summaryrefslogtreecommitdiff
path: root/lisp/gnus/mml.el
blob: 424215de941172d2952f71edb2b6bde38a960a00 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
;;; mml.el --- A package for parsing and validating MML documents

;; Copyright (C) 1998-2021 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

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

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

;;; Commentary:

;;; Code:

(require 'mm-util)
(require 'mm-bodies)
(require 'mm-encode)
(require 'mm-decode)
(require 'mml-sec)
(eval-when-compile (require 'cl-lib))
(eval-when-compile (require 'url))
(eval-when-compile (require 'gnus-util))

(autoload 'message-make-message-id "message")
(declare-function gnus-setup-posting-charset "gnus-msg" (group))
(autoload 'gnus-completing-read "gnus-util")
(autoload 'message-fetch-field "message")
(autoload 'message-mark-active-p "message")
(autoload 'message-info "message")
(autoload 'fill-flowed-encode "flow-fill")
(autoload 'message-posting-charset "message")
(autoload 'dnd-get-local-file-name "dnd")

(autoload 'message-options-set    "message")
(autoload 'message-narrow-to-head "message")
(autoload 'message-in-body-p      "message")
(autoload 'message-mail-p         "message")

(defvar gnus-article-mime-handles)
(defvar gnus-newsrc-hashtb)
(defvar message-deletable-headers)
(defvar message-options)
(defvar message-posting-charset)
(defvar message-required-mail-headers)
(defvar message-required-news-headers)
(defvar dnd-protocol-alist)
(defvar mml-dnd-protocol-alist)

(defcustom mml-content-type-parameters
  '(name access-type expiration size permission format)
  "A list of acceptable parameters in MML tag.
These parameters are generated in Content-Type header if exists."
  :version "22.1"
  :type '(repeat (symbol :tag "Parameter"))
  :group 'message)

(defcustom mml-content-disposition-parameters
  '(filename creation-date modification-date read-date)
  "A list of acceptable parameters in MML tag.
These parameters are generated in Content-Disposition header if exists."
  :version "22.1"
  :type '(repeat (symbol :tag "Parameter"))
  :group 'message)

(defcustom mml-content-disposition-alist
  '((text (rtf . "attachment") (t . "inline"))
    (t . "attachment"))
  "Alist of MIME types or regexps matching file names and default dispositions.
Each element should be one of the following three forms:

  (REGEXP . DISPOSITION)
  (SUPERTYPE (SUBTYPE . DISPOSITION) (SUBTYPE . DISPOSITION)...)
  (TYPE . DISPOSITION)

Where REGEXP is a string which matches the file name (if any) of an
attachment, SUPERTYPE, SUBTYPE and TYPE should be symbols which are a
MIME supertype (e.g., text), a MIME subtype (e.g., plain) and a MIME
type (e.g., text/plain) respectively, and DISPOSITION should be either
the string \"attachment\" or the string \"inline\".  The value t for
SUPERTYPE, SUBTYPE or TYPE matches any of those types.  The first
match found will be used."
  :version "23.1" ;; No Gnus
  :type (let ((dispositions '(radio :format "DISPOSITION: %v"
				    :value "attachment"
				    (const :format "%v " "attachment")
				    (const :format "%v\n" "inline"))))
	  `(repeat
	    :offset 0
	    (choice :format "%[Value Menu%]%v"
		    (cons :tag "(REGEXP . DISPOSITION)" :extra-offset 4
			  (regexp :tag "REGEXP" :value ".*")
			  ,dispositions)
		    (cons :tag "(SUPERTYPE (SUBTYPE . DISPOSITION)...)"
			  :indent 0
			  (symbol :tag "    SUPERTYPE" :value text)
			  (repeat :format "%v%i\n" :offset 0 :extra-offset 4
				  (cons :format "%v" :extra-offset 5
					(symbol :tag "SUBTYPE" :value t)
					,dispositions)))
		    (cons :tag "(TYPE . DISPOSITION)" :extra-offset 4
			  (symbol :tag "TYPE" :value t)
			  ,dispositions))))
  :group 'message)

(defcustom mml-insert-mime-headers-always t
  "If non-nil, always put Content-Type: text/plain at top of empty parts.
It is necessary to work against a bug in certain clients."
  :version "24.1"
  :type 'boolean
  :group 'message)

(defcustom mml-enable-flowed t
  "If non-nil, enable format=flowed usage when encoding a message.
This is only performed when filling on text/plain with hard
newlines in the text."
  :version "24.1"
  :type 'boolean
  :group 'message)

(defvar mml-tweak-type-alist nil
  "A list of (TYPE . FUNCTION) for tweaking MML parts.
TYPE is a string containing a regexp to match the MIME type.  FUNCTION
is a Lisp function which is called with the MML handle to tweak the
part.  This variable is used only when no TWEAK parameter exists in
the MML handle.")

(defvar mml-tweak-function-alist nil
  "A list of (NAME . FUNCTION) for tweaking MML parts.
NAME is a string containing the name of the TWEAK parameter in the MML
handle.  FUNCTION is a Lisp function which is called with the MML
handle to tweak the part.")

(defvar mml-tweak-sexp-alist
  '((mml-externalize-attachments . mml-tweak-externalize-attachments))
  "A list of (SEXP . FUNCTION) for tweaking MML parts.
SEXP is an s-expression.  If the evaluation of SEXP is non-nil, FUNCTION
is called.  FUNCTION is a Lisp function which is called with the MML
handle to tweak the part.")

(defvar mml-externalize-attachments nil
  "If non-nil, local-file attachments are generated as external parts.")

(defcustom mml-generate-multipart-alist nil
  "Alist of multipart generation functions.
Each entry has the form (NAME . FUNCTION), where
NAME is a string containing the name of the part (without the
leading \"/multipart/\"),
FUNCTION is a Lisp function which is called to generate the part.

The Lisp function has to supply the appropriate MIME headers and the
contents of this part."
  :group 'message
  :type '(alist :key-type string :value-type function))

(defvar mml-syntax-table
  (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
    (modify-syntax-entry ?\\ "/" table)
    (modify-syntax-entry ?< "(" table)
    (modify-syntax-entry ?> ")" table)
    (modify-syntax-entry ?@ "w" table)
    (modify-syntax-entry ?/ "w" table)
    (modify-syntax-entry ?= " " table)
    (modify-syntax-entry ?* " " table)
    (modify-syntax-entry ?\; " " table)
    (modify-syntax-entry ?\' " " table)
    table))

(defvar mml-boundary-function 'mml-make-boundary
  "A function called to suggest a boundary.
The function may be called several times, and should try to make a new
suggestion each time.  The function is called with one parameter,
which is a number that says how many times the function has been
called for this message.")

(defvar mml-confirmation-set nil
  "A list of symbols, each of which disables some warning.
`unknown-encoding': always send messages contain characters with
unknown encoding; `use-ascii': always use ASCII for those characters
with unknown encoding; `multipart': always send messages with more than
one charsets.")

(defvar mml-generate-default-type "text/plain"
  "Content type by which the Content-Type header can be omitted.
The Content-Type header will not be put in the MIME part if the type
equals the value and there's no parameter (e.g. charset, format, etc.)
and `mml-insert-mime-headers-always' is nil.  The value will be bound
to \"message/rfc822\" when encoding an article to be forwarded as a MIME
part.  This is for the internal use, you should never modify the value.")

(defvar mml-buffer-list nil)

(defun mml-generate-new-buffer (name)
  (let ((buf (generate-new-buffer name)))
    (push buf mml-buffer-list)
    buf))

(defun mml-destroy-buffers ()
  (let (kill-buffer-hook)
    (mapc 'kill-buffer mml-buffer-list)
    (setq mml-buffer-list nil)))

(defun mml-parse ()
  "Parse the current buffer as an MML document."
  (save-excursion
    (goto-char (point-min))
    (with-syntax-table mml-syntax-table
      (mml-parse-1))))

(defun mml-parse-1 ()
  "Parse the current buffer as an MML document."
  (let (struct tag point contents charsets warn use-ascii no-markup-p raw)
    (while (and (not (eobp))
		(not (looking-at "<#/multipart")))
      (cond
       ((looking-at "<#secure")
	;; The secure part is essentially a meta-meta tag, which
	;; expands to either a part tag if there are no other parts in
	;; the document or a multipart tag if there are other parts
	;; included in the message
	(let* (secure-mode
	       (taginfo (mml-read-tag))
	       (keyfile (cdr (assq 'keyfile taginfo)))
	       (certfiles (delq nil (mapcar (lambda (tag)
					      (if (eq (car-safe tag) 'certfile)
						  (cdr tag)))
					    taginfo)))
	       (recipients (cdr (assq 'recipients taginfo)))
	       (sender (cdr (assq 'sender taginfo)))
	       (location (cdr (assq 'tag-location taginfo)))
	       (mode (cdr (assq 'mode taginfo)))
	       (method (cdr (assq 'method taginfo)))
	       tags)
	  (save-excursion
	    (if (re-search-forward
		 "<#/?\\(multipart\\|part\\|external\\|mml\\)." nil t)
		(setq secure-mode "multipart")
	      (setq secure-mode "part")))
	  (save-excursion
	    (goto-char location)
	    (re-search-forward "<#secure[^\n]*>\n"))
	  (delete-region (match-beginning 0) (match-end 0))
	  (cond ((string= mode "sign")
		 (setq tags (list "sign" method)))
		((string= mode "encrypt")
		 (setq tags (list "encrypt" method)))
		((string= mode "signencrypt")
		 (setq tags (list "sign" method "encrypt" method)))
		(t
		 (error "Unknown secure mode %s" mode)))
	  (eval `(mml-insert-tag ,secure-mode
				 ,@tags
				 ,(if keyfile "keyfile")
				 ,keyfile
				 ,@(apply #'append
					  (mapcar (lambda (certfile)
						    (list "certfile" certfile))
						  certfiles))
				 ,(if recipients "recipients")
				 ,recipients
				 ,(if sender "sender")
				 ,sender))
	  ;; restart the parse
	  (goto-char location)))
       ((looking-at "<#multipart")
	(push (nconc (mml-read-tag) (mml-parse-1)) struct))
       ((looking-at "<#external")
	(push (nconc (mml-read-tag) (list (cons 'contents (mml-read-part))))
	      struct))
       (t
	(if (or (looking-at "<#part") (looking-at "<#mml"))
	    (setq tag (mml-read-tag)
		  no-markup-p nil
		  warn nil)
	  (setq tag (list 'part (cons 'type "text/plain"))
		no-markup-p t
		warn t))
	(setq raw (cdr (assq 'raw tag))
	      point (point)
	      contents (mml-read-part (eq 'mml (car tag)))
	      charsets (cond
			(raw nil)
			((assq 'charset tag)
			 (list
			  (intern (downcase (cdr (assq 'charset tag))))))
			(t
			 (mm-find-mime-charset-region point (point)
						      mm-hack-charsets))))
	;; We have a part that already has a transfer encoding.  Undo
	;; that so that we don't double-encode later.
	(when (and raw
		   (cdr (assq 'data-encoding tag)))
	  (with-temp-buffer
	    (set-buffer-multibyte nil)
	    (insert contents)
	    (mm-decode-content-transfer-encoding
	     (intern (cdr (assq 'data-encoding tag)))
	     (cdr (assq 'type tag)))
	    (setq contents (buffer-string))))
	(when (and (not raw) (memq nil charsets))
	  (if (or (memq 'unknown-encoding mml-confirmation-set)
		  (message-options-get 'unknown-encoding)
		  (and (y-or-n-p "\
Message contains characters with unknown encoding.  Really send? ")
		       (message-options-set 'unknown-encoding t)))
	      (if (setq use-ascii
			(or (memq 'use-ascii mml-confirmation-set)
			    (message-options-get 'use-ascii)
			    (and (y-or-n-p "Use ASCII as charset? ")
				 (message-options-set 'use-ascii t))))
		  (setq charsets (delq nil charsets))
		(setq warn nil))
	    (error "Edit your message to remove those characters")))
	(if (or raw
		(eq 'mml (car tag))
		(< (length charsets) 2))
	    (if (or (not no-markup-p)
		    ;; Don't create blank parts.
		    (string-match "[^ \t\r\n]" contents))
		(push (nconc tag (list (cons 'contents contents)))
		      struct))
	  (let ((nstruct (mml-parse-singlepart-with-multiple-charsets
			  tag point (point) use-ascii)))
	    (when (and warn
		       (not (memq 'multipart mml-confirmation-set))
		       (not (message-options-get 'multipart))
		       (not (and (y-or-n-p (format "\
A message part needs to be split into %d charset parts.  Really send? "
						   (length nstruct)))
				 (message-options-set 'multipart t))))
	      (error "Edit your message to use only one charset"))
	    (setq struct (nconc nstruct struct)))))))
    (unless (eobp)
      (forward-line 1))
    (nreverse struct)))

(defun mml-parse-singlepart-with-multiple-charsets
  (orig-tag beg end &optional use-ascii)
  (save-excursion
    (save-restriction
      (narrow-to-region beg end)
      (goto-char (point-min))
      (let ((current (or (mm-mime-charset (mm-charset-after))
			 (and use-ascii 'us-ascii)))
	    charset struct space newline paragraph)
	(while (not (eobp))
	  (setq charset (mm-mime-charset (mm-charset-after)))
	  (cond
	   ;; The charset remains the same.
	   ((eq charset 'us-ascii))
	   ((or (and use-ascii (not charset))
		(eq charset current))
	    (setq space nil
		  newline nil
		  paragraph nil))
	   ;; The initial charset was ascii.
	   ((eq current 'us-ascii)
	    (setq current charset
		  space nil
		  newline nil
		  paragraph nil))
	   ;; We have a change in charsets.
	   (t
	    (push (append
		   orig-tag
		   (list (cons 'contents
			       (buffer-substring-no-properties
				beg (or paragraph newline space (point))))))
		  struct)
	    (setq beg (or paragraph newline space (point))
		  current charset
		  space nil
		  newline nil
		  paragraph nil)))
	  ;; Compute places where it might be nice to break the part.
	  (cond
	   ((memq (following-char) '(?  ?\t))
	    (setq space (1+ (point))))
	   ((and (eq (following-char) ?\n)
		 (not (bobp))
		 (eq (char-after (1- (point))) ?\n))
	    (setq paragraph (point)))
	   ((eq (following-char) ?\n)
	    (setq newline (1+ (point)))))
	  (forward-char 1))
	;; Do the final part.
	(unless (= beg (point))
	  (push (append orig-tag
			(list (cons 'contents
				    (buffer-substring-no-properties
				     beg (point)))))
		struct))
	struct))))

(defun mml-read-tag ()
  "Read a tag and return the contents."
  (let ((orig-point (point))
	contents name elem val)
    (forward-char 2)
    (setq name (buffer-substring-no-properties
		(point) (progn (forward-sexp 1) (point))))
    (skip-chars-forward " \t\n")
    (while (not (looking-at ">[ \t]*\n?"))
      (setq elem (buffer-substring-no-properties
		  (point) (progn (forward-sexp 1) (point))))
      (skip-chars-forward "= \t\n")
      (setq val (buffer-substring-no-properties
		 (point) (progn (forward-sexp 1) (point))))
      (when (string-match "\\`\"" val)
	(setq val (read val))) ;; inverse of prin1 in mml-insert-tag
      (push (cons (intern elem) val) contents)
      (skip-chars-forward " \t\n"))
    (goto-char (match-end 0))
    ;; Don't skip the leading space.
    ;;(skip-chars-forward " \t\n")
    ;; Put the tag location into the returned contents
    (setq contents (append (list (cons 'tag-location orig-point)) contents))
    (cons (intern name) (nreverse contents))))

(defun mml-buffer-substring-no-properties-except-some (start end)
  (let ((str (buffer-substring-no-properties start end))
	(bufstart start)
	tmp)
    ;; Copy over all hard newlines.
    (while (setq tmp (text-property-any start end 'hard t))
      (put-text-property (- tmp bufstart) (- tmp bufstart -1)
			 'hard t str)
      (setq start (1+ tmp)))
    ;; Copy over all `display' properties (which are usually images).
    (setq start bufstart)
    (while (setq tmp (text-property-not-all start end 'display nil))
      (put-text-property (- tmp bufstart) (- tmp bufstart -1)
			 'display (get-text-property tmp 'display)
			 str)
      (setq start (1+ tmp)))
    str))

(defun mml-read-part (&optional mml)
  "Return the buffer up till the next part, multipart or closing part or multipart.
If MML is non-nil, return the buffer up till the correspondent mml tag."
  (let ((beg (point)) (count 1))
    ;; If the tag ended at the end of the line, we go to the next line.
    (when (looking-at "[ \t]*\n")
      (forward-line 1))
    (if mml
	(progn
	  (while (and (> count 0) (not (eobp)))
	    (if (re-search-forward "<#\\(/\\)?mml." nil t)
		(setq count (+ count (if (match-beginning 1) -1 1)))
	      (goto-char (point-max))))
	  (mml-buffer-substring-no-properties-except-some
	   beg (if (> count 0)
		   (point)
		 (match-beginning 0))))
      (if (re-search-forward
	   "<#\\(/\\)?\\(multipart\\|part\\|external\\|mml\\)." nil t)
	  (prog1
	      (mml-buffer-substring-no-properties-except-some
	       beg (match-beginning 0))
	    (if (or (not (match-beginning 1))
		    (equal (match-string 2) "multipart"))
		(goto-char (match-beginning 0))
	      (when (looking-at "[ \t]*\n")
		(forward-line 1))))
	(mml-buffer-substring-no-properties-except-some
	 beg (goto-char (point-max)))))))

(defvar mml-boundary nil)
(defvar mml-base-boundary "-=-=")
(defvar mml-multipart-number 0)
(defvar mml-inhibit-compute-boundary nil)

(declare-function libxml-parse-html-region "xml.c"
		  (start end &optional base-url discard-comments))

(defun mml-generate-mime (&optional multipart-type content-type)
  "Generate a MIME message based on the current MML document.
MULTIPART-TYPE defaults to \"mixed\", but can also
be \"related\" or \"alternate\".

If CONTENT-TYPE (and there's only one part), override the content
type detected."
  (let ((cont (mml-parse))
	(mml-multipart-number mml-multipart-number)
	(options message-options))
    (if (not cont)
	nil
      (when (and (consp (car cont))
		 (= (length cont) 1)
		 content-type)
	(setcdr (assq 'type (cdr (car cont))) content-type))
      (when (fboundp 'libxml-parse-html-region)
	(setq cont (mapcar 'mml-expand-all-html-into-multipart-related cont)))
      (prog1
	  (with-temp-buffer
	    (set-buffer-multibyte nil)
	    (setq message-options options)
	    (cond
	     ((and (consp (car cont))
		   (= (length cont) 1))
	      (mml-generate-mime-1 (car cont)))
	     ((eq (car cont) 'multipart)
	      (mml-generate-mime-1 cont))
	     (t
	      (mml-generate-mime-1
	       (nconc (list 'multipart (cons 'type (or multipart-type "mixed")))
		      cont))))
	    (setq options message-options)
	    (buffer-string))
	(setq message-options options)))))

(defun mml-expand-all-html-into-multipart-related (cont)
  (cond ((and (eq (car cont) 'part)
	      (equal (cdr (assq 'type cont)) "text/html"))
	 (mml-expand-html-into-multipart-related cont))
	((eq (car cont) 'multipart)
	 (let ((cur (cdr cont)))
	   (while (consp cur)
	     (setcar cur (mml-expand-all-html-into-multipart-related (car cur)))
	     (setf cur (cdr cur))))
	 cont)
	(t cont)))

(defun mml-expand-html-into-multipart-related (cont)
  (let ((new-parts nil)
	(cid 1))
    (mm-with-multibyte-buffer
      (insert (cdr (assq 'contents cont)))
      (goto-char (point-min))
      (with-syntax-table mml-syntax-table
	(while (re-search-forward "<img\\b" nil t)
	  (goto-char (match-beginning 0))
	  (let* ((start (point))
		 (img (nth 2
			   (nth 2
				(libxml-parse-html-region
				 (point) (progn (forward-sexp) (point))))))
		 (end (point))
		 (parsed (url-generic-parse-url (cdr (assq 'src (cadr img))))))
	    (when (and (null (url-type parsed))
		       (url-filename parsed)
		       (file-exists-p (url-filename parsed)))
	      (goto-char start)
	      (when (search-forward (url-filename parsed) end t)
		(let ((cid (format "fsf.%d" cid)))
		  (replace-match (concat "cid:" cid) t t)
		  (push (list cid (url-filename parsed)
			      (get-text-property start 'display))
			new-parts))
		(setq cid (1+ cid)))))))
      ;; We have local images that we want to include.
      (when new-parts
	(setcdr (assq 'contents cont) (buffer-string))
	(setq cont
	      (nconc (list 'multipart (cons 'type "related"))
		     (list cont)))
	(dolist (new-part (nreverse new-parts))
	  (setq cont
		(nconc cont
		       (list `(part (type . "image/png")
				    ,@(mml--possibly-alter-image
				       (nth 1 new-part)
				       (nth 2 new-part))
				    (id . ,(concat "<" (nth 0 new-part)
						   ">"))))))))
      cont)))

(autoload 'image-property "image")

;; FIXME presumably (built-in) ImageMagick could replace exiftool?
(defun mml--possibly-alter-image (file-name image)
  (if (or (null image)
	  (not (consp image))
	  (not (eq (car image) 'image))
	  (not (image-property image :rotation))
	  (not (executable-find "exiftool")))
      `((filename . ,file-name))
    `((filename . ,file-name)
      (buffer
       .
       ,(with-current-buffer (mml-generate-new-buffer " *mml rotation*")
	  (set-buffer-multibyte nil)
	  (call-process "exiftool"
			file-name
			(list (current-buffer) nil)
			nil
			(format "-Orientation#=%d"
				(cl-case (truncate
					  (image-property image :rotation))
				  (0 0)
				  (90 6)
				  (180 3)
				  (270 8)
				  (otherwise 0)))
			"-o" "-"
			"-")
	  (current-buffer))))))

(defun mml-generate-mime-1 (cont)
  (let ((mm-use-ultra-safe-encoding
	 (or mm-use-ultra-safe-encoding (assq 'sign cont))))
    (save-restriction
      (narrow-to-region (point) (point))
      (mml-tweak-part cont)
      (cond
       ((or (eq (car cont) 'part) (eq (car cont) 'mml))
	(let* ((raw (cdr (assq 'raw cont)))
	       (filename (cdr (assq 'filename cont)))
	       (type (or (cdr (assq 'type cont))
			 (if filename
			     (or (mm-default-file-encoding filename)
				 "application/octet-stream")
			   "text/plain")))
	       (charset (cdr (assq 'charset cont)))
	       (coding (mm-charset-to-coding-system charset))
	       encoding flowed coded)
	  (cond ((eq coding 'ascii)
		 (setq charset nil
		       coding nil))
		(charset
		 ;; The value of `charset' might be a bogus alias that
		 ;; `mm-charset-synonym-alist' provides, like `utf8',
		 ;; so we prefer the MIME charset that Emacs knows for
		 ;; the coding system `coding'.
		 (setq charset (or (mm-coding-system-to-mime-charset coding)
				   (intern (downcase charset))))))
	  (if (and (not raw)
		   (member (car (split-string type "/")) '("text" "message")))
	      (progn
		(with-temp-buffer
		  (cond
		   ((cdr (assq 'buffer cont))
		    (insert-buffer-substring (cdr (assq 'buffer cont))))
		   ((and filename
			 (not (equal (cdr (assq 'nofile cont)) "yes")))
		    (let ((coding-system-for-read coding))
		      (mm-insert-file-contents filename)))
		   ((eq 'mml (car cont))
		    (insert (cdr (assq 'contents cont))))
		   (t
		    (save-restriction
		      (narrow-to-region (point) (point))
		      (insert (cdr (assq 'contents cont)))
		      ;; Remove quotes from quoted tags.
		      (goto-char (point-min))
		      (while (re-search-forward
			      "<#!+/?\\(part\\|multipart\\|external\\|mml\\|secure\\)"
			      nil t)
			(delete-region (+ (match-beginning 0) 2)
				       (+ (match-beginning 0) 3))))))
		  (cond
		   ((eq (car cont) 'mml)
		    (let ((mml-boundary (mml-compute-boundary cont))
			  ;; It is necessary for the case where this
			  ;; function is called recursively since
			  ;; `m-g-d-t' will be bound to "message/rfc822"
			  ;; when encoding an article to be forwarded.
			  (mml-generate-default-type "text/plain"))
		      (mml-to-mime)
		      ;; Update handle so mml-compute-boundary can
		      ;; detect collisions with the nested parts.
		      (unless mml-inhibit-compute-boundary
			(setcdr (assoc 'contents cont) (buffer-string))))
		    (let ((mm-7bit-chars (concat mm-7bit-chars "\x1b")))
		      ;; ignore 0x1b, it is part of iso-2022-jp
		      (setq encoding (mm-body-7-or-8))))
		   ((string= (car (split-string type "/")) "message")
		    (let ((mm-7bit-chars (concat mm-7bit-chars "\x1b")))
		      ;; ignore 0x1b, it is part of iso-2022-jp
		      (setq encoding (mm-body-7-or-8))))
		   (t
		    ;; Only perform format=flowed filling on text/plain
		    ;; parts where there either isn't a format parameter
		    ;; in the mml tag or it says "flowed" and there
		    ;; actually are hard newlines in the text.
		    (let (use-hard-newlines)
		      (when (and mml-enable-flowed
				 (string= type "text/plain")
				 (not (string= (cdr (assq 'sign cont)) "pgp"))
				 (or (null (assq 'format cont))
				     (string= (cdr (assq 'format cont))
					      "flowed"))
				 (setq use-hard-newlines
				       (text-property-any
					(point-min) (point-max) 'hard 't)))
			(fill-flowed-encode)
			;; Indicate that `mml-insert-mime-headers' should
			;; insert a "; format=flowed" string unless the
			;; user has already specified it.
			(setq flowed (null (assq 'format cont)))))
		    ;; Prefer `utf-8' for text/calendar parts.
		    (if (or charset
			    (not (string= type "text/calendar")))
			(setq charset (mm-encode-body charset))
		      (let ((mm-coding-system-priorities
			     (cons 'utf-8 mm-coding-system-priorities)))
			(setq charset (mm-encode-body))))
		    (setq encoding (mm-body-encoding
				    charset (cdr (assq 'encoding cont))))))
		  (setq coded (buffer-string)))
		(mml-insert-mime-headers cont type charset encoding flowed)
		(insert "\n")
		(insert coded))
	    (with-temp-buffer
	      (set-buffer-multibyte nil)
	      (cond
	       ((cdr (assq 'buffer cont))
		;; multibyte string that inserted to a unibyte buffer
		;; will be converted to the unibyte version safely.
		(insert (with-current-buffer (cdr (assq 'buffer cont))
			  (buffer-string))))
	       ((and filename
		     (not (equal (cdr (assq 'nofile cont)) "yes")))
		(let ((coding-system-for-read mm-binary-coding-system))
		  (mm-insert-file-contents filename nil nil nil nil t))
		(unless charset
		  (setq charset (mm-coding-system-to-mime-charset
				 (mm-find-buffer-file-coding-system
				  filename)))))
	       (t
		(let ((contents (cdr (assq 'contents cont))))
		  (if (multibyte-string-p contents)
		      (progn
			(set-buffer-multibyte t)
			(insert contents)
			(unless raw
			  (setq charset	(mm-encode-body charset))))
		    (insert contents)))))
	      (if (setq encoding (cdr (assq 'encoding cont)))
		  (setq encoding (intern (downcase encoding))))
	      (setq encoding (mm-encode-buffer type encoding))
	      (setq coded (decode-coding-string (buffer-string) 'us-ascii)))
	    (mml-insert-mime-headers cont type charset encoding nil)
	    (insert "\n" coded))))
       ((eq (car cont) 'external)
	(insert "Content-Type: message/external-body")
	(let ((parameters (mml-parameter-string
			   cont '(expiration size permission)))
	      (name (cdr (assq 'name cont)))
	      (url (cdr (assq 'url cont))))
	  (when name
	    (setq name (mml-parse-file-name name))
	    (if (stringp name)
		(mml-insert-parameter
		 (mail-header-encode-parameter "name" name)
		 "access-type=local-file")
	      (mml-insert-parameter
	       (mail-header-encode-parameter
		"name" (file-name-nondirectory (nth 2 name)))
	       (mail-header-encode-parameter "site" (nth 1 name))
	       (mail-header-encode-parameter
		"directory" (file-name-directory (nth 2 name))))
	      (mml-insert-parameter
	       (concat "access-type="
		       (if (member (nth 0 name) '("ftp@" "anonymous@"))
			   "anon-ftp"
			 "ftp")))))
	  (when url
	    (mml-insert-parameter
	     (mail-header-encode-parameter "url" url)
	     "access-type=url"))
	  (when parameters
	    (mml-insert-parameter-string
	     cont '(expiration size permission)))
	  (insert "\n\n")
	  (insert "Content-Type: "
		  (or (cdr (assq 'type cont))
		      (if name
			  (or (mm-default-file-encoding name)
			      "application/octet-stream")
			"text/plain"))
		  "\n")
	  (insert "Content-ID: " (message-make-message-id) "\n")
	  (insert "Content-Transfer-Encoding: "
		  (or (cdr (assq 'encoding cont)) "binary"))
	  (insert "\n\n")
	  (insert (or (cdr (assq 'contents cont))))
	  (insert "\n")))
       ((eq (car cont) 'multipart)
	(let* ((type (or (cdr (assq 'type cont)) "mixed"))
	       (mml-generate-default-type (if (equal type "digest")
					      "message/rfc822"
					    "text/plain"))
	       (handler (assoc type mml-generate-multipart-alist)))
	  (if handler
	      (funcall (cdr handler) cont)
	    ;; No specific handler.  Use default one.
	    (let ((mml-boundary (mml-compute-boundary cont)))
	      (insert (format "Content-Type: multipart/%s; boundary=\"%s\""
			      type mml-boundary)
		      (if (cdr (assq 'start cont))
			  (format "; start=\"%s\"\n" (cdr (assq 'start cont)))
			"\n"))
	      (let ((cont cont) part)
		(while (setq part (pop cont))
		  ;; Skip `multipart' and attributes.
		  (when (and (consp part) (consp (cdr part)))
		    (insert "\n--" mml-boundary "\n")
		    (mml-generate-mime-1 part)
		    (goto-char (point-max)))))
	      (insert "\n--" mml-boundary "--\n")))))
       (t
	(error "Invalid element: %S" cont)))
      ;; handle sign & encrypt tags in a semi-smart way.
      (let ((sign-item (assoc (cdr (assq 'sign cont)) mml-sign-alist))
	    (encrypt-item (assoc (cdr (assq 'encrypt cont))
				 mml-encrypt-alist))
	    sender recipients)
	(when (or sign-item encrypt-item)
	  (when (setq sender (cdr (assq 'sender cont)))
	    (message-options-set 'mml-sender sender)
	    (message-options-set 'message-sender sender))
	  (if (setq recipients (cdr (assq 'recipients cont)))
	      (message-options-set 'message-recipients recipients))
	  (let ((style (mml-signencrypt-style
			(car (or sign-item encrypt-item)))))
	    ;; check if: we're both signing & encrypting, both methods
	    ;; are the same (why would they be different?!), and that
	    ;; the signencrypt style allows for combined operation.
	    (if (and sign-item encrypt-item (equal (car sign-item)
						   (car encrypt-item))
		     (equal style 'combined))
		(funcall (nth 1 encrypt-item) cont t)
	      ;; otherwise, revert to the old behavior.
	      (when sign-item
		(funcall (nth 1 sign-item) cont))
	      (when encrypt-item
		(funcall (nth 1 encrypt-item) cont)))))))))

(defun mml-compute-boundary (cont)
  "Return a unique boundary that does not exist in CONT."
  (let ((mml-boundary (funcall mml-boundary-function
			       (cl-incf mml-multipart-number))))
    (unless mml-inhibit-compute-boundary
      ;; This function tries again and again until it has found
      ;; a unique boundary.
      (while (not (catch 'not-unique
		    (mml-compute-boundary-1 cont)))))
    mml-boundary))

(defun mml-compute-boundary-1 (cont)
  (cond
   ((member (car cont) '(part mml))
    (mm-with-multibyte-buffer
      (let ((mml-inhibit-compute-boundary t)
	    (mml-multipart-number 0)
	    mml-sign-alist mml-encrypt-alist)
	(mml-generate-mime-1 cont))
      (goto-char (point-min))
      (when (re-search-forward (concat "^--" (regexp-quote mml-boundary))
			       nil t)
	(setq mml-boundary (funcall mml-boundary-function
				    (cl-incf mml-multipart-number)))
	(throw 'not-unique nil))))
   ((eq (car cont) 'multipart)
    (mapc 'mml-compute-boundary-1 (cddr cont))))
  t)

(defun mml-make-boundary (number)
  (concat (make-string (% number 60) ?=)
	  (if (> number 17)
	      (format "%x" number)
	    "")
	  mml-base-boundary))

(defun mml-content-disposition (type &optional filename)
  "Return a default disposition name suitable to TYPE or FILENAME."
  (let ((defs mml-content-disposition-alist)
	disposition def types)
    (while (and (not disposition) defs)
      (setq def (pop defs))
      (cond ((stringp (car def))
	     (when (and filename
			(string-match (car def) filename))
	       (setq disposition (cdr def))))
	    ((consp (cdr def))
	     (when (string= (car (setq types (split-string type "/")))
			    (car def))
	       (setq type (cadr types)
		     types (cdr def))
	       (while (and (not disposition) types)
		 (setq def (pop types))
		 (when (or (eq (car def) t) (string= type (car def)))
		   (setq disposition (cdr def))))))
	    (t
	     (when (or (eq (car def) t) (string= type (car def)))
	       (setq disposition (cdr def))))))
    (or disposition "attachment")))

(defun mml-insert-mime-headers (cont type charset encoding flowed)
  (let (parameters id disposition description)
    (setq parameters
	  (mml-parameter-string
	   cont mml-content-type-parameters))
    (when (or charset
	      parameters
	      flowed
	      (not (equal type mml-generate-default-type))
	      mml-insert-mime-headers-always)
      (when (consp charset)
	(error
	 "Can't encode a part with several charsets"))
      (insert "Content-Type: " type)
      (when charset
	(mml-insert-parameter
	 (mail-header-encode-parameter "charset" (symbol-name charset))))
      (when flowed
	(mml-insert-parameter "format=flowed"))
      (when parameters
	(mml-insert-parameter-string
	 cont mml-content-type-parameters))
      (insert "\n"))
    (when (setq id (cdr (assq 'id cont)))
      (insert "Content-ID: " id "\n"))
    (setq parameters
	  (mml-parameter-string
	   cont mml-content-disposition-parameters))
    (when (or (setq disposition (cdr (assq 'disposition cont)))
	      parameters)
      (insert "Content-Disposition: "
	      (or disposition
		  (mml-content-disposition type (cdr (assq 'filename cont)))))
      (when parameters
	(let ((cont (copy-sequence cont)))
	  ;; Set the file name to what's specified by the user.
	  (when-let ((recipient-filename (cdr (assq 'recipient-filename cont))))
	    (setcdr cont
		    (cons (cons 'filename recipient-filename)
			  (cdr cont))))
	  (mml-insert-parameter-string
	   cont mml-content-disposition-parameters)))
      (insert "\n"))
    (unless (eq encoding '7bit)
      (insert (format "Content-Transfer-Encoding: %s\n" encoding)))
    (when (setq description (cdr (assq 'description cont)))
      (insert "Content-Description: "
	      ;; The current buffer is unibyte, so do the description
	      ;; encoding in a temporary buffer.
	      (with-temp-buffer
		(insert description "\n")
		(mail-encode-encoded-word-region (point-min) (point-max))
		(buffer-string))))))

(defun mml-parameter-string (cont types)
  (let ((string "")
	value type)
    (while (setq type (pop types))
      (when (setq value (cdr (assq type cont)))
	;; Strip directory component from the filename parameter.
	(when (eq type 'filename)
	  (setq value (file-name-nondirectory value)))
	(setq string (concat string "; "
			     (mail-header-encode-parameter
			      (symbol-name type) value)))))
    (when (not (zerop (length string)))
      string)))

(defun mml-insert-parameter-string (cont types)
  (let (value type)
    (while (setq type (pop types))
      (when (setq value (cdr (assq type cont)))
	;; Strip directory component from the filename parameter.
	(when (eq type 'filename)
	  (setq value (file-name-nondirectory value)))
	(mml-insert-parameter
	 (mail-header-encode-parameter
	  (symbol-name type) value))))))

(defvar ange-ftp-name-format)
(defvar efs-path-regexp)

(defun mml-parse-file-name (path)
  (if (if (boundp 'efs-path-regexp)
	  (string-match efs-path-regexp path)
	(if (boundp 'ange-ftp-name-format)
	    (string-match (car ange-ftp-name-format) path)))
      (list (match-string 1 path) (match-string 2 path)
	    (substring path (1+ (match-end 2))))
    path))

(defun mml-insert-buffer (buffer)
  "Insert BUFFER at point and quote any MML markup."
  (save-restriction
    (narrow-to-region (point) (point))
    (insert-buffer-substring buffer)
    (mml-quote-region (point-min) (point-max))
    (goto-char (point-max))))

;;;
;;; Transforming MIME to MML
;;;

;; message-narrow-to-head autoloads message.
(declare-function message-remove-header "message"
                  (header &optional is-regexp first reverse))

(defun mime-to-mml (&optional handles)
  "Translate the current buffer (which should be a message) into MML.
If HANDLES is non-nil, use it instead reparsing the buffer."
  ;; First decode the head.
  (save-restriction
    (message-narrow-to-head)
    (let ((rfc2047-quote-decoded-words-containing-tspecials t))
      (mail-decode-encoded-word-region (point-min) (point-max))))
  (unless handles
    (setq handles (mm-dissect-buffer t)))
  (goto-char (point-min))
  (if (search-forward "\n\n" nil 'move)
      (delete-region (point) (point-max))
    ;; No content in the part that is the sole part of this message.
    (insert (if (bolp) "\n" "\n\n")))
  (if (stringp (car handles))
      (mml-insert-mime handles)
    (mml-insert-mime handles t))
  (mm-destroy-parts handles)
  (save-restriction
    (message-narrow-to-head)
    ;; Remove them, they are confusing.
    (message-remove-header "Content-Type")
    (message-remove-header "MIME-Version")
    (message-remove-header "Content-Disposition")
    (message-remove-header "Content-Transfer-Encoding")))

(autoload 'message-encode-message-body "message")
(declare-function message-narrow-to-headers-or-head "message" ())

;;;###autoload
(defun mml-to-mime ()
  "Translate the current buffer from MML to MIME."
  ;; `message-encode-message-body' will insert an encoded Content-Description
  ;; header in the message header if the body contains a single part
  ;; that is specified by a user with a MML tag containing a description
  ;; token.  So, we encode the message header first to prevent the encoded
  ;; Content-Description header from being encoded again.
  (save-restriction
    (message-narrow-to-headers-or-head)
    ;; Skip past any From_ headers.
    (while (looking-at "From ")
      (forward-line 1))
    (mail-encode-encoded-word-buffer))
  (message-encode-message-body))

(defun mml-insert-mime (handle &optional no-markup)
  (let (textp buffer mmlp)
    ;; Determine type and stuff.
    (unless (stringp (car handle))
      (unless (setq textp (equal (mm-handle-media-supertype handle) "text"))
	(with-current-buffer (setq buffer (mml-generate-new-buffer " *mml*"))
	  (if (eq (mail-content-type-get (mm-handle-type handle) 'charset)
		  'gnus-decoded)
	      ;; A part that mm-uu dissected from a non-MIME message
	      ;; because of `gnus-article-emulate-mime'.
	      (progn
		(mm-enable-multibyte)
		(insert-buffer-substring (mm-handle-buffer handle)))
	    (mm-insert-part handle 'no-cache)
	    (if (setq mmlp (equal (mm-handle-media-type handle)
				  "message/rfc822"))
		(mime-to-mml))))))
    (if mmlp
	(mml-insert-mml-markup handle nil t t)
      (unless (and no-markup
		   (equal (mm-handle-media-type handle) "text/plain"))
	(mml-insert-mml-markup handle buffer textp)))
    (cond
     (mmlp
      (insert-buffer-substring buffer)
      (goto-char (point-max))
      (insert "<#/mml>\n"))
     ((stringp (car handle))
      (mapc 'mml-insert-mime (cdr handle))
      (insert "<#/multipart>\n"))
     (textp
      (let ((charset (mail-content-type-get
		      (mm-handle-type handle) 'charset))
	    (start (point)))
	(if (eq charset 'gnus-decoded)
	    (mm-insert-part handle)
	  (insert (mm-decode-string (mm-get-part handle) charset)))
	(mml-quote-region start (point)))
      (goto-char (point-max)))
     (t
      (insert "<#/part>\n")))))

(defun mml-insert-mml-markup (handle &optional buffer nofile mmlp)
  "Take a MIME handle and insert an MML tag."
  (if (stringp (car handle))
      (progn
	(insert "<#multipart type=" (mm-handle-media-subtype handle))
	(let ((start (mm-handle-multipart-ctl-parameter handle 'start)))
	  (when start
	    (insert " start=\"" start "\"")))
	(insert ">\n"))
    (if mmlp
	(insert "<#mml type=" (mm-handle-media-type handle))
      (insert "<#part type=" (mm-handle-media-type handle)))
    (dolist (elem (append (cdr (mm-handle-type handle))
			  (cdr (mm-handle-disposition handle))))
      (unless (symbolp (cdr elem))
	(insert " " (symbol-name (car elem)) "=\"" (cdr elem) "\"")))
    (when (mm-handle-id handle)
      (insert " id=\"" (mm-handle-id handle) "\""))
    (when (mm-handle-disposition handle)
      (insert " disposition=" (car (mm-handle-disposition handle))))
    (when buffer
      (insert " buffer=\"" (buffer-name buffer) "\""))
    (when nofile
      (insert " nofile=yes"))
    (when (mm-handle-description handle)
      (insert " description=\"" (mm-handle-description handle) "\""))
    (insert ">\n")))

(defun mml-insert-parameter (&rest parameters)
  "Insert PARAMETERS in a nice way."
  (let (start end)
    (dolist (param parameters)
      (insert ";")
      (setq start (point))
      (insert " " param)
      (setq end (point))
      (goto-char start)
      (end-of-line)
      (if (> (current-column) 76)
	  (progn
	    (goto-char start)
	    (insert "\n")
	    (goto-char (1+ end)))
	(goto-char end)))))

;;;
;;; Mode for inserting and editing MML forms
;;;

(defvar mml-mode-map
  (let ((sign (make-sparse-keymap))
	(encrypt (make-sparse-keymap))
	(signpart (make-sparse-keymap))
	(encryptpart (make-sparse-keymap))
	(map (make-sparse-keymap))
	(main (make-sparse-keymap)))
    (define-key map "\C-s" 'mml-secure-message-sign)
    (define-key map "\C-c" 'mml-secure-message-encrypt)
    (define-key map "\C-e" 'mml-secure-message-sign-encrypt)
    (define-key map "\C-p\C-s" 'mml-secure-sign)
    (define-key map "\C-p\C-c" 'mml-secure-encrypt)
    (define-key sign "p" 'mml-secure-message-sign-pgpmime)
    (define-key sign "o" 'mml-secure-message-sign-pgp)
    (define-key sign "s" 'mml-secure-message-sign-smime)
    (define-key signpart "p" 'mml-secure-sign-pgpmime)
    (define-key signpart "o" 'mml-secure-sign-pgp)
    (define-key signpart "s" 'mml-secure-sign-smime)
    (define-key encrypt "p" 'mml-secure-message-encrypt-pgpmime)
    (define-key encrypt "o" 'mml-secure-message-encrypt-pgp)
    (define-key encrypt "s" 'mml-secure-message-encrypt-smime)
    (define-key encryptpart "p" 'mml-secure-encrypt-pgpmime)
    (define-key encryptpart "o" 'mml-secure-encrypt-pgp)
    (define-key encryptpart "s" 'mml-secure-encrypt-smime)
    (define-key map "\C-n" 'mml-unsecure-message)
    (define-key map "f" 'mml-attach-file)
    (define-key map "b" 'mml-attach-buffer)
    (define-key map "e" 'mml-attach-external)
    (define-key map "q" 'mml-quote-region)
    (define-key map "m" 'mml-insert-multipart)
    (define-key map "p" 'mml-insert-part)
    (define-key map "v" 'mml-validate)
    (define-key map "P" 'mml-preview)
    (define-key map "s" sign)
    (define-key map "S" signpart)
    (define-key map "c" encrypt)
    (define-key map "C" encryptpart)
    ;;(define-key map "n" 'mml-narrow-to-part)
    ;; `M-m' conflicts with `back-to-indentation'.
    ;; (define-key main "\M-m" map)
    (define-key main "\C-c\C-m" map)
    main))

(easy-menu-define
  mml-menu mml-mode-map ""
  '("Attachments"
    ["Attach File..." mml-attach-file :help "Attach a file at point"]
    ["Attach Buffer..." mml-attach-buffer
     :help "Attach a buffer to the outgoing message"]
    ["Attach External..." mml-attach-external
     :help "Attach reference to an external file"]
    ;; FIXME: Is it possible to do this without using
    ;; `gnus-gcc-externalize-attachments'?
    ["Externalize Attachments"
     (lambda ()
       (interactive)
       (setq gnus-gcc-externalize-attachments
	     (not gnus-gcc-externalize-attachments))
       (message "gnus-gcc-externalize-attachments is `%s'."
		gnus-gcc-externalize-attachments))
     :visible (and (boundp 'gnus-gcc-externalize-attachments)
		   (memq gnus-gcc-externalize-attachments
			 '(all t nil)))
     :style toggle
     :selected gnus-gcc-externalize-attachments
     :help "Save attachments as external parts in Gcc copies"]
    "----"
    ;;
    ("Change Security Method"
     ["PGP/MIME"
      (lambda () (interactive) (setq mml-secure-method "pgpmime"))
      :help "Set Security Method to PGP/MIME"
      :style radio
      :selected (equal mml-secure-method "pgpmime") ]
     ["S/MIME"
      (lambda () (interactive) (setq mml-secure-method "smime"))
      :help "Set Security Method to S/MIME"
      :style radio
      :selected (equal mml-secure-method "smime") ]
     ["Inline PGP"
      (lambda () (interactive) (setq mml-secure-method "pgp"))
      :help "Set Security Method to inline PGP"
      :style radio
      :selected (equal mml-secure-method "pgp") ] )
    ;;
    ["Sign Message" mml-secure-message-sign t]
    ["Encrypt Message" mml-secure-message-encrypt t]
    ["Sign and Encrypt Message" mml-secure-message-sign-encrypt t]
    ["Encrypt/Sign off" mml-unsecure-message
     :help "Don't Encrypt/Sign Message"]
    ;; Do we have separate encrypt and encrypt/sign commands for parts?
    ["Sign Part" mml-secure-sign t]
    ["Encrypt Part" mml-secure-encrypt t]
    "----"
    ;; Maybe we could remove these, because people who write MML most probably
    ;; don't use the menu:
    ["Insert Part..." mml-insert-part
     :active (message-in-body-p)]
    ["Insert Multipart..." mml-insert-multipart
     :active (message-in-body-p)]
    ;;
    ;;["Narrow" mml-narrow-to-part t]
    ["Quote MML in region" mml-quote-region
     :active (message-mark-active-p)
     :help "Quote MML tags in region"]
    ["Validate MML" mml-validate t]
    ["Preview" mml-preview t]
    "----"
    ["Emacs MIME manual" (lambda () (interactive) (message-info 4))
     :help "Display the Emacs MIME manual"]
    ["PGG manual" (lambda () (interactive) (message-info mml2015-use))
     :visible (and (boundp 'mml2015-use) (equal mml2015-use 'pgg))
     :help "Display the PGG manual"]
    ["EasyPG manual" (lambda () (interactive) (require 'mml2015) (message-info mml2015-use))
     :visible (and (boundp 'mml2015-use) (equal mml2015-use 'epg))
     :help "Display the EasyPG manual"]))

(define-minor-mode mml-mode
  "Minor mode for editing MML.
MML is the MIME Meta Language, a minor mode for composing MIME articles.
See Info node `(emacs-mime)Composing'.

\\{mml-mode-map}"
  :lighter " MML" :keymap mml-mode-map
  (when mml-mode
    (when (boundp 'dnd-protocol-alist)
      (setq-local dnd-protocol-alist
                  (append mml-dnd-protocol-alist dnd-protocol-alist)))))

;;;
;;; Helper functions for reading MIME stuff from the minibuffer and
;;; inserting stuff to the buffer.
;;;

(defcustom mml-default-directory mm-default-directory
  "The default directory where mml will find files.
If not set, `default-directory' will be used."
  :type '(choice directory (const :tag "Default" nil))
  :version "23.1" ;; No Gnus
  :group 'message)

(defun mml-minibuffer-read-file (prompt)
  (let* ((completion-ignored-extensions nil)
	 (buffer-file-name nil)
	 (file (read-file-name prompt
			       (or mml-default-directory default-directory)
			       nil t)))
    ;; Prevent some common errors.  This is inspired by similar code in
    ;; VM.
    (when (file-directory-p file)
      (error "%s is a directory, cannot attach" file))
    (unless (file-exists-p file)
      (error "No such file: %s" file))
    (unless (file-readable-p file)
      (error "Permission denied: %s" file))
    file))

(declare-function mailcap-parse-mimetypes "mailcap" (&optional path force))
(declare-function mailcap-mime-types "mailcap" ())

(defun mml-minibuffer-read-type (name &optional default)
  (require 'mailcap)
  (mailcap-parse-mimetypes)
  (let* ((default (or default
		      (mm-default-file-encoding name)
		      ;; Perhaps here we should check what the file
		      ;; looks like, and offer text/plain if it looks
		      ;; like text/plain.
		      "application/octet-stream"))
	 (string (gnus-completing-read
		  "Content type"
		  (mailcap-mime-types)
                  nil nil nil default)))
    (if (not (equal string ""))
	string
      default)))

(defun mml-minibuffer-read-description (&optional default)
  (let ((description (read-string "One line description: " default)))
    (when (string-match "\\`[ \t]*\\'" description)
      (setq description nil))
    description))

(defun mml-minibuffer-read-disposition (type &optional default filename)
  (unless default
    (setq default (mml-content-disposition type filename)))
  (let ((disposition (gnus-completing-read
		      "Disposition"
		      '("attachment" "inline")
		      t nil nil default)))
    (if (not (equal disposition ""))
	disposition
      default)))

(defun mml-quote-region (beg end)
  "Quote the MML tags in the region."
  (interactive "r")
  (save-excursion
    (save-restriction
      ;; Temporarily narrow the region to defend from changes
      ;; invalidating END.
      (narrow-to-region beg end)
      (goto-char (point-min))
      ;; Quote parts.
      (while (re-search-forward
	      "<#!*/?\\(multipart\\|part\\|external\\|mml\\|secure\\)" nil t)
	;; Insert ! after the #.
	(goto-char (+ (match-beginning 0) 2))
	(insert "!")))))

(defun mml-insert-tag (name &rest plist)
  "Insert an MML tag described by NAME and PLIST."
  (when (symbolp name)
    (setq name (symbol-name name)))
  (insert "<#" name)
  (while plist
    (let ((key (pop plist))
	  (value (pop plist)))
      (when value
	;; Quote VALUE if it contains suspicious characters.
	(when (string-match "[][\"'\\~/*;()<>= \t\n[:multibyte:]]" value)
	  (setq value (with-output-to-string
			(let (print-escape-nonascii)
			  (prin1 value)))))
	(insert (format " %s=%s" key value)))))
  (insert ">\n"))

(defun mml-insert-empty-tag (name &rest plist)
  "Insert an empty MML tag described by NAME and PLIST."
  (when (symbolp name)
    (setq name (symbol-name name)))
  (apply #'mml-insert-tag name plist)
  (insert "<#/" name ">\n"))

;;; Attachment functions.

(defcustom mml-dnd-protocol-alist
  '(("^file:///" . mml-dnd-attach-file)
    ("^file://"  . dnd-open-file)
    ("^file:"    . mml-dnd-attach-file))
  "The functions to call when a drop in `mml-mode' is made.
See `dnd-protocol-alist' for more information.  When nil, behave
as in other buffers."
  :type '(choice (repeat (cons (regexp) (function)))
		 (const :tag "Behave as in other buffers" nil))
  :version "22.1" ;; Gnus 5.10.9
  :group 'message)

(defcustom mml-dnd-attach-options nil
  "Which options should be queried when attaching a file via drag and drop.

If it is a list, valid members are `type', `description' and
`disposition'.  `disposition' implies `type'.  If it is nil,
don't ask for options.  If it is t, ask the user whether or not
to specify options."
  :type '(choice
	  (const :tag "None" nil)
	  (const :tag "Query" t)
	  (list :value (type description disposition)
	   (set :inline t
		(const type)
		(const description)
		(const disposition))))
  :version "22.1" ;; Gnus 5.10.9
  :group 'message)

;;;###autoload
(defun mml-attach-file (file &optional type description disposition)
  "Attach a file to the outgoing MIME message.
The file is not inserted or encoded until you send the message with
`\\[message-send-and-exit]' or `\\[message-send]' in Message mode,
or `\\[mail-send-and-exit]' or `\\[mail-send]' in Mail mode.

FILE is the name of the file to attach.  TYPE is its
content-type, a string of the form \"type/subtype\".  DESCRIPTION
is a one-line description of the attachment.  The DISPOSITION
specifies how the attachment is intended to be displayed.  It can
be either \"inline\" (displayed automatically within the message
body) or \"attachment\" (separate from the body).

If given a prefix interactively, no prompting will be done for
the TYPE, DESCRIPTION or DISPOSITION values.  Instead defaults
will be computed and used."
  (interactive
   (let* ((file (mml-minibuffer-read-file "Attach file: "))
	  (type (if current-prefix-arg
		    (or (mm-default-file-encoding file)
			"application/octet-stream")
		  (mml-minibuffer-read-type file)))
	  (description (if current-prefix-arg
			   nil
			 (mml-minibuffer-read-description)))
	  (disposition (if current-prefix-arg
			   (mml-content-disposition type file)
			 (mml-minibuffer-read-disposition type nil file))))
     (list file type description disposition)))
  ;; If in the message header, attach at the end and leave point unchanged.
  (let ((head (unless (message-in-body-p) (point))))
    (if head (goto-char (point-max)))
    (mml-insert-empty-tag 'part
			  'type type
			  ;; icicles redefines read-file-name and returns a
			  ;; string w/ text properties :-/
			  'filename (substring-no-properties file)
			  'disposition (or disposition "attachment")
			  'description description)
    ;; When using Mail mode, make sure it does the mime encoding
    ;; when you send the message.
    (or (eq mail-user-agent 'message-user-agent)
	(setq mail-encode-mml t))
    (when head
      (unless (pos-visible-in-window-p)
	(message "The file \"%s\" has been attached at the end of the message"
		 (file-name-nondirectory file)))
      (goto-char head))))

(defun mml-dnd-attach-file (uri action)
  "Attach a drag and drop file.

Ask for type, description or disposition according to
`mml-dnd-attach-options'."
  (let ((file (dnd-get-local-file-name uri t)))
    (when (and file (file-regular-p file))
      (let ((mml-dnd-attach-options mml-dnd-attach-options)
	    type description disposition)
	(setq mml-dnd-attach-options
	      (when (and (eq mml-dnd-attach-options t)
			 (not
			  (y-or-n-p
			   "Use default type, disposition and description? ")))
		'(type description disposition)))
	(when (or (memq 'type mml-dnd-attach-options)
		  (memq 'disposition mml-dnd-attach-options))
	  (setq type (mml-minibuffer-read-type file)))
	(when (memq 'description mml-dnd-attach-options)
	  (setq description (mml-minibuffer-read-description)))
	(when (memq 'disposition mml-dnd-attach-options)
	  (setq disposition (mml-minibuffer-read-disposition type nil file)))
	(mml-attach-file file type description disposition)))))

(defun mml-attach-buffer (buffer &optional type description disposition)
  "Attach a buffer to the outgoing MIME message.
BUFFER is the name of the buffer to attach.  See
`mml-attach-file' for details of operation."
  (interactive
   (let* ((buffer (read-buffer "Attach buffer: "))
	  (type (mml-minibuffer-read-type buffer "text/plain"))
	  (description (mml-minibuffer-read-description))
	  (disposition (mml-minibuffer-read-disposition type nil)))
     (list buffer type description disposition)))
  ;; If in the message header, attach at the end and leave point unchanged.
  (let ((head (unless (message-in-body-p) (point))))
    (if head (goto-char (point-max)))
    (mml-insert-empty-tag 'part 'type type 'buffer buffer
			  'disposition disposition
			  'description description)
    ;; When using Mail mode, make sure it does the mime encoding
    ;; when you send the message.
    (or (eq mail-user-agent 'message-user-agent)
	(setq mail-encode-mml t))
    (when head
      (unless (pos-visible-in-window-p)
	(message
	 "The buffer \"%s\" has been attached at the end of the message"
	 buffer))
      (goto-char head))))

(defun mml-attach-external (file &optional type description)
  "Attach an external file into the buffer.
FILE is an ange-ftp/efs specification of the part location.
TYPE is the MIME type to use."
  (interactive
   (let* ((file (mml-minibuffer-read-file "Attach external file: "))
	  (type (mml-minibuffer-read-type file))
	  (description (mml-minibuffer-read-description)))
     (list file type description)))
  ;; If in the message header, attach at the end and leave point unchanged.
  (let ((head (unless (message-in-body-p) (point))))
    (if head (goto-char (point-max)))
    (mml-insert-empty-tag 'external 'type type 'name file
			  'disposition "attachment" 'description description)
    ;; When using Mail mode, make sure it does the mime encoding
    ;; when you send the message.
    (or (eq mail-user-agent 'message-user-agent)
	(setq mail-encode-mml t))
    (when head
      (unless (pos-visible-in-window-p)
	(message "The file \"%s\" has been attached at the end of the message"
		 (file-name-nondirectory file)))
      (goto-char head))))

(defun mml-insert-multipart (&optional type)
  (interactive (if (message-in-body-p)
		   (list (gnus-completing-read "Multipart type"
                                               '("mixed" "alternative"
                                                 "digest" "parallel"
                                                 "signed" "encrypted")
                                               nil "mixed"))
		 (error "Use this command in the message body")))
  (or type
      (setq type "mixed"))
  (mml-insert-empty-tag "multipart" 'type type)
  ;; When using Mail mode, make sure it does the mime encoding
  ;; when you send the message.
  (or (eq mail-user-agent 'message-user-agent)
      (setq mail-encode-mml t))
  (forward-line -1))

(defun mml-insert-part (&optional type)
  (interactive (if (message-in-body-p)
		   (list (mml-minibuffer-read-type ""))
		 (error "Use this command in the message body")))
  ;; When using Mail mode, make sure it does the mime encoding
  ;; when you send the message.
  (or (eq mail-user-agent 'message-user-agent)
      (setq mail-encode-mml t))
  (mml-insert-tag 'part 'type type 'disposition "inline")
  (save-excursion
    (mml-insert-tag '/part)))

(declare-function message-subscribed-p "message" ())
(declare-function message-make-mail-followup-to "message"
                  (&optional only-show-subscribed))
(declare-function message-position-on-field "message" (header &rest afters))

(defun mml-preview-insert-mail-followup-to ()
  "Insert a Mail-Followup-To header before previewing an article.
Should be adopted if code in `message-send-mail' is changed."
  (when (and (message-mail-p)
	     (message-subscribed-p)
	     (not (mail-fetch-field "mail-followup-to"))
	     (message-make-mail-followup-to))
    (message-position-on-field "Mail-Followup-To" "X-Draft-From")
    (insert (message-make-mail-followup-to))))

(defvar mml-preview-buffer nil)

(autoload 'widget-button-press "wid-edit" nil t)
(declare-function widget-event-point "wid-edit" (event))
;; If gnus-buffer-configuration is bound this is loaded.
(declare-function gnus-configure-windows "gnus-win" (setting &optional force))
;; Called after message-mail-p, which autoloads message.
(declare-function message-news-p                "message" ())
(declare-function message-options-set-recipient "message" ())
(declare-function message-generate-headers      "message" (headers))
(declare-function message-sort-headers          "message" ())

(defun mml-preview (&optional raw)
  "Display current buffer with Gnus, in a new buffer.
If RAW, display a raw encoded MIME message.

The window layout for the preview buffer is controlled by the variables
`special-display-buffer-names', `special-display-regexps', or
`gnus-buffer-configuration' (the first match made will be used),
or the `pop-to-buffer' function."
  (interactive "P")
  (setq mml-preview-buffer (generate-new-buffer
			    (concat (if raw "*Raw MIME preview of "
				      "*MIME preview of ") (buffer-name))))
  (require 'gnus-msg)		      ; for gnus-setup-posting-charset
  (save-excursion
    (let* ((buf (current-buffer))
	   (article-editing (eq major-mode 'gnus-article-edit-mode))
	   (message-options message-options)
	   (message-this-is-mail (message-mail-p))
	   (message-this-is-news (message-news-p))
	   (message-posting-charset (or (gnus-setup-posting-charset
					 (save-restriction
					   (message-narrow-to-headers-or-head)
					   (message-fetch-field "Newsgroups")))
					message-posting-charset)))
      (message-options-set-recipient)
      (when (boundp 'gnus-buffers)
	(push mml-preview-buffer gnus-buffers))
      (save-restriction
	(widen)
	(set-buffer mml-preview-buffer)
	(erase-buffer)
	(insert-buffer-substring buf))
      (mml-preview-insert-mail-followup-to)
      (let ((message-deletable-headers (if (message-news-p)
					   nil
					 message-deletable-headers))
	    (mail-header-separator (if article-editing
				       ""
				     mail-header-separator)))
	(message-generate-headers
	 (copy-sequence (if (message-news-p)
			    message-required-news-headers
			  message-required-mail-headers)))
	(unless article-editing
	  (if (re-search-forward
	       (concat "^" (regexp-quote mail-header-separator) "\n") nil t)
	      (replace-match "\n"))
	  (setq mail-header-separator ""))
	(message-sort-headers)
	(mml-to-mime))
      (if raw
	  (let ((s (buffer-string)))
	    ;; Insert the content into unibyte buffer.
	    (erase-buffer)
	    (mm-disable-multibyte)
	    (insert s))
	(let ((gnus-newsgroup-charset (car message-posting-charset))
	      gnus-article-prepare-hook gnus-original-article-buffer
	      gnus-displaying-mime)
	  (run-hooks 'gnus-article-decode-hook)
	  (let ((gnus-newsgroup-name "dummy")
		(gnus-newsrc-hashtb (or gnus-newsrc-hashtb
					(gnus-make-hashtable 5))))
	    (gnus-article-prepare-display))))
      ;; Disable article-mode-map.
      (use-local-map nil)
      (add-hook 'kill-buffer-hook
		(lambda ()
		  (mm-destroy-parts gnus-article-mime-handles)) nil t)
      (setq buffer-read-only t)
      (local-set-key "q" (lambda () (interactive) (kill-buffer nil)))
      (local-set-key "=" (lambda () (interactive) (delete-other-windows)))
      (local-set-key "\r"
		     (lambda ()
		       (interactive)
		       (widget-button-press (point))))
      (local-set-key [mouse-2]
		     (lambda (event)
		       (interactive "@e")
		       (widget-button-press (widget-event-point event) event)))
      ;; FIXME: Buffer is in article mode, but most tool bar commands won't
      ;; work.  Maybe only keep the following icons: search, print, quit
      (goto-char (point-min))))
  (if (and (not (special-display-p (buffer-name mml-preview-buffer)))
	   (boundp 'gnus-buffer-configuration)
	   (assq 'mml-preview gnus-buffer-configuration))
      (let ((gnus-message-buffer (current-buffer)))
	(gnus-configure-windows 'mml-preview))
    (pop-to-buffer mml-preview-buffer)))

(defun mml-validate ()
  "Validate the current MML document."
  (interactive)
  (mml-parse))

(defun mml-tweak-part (cont)
  "Tweak a MML part."
  (let ((tweak (cdr (assq 'tweak cont)))
	func)
    (cond
     (tweak
      (setq func
	    (or (cdr (assoc tweak mml-tweak-function-alist))
		(intern tweak))))
     (mml-tweak-type-alist
      (let ((alist mml-tweak-type-alist)
	    (type (or (cdr (assq 'type cont)) "text/plain")))
	(while alist
	  (if (string-match (caar alist) type)
	      (setq func (cdar alist)
		    alist nil)
	    (setq alist (cdr alist)))))))
    (if func
	(funcall func cont)
      cont)
    (let ((alist mml-tweak-sexp-alist))
      (while alist
	(if (eval (caar alist))
	    (funcall (cdar alist) cont))
	(setq alist (cdr alist)))))
  cont)

(defun mml-tweak-externalize-attachments (cont)
  "Tweak attached files as external parts."
  (let (filename-cons)
    (when (and (eq (car cont) 'part)
	       (not (cdr (assq 'buffer cont)))
	       (and (setq filename-cons (assq 'filename cont))
		    (not (equal (cdr (assq 'nofile cont)) "yes"))))
      (setcar cont 'external)
      (setcar filename-cons 'name))))

(provide 'mml)

;;; mml.el ends here