summaryrefslogtreecommitdiffstats
path: root/parser/html/nsHtml5TreeOperation.cpp
blob: 0a9a574eba08f2dcbd317e2c6c73fff940f95dd8 (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
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et tw=78: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsHtml5TreeOperation.h"
#include "nsContentUtils.h"
#include "nsDocElementCreatedNotificationRunner.h"
#include "nsNodeUtils.h"
#include "nsAttrName.h"
#include "nsHtml5TreeBuilder.h"
#include "nsIDOMMutationEvent.h"
#include "mozAutoDocUpdate.h"
#include "nsBindingManager.h"
#include "nsXBLBinding.h"
#include "nsHtml5DocumentMode.h"
#include "nsHtml5HtmlAttributes.h"
#include "nsContentCreatorFunctions.h"
#include "nsIScriptElement.h"
#include "nsIDTD.h"
#include "nsISupportsImpl.h"
#include "nsIDOMHTMLFormElement.h"
#include "nsIFormControl.h"
#include "nsIStyleSheetLinkingElement.h"
#include "nsIDOMDocumentType.h"
#include "nsIObserverService.h"
#include "mozilla/Services.h"
#include "nsIMutationObserver.h"
#include "nsIFormProcessor.h"
#include "nsIServiceManager.h"
#include "nsEscape.h"
#include "mozilla/dom/Comment.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/HTMLImageElement.h"
#include "mozilla/dom/HTMLTemplateElement.h"
#include "nsHtml5SVGLoadDispatcher.h"
#include "nsIURI.h"
#include "nsIProtocolHandler.h"
#include "nsNetUtil.h"
#include "nsIHTMLDocument.h"
#include "mozilla/Likely.h"
#include "nsTextNode.h"

using namespace mozilla;

static NS_DEFINE_CID(kFormProcessorCID, NS_FORMPROCESSOR_CID);

/**
 * Helper class that opens a notification batch if the current doc
 * is different from the executor doc.
 */
class MOZ_STACK_CLASS nsHtml5OtherDocUpdate {
  public:
    nsHtml5OtherDocUpdate(nsIDocument* aCurrentDoc, nsIDocument* aExecutorDoc)
    {
      NS_PRECONDITION(aCurrentDoc, "Node has no doc?");
      NS_PRECONDITION(aExecutorDoc, "Executor has no doc?");
      if (MOZ_LIKELY(aCurrentDoc == aExecutorDoc)) {
        mDocument = nullptr;
      } else {
        mDocument = aCurrentDoc;
        aCurrentDoc->BeginUpdate(UPDATE_CONTENT_MODEL);        
      }
    }

    ~nsHtml5OtherDocUpdate()
    {
      if (MOZ_UNLIKELY(mDocument)) {
        mDocument->EndUpdate(UPDATE_CONTENT_MODEL);
      }
    }
  private:
    nsCOMPtr<nsIDocument> mDocument;
};

nsHtml5TreeOperation::nsHtml5TreeOperation()
 : mOpCode(eTreeOpUninitialized)
{
  MOZ_COUNT_CTOR(nsHtml5TreeOperation);
}

nsHtml5TreeOperation::~nsHtml5TreeOperation()
{
  MOZ_COUNT_DTOR(nsHtml5TreeOperation);
  NS_ASSERTION(mOpCode != eTreeOpUninitialized, "Uninitialized tree op.");
  switch(mOpCode) {
    case eTreeOpAddAttributes:
      delete mTwo.attributes;
      break;
    case eTreeOpCreateHTMLElementNetwork:
    case eTreeOpCreateHTMLElementNotNetwork:
    case eTreeOpCreateSVGElementNetwork:
    case eTreeOpCreateSVGElementNotNetwork:
    case eTreeOpCreateMathMLElement:
      delete mThree.attributes;
      break;
    case eTreeOpAppendDoctypeToDocument:
      delete mTwo.stringPair;
      break;
    case eTreeOpFosterParentText:
    case eTreeOpAppendText:
    case eTreeOpAppendComment:
    case eTreeOpAppendCommentToDocument:
    case eTreeOpAddViewSourceHref:
    case eTreeOpAddViewSourceBase:
      delete[] mTwo.unicharPtr;
      break;
    case eTreeOpSetDocumentCharset:
    case eTreeOpNeedsCharsetSwitchTo:
      delete[] mOne.charPtr;
      break;
    case eTreeOpProcessOfflineManifest:
      free(mOne.unicharPtr);
      break;
    default: // keep the compiler happy
      break;
  }
}

nsresult
nsHtml5TreeOperation::AppendTextToTextNode(const char16_t* aBuffer,
                                           uint32_t aLength,
                                           nsIContent* aTextNode,
                                           nsHtml5DocumentBuilder* aBuilder)
{
  NS_PRECONDITION(aTextNode, "Got null text node.");
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  uint32_t oldLength = aTextNode->TextLength();
  CharacterDataChangeInfo info = {
    true,
    oldLength,
    oldLength,
    aLength
  };
  nsNodeUtils::CharacterDataWillChange(aTextNode, &info);

  nsresult rv = aTextNode->AppendText(aBuffer, aLength, false);
  NS_ENSURE_SUCCESS(rv, rv);

  nsNodeUtils::CharacterDataChanged(aTextNode, &info);
  return rv;
}


nsresult
nsHtml5TreeOperation::AppendText(const char16_t* aBuffer,
                                 uint32_t aLength,
                                 nsIContent* aParent,
                                 nsHtml5DocumentBuilder* aBuilder)
{
  nsresult rv = NS_OK;
  nsIContent* lastChild = aParent->GetLastChild();
  if (lastChild && lastChild->IsNodeOfType(nsINode::eTEXT)) {
    nsHtml5OtherDocUpdate update(aParent->OwnerDoc(),
                                 aBuilder->GetDocument());
    return AppendTextToTextNode(aBuffer, 
                                aLength, 
                                lastChild, 
                                aBuilder);
  }

  nsNodeInfoManager* nodeInfoManager = aParent->OwnerDoc()->NodeInfoManager();
  RefPtr<nsTextNode> text = new nsTextNode(nodeInfoManager);
  NS_ASSERTION(text, "Infallible malloc failed?");
  rv = text->SetText(aBuffer, aLength, false);
  NS_ENSURE_SUCCESS(rv, rv);

  return Append(text, aParent, aBuilder);
}

nsresult
nsHtml5TreeOperation::Append(nsIContent* aNode,
                             nsIContent* aParent,
                             nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsresult rv = NS_OK;
  nsHtml5OtherDocUpdate update(aParent->OwnerDoc(),
                               aBuilder->GetDocument());
  uint32_t childCount = aParent->GetChildCount();
  rv = aParent->AppendChildTo(aNode, false);
  if (NS_SUCCEEDED(rv)) {
    aNode->SetParserHasNotified();
    nsNodeUtils::ContentAppended(aParent, aNode, childCount);
  }
  return rv;
}

nsresult
nsHtml5TreeOperation::AppendToDocument(nsIContent* aNode,
                                       nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->GetDocument() == aNode->OwnerDoc());
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsresult rv = NS_OK;

  nsIDocument* doc = aBuilder->GetDocument();
  uint32_t childCount = doc->GetChildCount();
  rv = doc->AppendChildTo(aNode, false);
  if (rv == NS_ERROR_DOM_HIERARCHY_REQUEST_ERR) {
    aNode->SetParserHasNotified();
    return NS_OK;
  }
  NS_ENSURE_SUCCESS(rv, rv);
  aNode->SetParserHasNotified();
  nsNodeUtils::ContentInserted(doc, aNode, childCount);

  NS_ASSERTION(!nsContentUtils::IsSafeToRunScript(),
               "Someone forgot to block scripts");
  if (aNode->IsElement()) {
    nsContentUtils::AddScriptRunner(
        new nsDocElementCreatedNotificationRunner(doc));
  }
  return rv;
}

static bool
IsElementOrTemplateContent(nsINode* aNode) {
  if (aNode) {
    if (aNode->IsElement()) {
      return true;
    } else if (aNode->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
      // Check if the node is a template content.
      mozilla::dom::DocumentFragment* frag =
        static_cast<mozilla::dom::DocumentFragment*>(aNode);
      nsIContent* fragHost = frag->GetHost();
      if (fragHost && nsNodeUtils::IsTemplateElement(fragHost)) {
        return true;
      }
    }
  }
  return false;
}

void
nsHtml5TreeOperation::Detach(nsIContent* aNode, nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsCOMPtr<nsINode> parent = aNode->GetParentNode();
  if (parent) {
    nsHtml5OtherDocUpdate update(parent->OwnerDoc(),
        aBuilder->GetDocument());
    int32_t pos = parent->IndexOf(aNode);
    NS_ASSERTION((pos >= 0), "Element not found as child of its parent");
    parent->RemoveChildAt(pos, true);
  }
}

nsresult
nsHtml5TreeOperation::AppendChildrenToNewParent(nsIContent* aNode,
                                                nsIContent* aParent,
                                                nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsHtml5OtherDocUpdate update(aParent->OwnerDoc(),
                               aBuilder->GetDocument());

  uint32_t childCount = aParent->GetChildCount();
  bool didAppend = false;
  while (aNode->HasChildren()) {
    nsCOMPtr<nsIContent> child = aNode->GetFirstChild();
    aNode->RemoveChildAt(0, true);
    nsresult rv = aParent->AppendChildTo(child, false);
    NS_ENSURE_SUCCESS(rv, rv);
    didAppend = true;
  }
  if (didAppend) {
    nsNodeUtils::ContentAppended(aParent, aParent->GetChildAt(childCount),
                                 childCount);
  }
  return NS_OK;
}

nsresult
nsHtml5TreeOperation::FosterParent(nsIContent* aNode,
                                   nsIContent* aParent,
                                   nsIContent* aTable,
                                   nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsIContent* foster = aTable->GetParent();

  if (IsElementOrTemplateContent(foster)) {

    nsHtml5OtherDocUpdate update(foster->OwnerDoc(),
                                 aBuilder->GetDocument());

    uint32_t pos = foster->IndexOf(aTable);
    nsresult rv = foster->InsertChildAt(aNode, pos, false);
    NS_ENSURE_SUCCESS(rv, rv);
    nsNodeUtils::ContentInserted(foster, aNode, pos);
    return rv;
  }

  return Append(aNode, aParent, aBuilder);
}

nsresult
nsHtml5TreeOperation::AddAttributes(nsIContent* aNode,
                                    nsHtml5HtmlAttributes* aAttributes,
                                    nsHtml5DocumentBuilder* aBuilder)
{
  dom::Element* node = aNode->AsElement();
  nsHtml5OtherDocUpdate update(node->OwnerDoc(),
                               aBuilder->GetDocument());

  int32_t len = aAttributes->getLength();
  for (int32_t i = len; i > 0;) {
    --i;
    // prefix doesn't need regetting. it is always null or a static atom
    // local name is never null
    nsCOMPtr<nsIAtom> localName =
      Reget(aAttributes->getLocalNameNoBoundsCheck(i));
    int32_t nsuri = aAttributes->getURINoBoundsCheck(i);
    if (!node->HasAttr(nsuri, localName)) {
      // prefix doesn't need regetting. it is always null or a static atom
      // local name is never null
      nsString value; // Not Auto, because using it to hold nsStringBuffer*
      aAttributes->getValueNoBoundsCheck(i).ToString(value);
      node->SetAttr(
        nsuri, localName, aAttributes->getPrefixNoBoundsCheck(i), value, true);
      // XXX what to do with nsresult?
    }
  }
  return NS_OK;
}


nsIContent*
nsHtml5TreeOperation::CreateHTMLElement(
  nsIAtom* aName,
  nsHtml5HtmlAttributes* aAttributes,
  mozilla::dom::FromParser aFromParser,
  nsNodeInfoManager* aNodeInfoManager,
  nsHtml5DocumentBuilder* aBuilder,
  mozilla::dom::HTMLContentCreatorFunction aCreator)
{
  bool isKeygen = (aName == nsHtml5Atoms::keygen);
  if (MOZ_UNLIKELY(isKeygen)) {
    aName = nsHtml5Atoms::select;
    aCreator = NS_NewHTMLSelectElement;
  }

  RefPtr<dom::NodeInfo> nodeInfo = aNodeInfoManager->GetNodeInfo(
    aName, nullptr, kNameSpaceID_XHTML, nsIDOMNode::ELEMENT_NODE);
  NS_ASSERTION(nodeInfo, "Got null nodeinfo.");
  nsCOMPtr<dom::Element> newElement = aCreator(nodeInfo.forget(), aFromParser);

  MOZ_ASSERT(newElement, "Element creation created null pointer.");

  dom::Element* newContent = newElement;
  aBuilder->HoldElement(newElement.forget());

  if (aCreator == NS_NewCustomElement) {
    // Not inlining the call below into NS_NewCustomElement itself, because
    // in the near future, the code here will need to break out of an update
    // batch here.
    nsContentUtils::SetupCustomElement(newContent);
  }

  if (MOZ_UNLIKELY(aName == nsHtml5Atoms::style || aName == nsHtml5Atoms::link)) {
    nsCOMPtr<nsIStyleSheetLinkingElement> ssle(do_QueryInterface(newContent));
    if (ssle) {
      ssle->InitStyleLinkElement(false);
      ssle->SetEnableUpdates(false);
    }
  } else if (MOZ_UNLIKELY(isKeygen)) {
    // Adapted from CNavDTD
    nsresult rv;
    nsCOMPtr<nsIFormProcessor> theFormProcessor =
      do_GetService(kFormProcessorCID, &rv);
    if (NS_FAILED(rv)) {
      return newContent;
    }

    nsTArray<nsString> theContent;
    nsAutoString theAttribute;

    (void) theFormProcessor->ProvideContent(NS_LITERAL_STRING("select"),
                                            theContent,
                                            theAttribute);

    newContent->SetAttr(kNameSpaceID_None,
                        nsGkAtoms::moztype,
                        nullptr,
                        theAttribute,
                        false);

    RefPtr<dom::NodeInfo> optionNodeInfo =
      aNodeInfoManager->GetNodeInfo(nsHtml5Atoms::option,
                                    nullptr,
                                    kNameSpaceID_XHTML,
                                    nsIDOMNode::ELEMENT_NODE);

    for (uint32_t i = 0; i < theContent.Length(); ++i) {
      RefPtr<dom::NodeInfo> ni = optionNodeInfo;
      nsCOMPtr<dom::Element> optionElt =
        NS_NewHTMLOptionElement(ni.forget(), aFromParser);
      RefPtr<nsTextNode> optionText = new nsTextNode(aNodeInfoManager);
      (void) optionText->SetText(theContent[i], false);
      optionElt->AppendChildTo(optionText, false);
      newContent->AppendChildTo(optionElt, false);
    }
    newContent->DoneAddingChildren(false);
  }

  if (!aAttributes) {
    return newContent;
  }

  int32_t len = aAttributes->getLength();
  for (int32_t i = 0; i < len; i++) {
    // prefix doesn't need regetting. it is always null or a static atom
    // local name is never null
    nsCOMPtr<nsIAtom> localName =
      Reget(aAttributes->getLocalNameNoBoundsCheck(i));
    nsCOMPtr<nsIAtom> prefix = aAttributes->getPrefixNoBoundsCheck(i);
    int32_t nsuri = aAttributes->getURINoBoundsCheck(i);

    nsString value; // Not Auto, because using it to hold nsStringBuffer*
    aAttributes->getValueNoBoundsCheck(i).ToString(value);
    if (nsHtml5Atoms::a == aName && nsHtml5Atoms::name == localName) {
      // This is an HTML5-incompliant Geckoism.
      // Remove when fixing bug 582361
      NS_ConvertUTF16toUTF8 cname(value);
      NS_ConvertUTF8toUTF16 uv(nsUnescape(cname.BeginWriting()));
      newContent->SetAttr(nsuri,
                          localName,
                          prefix,
                          uv,
                          false);
    } else {
      newContent->SetAttr(nsuri,
                          localName,
                          prefix,
                          value,
                          false);

      // Custom element setup may be needed if there is an "is" attribute.
        if (nsContentUtils::IsWebComponentsEnabled() &&
            kNameSpaceID_None == nsuri &&
            !prefix && nsGkAtoms::is == localName) {
        nsContentUtils::SetupCustomElement(newContent, &value);
      }
    }
  }
  return newContent;
}

nsIContent*
nsHtml5TreeOperation::CreateSVGElement(
  nsIAtom* aName,
  nsHtml5HtmlAttributes* aAttributes,
  mozilla::dom::FromParser aFromParser,
  nsNodeInfoManager* aNodeInfoManager,
  nsHtml5DocumentBuilder* aBuilder,
  mozilla::dom::SVGContentCreatorFunction aCreator)
{
  nsCOMPtr<nsIContent> newElement;
  if (MOZ_LIKELY(aNodeInfoManager->SVGEnabled())) {
    RefPtr<dom::NodeInfo> nodeInfo = aNodeInfoManager->GetNodeInfo(
      aName, nullptr, kNameSpaceID_SVG, nsIDOMNode::ELEMENT_NODE);
    MOZ_ASSERT(nodeInfo, "Got null nodeinfo.");

    mozilla::DebugOnly<nsresult> rv =
      aCreator(getter_AddRefs(newElement), nodeInfo.forget(), aFromParser);
    MOZ_ASSERT(NS_SUCCEEDED(rv) && newElement);
  } else {
    RefPtr<dom::NodeInfo> nodeInfo = aNodeInfoManager->GetNodeInfo(
      aName, nullptr, kNameSpaceID_disabled_SVG, nsIDOMNode::ELEMENT_NODE);
    MOZ_ASSERT(nodeInfo, "Got null nodeinfo.");

    // The mismatch between NS_NewXMLElement and SVGContentCreatorFunction
    // argument types is annoying.
    nsCOMPtr<dom::Element> xmlElement;
    mozilla::DebugOnly<nsresult> rv =
      NS_NewXMLElement(getter_AddRefs(xmlElement), nodeInfo.forget());
    MOZ_ASSERT(NS_SUCCEEDED(rv) && xmlElement);
    newElement = xmlElement;
  }

  dom::Element* newContent = newElement->AsElement();
  aBuilder->HoldElement(newElement.forget());

  if (MOZ_UNLIKELY(aName == nsHtml5Atoms::style)) {
    nsCOMPtr<nsIStyleSheetLinkingElement> ssle(do_QueryInterface(newContent));
    if (ssle) {
      ssle->InitStyleLinkElement(false);
      ssle->SetEnableUpdates(false);
    }
  }

  if (!aAttributes) {
    return newContent;
  }

  int32_t len = aAttributes->getLength();
  for (int32_t i = 0; i < len; i++) {
    // prefix doesn't need regetting. it is always null or a static atom
    // local name is never null
    nsCOMPtr<nsIAtom> localName =
      Reget(aAttributes->getLocalNameNoBoundsCheck(i));
    nsCOMPtr<nsIAtom> prefix = aAttributes->getPrefixNoBoundsCheck(i);
    int32_t nsuri = aAttributes->getURINoBoundsCheck(i);

    nsString value; // Not Auto, because using it to hold nsStringBuffer*
    aAttributes->getValueNoBoundsCheck(i).ToString(value);
    newContent->SetAttr(nsuri, localName, prefix, value, false);
  }
  return newContent;
}

nsIContent*
nsHtml5TreeOperation::CreateMathMLElement(nsIAtom* aName,
                                          nsHtml5HtmlAttributes* aAttributes,
                                          nsNodeInfoManager* aNodeInfoManager,
                                          nsHtml5DocumentBuilder* aBuilder)
{
  nsCOMPtr<dom::Element> newElement;
  if (MOZ_LIKELY(aNodeInfoManager->MathMLEnabled())) {
    RefPtr<dom::NodeInfo> nodeInfo = aNodeInfoManager->GetNodeInfo(
      aName, nullptr, kNameSpaceID_MathML, nsIDOMNode::ELEMENT_NODE);
    NS_ASSERTION(nodeInfo, "Got null nodeinfo.");

    mozilla::DebugOnly<nsresult> rv =
      NS_NewMathMLElement(getter_AddRefs(newElement), nodeInfo.forget());
    MOZ_ASSERT(NS_SUCCEEDED(rv) && newElement);
  } else {
    RefPtr<dom::NodeInfo> nodeInfo = aNodeInfoManager->GetNodeInfo(
      aName, nullptr, kNameSpaceID_disabled_MathML, nsIDOMNode::ELEMENT_NODE);
    NS_ASSERTION(nodeInfo, "Got null nodeinfo.");

    mozilla::DebugOnly<nsresult> rv =
      NS_NewXMLElement(getter_AddRefs(newElement), nodeInfo.forget());
    MOZ_ASSERT(NS_SUCCEEDED(rv) && newElement);
  }

  dom::Element* newContent = newElement;
  aBuilder->HoldElement(newElement.forget());

  if (!aAttributes) {
    return newContent;
  }

  int32_t len = aAttributes->getLength();
  for (int32_t i = 0; i < len; i++) {
    // prefix doesn't need regetting. it is always null or a static atom
    // local name is never null
    nsCOMPtr<nsIAtom> localName =
      Reget(aAttributes->getLocalNameNoBoundsCheck(i));
    nsCOMPtr<nsIAtom> prefix = aAttributes->getPrefixNoBoundsCheck(i);
    int32_t nsuri = aAttributes->getURINoBoundsCheck(i);

    nsString value; // Not Auto, because using it to hold nsStringBuffer*
    aAttributes->getValueNoBoundsCheck(i).ToString(value);
    newContent->SetAttr(nsuri, localName, prefix, value, false);
  }
  return newContent;
}

void
nsHtml5TreeOperation::SetFormElement(nsIContent* aNode, nsIContent* aParent)
{
  nsCOMPtr<nsIFormControl> formControl(do_QueryInterface(aNode));
  nsCOMPtr<nsIDOMHTMLImageElement> domImageElement = do_QueryInterface(aNode);
  // NS_ASSERTION(formControl, "Form-associated element did not implement nsIFormControl.");
  // TODO: uncomment the above line when <keygen> (bug 101019) is supported by Gecko
  nsCOMPtr<nsIDOMHTMLFormElement> formElement(do_QueryInterface(aParent));
  NS_ASSERTION(formElement, "The form element doesn't implement nsIDOMHTMLFormElement.");
  // avoid crashing on <keygen>
  if (formControl &&
      !aNode->HasAttr(kNameSpaceID_None, nsGkAtoms::form)) {
    formControl->SetForm(formElement);
  } else if (domImageElement) {
    RefPtr<dom::HTMLImageElement> imageElement =
      static_cast<dom::HTMLImageElement*>(domImageElement.get());
    MOZ_ASSERT(imageElement);
    imageElement->SetForm(formElement);
  }
}

nsresult
nsHtml5TreeOperation::AppendIsindexPrompt(nsIContent* parent, nsHtml5DocumentBuilder* aBuilder)
{
  nsXPIDLString prompt;
  nsresult rv =
      nsContentUtils::GetLocalizedString(nsContentUtils::eFORMS_PROPERTIES,
                                         "IsIndexPromptWithSpace", prompt);
  uint32_t len = prompt.Length();
  if (NS_FAILED(rv)) {
    return rv;
  }
  if (!len) {
    // Don't bother appending a zero-length text node.
    return NS_OK;
  }
  return AppendText(prompt.BeginReading(), len, parent, aBuilder);
}

nsresult
nsHtml5TreeOperation::FosterParentText(nsIContent* aStackParent,
                                       char16_t* aBuffer,
                                       uint32_t aLength,
                                       nsIContent* aTable,
                                       nsHtml5DocumentBuilder* aBuilder)
{
  MOZ_ASSERT(aBuilder);
  MOZ_ASSERT(aBuilder->IsInDocUpdate());
  nsresult rv = NS_OK;
  nsIContent* foster = aTable->GetParent();

  if (IsElementOrTemplateContent(foster)) {
    nsHtml5OtherDocUpdate update(foster->OwnerDoc(),
                                 aBuilder->GetDocument());

    uint32_t pos = foster->IndexOf(aTable);

    nsIContent* previousSibling = aTable->GetPreviousSibling();
    if (previousSibling && previousSibling->IsNodeOfType(nsINode::eTEXT)) {
      return AppendTextToTextNode(aBuffer,
                                  aLength,
                                  previousSibling,
                                  aBuilder);
    }

    nsNodeInfoManager* nodeInfoManager = aStackParent->OwnerDoc()->NodeInfoManager();
    RefPtr<nsTextNode> text = new nsTextNode(nodeInfoManager);
    NS_ASSERTION(text, "Infallible malloc failed?");
    rv = text->SetText(aBuffer, aLength, false);
    NS_ENSURE_SUCCESS(rv, rv);

    rv = foster->InsertChildAt(text, pos, false);
    NS_ENSURE_SUCCESS(rv, rv);
    nsNodeUtils::ContentInserted(foster, text, pos);
    return rv;
  }

  return AppendText(aBuffer, aLength, aStackParent, aBuilder);
}

nsresult
nsHtml5TreeOperation::AppendComment(nsIContent* aParent,
                                    char16_t* aBuffer,
                                    int32_t aLength,
                                    nsHtml5DocumentBuilder* aBuilder)
{
  nsNodeInfoManager* nodeInfoManager = aParent->OwnerDoc()->NodeInfoManager();
  RefPtr<dom::Comment> comment = new dom::Comment(nodeInfoManager);
  NS_ASSERTION(comment, "Infallible malloc failed?");
  nsresult rv = comment->SetText(aBuffer, aLength, false);
  NS_ENSURE_SUCCESS(rv, rv);

  return Append(comment, aParent, aBuilder);
}

nsresult
nsHtml5TreeOperation::AppendCommentToDocument(char16_t* aBuffer,
                                              int32_t aLength,
                                              nsHtml5DocumentBuilder* aBuilder)
{
  RefPtr<dom::Comment> comment =
    new dom::Comment(aBuilder->GetNodeInfoManager());
  NS_ASSERTION(comment, "Infallible malloc failed?");
  nsresult rv = comment->SetText(aBuffer, aLength, false);
  NS_ENSURE_SUCCESS(rv, rv);

  return AppendToDocument(comment, aBuilder);
}

nsresult
nsHtml5TreeOperation::AppendDoctypeToDocument(nsIAtom* aName,
                                              const nsAString& aPublicId,
                                              const nsAString& aSystemId,
                                              nsHtml5DocumentBuilder* aBuilder)
{
  // Adapted from nsXMLContentSink
  // Create a new doctype node
  nsCOMPtr<nsIDOMDocumentType> docType;
  NS_NewDOMDocumentType(getter_AddRefs(docType),
                        aBuilder->GetNodeInfoManager(),
                        aName,
                        aPublicId,
                        aSystemId,
                        NullString());
  NS_ASSERTION(docType, "Doctype creation failed.");
  nsCOMPtr<nsIContent> asContent = do_QueryInterface(docType);
  return AppendToDocument(asContent, aBuilder);
}

nsIContent*
nsHtml5TreeOperation::GetDocumentFragmentForTemplate(nsIContent* aNode)
{
  dom::HTMLTemplateElement* tempElem =
    static_cast<dom::HTMLTemplateElement*>(aNode);
  RefPtr<dom::DocumentFragment> frag = tempElem->Content();
  return frag;
}

nsIContent*
nsHtml5TreeOperation::GetFosterParent(nsIContent* aTable, nsIContent* aStackParent)
{
  nsIContent* tableParent = aTable->GetParent();
  return IsElementOrTemplateContent(tableParent) ? tableParent : aStackParent;
}

void
nsHtml5TreeOperation::PreventScriptExecution(nsIContent* aNode)
{
  nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(aNode);
  MOZ_ASSERT(sele);
  sele->PreventExecution();
}

void
nsHtml5TreeOperation::DoneAddingChildren(nsIContent* aNode)
{
  aNode->DoneAddingChildren(aNode->HasParserNotified());
}

void
nsHtml5TreeOperation::DoneCreatingElement(nsIContent* aNode)
{
  aNode->DoneCreatingElement();
}

void
nsHtml5TreeOperation::SvgLoad(nsIContent* aNode)
{
  nsCOMPtr<nsIRunnable> event = new nsHtml5SVGLoadDispatcher(aNode);
  if (NS_FAILED(NS_DispatchToMainThread(event))) {
    NS_WARNING("failed to dispatch svg load dispatcher");
  }
}

void
nsHtml5TreeOperation::MarkMalformedIfScript(nsIContent* aNode)
{
  nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(aNode);
  if (sele) {
    // Make sure to serialize this script correctly, for nice round tripping.
    sele->SetIsMalformed();
  }
}

nsresult
nsHtml5TreeOperation::Perform(nsHtml5TreeOpExecutor* aBuilder,
                              nsIContent** aScriptElement)
{
  switch(mOpCode) {
    case eTreeOpUninitialized: {
      MOZ_CRASH("eTreeOpUninitialized");
    }
    case eTreeOpAppend: {
      nsIContent* node = *(mOne.node);
      nsIContent* parent = *(mTwo.node);
      return Append(node, parent, aBuilder);
    }
    case eTreeOpDetach: {
      nsIContent* node = *(mOne.node);
      Detach(node, aBuilder);
      return NS_OK;
    }
    case eTreeOpAppendChildrenToNewParent: {
      nsCOMPtr<nsIContent> node = *(mOne.node);
      nsIContent* parent = *(mTwo.node);
      return AppendChildrenToNewParent(node, parent, aBuilder);
    }
    case eTreeOpFosterParent: {
      nsIContent* node = *(mOne.node);
      nsIContent* parent = *(mTwo.node);
      nsIContent* table = *(mThree.node);
      return FosterParent(node, parent, table, aBuilder);
    }
    case eTreeOpAppendToDocument: {
      nsIContent* node = *(mOne.node);
      return AppendToDocument(node, aBuilder);
    }
    case eTreeOpAddAttributes: {
      nsIContent* node = *(mOne.node);
      nsHtml5HtmlAttributes* attributes = mTwo.attributes;
      return AddAttributes(node, attributes, aBuilder);
    }
    case eTreeOpDocumentMode: {
      aBuilder->SetDocumentMode(mOne.mode);
      return NS_OK;
    }
    case eTreeOpCreateHTMLElementNetwork:
    case eTreeOpCreateHTMLElementNotNetwork: {
      nsIContent** target = mOne.node;
      mozilla::dom::HTMLContentCreatorFunction creator = mFour.htmlCreator;
      nsCOMPtr<nsIAtom> name = Reget(mTwo.atom);
      nsHtml5HtmlAttributes* attributes = mThree.attributes;
      nsIContent* intendedParent = mFive.node ? *(mFive.node) : nullptr;

      // intendedParent == nullptr is a special case where the
      // intended parent is the document.
      nsNodeInfoManager* nodeInfoManager =
        intendedParent ? intendedParent->OwnerDoc()->NodeInfoManager()
                       : aBuilder->GetNodeInfoManager();

      *target = CreateHTMLElement(name,
                                  attributes,
                                  mOpCode == eTreeOpCreateHTMLElementNetwork
                                    ? dom::FROM_PARSER_NETWORK
                                    : dom::FROM_PARSER_DOCUMENT_WRITE,
                                  nodeInfoManager,
                                  aBuilder,
                                  creator);
      return NS_OK;
    }
    case eTreeOpCreateSVGElementNetwork:
    case eTreeOpCreateSVGElementNotNetwork: {
      nsIContent** target = mOne.node;
      mozilla::dom::SVGContentCreatorFunction creator = mFour.svgCreator;
      nsCOMPtr<nsIAtom> name = Reget(mTwo.atom);
      nsHtml5HtmlAttributes* attributes = mThree.attributes;
      nsIContent* intendedParent = mFive.node ? *(mFive.node) : nullptr;

      // intendedParent == nullptr is a special case where the
      // intended parent is the document.
      nsNodeInfoManager* nodeInfoManager =
        intendedParent ? intendedParent->OwnerDoc()->NodeInfoManager()
                       : aBuilder->GetNodeInfoManager();

      *target = CreateSVGElement(name,
                                 attributes,
                                 mOpCode == eTreeOpCreateSVGElementNetwork
                                   ? dom::FROM_PARSER_NETWORK
                                   : dom::FROM_PARSER_DOCUMENT_WRITE,
                                 nodeInfoManager,
                                 aBuilder,
                                 creator);
      return NS_OK;
    }
    case eTreeOpCreateMathMLElement: {
      nsIContent** target = mOne.node;
      nsCOMPtr<nsIAtom> name = Reget(mTwo.atom);
      nsHtml5HtmlAttributes* attributes = mThree.attributes;
      nsIContent* intendedParent = mFive.node ? *(mFive.node) : nullptr;

      // intendedParent == nullptr is a special case where the
      // intended parent is the document.
      nsNodeInfoManager* nodeInfoManager = intendedParent ?
         intendedParent->OwnerDoc()->NodeInfoManager() :
         aBuilder->GetNodeInfoManager();

      *target =
        CreateMathMLElement(name, attributes, nodeInfoManager, aBuilder);
      return NS_OK;
    }
    case eTreeOpSetFormElement: {
      nsIContent* node = *(mOne.node);
      nsIContent* parent = *(mTwo.node);
      SetFormElement(node, parent);
      return NS_OK;
    }
    case eTreeOpAppendText: {
      nsIContent* parent = *mOne.node;
      char16_t* buffer = mTwo.unicharPtr;
      uint32_t length = mFour.integer;
      return AppendText(buffer, length, parent, aBuilder);
    }
    case eTreeOpAppendIsindexPrompt: {
      nsIContent* parent = *mOne.node;
      return AppendIsindexPrompt(parent, aBuilder);
    }
    case eTreeOpFosterParentText: {
      nsIContent* stackParent = *mOne.node;
      char16_t* buffer = mTwo.unicharPtr;
      uint32_t length = mFour.integer;
      nsIContent* table = *mThree.node;
      return FosterParentText(stackParent, buffer, length, table, aBuilder);
    }
    case eTreeOpAppendComment: {
      nsIContent* parent = *mOne.node;
      char16_t* buffer = mTwo.unicharPtr;
      int32_t length = mFour.integer;
      return AppendComment(parent, buffer, length, aBuilder);
    }
    case eTreeOpAppendCommentToDocument: {
      char16_t* buffer = mTwo.unicharPtr;
      int32_t length = mFour.integer;
      return AppendCommentToDocument(buffer, length, aBuilder);
    }
    case eTreeOpAppendDoctypeToDocument: {
      nsCOMPtr<nsIAtom> name = Reget(mOne.atom);
      nsHtml5TreeOperationStringPair* pair = mTwo.stringPair;
      nsString publicId;
      nsString systemId;
      pair->Get(publicId, systemId);
      return AppendDoctypeToDocument(name, publicId, systemId, aBuilder);
    }
    case eTreeOpGetDocumentFragmentForTemplate: {
      nsIContent* node = *(mOne.node);
      *mTwo.node = GetDocumentFragmentForTemplate(node);
      return NS_OK;
    }
    case eTreeOpGetFosterParent: {
      nsIContent* table = *(mOne.node);
      nsIContent* stackParent = *(mTwo.node);
      nsIContent* fosterParent = GetFosterParent(table, stackParent);
      *mThree.node = fosterParent;
      return NS_OK;
    }
    case eTreeOpMarkAsBroken: {
      return mOne.result;
    }
    case eTreeOpRunScript: {
      nsIContent* node = *(mOne.node);
      nsAHtml5TreeBuilderState* snapshot = mTwo.state;
      if (snapshot) {
        aBuilder->InitializeDocWriteParserState(snapshot, mFour.integer);
      }
      *aScriptElement = node;
      return NS_OK;
    }
    case eTreeOpRunScriptAsyncDefer: {
      nsIContent* node = *(mOne.node);
      aBuilder->RunScript(node);
      return NS_OK;
    }
    case eTreeOpPreventScriptExecution: {
      nsIContent* node = *(mOne.node);
      PreventScriptExecution(node);
      return NS_OK;
    }
    case eTreeOpDoneAddingChildren: {
      nsIContent* node = *(mOne.node);
      node->DoneAddingChildren(node->HasParserNotified());
      return NS_OK;
    }
    case eTreeOpDoneCreatingElement: {
      nsIContent* node = *(mOne.node);
      DoneCreatingElement(node);
      return NS_OK;
    }
    case eTreeOpSetDocumentCharset: {
      char* str = mOne.charPtr;
      int32_t charsetSource = mFour.integer;
      nsDependentCString dependentString(str);
      aBuilder->SetDocumentCharsetAndSource(dependentString, charsetSource);
      return NS_OK;
    }
    case eTreeOpNeedsCharsetSwitchTo: {
      char* str = mOne.charPtr;
      int32_t charsetSource = mFour.integer;
      int32_t lineNumber = mTwo.integer;
      aBuilder->NeedsCharsetSwitchTo(str, charsetSource, (uint32_t)lineNumber);
      return NS_OK;
    }
    case eTreeOpUpdateStyleSheet: {
      nsIContent* node = *(mOne.node);
      aBuilder->UpdateStyleSheet(node);
      return NS_OK;
    }
    case eTreeOpProcessMeta: {
      nsIContent* node = *(mOne.node);
      return aBuilder->ProcessMETATag(node);
    }
    case eTreeOpProcessOfflineManifest: {
      char16_t* str = mOne.unicharPtr;
      nsDependentString dependentString(str);
      aBuilder->ProcessOfflineManifest(dependentString);
      return NS_OK;
    }
    case eTreeOpMarkMalformedIfScript: {
      nsIContent* node = *(mOne.node);
      MarkMalformedIfScript(node);
      return NS_OK;
    }
    case eTreeOpStreamEnded: {
      aBuilder->DidBuildModel(false); // this causes a notifications flush anyway
      return NS_OK;
    }
    case eTreeOpSetStyleLineNumber: {
      nsIContent* node = *(mOne.node);
      nsCOMPtr<nsIStyleSheetLinkingElement> ssle = do_QueryInterface(node);
      NS_ASSERTION(ssle, "Node didn't QI to style.");
      ssle->SetLineNumber(mFour.integer);
      return NS_OK;
    }
    case eTreeOpSetScriptLineNumberAndFreeze: {
      nsIContent* node = *(mOne.node);
      nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(node);
      NS_ASSERTION(sele, "Node didn't QI to script.");
      sele->SetScriptLineNumber(mFour.integer);
      sele->FreezeUriAsyncDefer();
      return NS_OK;
    }
    case eTreeOpSvgLoad: {
      nsIContent* node = *(mOne.node);
      SvgLoad(node);
      return NS_OK;
    }
    case eTreeOpMaybeComplainAboutCharset: {
      char* msgId = mOne.charPtr;
      bool error = mTwo.integer;
      int32_t lineNumber = mThree.integer;
      aBuilder->MaybeComplainAboutCharset(msgId, error, (uint32_t)lineNumber);
      return NS_OK;
    }
    case eTreeOpAddClass: {
      nsIContent* node = *(mOne.node);
      char16_t* str = mTwo.unicharPtr;
      nsDependentString depStr(str);
      // See viewsource.css for the possible classes
      nsAutoString klass;
      node->GetAttr(kNameSpaceID_None, nsGkAtoms::_class, klass);
      if (!klass.IsEmpty()) {
        klass.Append(' ');
        klass.Append(depStr);
        node->SetAttr(kNameSpaceID_None, nsGkAtoms::_class, klass, true);
      } else {
        node->SetAttr(kNameSpaceID_None, nsGkAtoms::_class, depStr, true);
      }
      return NS_OK;
    }
    case eTreeOpAddViewSourceHref: {
      nsIContent* node = *mOne.node;
      char16_t* buffer = mTwo.unicharPtr;
      int32_t length = mFour.integer;

      nsDependentString relative(buffer, length);

      nsIDocument* doc = aBuilder->GetDocument();

      const nsCString& charset = doc->GetDocumentCharacterSet();
      nsCOMPtr<nsIURI> uri;
      nsresult rv = NS_NewURI(getter_AddRefs(uri),
                              relative,
                              charset.get(),
                              aBuilder->GetViewSourceBaseURI());
      NS_ENSURE_SUCCESS(rv, NS_OK);

      // Reuse the fix for bug 467852
      // URLs that execute script (e.g. "javascript:" URLs) should just be
      // ignored.  There's nothing reasonable we can do with them, and allowing
      // them to execute in the context of the view-source window presents a
      // security risk.  Just return the empty string in this case.
      bool openingExecutesScript = false;
      rv = NS_URIChainHasFlags(uri,
                               nsIProtocolHandler::URI_OPENING_EXECUTES_SCRIPT,
                               &openingExecutesScript);
      if (NS_FAILED(rv) || openingExecutesScript) {
        return NS_OK;
      }

      nsAutoCString viewSourceUrl;

      // URLs that return data (e.g. "http:" URLs) should be prefixed with
      // "view-source:".  URLs that don't return data should just be returned
      // undecorated.
      bool doesNotReturnData = false;
      rv = NS_URIChainHasFlags(uri,
                               nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA,
                               &doesNotReturnData);
      NS_ENSURE_SUCCESS(rv, NS_OK);
      if (!doesNotReturnData) {
        viewSourceUrl.AssignLiteral("view-source:");
      }

      nsAutoCString spec;
      rv = uri->GetSpec(spec);
      NS_ENSURE_SUCCESS(rv, rv);

      viewSourceUrl.Append(spec);

      nsAutoString utf16;
      CopyUTF8toUTF16(viewSourceUrl, utf16);

      node->SetAttr(kNameSpaceID_None, nsGkAtoms::href, utf16, true);
      return NS_OK;
    }
    case eTreeOpAddViewSourceBase: {
      char16_t* buffer = mTwo.unicharPtr;
      int32_t length = mFour.integer;
      nsDependentString baseUrl(buffer, length);
      aBuilder->AddBase(baseUrl);
      return NS_OK;
    }
    case eTreeOpAddError: {
      nsIContent* node = *(mOne.node);
      char* msgId = mTwo.charPtr;
      nsCOMPtr<nsIAtom> atom = Reget(mThree.atom);
      nsCOMPtr<nsIAtom> otherAtom = Reget(mFour.atom);
      // See viewsource.css for the possible classes in addition to "error".
      nsAutoString klass;
      node->GetAttr(kNameSpaceID_None, nsGkAtoms::_class, klass);
      if (!klass.IsEmpty()) {
        klass.AppendLiteral(" error");
        node->SetAttr(kNameSpaceID_None, nsGkAtoms::_class, klass, true);
      } else {
        node->SetAttr(kNameSpaceID_None,
                      nsGkAtoms::_class,
                      NS_LITERAL_STRING("error"),
                      true);
      }

      nsresult rv;
      nsXPIDLString message;
      if (otherAtom) {
        const char16_t* params[] = { atom->GetUTF16String(),
                                      otherAtom->GetUTF16String() };
        rv = nsContentUtils::FormatLocalizedString(
          nsContentUtils::eHTMLPARSER_PROPERTIES, msgId, params, message);
        NS_ENSURE_SUCCESS(rv, NS_OK);
      } else if (atom) {
        const char16_t* params[] = { atom->GetUTF16String() };
        rv = nsContentUtils::FormatLocalizedString(
          nsContentUtils::eHTMLPARSER_PROPERTIES, msgId, params, message);
        NS_ENSURE_SUCCESS(rv, NS_OK);
      } else {
        rv = nsContentUtils::GetLocalizedString(
          nsContentUtils::eHTMLPARSER_PROPERTIES, msgId, message);
        NS_ENSURE_SUCCESS(rv, NS_OK);
      }

      nsAutoString title;
      node->GetAttr(kNameSpaceID_None, nsGkAtoms::title, title);
      if (!title.IsEmpty()) {
        title.Append('\n');
        title.Append(message);
        node->SetAttr(kNameSpaceID_None, nsGkAtoms::title, title, true);
      } else {
        node->SetAttr(kNameSpaceID_None, nsGkAtoms::title, message, true);
      }
      return rv;
    }
    case eTreeOpAddLineNumberId: {
      nsIContent* node = *(mOne.node);
      int32_t lineNumber = mFour.integer;
      nsAutoString val(NS_LITERAL_STRING("line"));
      val.AppendInt(lineNumber);
      node->SetAttr(kNameSpaceID_None, nsGkAtoms::id, val, true);
      return NS_OK;
    }
    case eTreeOpStartLayout: {
      aBuilder->StartLayout(); // this causes a notification flush anyway
      return NS_OK;
    }
    default: {
      MOZ_CRASH("Bogus tree op");
    }
  }
  return NS_OK; // keep compiler happy
}