/delivery-status" "message/rfc822"
 308     "message/partial" "message/external-body" "application/emacs-lisp"
 309     "application/x-emacs-lisp"
 310     "application/pgp-signature" "application/x-pkcs7-signature"
 311     "application/pkcs7-signature" "application/x-pkcs7-mime"
 312     "application/pkcs7-mime"
 313     "application/x-gtar-compressed"
 314     "application/x-tar"
 315     "application/zip"
 316     ;; Mutt still uses this even though it has already been withdrawn.
 317     "application/pgp")
 318   "List of media types that are to be displayed inline.
 319 See also `mm-inline-media-tests', which says how to display a media
 320 type inline."
 321   :type '(repeat regexp)
 322   :group 'mime-display)
 323
 324 (defcustom mm-keep-viewer-alive-types
 325   '("application/postscript" "application/msword" "application/vnd.ms-excel"
 326     "application/pdf" "application/x-dvi")
 327   "List of media types for which the external viewer will not be killed
 328 when selecting a different article."
 329   :version "22.1"
 330   :type '(repeat regexp)
 331   :group 'mime-display)
 332
 333 (defcustom mm-automatic-display
 334   '("text/plain" "text/enriched" "text/richtext" "text/html" "text/x-verbatim"
 335     "text/x-vcard" "image/.*" "message/delivery-status" "multipart/.*"
 336     "message/rfc822" "text/x-patch" "text/dns" "application/pgp-signature"
 337     "application/emacs-lisp" "application/x-emacs-lisp"
 338     "application/x-pkcs7-signature"
 339     "application/pkcs7-signature" "application/x-pkcs7-mime"
 340     "application/pkcs7-mime"
 341     ;; Mutt still uses this even though it has already been withdrawn.
 342     "application/pgp\\'"
 343      "text/x-org")
 344   "A list of MIME types to be displayed automatically."
 345   :type '(repeat regexp)
 346   :group 'mime-display)
 347
 348 (defcustom mm-attachment-override-types '("text/x-vcard"
 349                                           "application/pkcs7-mime"
 350                                           "application/x-pkcs7-mime"
 351                                           "application/pkcs7-signature"
 352                                           "application/x-pkcs7-signature")
 353   "Types to have \"attachment\" ignored if they can be displayed inline."
 354   :type '(repeat regexp)
 355   :group 'mime-display)
 356
 357 (defcustom mm-inline-override-types nil
 358   "Types to be treated as attachments even if they can be displayed inline."
 359   :type '(repeat regexp)
 360   :group 'mime-display)
 361
 362 (defcustom mm-automatic-external-display nil
 363   "List of MIME type regexps that will be displayed externally automatically."
 364   :type '(repeat regexp)
 365   :group 'mime-display)
 366
 367 (defcustom mm-discouraged-alternatives nil
 368   "List of MIME types that are discouraged when viewing multipart/alternative.
 369 Viewing agents are supposed to view the last possible part of a message,
 370 as that is supposed to be the richest.  However, users may prefer other
 371 types instead, and this list says what types are most unwanted.  If,
 372 for instance, text/html parts are very unwanted, and text/richtext are
 373 somewhat unwanted, then the value of this variable should be set
 374 to:
 375
 376  (\"text/html\" \"text/richtext\")
 377
 378 Adding \"image/.*\" might also be useful.  Spammers use it as the
 379 preferred part of multipart/alternative messages.  See also
 380 `gnus-buttonized-mime-types', to which adding \"multipart/alternative\"
 381 enables you to choose manually one of two types those mails include."
 382   :type '(repeat regexp) ;; See `mm-preferred-alternative-precedence'.
 383   :group 'mime-display)
 384
 385 (defcustom mm-tmp-directory temporary-file-directory
 386   "Where mm will store its temporary files."
 387   :type 'directory
 388   :group 'mime-display)
 389
 390 (defcustom mm-inline-large-images nil
 391   "If t, then all images fit in the buffer.
 392 If `resize', try to resize the images so they fit."
 393   :type '(radio
 394           (const :tag "Inline large images as they are." t)
 395           (const :tag "Resize large images." resize)
 396           (const :tag "Do not inline large images." nil))
 397   :group 'mime-display)
 398
 399 (defcustom mm-file-name-rewrite-functions
 400   '(mm-file-name-delete-control mm-file-name-delete-gotchas)
 401   "List of functions used for rewriting file names of MIME parts.
 402 Each function takes a file name as input and returns a file name.
 403
 404 Ready-made functions include `mm-file-name-delete-control',
 405 `mm-file-name-delete-gotchas' (you should not remove these two
 406 functions), `mm-file-name-delete-whitespace',
 407 `mm-file-name-trim-whitespace', `mm-file-name-collapse-whitespace',
 408 `mm-file-name-replace-whitespace', `capitalize', `downcase',
 409 `upcase', and `upcase-initials'."
 410   :type '(list (set :inline t
 411                     (const mm-file-name-delete-control)
 412                     (const mm-file-name-delete-gotchas)
 413                     (const mm-file-name-delete-whitespace)
 414                     (const mm-file-name-trim-whitespace)
 415                     (const mm-file-name-collapse-whitespace)
 416                     (const mm-file-name-replace-whitespace)
 417                     (const capitalize)
 418                     (const downcase)
 419                     (const upcase)
 420                     (const upcase-initials)
 421                (repeat :inline t
 422                        :tag "Function"
 423                        function)))
 424   :version "23.1" ;; No Gnus
 425   :group 'mime-display)
 426
 427
 428 (defvar mm-path-name-rewrite-functions nil
 429   "*List of functions for rewriting the full file names of MIME parts.
 430 This is used when viewing parts externally, and is meant for
 431 transforming the absolute name so that non-compliant programs can find
 432 the file where it's saved.
 433
 434 Each function takes a file name as input and returns a file name.")
 435
 436 (defvar mm-file-name-replace-whitespace nil
 437   "String used for replacing whitespace characters; default is `\"_\"'.")
 438
 439 (defcustom mm-default-directory nil
 440   "The default directory where mm will save files.
 441 If not set, `default-directory' will be used."
 442   :type '(choice directory (const :tag "Default" nil))
 443   :group 'mime-display)
 444
 445 (defcustom mm-attachment-file-modes 384
 446   "Set the mode bits of saved attachments to this integer."
 447   :version "22.1"
 448   :type 'integer
 449   :group 'mime-display)
 450
 451 (defcustom mm-external-terminal-program "xterm"
 452   "The program to start an external terminal."
 453   :version "22.1"
 454   :type 'string
 455   :group 'mime-display)
 456
 457 ;;; Internal variables.
 458
 459 (defvar mm-last-shell-command "")
 460 (defvar mm-content-id-alist nil)
 461 (defvar mm-postponed-undisplay-list nil)
 462 (defvar mm-inhibit-auto-detect-attachment nil)
 463 (defvar mm-temp-files-to-be-deleted nil
 464   "List of temporary files scheduled to be deleted.")
 465 (defvar mm-temp-files-cache-file (concat ".mm-temp-files-" (user-login-name))
 466   "Name of a file that caches a list of temporary files to be deleted.
 467 The file will be saved in the directory `mm-tmp-directory'.")
 468
 469 ;; According to RFC2046, in particular, in a digest, the default
 470 ;; Content-Type value for a body part is changed from "text/plain" to
 471 ;; "message/rfc822".
 472 (defvar mm-dissect-default-type "text/plain")
 473
 474 (autoload 'mml2015-verify "mml2015")
 475 (autoload 'mml2015-verify-test "mml2015")
 476 (autoload 'mml-smime-verify "mml-smime")
 477 (autoload 'mml-smime-verify-test "mml-smime")
 478
 479 (defvar mm-verify-function-alist
 480   '(("application/pgp-signature" mml2015-verify "PGP" mml2015-verify-test)
 481     ("application/x-gnus-pgp-signature" mm-uu-pgp-signed-extract-1 "PGP"
 482      mm-uu-pgp-signed-test)
 483     ("application/pkcs7-signature" mml-smime-verify "S/MIME"
 484      mml-smime-verify-test)
 485     ("application/x-pkcs7-signature" mml-smime-verify "S/MIME"
 486      mml-smime-verify-test)))
 487
 488 (defcustom mm-verify-option 'never
 489   "Option of verifying signed parts.
 490 `never', not verify; `always', always verify;
 491 `known', only verify known protocols.  Otherwise, ask user.
 492
 493 When set to `always' or `known', you should add
 494 \"multipart/signed\" to `gnus-buttonized-mime-types' to see
 495 result of the verification."
 496   :version "22.1"
 497   :type '(choice (item always)
 498                  (item never)
 499                  (item :tag "only known protocols" known)
 500                  (item :tag "ask" nil))
 501   :group 'mime-security)
 502
 503 (autoload 'mml2015-decrypt "mml2015")
 504 (autoload 'mml2015-decrypt-test "mml2015")
 505
 506 (defvar mm-decrypt-function-alist
 507   '(("application/pgp-encrypted" mml2015-decrypt "PGP" mml2015-decrypt-test)
 508     ("application/x-gnus-pgp-encrypted" mm-uu-pgp-encrypted-extract-1 "PGP"
 509      mm-uu-pgp-encrypted-test)))
 510
 511 (defcustom mm-decrypt-option nil
 512   "Option of decrypting encrypted parts.
 513 `never', not decrypt; `always', always decrypt;
 514 `known', only decrypt known protocols.  Otherwise, ask user."
 515   :version "22.1"
 516   :type '(choice (item always)
 517                  (item never)
 518                  (item :tag "only known protocols" known)
 519                  (item :tag "ask" nil))
 520   :group 'mime-security)
 521
 522 (defvar mm-viewer-completion-map
 523   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 524     (set-keymap-parent map minibuffer-local-completion-map)
 525     ;; Should we bind other key to minibuffer-complete-word?
 526     (define-key map " " 'self-insert-command)
 527     map)
 528   "Keymap for input viewer with completion.")
 529
 530 ;;; The functions.
 531
 532 (defun mm-alist-to-plist (alist)
 533   "Convert association list ALIST into the equivalent property-list form.
 534 The plist is returned.  This converts from
 535
 536 \((a . 1) (b . 2) (c . 3))
 537
 538 into
 539
 540 \(a 1 b 2 c 3)
 541
 542 The original alist is not modified."
 543   (let (plist)
 544     (while alist
 545       (let ((el (car alist)))
 546         (setq plist (cons (cdr el) (cons (car el) plist))))
 547       (setq alist (cdr alist)))
 548     (nreverse plist)))
 549
 550 (defun mm-keep-viewer-alive-p (handle)
 551   "Say whether external viewer for HANDLE should stay alive."
 552   (let ((types mm-keep-viewer-alive-types)
 553         (type (mm-handle-media-type handle))
 554         ty)
 555     (catch 'found
 556       (while (setq ty (pop types))
 557         (when (string-match ty type)
 558           (throw 'found t))))))
 559
 560 (defun mm-handle-set-external-undisplayer (handle function)
 561   "Set the undisplayer for HANDLE to FUNCTION.
 562 Postpone undisplaying of viewers for types in
 563 `mm-keep-viewer-alive-types'."
 564   (if (mm-keep-viewer-alive-p handle)
 565       (let ((new-handle (copy-sequence handle)))
 566         (mm-handle-set-undisplayer new-handle function)
 567         (mm-handle-set-undisplayer handle nil)
 568         (push new-handle mm-postponed-undisplay-list))
 569     (mm-handle-set-undisplayer handle function)))
 570
 571 (defun mm-destroy-postponed-undisplay-list ()
 572   (when mm-postponed-undisplay-list
 573     (message "Destroying external MIME viewers")
 574     (mm-destroy-parts mm-postponed-undisplay-list)))
 575
 576 (defun mm-temp-files-delete ()
 577   "Delete temporary files and those parent directories.
 578 Note that the deletion may fail if a program is catching hold of a file
 579 under Windows or Cygwin.  In that case, it schedules the deletion of
 580 files left at the next time."
 581   (let* ((coding-system-for-read mm-universal-coding-system)
 582          (coding-system-for-write mm-universal-coding-system)
 583          (cache-file (expand-file-name mm-temp-files-cache-file
 584                                        mm-tmp-directory))
 585          (cache (when (file-exists-p cache-file)
 586                   (mm-with-multibyte-buffer
 587                     (insert-file-contents cache-file)
 588                     (split-string (buffer-string) "\n" t))))
 589          fails)
 590     (dolist (temp (append cache mm-temp-files-to-be-deleted))
 591       (when (and (file-exists-p temp)
 592                  (if (file-directory-p temp)
 593                      ;; A parent directory left at the previous time.
 594                      (progn
 595                        (ignore-errors (delete-directory temp))
 596                        (file-exists-p temp))
 597                    ;; Delete a temporary file and its parent directory.
 598                    (ignore-errors (delete-file temp))
 599                    (or (file-exists-p temp)
 600                        (progn
 601                          (setq temp (file-name-directory temp))
 602                          (ignore-errors (delete-directory temp))
 603                          (file-exists-p temp)))))
 604         (push temp fails)))
 605     (if fails
 606         ;; Schedule the deletion of the files left at the next time.
 607         (progn
 608           (write-region (concat (mapconcat 'identity (nreverse fails) "\n")
 609                                 "\n")
 610                         nil cache-file nil 'silent)
 611           (set-file-modes cache-file #o600))
 612       (when (file-exists-p cache-file)
 613         (ignore-errors (delete-file cache-file))))
 614     (setq mm-temp-files-to-be-deleted nil)))
 615
 616 (autoload 'message-fetch-field "message")
 617
 618 (defun mm-dissect-buffer (&optional no-strict-mime loose-mime from)
 619   "Dissect the current buffer and return a list of MIME handles.
 620 If NO-STRICT-MIME, don't require the message to have a
 621 MIME-Version header before proceeding."
 622   (save-excursion
 623     (let (ct ctl type subtype cte cd description id result)
 624       (save-restriction
 625         (mail-narrow-to-head)
 626         (when (or no-strict-mime
 627                   loose-mime
 628                   (mail-fetch-field "mime-version"))
 629           (setq ct (mail-fetch-field "content-type")
 630                 ctl (and ct (mail-header-parse-content-type ct))
 631                 cte (mail-fetch-field "content-transfer-encoding")
 632                 cd (or (mail-fetch-field "content-disposition")
 633                        (when (and ctl
 634                                   (eq 'mm-inline-text
 635                                       (cadr (mm-assoc-string-match
 636                                              mm-inline-media-tests
 637                                              (car ctl)))))
 638                          "inline"))
 639                 ;; Newlines in description should be stripped so as
 640                 ;; not to break the MIME tag into two or more lines.
 641                 description (message-fetch-field "content-description")
 642                 id (mail-fetch-field "content-id"))
 643           (unless from
 644             (setq from (mail-fetch-field "from")))
 645           ;; FIXME: In some circumstances, this code is running within
 646           ;; a unibyte macro.  mail-extract-address-components
 647           ;; creates unibyte buffers. This `if', though not a perfect
 648           ;; solution, avoids most of them.
 649           (if from
 650               (setq from (cadr (mail-extract-address-components from))))
 651           (if description
 652               (setq description (mail-decode-encoded-word-string
 653                                  description)))))
 654       (if (or (not ctl)
 655               (not (string-match "/" (car ctl))))
 656             (mm-dissect-singlepart
 657            (list mm-dissect-default-type)
 658              (and cte (intern (downcase (mail-header-strip cte))))
 659            no-strict-mime
 660            (and cd (mail-header-parse-content-disposition cd))
 661            description)
 662         (setq type (split-string (car ctl) "/"))
 663         (setq subtype (cadr type)
 664               type (car type))
 665         (setq
 666          result
 667          (cond
 668           ((equal type "multipart")
 669            (let ((mm-dissect-default-type (if (equal subtype "digest")
 670                                               "message/rfc822"
 671                                             "text/plain"))
 672                  (start (cdr (assq 'start (cdr ctl)))))
 673              (add-text-properties 0 (length (car ctl))
 674                                   (mm-alist-to-plist (cdr ctl)) (car ctl))
 675
 676              ;; what really needs to be done here is a way to link a
 677              ;; MIME handle back to it's parent MIME handle (in a multilevel
 678              ;; MIME article).  That would probably require changing
 679              ;; the mm-handle API so we simply store the multipart buffer
 680              ;; name as a text property of the "multipart/whatever" string.
 681              (add-text-properties 0 (length (car ctl))
 682                                   (list 'buffer (mm-copy-to-buffer)
 683                                         'from from
 684                                         'start start)
 685                                   (car ctl))
 686              (cons (car ctl) (mm-dissect-multipart ctl from))))
 687           (t
 688            (mm-possibly-verify-or-decrypt
 689             (mm-dissect-singlepart
 690              ctl
 691              (and cte (intern (downcase (mail-header-strip cte))))
 692              no-strict-mime
 693              (and cd (mail-header-parse-content-disposition cd))
 694              description id)
 695             ctl from))))
 696         (when id
 697           (when (string-match " *<\\(.*\\)> *" id)
 698             (setq id (match-string 1 id)))
 699           (push (cons id result) mm-content-id-alist))
 700         result))))
 701
 702 (defun mm-dissect-singlepart (ctl cte &optional force cdl description id)
 703   (when (or force
 704             (if (equal "text/plain" (car ctl))
 705                 (assoc 'format ctl)
 706               t))
 707     ;; Guess what the type of application/octet-stream parts should
 708     ;; really be.
 709     (let ((filename (cdr (assq 'filename (cdr cdl)))))
 710       (when (and (not mm-inhibit-auto-detect-attachment)
 711                  (equal (car ctl) "application/octet-stream")
 712                  filename
 713                  (string-match "\\.\\([^.]+\\)$" filename))
 714         (let ((new-type (mailcap-extension-to-mime (match-string 1 filename))))
 715           (when new-type
 716             (setcar ctl new-type)))))
 717     (let ((handle
 718            (mm-make-handle
 719             (mm-copy-to-buffer) ctl cte nil cdl description nil id))
 720           (decoder (assoc (car ctl) (mm-archive-decoders))))
 721       (if (and decoder
 722                ;; Do automatic decoding
 723                (cadr decoder)
 724                (executable-find (caddr decoder)))
 725           (mm-dissect-archive handle)
 726         handle))))
 727
 728 (defun mm-dissect-multipart (ctl from)
 729   (goto-char (point-min))
 730   (let* ((boundary (concat "\n--" (mail-content-type-get ctl 'boundary)))
 731          (close-delimiter (concat (regexp-quote boundary) "--[ \t]*$"))
 732          start parts
 733          (end (save-excursion
 734                 (goto-char (point-max))
 735                 (if (re-search-backward close-delimiter nil t)
 736                     (match-beginning 0)
 737                   (point-max))))
 738          (mm-inhibit-auto-detect-attachment
 739           (equal (car ctl) "multipart/encrypted")))
 740     (setq boundary (concat (regexp-quote boundary) "[ \t]*$"))
 741     (while (and (< (point) end) (re-search-forward boundary end t))
 742       (goto-char (match-beginning 0))
 743       (when start
 744         (save-excursion
 745           (save-restriction
 746             (narrow-to-region start (point))
 747             (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 748       (end-of-line 2)
 749       (or (looking-at boundary)
 750           (forward-line 1))
 751       (setq start (point)))
 752     (when (and start (< start end))
 753       (save-excursion
 754         (save-restriction
 755           (narrow-to-region start end)
 756           (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 757     (mm-possibly-verify-or-decrypt (nreverse parts) ctl from)))
 758
 759 (defun mm-copy-to-buffer ()
 760   "Copy the contents of the current buffer to a fresh buffer."
 761   (let ((obuf (current-buffer))
 762         (mb (mm-multibyte-p))
 763         beg)
 764     (goto-char (point-min))
 765     (search-forward-regexp "^\n" nil t)
 766     (setq beg (point))
 767     (with-current-buffer
 768           (generate-new-buffer " *mm*")
 769       ;; Preserve the data's unibyteness (for url-insert-file-contents).
 770       (set-buffer-multibyte mb)
 771       (insert-buffer-substring obuf beg)
 772       (current-buffer))))
 773
 774 (defun mm-display-parts (handle &optional no-default)
 775   (if (stringp (car handle))
 776       (mapcar 'mm-display-parts (cdr handle))
 777     (if (bufferp (car handle))
 778         (save-restriction
 779           (narrow-to-region (point) (point))
 780           (mm-display-part handle)
 781           (goto-char (point-max)))
 782       (mapcar 'mm-display-parts handle))))
 783
 784 (autoload 'mailcap-parse-mailcaps "mailcap")
 785 (autoload 'mailcap-mime-info "mailcap")
 786
 787 (defun mm-head-p (&optional point)
 788   "Return non-nil if point is in the article header."
 789   (let ((point (or point (point))))
 790     (save-excursion
 791       (goto-char point)
 792       (and (not (re-search-backward "^$" nil t))
 793            (re-search-forward "^$" nil t)))))
 794
 795 (defun mm-display-part (handle &optional no-default force)
 796   "Display the MIME part represented by HANDLE.
 797 Returns nil if the part is removed; inline if displayed inline;
 798 external if displayed external."
 799   (save-excursion
 800     (mailcap-parse-mailcaps)
 801     (if (and (not force)
 802              (mm-handle-displayed-p handle))
 803         (mm-remove-part handle)
 804       (let* ((ehandle (if (equal (mm-handle-media-type handle)
 805                                  "message/external-body")
 806                           (progn
 807                             (unless (mm-handle-cache handle)
 808                               (mm-extern-cache-contents handle))
 809                             (mm-handle-cache handle))
 810                         handle))
 811              (type (mm-handle-media-type ehandle))
 812              (method (mailcap-mime-info type))
 813              (filename (or (mail-content-type-get
 814                             (mm-handle-disposition handle) 'filename)
 815                            (mail-content-type-get
 816                             (mm-handle-type handle) 'name)
 817                            "<file>"))
 818              (external mm-enable-external)
 819              (decoder (assoc (car (mm-handle-type handle))
 820                              (mm-archive-decoders))))
 821         (cond
 822          ((and decoder
 823                (executable-find (caddr decoder)))
 824           (mm-archive-dissect-and-inline handle)
 825           'inline)
 826          ((and (mm-inlinable-p ehandle)
 827                (mm-inlined-p ehandle))
 828           (when force
 829             (if (mm-head-p)
 830                 (re-search-forward "^$" nil t)
 831               (forward-line 1)))
 832           (mm-display-inline handle)
 833           'inline)
 834          ((or method
 835               (not no-default))
 836           (if (and (not method)
 837                    (equal "text" (car (split-string type "/"))))
 838               (progn
 839                 (forward-line 1)
 840                 (mm-insert-inline handle (mm-get-part handle))
 841                 'inline)
 842             (setq external
 843                   (and method         ;; If nil, we always use "save".
 844                        (or (eq mm-enable-external t)
 845                            (and (eq mm-enable-external 'ask)
 846                                 (y-or-n-p
 847                                  (concat
 848                                   "Display part (" type
 849                                   ") "
 850                                   (if (stringp method)
 851                                       (concat
 852                                        "using external program \""
 853                                        (format method filename) "\"")
 854                                     (format-message
 855                                      "by calling `%s' on the contents)" method))
 856                                   "? "))))))
 857             (if external
 858                 (mm-display-external
 859                  handle (or method 'mailcap-save-binary-file))
 860               (mm-display-external
 861                handle 'mailcap-save-binary-file)))))))))
 862
 863 (declare-function gnus-configure-windows "gnus-win" (setting &optional force))
 864 (defvar mailcap-mime-extensions)        ; mailcap-mime-info autoloads
 865 (declare-function term-mode "term" ())
 866 (declare-function term-char-mode "term" ())
 867
 868 (defun mm-display-external (handle method)
 869   "Display HANDLE using METHOD."
 870   (let ((outbuf (current-buffer)))
 871     (mm-with-unibyte-buffer
 872       (if (functionp method)
 873           (let ((cur (current-buffer)))
 874             (if (eq method 'mailcap-save-binary-file)
 875                 (progn
 876                   (set-buffer (generate-new-buffer " *mm*"))
 877                   (setq method nil))
 878               (mm-insert-part handle)
 879               (mm-add-meta-html-tag handle)
 880               (let ((win (get-buffer-window cur t)))
 881                 (when win
 882                   (select-window win)))
 883               (switch-to-buffer (generate-new-buffer " *mm*")))
 884             (buffer-disable-undo)
 885             (set-buffer-file-coding-system mm-binary-coding-system)
 886             (insert-buffer-substring cur)
 887             (goto-char (point-min))
 888             (when method
 889               (message "Viewing with %s" method))
 890             (let ((mm (current-buffer))
 891                   (non-viewer (assq 'non-viewer
 892                                     (mailcap-mime-info
 893                                      (mm-handle-media-type handle) t))))
 894               (unwind-protect
 895                   (if method
 896                       (progn
 897                         (when (and (boundp 'gnus-summary-buffer)
 898                                    (bufferp gnus-summary-buffer)
 899                                    (buffer-name gnus-summary-buffer))
 900                           ;; So that we pop back to the right place, sort of.
 901                           (switch-to-buffer gnus-summary-buffer)
 902                           (switch-to-buffer mm))
 903                         (delete-other-windows)
 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 (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 (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          ((or (functionp object)
1142               (and (listp object)
1143                    (eq (car object) 'lambda)))
1144           (funcall object))
1145          ;; Externally displayed part.
1146          ((consp object)
1147           (condition-case ()
1148               (while (get-buffer-process (cdr object))
1149                 (interrupt-process (get-buffer-process (cdr object)))
1150                 (message "Waiting for external displayer to die...")
1151                 (sit-for 1))
1152             (quit)
1153             (error))
1154           (ignore-errors (and (cdr object) (kill-buffer (cdr object))))
1155           (message "Waiting for external displayer to die...done")
1156           (ignore-errors (delete-file (car object)))
1157           (ignore-errors (delete-directory (file-name-directory
1158                                             (car object)))))
1159          ((bufferp object)
1160           (when (buffer-live-p object)
1161             (kill-buffer object)))))
1162       (mm-handle-set-undisplayer handle nil))))
1163
1164 (defun mm-display-inline (handle)
1165   (let* ((type (mm-handle-media-type handle))
1166          (function (cadr (mm-assoc-string-match mm-inline-media-tests type))))
1167     (funcall function handle)
1168     (goto-char (point-min))))
1169
1170 (defun mm-assoc-string-match (alist type)
1171   (dolist (elem alist)
1172     (when (string-match (car elem) type)
1173       (return elem))))
1174
1175 (defun mm-automatic-display-p (handle)
1176   "Say whether the user wants HANDLE to be displayed automatically."
1177   (let ((methods mm-automatic-display)
1178         (type (mm-handle-media-type handle))
1179         method result)
1180     (while (setq method (pop methods))
1181       (when (and (not (mm-inline-override-p handle))
1182                  (string-match method type))
1183         (setq result t
1184               methods nil)))
1185     result))
1186
1187 (defun mm-inlinable-p (handle &optional type)
1188   "Say whether HANDLE can be displayed inline.
1189 TYPE is the mime-type of the object; it defaults to the one given
1190 in HANDLE."
1191   (unless type (setq type (mm-handle-media-type handle)))
1192   (let ((alist mm-inline-media-tests)
1193         test)
1194     (while alist
1195       (when (string-match (caar alist) type)
1196         (setq test (caddar alist)
1197               alist nil)
1198         (setq test (funcall test handle)))
1199       (pop alist))
1200     test))
1201
1202 (defun mm-inlined-p (handle)
1203   "Say whether the user wants HANDLE to be displayed inline."
1204   (let ((methods mm-inlined-types)
1205         (type (mm-handle-media-type handle))
1206         method result)
1207     (while (setq method (pop methods))
1208       (when (and (not (mm-inline-override-p handle))
1209                  (string-match method type))
1210         (setq result t
1211               methods nil)))
1212     result))
1213
1214 (defun mm-attachment-override-p (handle)
1215   "Say whether HANDLE should have attachment behavior overridden."
1216   (let ((types mm-attachment-override-types)
1217         (type (mm-handle-media-type handle))
1218         ty)
1219     (catch 'found
1220       (while (setq ty (pop types))
1221         (when (and (string-match ty type)
1222                    (mm-inlinable-p handle))
1223           (throw 'found t))))))
1224
1225 (defun mm-inline-override-p (handle)
1226   "Say whether HANDLE should have inline behavior overridden."
1227   (let ((types mm-inline-override-types)
1228         (type (mm-handle-media-type handle))
1229         ty)
1230     (catch 'found
1231       (while (setq ty (pop types))
1232         (when (string-match ty type)
1233           (throw 'found t))))))
1234
1235 (defun mm-automatic-external-display-p (type)
1236   "Return the user-defined method for TYPE."
1237   (let ((methods mm-automatic-external-display)
1238         method result)
1239     (while (setq method (pop methods))
1240       (when (string-match method type)
1241         (setq result t
1242               methods nil)))
1243     result))
1244
1245 (defun mm-destroy-part (handle)
1246   "Destroy the data structures connected to HANDLE."
1247   (when (listp handle)
1248     (mm-remove-part handle)
1249     (when (buffer-live-p (mm-handle-buffer handle))
1250       (kill-buffer (mm-handle-buffer handle)))))
1251
1252 (defun mm-handle-displayed-p (handle)
1253   "Say whether HANDLE is displayed or not."
1254   (mm-handle-undisplayer handle))
1255
1256 ;;;
1257 ;;; Functions for outputting parts
1258 ;;;
1259
1260 (defmacro mm-with-part (handle &rest forms)
1261   "Run FORMS in the temp buffer containing the contents of HANDLE."
1262   ;; The handle-buffer's content is a sequence of bytes, not a sequence of
1263   ;; chars, so the buffer should be unibyte.  It may happen that the
1264   ;; handle-buffer is multibyte for some reason, in which case now is a good
1265   ;; time to adjust it, since we know at this point that it should
1266   ;; be unibyte.
1267   `(let* ((handle ,handle))
1268      (when (and (mm-handle-buffer handle)
1269                 (buffer-name (mm-handle-buffer handle)))
1270        (with-temp-buffer
1271          (mm-disable-multibyte)
1272          (insert-buffer-substring (mm-handle-buffer handle))
1273          (mm-decode-content-transfer-encoding
1274           (mm-handle-encoding handle)
1275           (mm-handle-media-type handle))
1276          ,@forms))))
1277 (put 'mm-with-part 'lisp-indent-function 1)
1278 (put 'mm-with-part 'edebug-form-spec '(body))
1279
1280 (defun mm-get-part (handle &optional no-cache)
1281   "Return the contents of HANDLE as a string.
1282 If NO-CACHE is non-nil, cached contents of a message/external-body part
1283 are ignored."
1284   (if (and (not no-cache)
1285            (equal (mm-handle-media-type handle) "message/external-body"))
1286       (progn
1287         (unless (mm-handle-cache handle)
1288           (mm-extern-cache-contents handle))
1289         (with-current-buffer (mm-handle-buffer (mm-handle-cache handle))
1290           (buffer-string)))
1291     (mm-with-part handle
1292       (buffer-string))))
1293
1294 (defun mm-insert-part (handle &optional no-cache)
1295   "Insert the contents of HANDLE in the current buffer.
1296 If NO-CACHE is non-nil, cached contents of a message/external-body part
1297 are ignored."
1298   (let ((text (cond ((eq (mail-content-type-get (mm-handle-type handle)
1299                                                 'charset)
1300                          'gnus-decoded)
1301                      (with-current-buffer (mm-handle-buffer handle)
1302                        (buffer-string)))
1303                     ((mm-multibyte-p)
1304                      (string-to-multibyte (mm-get-part handle no-cache)))
1305                     (t
1306                      (mm-get-part handle no-cache)))))
1307     (save-restriction
1308       (widen)
1309       (goto-char
1310        (prog1
1311            (point)
1312          (if (and (eq (get-char-property (max (point-min) (1- (point))) 'face)
1313                       'mm-uu-extract)
1314                   (eq (get-char-property 0 'face text) 'mm-uu-extract))
1315              ;; Separate the extracted parts that have the same faces.
1316              (insert "\n" text)
1317            (insert text)))))))
1318
1319 (defun mm-file-name-delete-whitespace (file-name)
1320   "Remove all whitespace characters from FILE-NAME."
1321   (while (string-match "\\s-+" file-name)
1322     (setq file-name (replace-match "" t t file-name)))
1323   file-name)
1324
1325 (defun mm-file-name-trim-whitespace (file-name)
1326   "Remove leading and trailing whitespace characters from FILE-NAME."
1327   (when (string-match "\\`\\s-+" file-name)
1328     (setq file-name (substring file-name (match-end 0))))
1329   (when (string-match "\\s-+\\'" file-name)
1330     (setq file-name (substring file-name 0 (match-beginning 0))))
1331   file-name)
1332
1333 (defun mm-file-name-collapse-whitespace (file-name)
1334   "Collapse multiple whitespace characters in FILE-NAME."
1335   (while (string-match "\\s-\\s-+" file-name)
1336     (setq file-name (replace-match " " t t file-name)))
1337   file-name)
1338
1339 (defun mm-file-name-replace-whitespace (file-name)
1340   "Replace whitespace characters in FILE-NAME with underscores.
1341 Set the option `mm-file-name-replace-whitespace' to any other
1342 string if you do not like underscores."
1343   (let ((s (or mm-file-name-replace-whitespace "_")))
1344     (while (string-match "\\s-" file-name)
1345       (setq file-name (replace-match s t t file-name))))
1346   file-name)
1347
1348 (defun mm-file-name-delete-control (filename)
1349   "Delete control characters from FILENAME."
1350   (replace-regexp-in-string "[\x00-\x1f\x7f]" "" filename))
1351
1352 (defun mm-file-name-delete-gotchas (filename)
1353   "Delete shell gotchas from FILENAME."
1354   (setq filename (replace-regexp-in-string "[<>|]" "" filename))
1355   (replace-regexp-in-string "^[.-]+" "" filename))
1356
1357 (defun mm-save-part (handle &optional prompt)
1358   "Write HANDLE to a file.
1359 PROMPT overrides the default one used to ask user for a file name."
1360   (let ((filename (or (mail-content-type-get
1361                        (mm-handle-disposition handle) 'filename)
1362                       (mail-content-type-get
1363                        (mm-handle-type handle) 'name)))
1364         file)
1365     (when filename
1366       (setq filename (gnus-map-function mm-file-name-rewrite-functions
1367                                         (file-name-nondirectory filename))))
1368     (while
1369         (progn
1370           (setq file
1371                 (read-file-name
1372                  (or prompt
1373                      (format "Save MIME part to (default %s): "
1374                              (or filename "")))
1375                  (or mm-default-directory default-directory)
1376                  (expand-file-name (or filename "")
1377                                    (or mm-default-directory default-directory))))
1378           (cond ((or (not file) (equal file ""))
1379                  (message "Please enter a file name")
1380                  t)
1381                 ((and (file-directory-p file)
1382                       (not filename))
1383                  (message "Please enter a non-directory file name")
1384                  t)
1385                 (t nil)))
1386       (sit-for 2)
1387       (discard-input))
1388     (if (file-directory-p file)
1389         (setq file (expand-file-name filename file))
1390       (setq file (expand-file-name
1391                   file (or mm-default-directory default-directory))))
1392     (setq mm-default-directory (file-name-directory file))
1393     (and (or (not (file-exists-p file))
1394              (yes-or-no-p (format "File %s already exists; overwrite? "
1395                                   file)))
1396          (progn
1397            (mm-save-part-to-file handle file)
1398            file))))
1399
1400 (defun mm-add-meta-html-tag (handle &optional charset force-charset)
1401   "Add meta html tag to specify CHARSET of HANDLE in the current buffer.
1402 CHARSET defaults to the one HANDLE specifies.  Existing meta tag that
1403 specifies charset will not be modified unless FORCE-CHARSET is non-nil.
1404 Return t if meta tag is added or replaced."
1405   (when (equal (mm-handle-media-type handle) "text/html")
1406     (when (or charset
1407               (setq charset (mail-content-type-get (mm-handle-type handle)
1408                                                    'charset)))
1409       (setq charset (format "\
1410 <meta http-equiv=\"Content-Type\" content=\"text/html; charset=%s\">" charset))
1411       (let ((case-fold-search t))
1412         (goto-char (point-min))
1413         (if (re-search-forward "\
1414 <meta\\s-+http-equiv=[\"']?content-type[\"']?\\s-+content=[\"']\
1415 text/\\(\\sw+\\)\\(?:;\\s-*charset=\\([^\"'>]+\\)\\)?[^>]*>" nil t)
1416             (if (and (not force-charset)
1417                      (match-beginning 2)
1418                      (string-match "\\`html\\'" (match-string 1)))
1419                 ;; Don't modify existing meta tag.
1420                 nil
1421               ;; Replace it with the one specifying charset.
1422               (replace-match charset)
1423               t)
1424           (if (re-search-forward "<head>\\s-*" nil t)
1425               (insert charset "\n")
1426             (re-search-forward "<html\\(?:\\s-+[^>]+\\|\\s-*\\)>\\s-*" nil t)
1427             (insert "<head>\n" charset "\n</head>\n"))
1428           t)))))
1429
1430 (defun mm-save-part-to-file (handle file)
1431   (mm-with-unibyte-buffer
1432     (mm-insert-part handle)
1433     (mm-add-meta-html-tag handle)
1434     (let ((current-file-modes (default-file-modes)))
1435       (set-default-file-modes mm-attachment-file-modes)
1436       (unwind-protect
1437           ;; Don't re-compress .gz & al.  Arguably we should make
1438           ;; `file-name-handler-alist' nil, but that would chop
1439           ;; ange-ftp, which is reasonable to use here.
1440           (mm-write-region (point-min) (point-max) file nil nil nil 'binary t)
1441         (set-default-file-modes current-file-modes)))))
1442
1443 (defun mm-pipe-part (handle &optional cmd)
1444   "Pipe HANDLE to a process.
1445 Use CMD as the process."
1446   (let ((name (mail-content-type-get (mm-handle-type handle) 'name))
1447         (command (or cmd
1448                      (read-shell-command
1449                       "Shell command on MIME part: " mm-last-shell-command))))
1450     (mm-with-unibyte-buffer
1451       (mm-insert-part handle)
1452       (mm-add-meta-html-tag handle)
1453       (let ((coding-system-for-write 'binary))
1454         (shell-command-on-region (point-min) (point-max) command nil)))))
1455
1456 (autoload 'gnus-completing-read "gnus-util")
1457
1458 (defun mm-interactively-view-part (handle)
1459   "Display HANDLE using METHOD."
1460   (let* ((type (mm-handle-media-type handle))
1461          (methods
1462           (mapcar (lambda (i) (cdr (assoc 'viewer i)))
1463                   (mailcap-mime-info type 'all)))
1464          (method (let ((minibuffer-local-completion-map
1465                         mm-viewer-completion-map))
1466                    (completing-read "Viewer: " methods))))
1467     (when (string= method "")
1468       (error "No method given"))
1469     (if (string-match "^[^% \t]+$" method)
1470         (setq method (concat method " %s")))
1471     (mm-display-external handle method)))
1472
1473 (defun mm-preferred-alternative (handles &optional preferred)
1474   "Say which of HANDLES are preferred."
1475   (let ((prec (if preferred (list preferred)
1476                 (mm-preferred-alternative-precedence handles)))
1477         p h result type handle)
1478     (while (setq p (pop prec))
1479       (setq h handles)
1480       (while h
1481         (setq handle (car h))
1482         (setq type (mm-handle-media-type handle))
1483         (when (and (equal p type)
1484                    (mm-automatic-display-p handle)
1485                    (or (stringp (car handle))
1486                        (not (mm-handle-disposition handle))
1487                        (equal (car (mm-handle-disposition handle))
1488                               "inline")))
1489           (setq result handle
1490                 h nil
1491                 prec nil))
1492         (pop h)))
1493     result))
1494
1495 (defun mm-preferred-alternative-precedence (handles)
1496   "Return the precedence based on HANDLES and `mm-discouraged-alternatives'."
1497   (setq handles (reverse handles))
1498   (dolist (disc (reverse mm-discouraged-alternatives))
1499     (dolist (handle (copy-sequence handles))
1500       (when (string-match disc (mm-handle-media-type handle))
1501         (setq handles (nconc (delete handle handles) (list handle))))))
1502   ;; Remove empty parts.
1503   (dolist (handle (copy-sequence handles))
1504     (when (and (bufferp (mm-handle-buffer handle))
1505                (not (with-current-buffer (mm-handle-buffer handle)
1506                       (goto-char (point-min))
1507                       (re-search-forward "[^ \t\n]" nil t))))
1508       (setq handles (nconc (delete handle handles) (list handle)))))
1509   (mapcar #'mm-handle-media-type handles))
1510
1511 (defun mm-get-content-id (id)
1512   "Return the handle(s) referred to by ID."
1513   (cdr (assoc id mm-content-id-alist)))
1514
1515 (defconst mm-image-type-regexps
1516   '(("/\\*.*XPM.\\*/" . xpm)
1517     ("P[1-6]" . pbm)
1518     ("GIF8" . gif)
1519     ("\377\330" . jpeg)
1520     ("\211PNG\r\n" . png)
1521     ("#define" . xbm)
1522     ("\\(MM\0\\*\\)\\|\\(II\\*\0\\)" . tiff)
1523     ("%!PS" . postscript))
1524   "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
1525 When the first bytes of an image file match REGEXP, it is assumed to
1526 be of image type IMAGE-TYPE.")
1527
1528 ;; Steal from image.el. image-type-from-data suffers multi-line matching bug.
1529 (defun mm-image-type-from-buffer ()
1530   "Determine the image type from data in the current buffer.
1531 Value is a symbol specifying the image type or nil if type cannot
1532 be determined."
1533   (let ((types mm-image-type-regexps)
1534         type)
1535     (goto-char (point-min))
1536     (while (and types (null type))
1537       (let ((regexp (car (car types)))
1538             (image-type (cdr (car types))))
1539         (when (looking-at regexp)
1540           (setq type image-type))
1541         (setq types (cdr types))))
1542     type))
1543
1544 (defun mm-get-image (handle)
1545   "Return an image instance based on HANDLE."
1546   (let ((type (mm-handle-media-subtype handle))
1547         spec)
1548     ;; Allow some common translations.
1549     (setq type
1550           (cond
1551            ((equal type "x-pixmap")
1552             "xpm")
1553            ((equal type "x-xbitmap")
1554             "xbm")
1555            ((equal type "x-portable-bitmap")
1556             "pbm")
1557            (t type)))
1558     (or (mm-handle-cache handle)
1559         (mm-with-unibyte-buffer
1560           (mm-insert-part handle)
1561           (prog1
1562               (setq spec
1563                     (ignore-errors
1564                       (create-image (buffer-string)
1565                                     (or (mm-image-type-from-buffer)
1566                                         (intern type))
1567                                     'data-p)))
1568             (mm-handle-set-cache handle spec))))))
1569
1570 (declare-function image-size "image.c" (spec &optional pixels frame))
1571
1572 (defun mm-image-fit-p (handle)
1573   "Say whether the image in HANDLE will fit the current window."
1574   (let ((image (mm-get-image handle)))
1575     (or (not image)
1576         (let* ((size (image-size image))
1577                (w (car size))
1578                (h (cdr size)))
1579           (or mm-inline-large-images
1580               (and (<= h (1- (window-height))) ; Don't include mode line.
1581                    (<= w (window-width))))))))
1582
1583 (defun mm-valid-image-format-p (format)
1584   "Say whether FORMAT can be displayed natively by Emacs."
1585   (and (display-graphic-p)
1586        (image-type-available-p format)))
1587
1588 (defun mm-valid-and-fit-image-p (format handle)
1589   "Say whether FORMAT can be displayed natively and HANDLE fits the window."
1590   (and (mm-valid-image-format-p format)
1591        (mm-image-fit-p handle)))
1592
1593 (defun mm-find-part-by-type (handles type &optional notp recursive)
1594   "Search in HANDLES for part with TYPE.
1595 If NOTP, returns first non-matching part.
1596 If RECURSIVE, search recursively."
1597   (let (handle)
1598     (while handles
1599       (if (and recursive (stringp (caar handles)))
1600           (if (setq handle (mm-find-part-by-type (cdar handles) type
1601                                                  notp recursive))
1602               (setq handles nil))
1603         (if (if notp
1604                 (not (equal (mm-handle-media-type (car handles)) type))
1605               (equal (mm-handle-media-type (car handles)) type))
1606             (setq handle (car handles)
1607                   handles nil)))
1608       (setq handles (cdr handles)))
1609     handle))
1610
1611 (defun mm-find-raw-part-by-type (ctl type &optional notp)
1612   (goto-char (point-min))
1613   (let* ((boundary (concat "--" (mm-handle-multipart-ctl-parameter ctl
1614                                                                    'boundary)))
1615          (close-delimiter (concat "^" (regexp-quote boundary) "--[ \t]*$"))
1616          start
1617          (end (save-excursion
1618                 (goto-char (point-max))
1619                 (if (re-search-backward close-delimiter nil t)
1620                     (match-beginning 0)
1621                   (point-max))))
1622          result)
1623     (setq boundary (concat "^" (regexp-quote boundary) "[ \t]*$"))
1624     (while (and (not result)
1625                 (re-search-forward boundary end t))
1626       (goto-char (match-beginning 0))
1627       (when start
1628         (save-excursion
1629           (save-restriction
1630             (narrow-to-region start (1- (point)))
1631             (when (let* ((ct (mail-fetch-field "content-type"))
1632                          (ctl (and ct (mail-header-parse-content-type ct))))
1633                     (if notp
1634                         (not (equal (car ctl) type))
1635                       (equal (car ctl) type)))
1636               (setq result (buffer-string))))))
1637       (forward-line 1)
1638       (setq start (point)))
1639     (when (and (not result) start)
1640       (save-excursion
1641         (save-restriction
1642           (narrow-to-region start end)
1643           (when (let* ((ct (mail-fetch-field "content-type"))
1644                        (ctl (and ct (mail-header-parse-content-type ct))))
1645                   (if notp
1646                       (not (equal (car ctl) type))
1647                     (equal (car ctl) type)))
1648             (setq result (buffer-string))))))
1649     result))
1650
1651 (defvar mm-security-handle nil)
1652
1653 (defsubst mm-set-handle-multipart-parameter (handle parameter value)
1654   ;; HANDLE could be a CTL.
1655   (when handle
1656     (put-text-property 0 (length (car handle)) parameter value
1657                        (car handle))))
1658
1659 (autoload 'mm-view-pkcs7 "mm-view")
1660
1661 (defun mm-possibly-verify-or-decrypt (parts ctl &optional from)
1662   (let ((type (car ctl))
1663         (subtype (cadr (split-string (car ctl) "/")))
1664         (mm-security-handle ctl) ;; (car CTL) is the type.
1665         protocol func functest)
1666     (cond
1667      ((or (equal type "application/x-pkcs7-mime")
1668           (equal type "application/pkcs7-mime"))
1669       (with-temp-buffer
1670         (when (and (cond
1671                     ((eq mm-decrypt-option 'never) nil)
1672                     ((eq mm-decrypt-option 'always) t)
1673                     ((eq mm-decrypt-option 'known) t)
1674                     (t (y-or-n-p
1675                         (format "Decrypt (S/MIME) part? "))))
1676                    (mm-view-pkcs7 parts from))
1677           (setq parts (mm-dissect-buffer t)))))
1678      ((equal subtype "signed")
1679       (unless (and (setq protocol
1680                          (mm-handle-multipart-ctl-parameter ctl 'protocol))
1681                    (not (equal protocol "multipart/mixed")))
1682         ;; The message is broken or draft-ietf-openpgp-multsig-01.
1683         (let ((protocols mm-verify-function-alist))
1684           (while protocols
1685             (if (and (or (not (setq functest (nth 3 (car protocols))))
1686                          (funcall functest parts ctl))
1687                      (mm-find-part-by-type parts (caar protocols) nil t))
1688                 (setq protocol (caar protocols)
1689                       protocols nil)
1690               (setq protocols (cdr protocols))))))
1691       (setq func (nth 1 (assoc protocol mm-verify-function-alist)))
1692       (when (cond
1693              ((eq mm-verify-option 'never) nil)
1694              ((eq mm-verify-option 'always) t)
1695              ((eq mm-verify-option 'known)
1696               (and func
1697                    (or (not (setq functest
1698                                   (nth 3 (assoc protocol
1699                                                 mm-verify-function-alist))))
1700                        (funcall functest parts ctl))))
1701              (t
1702               (y-or-n-p
1703                (format "Verify signed (%s) part? "
1704                        (or (nth 2 (assoc protocol mm-verify-function-alist))
1705                            (format "protocol=%s" protocol))))))
1706         (save-excursion
1707           (if func
1708               (setq parts (funcall func parts ctl))
1709             (mm-set-handle-multipart-parameter
1710              mm-security-handle 'gnus-details
1711              (format "Unknown sign protocol (%s)" protocol))))))
1712      ((equal subtype "encrypted")
1713       (unless (setq protocol
1714                     (mm-handle-multipart-ctl-parameter ctl 'protocol))
1715         ;; The message is broken.
1716         (let ((parts parts))
1717           (while parts
1718             (if (assoc (mm-handle-media-type (car parts))
1719                        mm-decrypt-function-alist)
1720                 (setq protocol (mm-handle-media-type (car parts))
1721                       parts nil)
1722               (setq parts (cdr parts))))))
1723       (setq func (nth 1 (assoc protocol mm-decrypt-function-alist)))
1724       (when (cond
1725              ((eq mm-decrypt-option 'never) nil)
1726              ((eq mm-decrypt-option 'always) t)
1727              ((eq mm-decrypt-option 'known)
1728               (and func
1729                    (or (not (setq functest
1730                                   (nth 3 (assoc protocol
1731                                                 mm-decrypt-function-alist))))
1732                        (funcall functest parts ctl))))
1733              (t
1734               (y-or-n-p
1735                (format "Decrypt (%s) part? "
1736                        (or (nth 2 (assoc protocol mm-decrypt-function-alist))
1737                            (format "protocol=%s" protocol))))))
1738         (save-excursion
1739           (if func
1740               (setq parts (funcall func parts ctl))
1741             (mm-set-handle-multipart-parameter
1742              mm-security-handle 'gnus-details
1743              (format "Unknown encrypt protocol (%s)" protocol))))))
1744      (t nil))
1745     parts))
1746
1747 (defun mm-multiple-handles (handles)
1748   (and (listp handles)
1749        (> (length handles) 1)
1750        (or (listp (car handles))
1751            (stringp (car handles)))))
1752
1753 (defun mm-complicated-handles (handles)
1754   (and (listp (car handles))
1755        (> (length handles) 1)))
1756
1757 (defun mm-merge-handles (handles1 handles2)
1758   (append
1759    (if (listp (car handles1))
1760        handles1
1761      (list handles1))
1762    (if (listp (car handles2))
1763        handles2
1764      (list handles2))))
1765
1766 (defun mm-readable-p (handle)
1767   "Say whether the content of HANDLE is readable."
1768   (and (< (with-current-buffer (mm-handle-buffer handle)
1769             (buffer-size)) 10000)
1770        (mm-with-unibyte-buffer
1771          (mm-insert-part handle)
1772          (and (eq (mm-body-7-or-8) '7bit)
1773               (not (mm-long-lines-p 76))))))
1774
1775 (declare-function libxml-parse-html-region "xml.c"
1776                   (start end &optional base-url discard-comments))
1777 (declare-function shr-insert-document "shr" (dom))
1778 (defvar shr-blocked-images)
1779 (defvar shr-use-fonts)
1780
1781 (defun mm-shr (handle)
1782   ;; Require since we bind its variables.
1783   (require 'shr)
1784   (let ((shr-width (if shr-use-fonts
1785                        nil
1786                      fill-column))
1787         (shr-content-function (lambda (id)
1788                                 (let ((handle (mm-get-content-id id)))
1789                                   (when handle
1790                                     (mm-with-part handle
1791                                       (buffer-string))))))
1792         (shr-inhibit-images mm-html-inhibit-images)
1793         (shr-blocked-images mm-html-blocked-images)
1794         charset char)
1795     (unless handle
1796       (setq handle (mm-dissect-buffer t)))
1797     (setq charset (mail-content-type-get (mm-handle-type handle) 'charset))
1798     (save-restriction
1799       (narrow-to-region (point) (point))
1800       (shr-insert-document
1801        (mm-with-part handle
1802          (insert (prog1
1803                      (if (and charset
1804                               (setq charset
1805                                     (mm-charset-to-coding-system charset
1806                                                                  nil t))
1807                               (not (eq charset 'ascii)))
1808                          (decode-coding-string (buffer-string) charset)
1809                        (string-as-multibyte (buffer-string)))
1810                    (erase-buffer)
1811                    (mm-enable-multibyte)))
1812          (goto-char (point-min))
1813          (setq case-fold-search t)
1814          (while (re-search-forward
1815                  "&#\\(?:x\\([89][0-9a-f]\\)\\|\\(1[2-5][0-9]\\)\\);" nil t)
1816            (when (setq char
1817                        (cdr (assq (if (match-beginning 1)
1818                                       (string-to-number (match-string 1) 16)
1819                                     (string-to-number (match-string 2)))
1820                                   mm-extra-numeric-entities)))
1821              (replace-match (char-to-string char))))
1822          ;; Remove "soft hyphens".
1823          (goto-char (point-min))
1824          (while (search-forward "" nil t)
1825            (replace-match "" t t))
1826          (libxml-parse-html-region (point-min) (point-max))))
1827       (unless (bobp)
1828         (insert "\n"))
1829       (mm-convert-shr-links)
1830       (mm-handle-set-undisplayer
1831        handle
1832        `(lambda ()
1833           (let ((inhibit-read-only t))
1834             (delete-region ,(point-min-marker)
1835                            ,(point-max-marker))))))))
1836
1837 (defvar shr-map)
1838 (defvar shr-image-map)
1839
1840 (autoload 'widget-convert-button "wid-edit")
1841
1842 (defun mm-convert-shr-links ()
1843   (let ((start (point-min))
1844         end)
1845     (while (and start
1846                 (< start (point-max)))
1847       (when (setq start (text-property-not-all start (point-max) 'shr-url nil))
1848         (setq end (next-single-property-change start 'shr-url nil (point-max)))
1849         (widget-convert-button
1850          'url-link start end
1851          :help-echo (get-text-property start 'help-echo)
1852          ;;; FIXME Should only use the image map on images.
1853          :keymap shr-image-map
1854          (get-text-property start 'shr-url))
1855         (put-text-property start end 'local-map nil)
1856         (dolist (overlay (overlays-at start))
1857           (overlay-put overlay 'face nil))
1858         (setq start end)))))
1859
1860 (defun mm-handle-filename (handle)
1861   "Return filename of HANDLE if any."
1862   (or (mail-content-type-get (mm-handle-type handle)
1863                              'name)
1864       (mail-content-type-get (mm-handle-disposition handle)
1865                              'filename)))
1866
1867 (provide 'mm-decode)
1868
1869 ;; Local Variables:
1870 ;; coding: utf-8
1871 ;; End:
1872
1873 ;;; mm-decode.el ends here