lisp/gnus/mm-decode.el

   1 ;;; mm-decode.el --- Functions for decoding MIME things
   2
   3 ;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;;      MORIOKA Tomohiko <morioka@jaist.ac.jp>
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;; Code:
  28
  29 (require 'mail-parse)
  30 (require 'mailcap)
  31 (require 'mm-bodies)
  32 (eval-when-compile (require 'cl)
  33                    (require 'term))
  34
  35 (eval-and-compile
  36   (autoload 'executable-find "executable")
  37   (autoload 'mm-inline-partial "mm-partial")
  38   (autoload 'mm-inline-external-body "mm-extern")
  39   (autoload 'mm-extern-cache-contents "mm-extern")
  40   (autoload 'mm-insert-inline "mm-view"))
  41
  42 (defvar gnus-current-window-configuration)
  43
  44 (add-hook 'gnus-exit-gnus-hook 'mm-destroy-postponed-undisplay-list)
  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 ;;; Convenience macros.
  62
  63 (defmacro mm-handle-buffer (handle)
  64   `(nth 0 ,handle))
  65 (defmacro mm-handle-type (handle)
  66   `(nth 1 ,handle))
  67 (defsubst mm-handle-media-type (handle)
  68   (if (stringp (car handle))
  69       (car handle)
  70     (car (mm-handle-type handle))))
  71 (defsubst mm-handle-media-supertype (handle)
  72   (car (split-string (mm-handle-media-type handle) "/")))
  73 (defsubst mm-handle-media-subtype (handle)
  74   (cadr (split-string (mm-handle-media-type handle) "/")))
  75 (defmacro mm-handle-encoding (handle)
  76   `(nth 2 ,handle))
  77 (defmacro mm-handle-undisplayer (handle)
  78   `(nth 3 ,handle))
  79 (defmacro mm-handle-set-undisplayer (handle function)
  80   `(setcar (nthcdr 3 ,handle) ,function))
  81 (defmacro mm-handle-disposition (handle)
  82   `(nth 4 ,handle))
  83 (defmacro mm-handle-description (handle)
  84   `(nth 5 ,handle))
  85 (defmacro mm-handle-cache (handle)
  86   `(nth 6 ,handle))
  87 (defmacro mm-handle-set-cache (handle contents)
  88   `(setcar (nthcdr 6 ,handle) ,contents))
  89 (defmacro mm-handle-id (handle)
  90   `(nth 7 ,handle))
  91 (defmacro mm-handle-multipart-original-buffer (handle)
  92   `(get-text-property 0 'buffer (car ,handle)))
  93 (defmacro mm-handle-multipart-from (handle)
  94   `(get-text-property 0 'from (car ,handle)))
  95 (defmacro mm-handle-multipart-ctl-parameter (handle parameter)
  96   `(get-text-property 0 ,parameter (car ,handle)))
  97
  98 (defmacro mm-make-handle (&optional buffer type encoding undisplayer
  99                                     disposition description cache
 100                                     id)
 101   `(list ,buffer ,type ,encoding ,undisplayer
 102          ,disposition ,description ,cache ,id))
 103
 104 (defcustom mm-text-html-renderer
 105   (cond ((locate-library "w3") 'w3)
 106         ((executable-find "w3m") (if (locate-library "w3m")
 107                                      'w3m
 108                                    'w3m-standalone))
 109         ((executable-find "links") 'links)
 110         ((executable-find "lynx") 'lynx)
 111         (t 'html2text))
 112   "Render of HTML contents.
 113 It is one of defined renderer types, or a rendering function.
 114 The defined renderer types are:
 115 `w3'   : use Emacs/W3;
 116 `w3m'  : use emacs-w3m;
 117 `w3m-standalone': use w3m;
 118 `links': use links;
 119 `lynx' : use lynx;
 120 `html2text' : use html2text;
 121 nil    : use external viewer."
 122   :version "22.1"
 123   :type '(choice (const w3)
 124                  (const w3m)
 125                  (const w3m-standalone)
 126                  (const links)
 127                  (const lynx)
 128                  (const html2text)
 129                  (const nil)
 130                  (function))
 131   :group 'mime-display)
 132
 133 (defvar mm-inline-text-html-renderer nil
 134   "Function used for rendering inline HTML contents.
 135 It is suggested to customize `mm-text-html-renderer' instead.")
 136
 137 (defcustom mm-inline-text-html-with-images nil
 138   "If non-nil, Gnus will allow retrieving images in HTML contents with
 139 the <img> tags.  It has no effect on Emacs/w3.  See also the
 140 documentation for the `mm-w3m-safe-url-regexp' variable."
 141   :version "22.1"
 142   :type 'boolean
 143   :group 'mime-display)
 144
 145 (defcustom mm-w3m-safe-url-regexp "\\`cid:"
 146   "Regexp matching URLs which are considered to be safe.
 147 Some HTML mails might contain a nasty trick used by spammers, using
 148 the <img> tag which is far more evil than the [Click Here!] button.
 149 It is most likely intended to check whether the ominous spam mail has
 150 reached your eyes or not, in which case the spammer knows for sure
 151 that your email address is valid.  It is done by embedding an
 152 identifier string into a URL that you might automatically retrieve
 153 when displaying the image.  The default value is \"\\\\`cid:\" which only
 154 matches parts embedded to the Multipart/Related type MIME contents and
 155 Gnus will never connect to the spammer's site arbitrarily.  You may
 156 set this variable to nil if you consider all urls to be safe."
 157   :version "22.1"
 158   :type '(choice (regexp :tag "Regexp")
 159                  (const :tag "All URLs are safe" nil))
 160   :group 'mime-display)
 161
 162 (defcustom mm-inline-text-html-with-w3m-keymap t
 163   "If non-nil, use emacs-w3m command keys in the article buffer."
 164   :version "22.1"
 165   :type 'boolean
 166   :group 'mime-display)
 167
 168 (defcustom mm-enable-external t
 169   "Indicate whether external MIME handlers should be used.
 170
 171 If t, all defined external MIME handlers are used.  If nil, files are saved by
 172 `mailcap-save-binary-file'.  If it is the symbol `ask', you are prompted
 173 before the external MIME handler is invoked."
 174   :version "22.1"
 175   :type '(choice (const :tag "Always" t)
 176                  (const :tag "Never" nil)
 177                  (const :tag "Ask" ask))
 178   :group 'mime-display)
 179
 180 (defcustom mm-inline-media-tests
 181   '(("image/p?jpeg"
 182      mm-inline-image
 183      (lambda (handle)
 184        (mm-valid-and-fit-image-p 'jpeg handle)))
 185     ("image/png"
 186      mm-inline-image
 187      (lambda (handle)
 188        (mm-valid-and-fit-image-p 'png handle)))
 189     ("image/gif"
 190      mm-inline-image
 191      (lambda (handle)
 192        (mm-valid-and-fit-image-p 'gif handle)))
 193     ("image/tiff"
 194      mm-inline-image
 195      (lambda (handle)
 196        (mm-valid-and-fit-image-p 'tiff handle)) )
 197     ("image/xbm"
 198      mm-inline-image
 199      (lambda (handle)
 200        (mm-valid-and-fit-image-p 'xbm handle)))
 201     ("image/x-xbitmap"
 202      mm-inline-image
 203      (lambda (handle)
 204        (mm-valid-and-fit-image-p 'xbm handle)))
 205     ("image/xpm"
 206      mm-inline-image
 207      (lambda (handle)
 208        (mm-valid-and-fit-image-p 'xpm handle)))
 209     ("image/x-xpixmap"
 210      mm-inline-image
 211      (lambda (handle)
 212        (mm-valid-and-fit-image-p 'xpm handle)))
 213     ("image/bmp"
 214      mm-inline-image
 215      (lambda (handle)
 216        (mm-valid-and-fit-image-p 'bmp handle)))
 217     ("image/x-portable-bitmap"
 218      mm-inline-image
 219      (lambda (handle)
 220        (mm-valid-and-fit-image-p 'pbm handle)))
 221     ("text/plain" mm-inline-text identity)
 222     ("text/enriched" mm-inline-text identity)
 223     ("text/richtext" mm-inline-text identity)
 224     ("text/x-patch" mm-display-patch-inline
 225      (lambda (handle)
 226        ;; If the diff-mode.el package is installed, the function is
 227        ;; autoloaded.  Checking (locate-library "diff-mode") would be trying
 228        ;; to cater to broken installations.  OTOH checking the function
 229        ;; makes it possible to install another package which provides an
 230        ;; alternative implementation of diff-mode.  --Stef
 231        (fboundp 'diff-mode)))
 232     ("application/emacs-lisp" mm-display-elisp-inline identity)
 233     ("application/x-emacs-lisp" mm-display-elisp-inline identity)
 234     ("text/html"
 235      mm-inline-text-html
 236      (lambda (handle)
 237        (or mm-inline-text-html-renderer
 238            mm-text-html-renderer)))
 239     ("text/x-vcard"
 240      mm-inline-text-vcard
 241      (lambda (handle)
 242        (or (featurep 'vcard)
 243            (locate-library "vcard"))))
 244     ("message/delivery-status" mm-inline-text identity)
 245     ("message/rfc822" mm-inline-message identity)
 246     ("message/partial" mm-inline-partial identity)
 247     ("message/external-body" mm-inline-external-body identity)
 248     ("text/.*" mm-inline-text identity)
 249     ("audio/wav" mm-inline-audio
 250      (lambda (handle)
 251        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 252             (device-sound-enabled-p))))
 253     ("audio/au"
 254      mm-inline-audio
 255      (lambda (handle)
 256        (and (or (featurep 'nas-sound) (featurep 'native-sound))
 257             (device-sound-enabled-p))))
 258     ("application/pgp-signature" ignore identity)
 259     ("application/x-pkcs7-signature" ignore identity)
 260     ("application/pkcs7-signature" ignore identity)
 261     ("application/x-pkcs7-mime" ignore identity)
 262     ("application/pkcs7-mime" ignore identity)
 263     ("multipart/alternative" ignore identity)
 264     ("multipart/mixed" ignore identity)
 265     ("multipart/related" ignore identity)
 266     ;; Disable audio and image
 267     ("audio/.*" ignore ignore)
 268     ("image/.*" ignore ignore)
 269     ;; Default to displaying as text
 270     (".*" mm-inline-text mm-readable-p))
 271   "Alist of media types/tests saying whether types can be displayed inline."
 272   :type '(repeat (list (regexp :tag "MIME type")
 273                        (function :tag "Display function")
 274                        (function :tag "Display test")))
 275   :group 'mime-display)
 276
 277 (defcustom mm-inlined-types
 278   '("image/.*" "text/.*" "message/delivery-status" "message/rfc822"
 279     "message/partial" "message/external-body" "application/emacs-lisp"
 280     "application/x-emacs-lisp"
 281     "application/pgp-signature" "application/x-pkcs7-signature"
 282     "application/pkcs7-signature" "application/x-pkcs7-mime"
 283     "application/pkcs7-mime"
 284     ;; Mutt still uses this even though it has already been withdrawn.
 285     "application/pgp")
 286   "List of media types that are to be displayed inline.
 287 See also `mm-inline-media-tests', which says how to display a media
 288 type inline."
 289   :type '(repeat regexp)
 290   :group 'mime-display)
 291
 292 (defcustom mm-keep-viewer-alive-types
 293   '("application/postscript" "application/msword" "application/vnd.ms-excel"
 294     "application/pdf" "application/x-dvi")
 295   "List of media types for which the external viewer will not be killed
 296 when selecting a different article."
 297   :version "22.1"
 298   :type '(repeat regexp)
 299   :group 'mime-display)
 300
 301 (defcustom mm-automatic-display
 302   '("text/plain" "text/enriched" "text/richtext" "text/html"
 303     "text/x-vcard" "image/.*" "message/delivery-status" "multipart/.*"
 304     "message/rfc822" "text/x-patch" "application/pgp-signature"
 305     "application/emacs-lisp" "application/x-emacs-lisp"
 306     "application/x-pkcs7-signature"
 307     "application/pkcs7-signature" "application/x-pkcs7-mime"
 308     "application/pkcs7-mime"
 309     ;; Mutt still uses this even though it has already been withdrawn.
 310     "application/pgp")
 311   "A list of MIME types to be displayed automatically."
 312   :type '(repeat regexp)
 313   :group 'mime-display)
 314
 315 (defcustom mm-attachment-override-types '("text/x-vcard"
 316                                           "application/pkcs7-mime"
 317                                           "application/x-pkcs7-mime"
 318                                           "application/pkcs7-signature"
 319                                           "application/x-pkcs7-signature")
 320   "Types to have \"attachment\" ignored if they can be displayed inline."
 321   :type '(repeat regexp)
 322   :group 'mime-display)
 323
 324 (defcustom mm-inline-override-types nil
 325   "Types to be treated as attachments even if they can be displayed inline."
 326   :type '(repeat regexp)
 327   :group 'mime-display)
 328
 329 (defcustom mm-automatic-external-display nil
 330   "List of MIME type regexps that will be displayed externally automatically."
 331   :type '(repeat regexp)
 332   :group 'mime-display)
 333
 334 (defcustom mm-discouraged-alternatives nil
 335   "List of MIME types that are discouraged when viewing multipart/alternative.
 336 Viewing agents are supposed to view the last possible part of a message,
 337 as that is supposed to be the richest.  However, users may prefer other
 338 types instead, and this list says what types are most unwanted.  If,
 339 for instance, text/html parts are very unwanted, and text/richtext are
 340 somewhat unwanted, then the value of this variable should be set
 341 to:
 342
 343  (\"text/html\" \"text/richtext\")
 344
 345 Adding \"image/.*\" might also be useful.  Spammers use it as the
 346 prefered part of multipart/alternative messages.  See also
 347 `gnus-buttonized-mime-types', to which adding \"multipart/alternative\"
 348 enables you to choose manually one of two types those mails include."
 349   :type '(repeat regexp) ;; See `mm-preferred-alternative-precedence'.
 350   :group 'mime-display)
 351
 352 (defcustom mm-tmp-directory
 353   (if (fboundp 'temp-directory)
 354       (temp-directory)
 355     (if (boundp 'temporary-file-directory)
 356         temporary-file-directory
 357       "/tmp/"))
 358   "Where mm will store its temporary files."
 359   :type 'directory
 360   :group 'mime-display)
 361
 362 (defcustom mm-inline-large-images nil
 363   "If non-nil, then all images fit in the buffer."
 364   :type 'boolean
 365   :group 'mime-display)
 366
 367 (defvar mm-file-name-rewrite-functions
 368   '(mm-file-name-delete-control mm-file-name-delete-gotchas)
 369   "*List of functions used for rewriting file names of MIME parts.
 370 Each function takes a file name as input and returns a file name.
 371
 372 Ready-made functions include
 373 `mm-file-name-delete-control'
 374 `mm-file-name-delete-gotchas'
 375 `mm-file-name-delete-whitespace',
 376 `mm-file-name-trim-whitespace',
 377 `mm-file-name-collapse-whitespace',
 378 `mm-file-name-replace-whitespace',
 379 `capitalize', `downcase', `upcase', and
 380 `upcase-initials'.")
 381
 382 (defvar mm-path-name-rewrite-functions nil
 383   "*List of functions for rewriting the full file names of MIME parts.
 384 This is used when viewing parts externally, and is meant for
 385 transforming the absolute name so that non-compliant programs can find
 386 the file where it's saved.
 387
 388 Each function takes a file name as input and returns a file name.")
 389
 390 (defvar mm-file-name-replace-whitespace nil
 391   "String used for replacing whitespace characters; default is `\"_\"'.")
 392
 393 (defcustom mm-default-directory nil
 394   "The default directory where mm will save files.
 395 If not set, `default-directory' will be used."
 396   :type '(choice directory (const :tag "Default" nil))
 397   :group 'mime-display)
 398
 399 (defcustom mm-attachment-file-modes 384
 400   "Set the mode bits of saved attachments to this integer."
 401   :version "22.1"
 402   :type 'integer
 403   :group 'mime-display)
 404
 405 (defcustom mm-external-terminal-program "xterm"
 406   "The program to start an external terminal."
 407   :version "22.1"
 408   :type 'string
 409   :group 'mime-display)
 410
 411 ;;; Internal variables.
 412
 413 (defvar mm-last-shell-command "")
 414 (defvar mm-content-id-alist nil)
 415 (defvar mm-postponed-undisplay-list nil)
 416
 417 ;; According to RFC2046, in particular, in a digest, the default
 418 ;; Content-Type value for a body part is changed from "text/plain" to
 419 ;; "message/rfc822".
 420 (defvar mm-dissect-default-type "text/plain")
 421
 422 (autoload 'mml2015-verify "mml2015")
 423 (autoload 'mml2015-verify-test "mml2015")
 424 (autoload 'mml-smime-verify "mml-smime")
 425 (autoload 'mml-smime-verify-test "mml-smime")
 426
 427 (defvar mm-verify-function-alist
 428   '(("application/pgp-signature" mml2015-verify "PGP" mml2015-verify-test)
 429     ("application/x-gnus-pgp-signature" mm-uu-pgp-signed-extract-1 "PGP"
 430      mm-uu-pgp-signed-test)
 431     ("application/pkcs7-signature" mml-smime-verify "S/MIME"
 432      mml-smime-verify-test)
 433     ("application/x-pkcs7-signature" mml-smime-verify "S/MIME"
 434      mml-smime-verify-test)))
 435
 436 (defcustom mm-verify-option 'never
 437   "Option of verifying signed parts.
 438 `never', not verify; `always', always verify;
 439 `known', only verify known protocols.  Otherwise, ask user."
 440   :version "22.1"
 441   :type '(choice (item always)
 442                  (item never)
 443                  (item :tag "only known protocols" known)
 444                  (item :tag "ask" nil))
 445   :group 'mime-security)
 446
 447 (autoload 'mml2015-decrypt "mml2015")
 448 (autoload 'mml2015-decrypt-test "mml2015")
 449
 450 (defvar mm-decrypt-function-alist
 451   '(("application/pgp-encrypted" mml2015-decrypt "PGP" mml2015-decrypt-test)
 452     ("application/x-gnus-pgp-encrypted" mm-uu-pgp-encrypted-extract-1 "PGP"
 453      mm-uu-pgp-encrypted-test)))
 454
 455 (defcustom mm-decrypt-option nil
 456   "Option of decrypting encrypted parts.
 457 `never', not decrypt; `always', always decrypt;
 458 `known', only decrypt known protocols.  Otherwise, ask user."
 459   :version "22.1"
 460   :type '(choice (item always)
 461                  (item never)
 462                  (item :tag "only known protocols" known)
 463                  (item :tag "ask" nil))
 464   :group 'mime-security)
 465
 466 (defvar mm-viewer-completion-map
 467   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 468     (set-keymap-parent map minibuffer-local-completion-map)
 469     ;; Should we bind other key to minibuffer-complete-word?
 470     (define-key map " " 'self-insert-command)
 471     map)
 472   "Keymap for input viewer with completion.")
 473
 474 (defvar mm-viewer-completion-map
 475   (let ((map (make-sparse-keymap 'mm-viewer-completion-map)))
 476     (set-keymap-parent map minibuffer-local-completion-map)
 477     ;; Should we bind other key to minibuffer-complete-word?
 478     (define-key map " " 'self-insert-command)
 479     map)
 480   "Keymap for input viewer with completion.")
 481
 482 ;;; The functions.
 483
 484 (defun mm-alist-to-plist (alist)
 485   "Convert association list ALIST into the equivalent property-list form.
 486 The plist is returned.  This converts from
 487
 488 \((a . 1) (b . 2) (c . 3))
 489
 490 into
 491
 492 \(a 1 b 2 c 3)
 493
 494 The original alist is not modified.  See also `destructive-alist-to-plist'."
 495   (let (plist)
 496     (while alist
 497       (let ((el (car alist)))
 498         (setq plist (cons (cdr el) (cons (car el) plist))))
 499       (setq alist (cdr alist)))
 500     (nreverse plist)))
 501
 502 (defun mm-keep-viewer-alive-p (handle)
 503   "Say whether external viewer for HANDLE should stay alive."
 504   (let ((types mm-keep-viewer-alive-types)
 505         (type (mm-handle-media-type handle))
 506         ty)
 507     (catch 'found
 508       (while (setq ty (pop types))
 509         (when (string-match ty type)
 510           (throw 'found t))))))
 511
 512 (defun mm-handle-set-external-undisplayer (handle function)
 513   "Set the undisplayer for HANDLE to FUNCTION.
 514 Postpone undisplaying of viewers for types in
 515 `mm-keep-viewer-alive-types'."
 516   (if (mm-keep-viewer-alive-p handle)
 517       (let ((new-handle (copy-sequence handle)))
 518         (mm-handle-set-undisplayer new-handle function)
 519         (mm-handle-set-undisplayer handle nil)
 520         (push new-handle mm-postponed-undisplay-list))
 521     (mm-handle-set-undisplayer handle function)))
 522
 523 (defun mm-destroy-postponed-undisplay-list ()
 524   (when mm-postponed-undisplay-list
 525     (message "Destroying external MIME viewers")
 526     (mm-destroy-parts mm-postponed-undisplay-list)))
 527
 528 (defun mm-dissect-buffer (&optional no-strict-mime loose-mime from)
 529   "Dissect the current buffer and return a list of MIME handles."
 530   (save-excursion
 531     (let (ct ctl type subtype cte cd description id result)
 532       (save-restriction
 533         (mail-narrow-to-head)
 534         (when (or no-strict-mime
 535                   loose-mime
 536                   (mail-fetch-field "mime-version"))
 537           (setq ct (mail-fetch-field "content-type")
 538                 ctl (and ct (mail-header-parse-content-type ct))
 539                 cte (mail-fetch-field "content-transfer-encoding")
 540                 cd (mail-fetch-field "content-disposition")
 541                 description (mail-fetch-field "content-description")
 542                 id (mail-fetch-field "content-id"))
 543           (unless from
 544             (setq from (mail-fetch-field "from")))
 545           ;; FIXME: In some circumstances, this code is running within
 546           ;; an unibyte macro.  mail-extract-address-components
 547           ;; creates unibyte buffers. This `if', though not a perfect
 548           ;; solution, avoids most of them.
 549           (if from
 550               (setq from (cadr (mail-extract-address-components from))))))
 551       (when cte
 552         (setq cte (mail-header-strip cte)))
 553       (if (or (not ctl)
 554               (not (string-match "/" (car ctl))))
 555           (mm-dissect-singlepart
 556            (list mm-dissect-default-type)
 557            (and cte (intern (downcase (mail-header-remove-whitespace
 558                                        (mail-header-remove-comments
 559                                         cte)))))
 560            no-strict-mime
 561            (and cd (mail-header-parse-content-disposition cd))
 562            description)
 563         (setq type (split-string (car ctl) "/"))
 564         (setq subtype (cadr type)
 565               type (pop type))
 566         (setq
 567          result
 568          (cond
 569           ((equal type "multipart")
 570            (let ((mm-dissect-default-type (if (equal subtype "digest")
 571                                               "message/rfc822"
 572                                             "text/plain"))
 573                  (start (cdr (assq 'start (cdr ctl)))))
 574              (add-text-properties 0 (length (car ctl))
 575                                   (mm-alist-to-plist (cdr ctl)) (car ctl))
 576
 577              ;; what really needs to be done here is a way to link a
 578              ;; MIME handle back to it's parent MIME handle (in a multilevel
 579              ;; MIME article).  That would probably require changing
 580              ;; the mm-handle API so we simply store the multipart buffer
 581              ;; name as a text property of the "multipart/whatever" string.
 582              (add-text-properties 0 (length (car ctl))
 583                                   (list 'buffer (mm-copy-to-buffer)
 584                                         'from from
 585                                         'start start)
 586                                   (car ctl))
 587              (cons (car ctl) (mm-dissect-multipart ctl from))))
 588           (t
 589            (mm-possibly-verify-or-decrypt
 590             (mm-dissect-singlepart
 591              ctl
 592              (and cte (intern (downcase (mail-header-remove-whitespace
 593                                          (mail-header-remove-comments
 594                                           cte)))))
 595              no-strict-mime
 596              (and cd (mail-header-parse-content-disposition cd))
 597              description id)
 598             ctl))))
 599         (when id
 600           (when (string-match " *<\\(.*\\)> *" id)
 601             (setq id (match-string 1 id)))
 602           (push (cons id result) mm-content-id-alist))
 603         result))))
 604
 605 (defun mm-dissect-singlepart (ctl cte &optional force cdl description id)
 606   (when (or force
 607             (if (equal "text/plain" (car ctl))
 608                 (assoc 'format ctl)
 609               t))
 610     (mm-make-handle
 611      (mm-copy-to-buffer) ctl cte nil cdl description nil id)))
 612
 613 (defun mm-dissect-multipart (ctl from)
 614   (goto-char (point-min))
 615   (let* ((boundary (concat "\n--" (mail-content-type-get ctl 'boundary)))
 616          (close-delimiter (concat (regexp-quote boundary) "--[ \t]*$"))
 617          start parts
 618          (end (save-excursion
 619                 (goto-char (point-max))
 620                 (if (re-search-backward close-delimiter nil t)
 621                     (match-beginning 0)
 622                   (point-max)))))
 623     (setq boundary (concat (regexp-quote boundary) "[ \t]*$"))
 624     (while (and (< (point) end) (re-search-forward boundary end t))
 625       (goto-char (match-beginning 0))
 626       (when start
 627         (save-excursion
 628           (save-restriction
 629             (narrow-to-region start (point))
 630             (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 631       (end-of-line 2)
 632       (or (looking-at boundary)
 633           (forward-line 1))
 634       (setq start (point)))
 635     (when (and start (< start end))
 636       (save-excursion
 637         (save-restriction
 638           (narrow-to-region start end)
 639           (setq parts (nconc (list (mm-dissect-buffer t nil from)) parts)))))
 640     (mm-possibly-verify-or-decrypt (nreverse parts) ctl)))
 641
 642 (defun mm-copy-to-buffer ()
 643   "Copy the contents of the current buffer to a fresh buffer."
 644   (save-excursion
 645     (let ((obuf (current-buffer))
 646           beg)
 647       (goto-char (point-min))
 648       (search-forward-regexp "^\n" nil t)
 649       (setq beg (point))
 650       (set-buffer
 651        ;; Preserve the data's unibyteness (for url-insert-file-contents).
 652        (let ((default-enable-multibyte-characters (mm-multibyte-p)))
 653          (generate-new-buffer " *mm*")))
 654       (insert-buffer-substring obuf beg)
 655       (current-buffer))))
 656
 657 (defun mm-display-parts (handle &optional no-default)
 658   (if (stringp (car handle))
 659       (mapcar 'mm-display-parts (cdr handle))
 660     (if (bufferp (car handle))
 661         (save-restriction
 662           (narrow-to-region (point) (point))
 663           (mm-display-part handle)
 664           (goto-char (point-max)))
 665       (mapcar 'mm-display-parts handle))))
 666
 667 (defun mm-display-part (handle &optional no-default)
 668   "Display the MIME part represented by HANDLE.
 669 Returns nil if the part is removed; inline if displayed inline;
 670 external if displayed external."
 671   (save-excursion
 672     (mailcap-parse-mailcaps)
 673     (if (mm-handle-displayed-p handle)
 674         (mm-remove-part handle)
 675       (let* ((type (mm-handle-media-type handle))
 676              (method (mailcap-mime-info type))
 677              (filename (or (mail-content-type-get
 678                             (mm-handle-disposition handle) 'filename)
 679                            (mail-content-type-get
 680                             (mm-handle-type handle) 'name)
 681                            "<file>"))
 682              (external mm-enable-external))
 683         (if (and (mm-inlinable-p handle)
 684                  (mm-inlined-p handle))
 685             (progn
 686               (forward-line 1)
 687               (mm-display-inline handle)
 688               'inline)
 689           (when (or method
 690                     (not no-default))
 691             (if (and (not method)
 692                      (equal "text" (car (split-string type))))
 693                 (progn
 694                   (forward-line 1)
 695                   (mm-insert-inline handle (mm-get-part handle))
 696                   'inline)
 697               (if (and method ;; If nil, we always use "save".
 698                        (stringp method) ;; 'mailcap-save-binary-file
 699                        (or (eq mm-enable-external t)
 700                            (and (eq mm-enable-external 'ask)
 701                                 (y-or-n-p
 702                                  (concat
 703                                   "Display part (" type
 704                                   ") using external program"
 705                                   ;; Can non-string method ever happen?
 706                                   (if (stringp method)
 707                                       (concat
 708                                        " \"" (format method filename) "\"")
 709                                     "")
 710                                   "? ")))))
 711                   (setq external t)
 712                 (setq external nil))
 713               (if external
 714                   (mm-display-external
 715                    handle (or method 'mailcap-save-binary-file))
 716                 (mm-display-external
 717                  handle 'mailcap-save-binary-file)))))))))
 718
 719 (defun mm-display-external (handle method)
 720   "Display HANDLE using METHOD."
 721   (let ((outbuf (current-buffer)))
 722     (mm-with-unibyte-buffer
 723       (if (functionp method)
 724           (let ((cur (current-buffer)))
 725             (if (eq method 'mailcap-save-binary-file)
 726                 (progn
 727                   (set-buffer (generate-new-buffer " *mm*"))
 728                   (setq method nil))
 729               (mm-insert-part handle)
 730               (let ((win (get-buffer-window cur t)))
 731                 (when win
 732                   (select-window win)))
 733               (switch-to-buffer (generate-new-buffer " *mm*")))
 734             (buffer-disable-undo)
 735             (mm-set-buffer-file-coding-system mm-binary-coding-system)
 736             (insert-buffer-substring cur)
 737             (goto-char (point-min))
 738             (when method
 739               (message "Viewing with %s" method))
 740             (let ((mm (current-buffer))
 741                   (non-viewer (assq 'non-viewer
 742                                     (mailcap-mime-info
 743                                      (mm-handle-media-type handle) t))))
 744               (unwind-protect
 745                   (if method
 746                       (funcall method)
 747                     (mm-save-part handle))
 748                 (when (and (not non-viewer)
 749                            method)
 750                   (mm-handle-set-undisplayer handle mm)))))
 751         ;; The function is a string to be executed.
 752         (mm-insert-part handle)
 753         (let* ((dir (mm-make-temp-file
 754                      (expand-file-name "emm." mm-tmp-directory) 'dir))
 755                (filename (or
 756                           (mail-content-type-get
 757                            (mm-handle-disposition handle) 'filename)
 758                           (mail-content-type-get
 759                            (mm-handle-type handle) 'name)))
 760                (mime-info (mailcap-mime-info
 761                            (mm-handle-media-type handle) t))
 762                (needsterm (or (assoc "needsterm" mime-info)
 763                               (assoc "needsterminal" mime-info)))
 764                (copiousoutput (assoc "copiousoutput" mime-info))
 765                file buffer)
 766           ;; We create a private sub-directory where we store our files.
 767           (set-file-modes dir 448)
 768           (if filename
 769               (setq file (expand-file-name
 770                           (gnus-map-function mm-file-name-rewrite-functions
 771                                              (file-name-nondirectory filename))
 772                           dir))
 773             ;; Use nametemplate (defined in RFC1524) if it is specified
 774             ;; in mailcap.
 775             (let ((suffix (cdr (assoc "nametemplate" mime-info))))
 776               (if (and suffix
 777                        (string-match "\\`%s\\(\\..+\\)\\'" suffix))
 778                   (setq suffix (match-string 1 suffix))
 779                 ;; Otherwise, use a suffix according to
 780                 ;; `mailcap-mime-extensions'.
 781                 (setq suffix (car (rassoc (mm-handle-media-type handle)
 782                                           mailcap-mime-extensions))))
 783               (setq file (mm-make-temp-file (expand-file-name "mm." dir)
 784                                             nil suffix))))
 785           (let ((coding-system-for-write mm-binary-coding-system))
 786             (write-region (point-min) (point-max) file nil 'nomesg))
 787           (message "Viewing with %s" method)
 788           (cond
 789            (needsterm
 790             (let ((command (mm-mailcap-command
 791                             method file (mm-handle-type handle))))
 792               (unwind-protect
 793                   (if window-system
 794                       (start-process "*display*" nil
 795                                      mm-external-terminal-program
 796                                      "-e" shell-file-name
 797                                      shell-command-switch command)
 798                     (require 'term)
 799                     (require 'gnus-win)
 800                     (set-buffer
 801                      (setq buffer
 802                            (make-term "display"
 803                                       shell-file-name
 804                                       nil
 805                                       shell-command-switch command)))
 806                     (term-mode)
 807                     (term-char-mode)
 808                     (set-process-sentinel
 809                      (get-buffer-process buffer)
 810                      `(lambda (process state)
 811                         (if (eq 'exit (process-status process))
 812                             (gnus-configure-windows
 813                              ',gnus-current-window-configuration))))
 814                     (gnus-configure-windows 'display-term))
 815                 (mm-handle-set-external-undisplayer handle (cons file buffer)))
 816               (message "Displaying %s..." command))
 817             'external)
 818            (copiousoutput
 819             (with-current-buffer outbuf
 820               (forward-line 1)
 821               (mm-insert-inline
 822                handle
 823                (unwind-protect
 824                    (progn
 825                      (call-process shell-file-name nil
 826                                    (setq buffer
 827                                          (generate-new-buffer " *mm*"))
 828                                    nil
 829                                    shell-command-switch
 830                                    (mm-mailcap-command
 831                                     method file (mm-handle-type handle)))
 832                      (if (buffer-live-p buffer)
 833                          (with-current-buffer buffer
 834                            (buffer-string))))
 835                  (progn
 836                    (ignore-errors (delete-file file))
 837                    (ignore-errors (delete-directory
 838                                    (file-name-directory file)))
 839                    (ignore-errors (kill-buffer buffer))))))
 840             'inline)
 841            (t
 842             ;; Deleting the temp file should be postponed for some wrappers,
 843             ;; shell scripts, and so on, which might exit right after having
 844             ;; started a viewer command as a background job.
 845             (let ((command (mm-mailcap-command
 846                             method file (mm-handle-type handle))))
 847               (unwind-protect
 848                   (progn
 849                     (start-process "*display*"
 850                                    (setq buffer
 851                                          (generate-new-buffer " *mm*"))
 852                                    shell-file-name
 853                                    shell-command-switch command)
 854                     (set-process-sentinel
 855                      (get-buffer-process buffer)
 856                      (lexical-let ;; Don't use `let'.
 857                          ;; Function used to remove temp file and directory.
 858                          ((fn `(lambda nil
 859                                  ;; Don't use `ignore-errors'.
 860                                  (condition-case nil
 861                                      (delete-file ,file)
 862                                    (error))
 863                                  (condition-case nil
 864                                      (delete-directory
 865                                       ,(file-name-directory file))
 866                                    (error))))
 867                           ;; Form uses to kill the process buffer and
 868                           ;; remove the undisplayer.
 869                           (fm `(progn
 870                                  (kill-buffer ,buffer)
 871                                  ,(macroexpand
 872                                    (list 'mm-handle-set-undisplayer
 873                                          (list 'quote handle)
 874                                          nil))))
 875                           ;; Message to be issued when the process exits.
 876                           (done (format "Displaying %s...done" command))
 877                           ;; In particular, the timer object (which is
 878                           ;; a vector in Emacs but is a list in XEmacs)
 879                           ;; requires that it is lexically scoped.
 880                           (timer (run-at-time 2.0 nil 'ignore)))
 881                        (lambda (process state)
 882                          (when (eq 'exit (process-status process))
 883                            (if (memq timer timer-list)
 884                                (timer-set-function timer fn)
 885                              (funcall fn))
 886                            (ignore-errors (eval fm))
 887                            (message "%s" done))))))
 888                 (mm-handle-set-external-undisplayer
 889                  handle (cons file buffer)))
 890               (message "Displaying %s..." command))
 891             'external)))))))
 892
 893 (defun mm-mailcap-command (method file type-list)
 894   (let ((ctl (cdr type-list))
 895         (beg 0)
 896         (uses-stdin t)
 897         out sub total)
 898     (while (string-match "%{\\([^}]+\\)}\\|'%s'\\|\"%s\"\\|%s\\|%t\\|%%"
 899                          method beg)
 900       (push (substring method beg (match-beginning 0)) out)
 901       (setq beg (match-end 0)
 902             total (match-string 0 method)
 903             sub (match-string 1 method))
 904       (cond
 905        ((string= total "%%")
 906         (push "%" out))
 907        ((or (string= total "%s")
 908             ;; We do our own quoting.
 909             (string= total "'%s'")
 910             (string= total "\"%s\""))
 911         (setq uses-stdin nil)
 912         (push (mm-quote-arg
 913                (gnus-map-function mm-path-name-rewrite-functions file)) out))
 914        ((string= total "%t")
 915         (push (mm-quote-arg (car type-list)) out))
 916        (t
 917         (push (mm-quote-arg (or (cdr (assq (intern sub) ctl)) "")) out))))
 918     (push (substring method beg (length method)) out)
 919     (when uses-stdin
 920       (push "<" out)
 921       (push (mm-quote-arg
 922              (gnus-map-function mm-path-name-rewrite-functions file))
 923             out))
 924     (mapconcat 'identity (nreverse out) "")))
 925
 926 (defun mm-remove-parts (handles)
 927   "Remove the displayed MIME parts represented by HANDLES."
 928   (if (and (listp handles)
 929            (bufferp (car handles)))
 930       (mm-remove-part handles)
 931     (let (handle)
 932       (while (setq handle (pop handles))
 933         (cond
 934          ((stringp handle)
 935           (when (buffer-live-p (get-text-property 0 'buffer handle))
 936             (kill-buffer (get-text-property 0 'buffer handle))))
 937          ((and (listp handle)
 938                (stringp (car handle)))
 939           (mm-remove-parts (cdr handle)))
 940          (t
 941           (mm-remove-part handle)))))))
 942
 943 (defun mm-destroy-parts (handles)
 944   "Remove the displayed MIME parts represented by HANDLES."
 945   (if (and (listp handles)
 946            (bufferp (car handles)))
 947       (mm-destroy-part handles)
 948     (let (handle)
 949       (while (setq handle (pop handles))
 950         (cond
 951          ((stringp handle)
 952           (when (buffer-live-p (get-text-property 0 'buffer handle))
 953             (kill-buffer (get-text-property 0 'buffer handle))))
 954          ((and (listp handle)
 955                (stringp (car handle)))
 956           (mm-destroy-parts handle))
 957          (t
 958           (mm-destroy-part handle)))))))
 959
 960 (defun mm-remove-part (handle)
 961   "Remove the displayed MIME part represented by HANDLE."
 962   (when (listp handle)
 963     (let ((object (mm-handle-undisplayer handle)))
 964       (ignore-errors
 965         (cond
 966          ;; Internally displayed part.
 967          ((mm-annotationp object)
 968           (delete-annotation object))
 969          ((or (functionp object)
 970               (and (listp object)
 971                    (eq (car object) 'lambda)))
 972           (funcall object))
 973          ;; Externally displayed part.
 974          ((consp object)
 975           (condition-case ()
 976               (while (get-buffer-process (cdr object))
 977                 (interrupt-process (get-buffer-process (cdr object)))
 978                 (message "Waiting for external displayer to die...")
 979                 (sit-for 1))
 980             (quit)
 981             (error))
 982           (ignore-errors (and (cdr object) (kill-buffer (cdr object))))
 983           (message "Waiting for external displayer to die...done")
 984           (ignore-errors (delete-file (car object)))
 985           (ignore-errors (delete-directory (file-name-directory
 986                                             (car object)))))
 987          ((bufferp object)
 988           (when (buffer-live-p object)
 989             (kill-buffer object)))))
 990       (mm-handle-set-undisplayer handle nil))))
 991
 992 (defun mm-display-inline (handle)
 993   (let* ((type (mm-handle-media-type handle))
 994          (function (cadr (mm-assoc-string-match mm-inline-media-tests type))))
 995     (funcall function handle)
 996     (goto-char (point-min))))
 997
 998 (defun mm-assoc-string-match (alist type)
 999   (dolist (elem alist)
1000     (when (string-match (car elem) type)
1001       (return elem))))
1002
1003 (defun mm-automatic-display-p (handle)
1004   "Say whether the user wants HANDLE to be displayed automatically."
1005   (let ((methods mm-automatic-display)
1006         (type (mm-handle-media-type handle))
1007         method result)
1008     (while (setq method (pop methods))
1009       (when (and (not (mm-inline-override-p handle))
1010                  (string-match method type))
1011         (setq result t
1012               methods nil)))
1013     result))
1014
1015 (defun mm-inlinable-p (handle)
1016   "Say whether HANDLE can be displayed inline."
1017   (let ((alist mm-inline-media-tests)
1018         (type (mm-handle-media-type handle))
1019         test)
1020     (while alist
1021       (when (string-match (caar alist) type)
1022         (setq test (caddar alist)
1023               alist nil)
1024         (setq test (funcall test handle)))
1025       (pop alist))
1026     test))
1027
1028 (defun mm-inlined-p (handle)
1029   "Say whether the user wants HANDLE to be displayed inline."
1030   (let ((methods mm-inlined-types)
1031         (type (mm-handle-media-type handle))
1032         method result)
1033     (while (setq method (pop methods))
1034       (when (and (not (mm-inline-override-p handle))
1035                  (string-match method type))
1036         (setq result t
1037               methods nil)))
1038     result))
1039
1040 (defun mm-attachment-override-p (handle)
1041   "Say whether HANDLE should have attachment behavior overridden."
1042   (let ((types mm-attachment-override-types)
1043         (type (mm-handle-media-type handle))
1044         ty)
1045     (catch 'found
1046       (while (setq ty (pop types))
1047         (when (and (string-match ty type)
1048                    (mm-inlinable-p handle))
1049           (throw 'found t))))))
1050
1051 (defun mm-inline-override-p (handle)
1052   "Say whether HANDLE should have inline behavior overridden."
1053   (let ((types mm-inline-override-types)
1054         (type (mm-handle-media-type handle))
1055         ty)
1056     (catch 'found
1057       (while (setq ty (pop types))
1058         (when (string-match ty type)
1059           (throw 'found t))))))
1060
1061 (defun mm-automatic-external-display-p (type)
1062   "Return the user-defined method for TYPE."
1063   (let ((methods mm-automatic-external-display)
1064         method result)
1065     (while (setq method (pop methods))
1066       (when (string-match method type)
1067         (setq result t
1068               methods nil)))
1069     result))
1070
1071 (defun mm-destroy-part (handle)
1072   "Destroy the data structures connected to HANDLE."
1073   (when (listp handle)
1074     (mm-remove-part handle)
1075     (when (buffer-live-p (mm-handle-buffer handle))
1076       (kill-buffer (mm-handle-buffer handle)))))
1077
1078 (defun mm-handle-displayed-p (handle)
1079   "Say whether HANDLE is displayed or not."
1080   (mm-handle-undisplayer handle))
1081
1082 ;;;
1083 ;;; Functions for outputting parts
1084 ;;;
1085
1086 (defmacro mm-with-part (handle &rest forms)
1087   "Run FORMS in the temp buffer containing the contents of HANDLE."
1088   `(let* ((handle ,handle)
1089           ;; The multibyteness of the temp buffer should be turned on
1090           ;; if inserting a multibyte string.  Contrarily, the buffer's
1091           ;; multibyteness should be off if inserting a unibyte string,
1092           ;; especially if a string contains 8bit data.
1093           (default-enable-multibyte-characters
1094             (with-current-buffer (mm-handle-buffer handle)
1095               (mm-multibyte-p))))
1096      (with-temp-buffer
1097        (insert-buffer-substring (mm-handle-buffer handle))
1098        (mm-disable-multibyte)
1099        (mm-decode-content-transfer-encoding
1100         (mm-handle-encoding handle)
1101         (mm-handle-media-type handle))
1102        ,@forms)))
1103 (put 'mm-with-part 'lisp-indent-function 1)
1104 (put 'mm-with-part 'edebug-form-spec '(body))
1105
1106 (defun mm-get-part (handle)
1107   "Return the contents of HANDLE as a string."
1108   (if (equal (mm-handle-media-type handle) "message/external-body")
1109       (progn
1110         (unless (mm-handle-cache handle)
1111           (mm-extern-cache-contents handle))
1112         (with-current-buffer (mm-handle-buffer (mm-handle-cache handle))
1113           (buffer-string)))
1114     (mm-with-part handle
1115       (buffer-string))))
1116
1117 (defun mm-insert-part (handle)
1118   "Insert the contents of HANDLE in the current buffer."
1119   (save-excursion
1120     (insert
1121      (cond ((eq (mail-content-type-get (mm-handle-type handle) 'charset)
1122                 'gnus-decoded)
1123             (with-current-buffer (mm-handle-buffer handle)
1124               (buffer-string)))
1125            ((mm-multibyte-p)
1126             (mm-string-as-multibyte (mm-get-part handle)))
1127            (t
1128             (mm-get-part handle))))))
1129
1130 (defun mm-file-name-delete-whitespace (file-name)
1131   "Remove all whitespace characters from FILE-NAME."
1132   (while (string-match "\\s-+" file-name)
1133     (setq file-name (replace-match "" t t file-name)))
1134   file-name)
1135
1136 (defun mm-file-name-trim-whitespace (file-name)
1137   "Remove leading and trailing whitespace characters from FILE-NAME."
1138   (when (string-match "\\`\\s-+" file-name)
1139     (setq file-name (substring file-name (match-end 0))))
1140   (when (string-match "\\s-+\\'" file-name)
1141     (setq file-name (substring file-name 0 (match-beginning 0))))
1142   file-name)
1143
1144 (defun mm-file-name-collapse-whitespace (file-name)
1145   "Collapse multiple whitespace characters in FILE-NAME."
1146   (while (string-match "\\s-\\s-+" file-name)
1147     (setq file-name (replace-match " " t t file-name)))
1148   file-name)
1149
1150 (defun mm-file-name-replace-whitespace (file-name)
1151   "Replace whitespace characters in FILE-NAME with underscores.
1152 Set the option `mm-file-name-replace-whitespace' to any other
1153 string if you do not like underscores."
1154   (let ((s (or mm-file-name-replace-whitespace "_")))
1155     (while (string-match "\\s-" file-name)
1156       (setq file-name (replace-match s t t file-name))))
1157   file-name)
1158
1159 (defun mm-file-name-delete-control (filename)
1160   "Delete control characters from FILENAME."
1161   (gnus-replace-in-string filename "[\x00-\x1f\x7f]" ""))
1162
1163 (defun mm-file-name-delete-gotchas (filename)
1164   "Delete shell gotchas from FILENAME."
1165   (setq filename (gnus-replace-in-string filename "[<>|]" ""))
1166   (gnus-replace-in-string filename "^[.-]+" ""))
1167
1168 (defun mm-save-part (handle)
1169   "Write HANDLE to a file."
1170   (let ((filename (or (mail-content-type-get
1171                        (mm-handle-disposition handle) 'filename)
1172                       (mail-content-type-get
1173                        (mm-handle-type handle) 'name)))
1174         file)
1175     (when filename
1176       (setq filename (gnus-map-function mm-file-name-rewrite-functions
1177                                         (file-name-nondirectory filename))))
1178     (setq file
1179           (mm-with-multibyte
1180            (read-file-name "Save MIME part to: "
1181                            (or mm-default-directory default-directory)
1182                            nil nil (or filename ""))))
1183     (setq mm-default-directory (file-name-directory file))
1184     (and (or (not (file-exists-p file))
1185              (yes-or-no-p (format "File %s already exists; overwrite? "
1186                                   file)))
1187          (progn
1188            (mm-save-part-to-file handle file)
1189            file))))
1190
1191 (defun mm-save-part-to-file (handle file)
1192   (mm-with-unibyte-buffer
1193     (mm-insert-part handle)
1194     (let ((coding-system-for-write 'binary)
1195           (current-file-modes (default-file-modes))
1196           ;; Don't re-compress .gz & al.  Arguably we should make
1197           ;; `file-name-handler-alist' nil, but that would chop
1198           ;; ange-ftp, which is reasonable to use here.
1199           (inhibit-file-name-operation 'write-region)
1200           (inhibit-file-name-handlers
1201            (cons 'jka-compr-handler inhibit-file-name-handlers)))
1202       (set-default-file-modes mm-attachment-file-modes)
1203       (unwind-protect
1204           (write-region (point-min) (point-max) file)
1205         (set-default-file-modes current-file-modes)))))
1206
1207 (defun mm-pipe-part (handle)
1208   "Pipe HANDLE to a process."
1209   (let* ((name (mail-content-type-get (mm-handle-type handle) 'name))
1210          (command
1211           (read-string "Shell command on MIME part: " mm-last-shell-command)))
1212     (mm-with-unibyte-buffer
1213       (mm-insert-part handle)
1214       (let ((coding-system-for-write 'binary))
1215         (shell-command-on-region (point-min) (point-max) command nil)))))
1216
1217 (defun mm-interactively-view-part (handle)
1218   "Display HANDLE using METHOD."
1219   (let* ((type (mm-handle-media-type handle))
1220          (methods
1221           (mapcar (lambda (i) (list (cdr (assoc 'viewer i))))
1222                   (mailcap-mime-info type 'all)))
1223          (method (let ((minibuffer-local-completion-map
1224                         mm-viewer-completion-map))
1225                    (completing-read "Viewer: " methods))))
1226     (when (string= method "")
1227       (error "No method given"))
1228     (if (string-match "^[^% \t]+$" method)
1229         (setq method (concat method " %s")))
1230     (mm-display-external handle method)))
1231
1232 (defun mm-preferred-alternative (handles &optional preferred)
1233   "Say which of HANDLES are preferred."
1234   (let ((prec (if preferred (list preferred)
1235                 (mm-preferred-alternative-precedence handles)))
1236         p h result type handle)
1237     (while (setq p (pop prec))
1238       (setq h handles)
1239       (while h
1240         (setq handle (car h))
1241         (setq type (mm-handle-media-type handle))
1242         (when (and (equal p type)
1243                    (mm-automatic-display-p handle)
1244                    (or (stringp (car handle))
1245                        (not (mm-handle-disposition handle))
1246                        (equal (car (mm-handle-disposition handle))
1247                               "inline")))
1248           (setq result handle
1249                 h nil
1250                 prec nil))
1251         (pop h)))
1252     result))
1253
1254 (defun mm-preferred-alternative-precedence (handles)
1255   "Return the precedence based on HANDLES and `mm-discouraged-alternatives'."
1256   (let ((seq (nreverse (mapcar #'mm-handle-media-type
1257                                handles))))
1258     (dolist (disc (reverse mm-discouraged-alternatives))
1259       (dolist (elem (copy-sequence seq))
1260         (when (string-match disc elem)
1261           (setq seq (nconc (delete elem seq) (list elem))))))
1262     seq))
1263
1264 (defun mm-get-content-id (id)
1265   "Return the handle(s) referred to by ID."
1266   (cdr (assoc id mm-content-id-alist)))
1267
1268 (defconst mm-image-type-regexps
1269   '(("/\\*.*XPM.\\*/" . xpm)
1270     ("P[1-6]" . pbm)
1271     ("GIF8" . gif)
1272     ("\377\330" . jpeg)
1273     ("\211PNG\r\n" . png)
1274     ("#define" . xbm)
1275     ("\\(MM\0\\*\\)\\|\\(II\\*\0\\)" . tiff)
1276     ("%!PS" . postscript))
1277   "Alist of (REGEXP . IMAGE-TYPE) pairs used to auto-detect image types.
1278 When the first bytes of an image file match REGEXP, it is assumed to
1279 be of image type IMAGE-TYPE.")
1280
1281 ;; Steal from image.el. image-type-from-data suffers multi-line matching bug.
1282 (defun mm-image-type-from-buffer ()
1283   "Determine the image type from data in the current buffer.
1284 Value is a symbol specifying the image type or nil if type cannot
1285 be determined."
1286   (let ((types mm-image-type-regexps)
1287         type)
1288     (goto-char (point-min))
1289     (while (and types (null type))
1290       (let ((regexp (car (car types)))
1291             (image-type (cdr (car types))))
1292         (when (looking-at regexp)
1293           (setq type image-type))
1294         (setq types (cdr types))))
1295     type))
1296
1297 (defun mm-get-image (handle)
1298   "Return an image instance based on HANDLE."
1299   (let ((type (mm-handle-media-subtype handle))
1300         spec)
1301     ;; Allow some common translations.
1302     (setq type
1303           (cond
1304            ((equal type "x-pixmap")
1305             "xpm")
1306            ((equal type "x-xbitmap")
1307             "xbm")
1308            ((equal type "x-portable-bitmap")
1309             "pbm")
1310            (t type)))
1311     (or (mm-handle-cache handle)
1312         (mm-with-unibyte-buffer
1313           (mm-insert-part handle)
1314           (prog1
1315               (setq spec
1316                     (ignore-errors
1317                       ;; Avoid testing `make-glyph' since W3 may define
1318                       ;; a bogus version of it.
1319                       (if (fboundp 'create-image)
1320                           (create-image (buffer-string)
1321                                         (or (mm-image-type-from-buffer)
1322                                             (intern type))
1323                                         'data-p)
1324                         (mm-create-image-xemacs type))))
1325             (mm-handle-set-cache handle spec))))))
1326
1327 (defun mm-create-image-xemacs (type)
1328   (cond
1329    ((equal type "xbm")
1330     ;; xbm images require special handling, since
1331     ;; the only way to create glyphs from these
1332     ;; (without a ton of work) is to write them
1333     ;; out to a file, and then create a file
1334     ;; specifier.
1335     (let ((file (mm-make-temp-file
1336                  (expand-file-name "emm" mm-tmp-directory)
1337                  nil ".xbm")))
1338       (unwind-protect
1339           (progn
1340             (write-region (point-min) (point-max) file)
1341             (make-glyph (list (cons 'x file))))
1342         (ignore-errors
1343           (delete-file file)))))
1344    (t
1345     (make-glyph
1346      (vector
1347       (or (mm-image-type-from-buffer)
1348           (intern type))
1349       :data (buffer-string))))))
1350
1351 (defun mm-image-fit-p (handle)
1352   "Say whether the image in HANDLE will fit the current window."
1353   (let ((image (mm-get-image handle)))
1354     (if (fboundp 'glyph-width)
1355         ;; XEmacs' glyphs can actually tell us about their width, so
1356         ;; lets be nice and smart about them.
1357         (or mm-inline-large-images
1358             (and (< (glyph-width image) (window-pixel-width))
1359                  (< (glyph-height image) (window-pixel-height))))
1360       (let* ((size (image-size image))
1361              (w (car size))
1362              (h (cdr size)))
1363         (or mm-inline-large-images
1364             (and (< h (1- (window-height))) ; Don't include mode line.
1365                  (< w (window-width))))))))
1366
1367 (defun mm-valid-image-format-p (format)
1368   "Say whether FORMAT can be displayed natively by Emacs."
1369   (cond
1370    ;; Handle XEmacs
1371    ((fboundp 'valid-image-instantiator-format-p)
1372     (valid-image-instantiator-format-p format))
1373    ;; Handle Emacs 21
1374    ((fboundp 'image-type-available-p)
1375     (and (display-graphic-p)
1376          (image-type-available-p format)))
1377    ;; Nobody else can do images yet.
1378    (t
1379     nil)))
1380
1381 (defun mm-valid-and-fit-image-p (format handle)
1382   "Say whether FORMAT can be displayed natively and HANDLE fits the window."
1383   (and (mm-valid-image-format-p format)
1384        (mm-image-fit-p handle)))
1385
1386 (defun mm-find-part-by-type (handles type &optional notp recursive)
1387   "Search in HANDLES for part with TYPE.
1388 If NOTP, returns first non-matching part.
1389 If RECURSIVE, search recursively."
1390   (let (handle)
1391     (while handles
1392       (if (and recursive (stringp (caar handles)))
1393           (if (setq handle (mm-find-part-by-type (cdar handles) type
1394                                                  notp recursive))
1395               (setq handles nil))
1396         (if (if notp
1397                 (not (equal (mm-handle-media-type (car handles)) type))
1398               (equal (mm-handle-media-type (car handles)) type))
1399             (setq handle (car handles)
1400                   handles nil)))
1401       (setq handles (cdr handles)))
1402     handle))
1403
1404 (defun mm-find-raw-part-by-type (ctl type &optional notp)
1405   (goto-char (point-min))
1406   (let* ((boundary (concat "--" (mm-handle-multipart-ctl-parameter ctl
1407                                                                    'boundary)))
1408          (close-delimiter (concat "^" (regexp-quote boundary) "--[ \t]*$"))
1409          start
1410          (end (save-excursion
1411                 (goto-char (point-max))
1412                 (if (re-search-backward close-delimiter nil t)
1413                     (match-beginning 0)
1414                   (point-max))))
1415          result)
1416     (setq boundary (concat "^" (regexp-quote boundary) "[ \t]*$"))
1417     (while (and (not result)
1418                 (re-search-forward boundary end t))
1419       (goto-char (match-beginning 0))
1420       (when start
1421         (save-excursion
1422           (save-restriction
1423             (narrow-to-region start (1- (point)))
1424             (when (let* ((ct (mail-fetch-field "content-type"))
1425                          (ctl (and ct (mail-header-parse-content-type ct))))
1426                     (if notp
1427                         (not (equal (car ctl) type))
1428                       (equal (car ctl) type)))
1429               (setq result (buffer-string))))))
1430       (forward-line 1)
1431       (setq start (point)))
1432     (when (and (not result) start)
1433       (save-excursion
1434         (save-restriction
1435           (narrow-to-region start end)
1436           (when (let* ((ct (mail-fetch-field "content-type"))
1437                        (ctl (and ct (mail-header-parse-content-type ct))))
1438                   (if notp
1439                       (not (equal (car ctl) type))
1440                     (equal (car ctl) type)))
1441             (setq result (buffer-string))))))
1442     result))
1443
1444 (defvar mm-security-handle nil)
1445
1446 (defsubst mm-set-handle-multipart-parameter (handle parameter value)
1447   ;; HANDLE could be a CTL.
1448   (when handle
1449     (put-text-property 0 (length (car handle)) parameter value
1450                        (car handle))))
1451
1452 (defun mm-possibly-verify-or-decrypt (parts ctl)
1453   (let ((type (car ctl))
1454         (subtype (cadr (split-string (car ctl) "/")))
1455         (mm-security-handle ctl) ;; (car CTL) is the type.
1456         protocol func functest)
1457     (cond
1458      ((or (equal type "application/x-pkcs7-mime")
1459           (equal type "application/pkcs7-mime"))
1460       (with-temp-buffer
1461         (when (and (cond
1462                     ((eq mm-decrypt-option 'never) nil)
1463                     ((eq mm-decrypt-option 'always) t)
1464                     ((eq mm-decrypt-option 'known) t)
1465                     (t (y-or-n-p
1466                         (format "Decrypt (S/MIME) part? "))))
1467                    (mm-view-pkcs7 parts))
1468           (setq parts (mm-dissect-buffer t)))))
1469      ((equal subtype "signed")
1470       (unless (and (setq protocol
1471                          (mm-handle-multipart-ctl-parameter ctl 'protocol))
1472                    (not (equal protocol "multipart/mixed")))
1473         ;; The message is broken or draft-ietf-openpgp-multsig-01.
1474         (let ((protocols mm-verify-function-alist))
1475           (while protocols
1476             (if (and (or (not (setq functest (nth 3 (car protocols))))
1477                          (funcall functest parts ctl))
1478                      (mm-find-part-by-type parts (caar protocols) nil t))
1479                 (setq protocol (caar protocols)
1480                       protocols nil)
1481               (setq protocols (cdr protocols))))))
1482       (setq func (nth 1 (assoc protocol mm-verify-function-alist)))
1483       (when (cond
1484              ((eq mm-verify-option 'never) nil)
1485              ((eq mm-verify-option 'always) t)
1486              ((eq mm-verify-option 'known)
1487               (and func
1488                    (or (not (setq functest
1489                                   (nth 3 (assoc protocol
1490                                                 mm-verify-function-alist))))
1491                        (funcall functest parts ctl))))
1492              (t
1493               (y-or-n-p
1494                (format "Verify signed (%s) part? "
1495                        (or (nth 2 (assoc protocol mm-verify-function-alist))
1496                            (format "protocol=%s" protocol))))))
1497         (save-excursion
1498           (if func
1499               (funcall func parts ctl)
1500             (mm-set-handle-multipart-parameter
1501              mm-security-handle 'gnus-details
1502              (format "Unknown sign protocol (%s)" protocol))))))
1503      ((equal subtype "encrypted")
1504       (unless (setq protocol
1505                     (mm-handle-multipart-ctl-parameter ctl 'protocol))
1506         ;; The message is broken.
1507         (let ((parts parts))
1508           (while parts
1509             (if (assoc (mm-handle-media-type (car parts))
1510                        mm-decrypt-function-alist)
1511                 (setq protocol (mm-handle-media-type (car parts))
1512                       parts nil)
1513               (setq parts (cdr parts))))))
1514       (setq func (nth 1 (assoc protocol mm-decrypt-function-alist)))
1515       (when (cond
1516              ((eq mm-decrypt-option 'never) nil)
1517              ((eq mm-decrypt-option 'always) t)
1518              ((eq mm-decrypt-option 'known)
1519               (and func
1520                    (or (not (setq functest
1521                                   (nth 3 (assoc protocol
1522                                                 mm-decrypt-function-alist))))
1523                        (funcall functest parts ctl))))
1524              (t
1525               (y-or-n-p
1526                (format "Decrypt (%s) part? "
1527                        (or (nth 2 (assoc protocol mm-decrypt-function-alist))
1528                            (format "protocol=%s" protocol))))))
1529         (save-excursion
1530           (if func
1531               (setq parts (funcall func parts ctl))
1532             (mm-set-handle-multipart-parameter
1533              mm-security-handle 'gnus-details
1534              (format "Unknown encrypt protocol (%s)" protocol))))))
1535      (t nil))
1536     parts))
1537
1538 (defun mm-multiple-handles (handles)
1539   (and (listp handles)
1540        (> (length handles) 1)
1541        (or (listp (car handles))
1542            (stringp (car handles)))))
1543
1544 (defun mm-complicated-handles (handles)
1545   (and (listp (car handles))
1546        (> (length handles) 1)))
1547
1548 (defun mm-merge-handles (handles1 handles2)
1549   (append
1550    (if (listp (car handles1))
1551        handles1
1552      (list handles1))
1553    (if (listp (car handles2))
1554        handles2
1555      (list handles2))))
1556
1557 (defun mm-readable-p (handle)
1558   "Say whether the content of HANDLE is readable."
1559   (and (< (with-current-buffer (mm-handle-buffer handle)
1560             (buffer-size)) 10000)
1561        (mm-with-unibyte-buffer
1562          (mm-insert-part handle)
1563          (and (eq (mm-body-7-or-8) '7bit)
1564               (not (mm-long-lines-p 76))))))
1565
1566 (provide 'mm-decode)
1567
1568 ;; arch-tag: 4f35d360-56b8-4030-9388-3ed82d359b9b
1569 ;;; mm-decode.el ends here