Add m-esr52 at 52.6.0

1 files changed, 8785 insertions, 0 deletions

diff --git a/editor/libeditor/HTMLEditRules.cpp b/editor/libeditor/HTMLEditRules.cpp
new file mode 100644
index 000000000..c2d61f767
--- /dev/null
+++ b/editor/libeditor/HTMLEditRules.cpp
@@ -0,0 +1,8785 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sw=2 et tw=79: */
+/* 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 "HTMLEditRules.h"
+
+#include <stdlib.h>
+
+#include "HTMLEditUtils.h"
+#include "TextEditUtils.h"
+#include "WSRunObject.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/CSSEditUtils.h"
+#include "mozilla/EditorUtils.h"
+#include "mozilla/HTMLEditor.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/dom/Selection.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/OwningNonNull.h"
+#include "mozilla/mozalloc.h"
+#include "nsAutoPtr.h"
+#include "nsAString.h"
+#include "nsAlgorithm.h"
+#include "nsCRT.h"
+#include "nsCRTGlue.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsDebug.h"
+#include "nsError.h"
+#include "nsGkAtoms.h"
+#include "nsIAtom.h"
+#include "nsIContent.h"
+#include "nsIContentIterator.h"
+#include "nsID.h"
+#include "nsIDOMCharacterData.h"
+#include "nsIDOMDocument.h"
+#include "nsIDOMElement.h"
+#include "nsIDOMNode.h"
+#include "nsIDOMText.h"
+#include "nsIFrame.h"
+#include "nsIHTMLAbsPosEditor.h"
+#include "nsIHTMLDocument.h"
+#include "nsINode.h"
+#include "nsLiteralString.h"
+#include "nsRange.h"
+#include "nsReadableUtils.h"
+#include "nsString.h"
+#include "nsStringFwd.h"
+#include "nsTArray.h"
+#include "nsTextNode.h"
+#include "nsThreadUtils.h"
+#include "nsUnicharUtils.h"
+#include <algorithm>
+
+// Workaround for windows headers
+#ifdef SetProp
+#undef SetProp
+#endif
+
+class nsISupports;
+
+namespace mozilla {
+
+class RulesInfo;
+
+using namespace dom;
+
+//const static char* kMOZEditorBogusNodeAttr="MOZ_EDITOR_BOGUS_NODE";
+//const static char* kMOZEditorBogusNodeValue="TRUE";
+
+enum
+{
+  kLonely = 0,
+  kPrevSib = 1,
+  kNextSib = 2,
+  kBothSibs = 3
+};
+
+/********************************************************
+ *  first some helpful functors we will use
+ ********************************************************/
+
+static bool IsBlockNode(const nsINode& node)
+{
+  return HTMLEditor::NodeIsBlockStatic(&node);
+}
+
+static bool IsInlineNode(const nsINode& node)
+{
+  return !IsBlockNode(node);
+}
+
+static bool
+IsStyleCachePreservingAction(EditAction action)
+{
+  return action == EditAction::deleteSelection ||
+         action == EditAction::insertBreak ||
+         action == EditAction::makeList ||
+         action == EditAction::indent ||
+         action == EditAction::outdent ||
+         action == EditAction::align ||
+         action == EditAction::makeBasicBlock ||
+         action == EditAction::removeList ||
+         action == EditAction::makeDefListItem ||
+         action == EditAction::insertElement ||
+         action == EditAction::insertQuotation;
+}
+
+class TableCellAndListItemFunctor final : public BoolDomIterFunctor
+{
+public:
+  // Used to build list of all li's, td's & th's iterator covers
+  virtual bool operator()(nsINode* aNode) const
+  {
+    return HTMLEditUtils::IsTableCell(aNode) ||
+           HTMLEditUtils::IsListItem(aNode);
+  }
+};
+
+class BRNodeFunctor final : public BoolDomIterFunctor
+{
+public:
+  virtual bool operator()(nsINode* aNode) const
+  {
+    return aNode->IsHTMLElement(nsGkAtoms::br);
+  }
+};
+
+class EmptyEditableFunctor final : public BoolDomIterFunctor
+{
+public:
+  explicit EmptyEditableFunctor(HTMLEditor* aHTMLEditor)
+    : mHTMLEditor(aHTMLEditor)
+  {}
+
+  virtual bool operator()(nsINode* aNode) const
+  {
+    if (mHTMLEditor->IsEditable(aNode) &&
+        (HTMLEditUtils::IsListItem(aNode) ||
+         HTMLEditUtils::IsTableCellOrCaption(*aNode))) {
+      bool bIsEmptyNode;
+      nsresult rv =
+        mHTMLEditor->IsEmptyNode(aNode, &bIsEmptyNode, false, false);
+      NS_ENSURE_SUCCESS(rv, false);
+      if (bIsEmptyNode) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+protected:
+  HTMLEditor* mHTMLEditor;
+};
+
+/********************************************************
+ * mozilla::HTMLEditRules
+ ********************************************************/
+
+HTMLEditRules::HTMLEditRules()
+  : mHTMLEditor(nullptr)
+  , mListenerEnabled(false)
+  , mReturnInEmptyLIKillsList(false)
+  , mDidDeleteSelection(false)
+  , mDidRangedDelete(false)
+  , mRestoreContentEditableCount(false)
+  , mJoinOffset(0)
+{
+  InitFields();
+}
+
+void
+HTMLEditRules::InitFields()
+{
+  mHTMLEditor = nullptr;
+  mDocChangeRange = nullptr;
+  mListenerEnabled = true;
+  mReturnInEmptyLIKillsList = true;
+  mDidDeleteSelection = false;
+  mDidRangedDelete = false;
+  mRestoreContentEditableCount = false;
+  mUtilRange = nullptr;
+  mJoinOffset = 0;
+  mNewBlock = nullptr;
+  mRangeItem = new RangeItem();
+  // populate mCachedStyles
+  mCachedStyles[0] = StyleCache(nsGkAtoms::b, EmptyString(), EmptyString());
+  mCachedStyles[1] = StyleCache(nsGkAtoms::i, EmptyString(), EmptyString());
+  mCachedStyles[2] = StyleCache(nsGkAtoms::u, EmptyString(), EmptyString());
+  mCachedStyles[3] = StyleCache(nsGkAtoms::font, NS_LITERAL_STRING("face"), EmptyString());
+  mCachedStyles[4] = StyleCache(nsGkAtoms::font, NS_LITERAL_STRING("size"), EmptyString());
+  mCachedStyles[5] = StyleCache(nsGkAtoms::font, NS_LITERAL_STRING("color"), EmptyString());
+  mCachedStyles[6] = StyleCache(nsGkAtoms::tt, EmptyString(), EmptyString());
+  mCachedStyles[7] = StyleCache(nsGkAtoms::em, EmptyString(), EmptyString());
+  mCachedStyles[8] = StyleCache(nsGkAtoms::strong, EmptyString(), EmptyString());
+  mCachedStyles[9] = StyleCache(nsGkAtoms::dfn, EmptyString(), EmptyString());
+  mCachedStyles[10] = StyleCache(nsGkAtoms::code, EmptyString(), EmptyString());
+  mCachedStyles[11] = StyleCache(nsGkAtoms::samp, EmptyString(), EmptyString());
+  mCachedStyles[12] = StyleCache(nsGkAtoms::var, EmptyString(), EmptyString());
+  mCachedStyles[13] = StyleCache(nsGkAtoms::cite, EmptyString(), EmptyString());
+  mCachedStyles[14] = StyleCache(nsGkAtoms::abbr, EmptyString(), EmptyString());
+  mCachedStyles[15] = StyleCache(nsGkAtoms::acronym, EmptyString(), EmptyString());
+  mCachedStyles[16] = StyleCache(nsGkAtoms::backgroundColor, EmptyString(), EmptyString());
+  mCachedStyles[17] = StyleCache(nsGkAtoms::sub, EmptyString(), EmptyString());
+  mCachedStyles[18] = StyleCache(nsGkAtoms::sup, EmptyString(), EmptyString());
+}
+
+HTMLEditRules::~HTMLEditRules()
+{
+  // remove ourselves as a listener to edit actions
+  // In some cases, we have already been removed by
+  // ~HTMLEditor, in which case we will get a null pointer here
+  // which we ignore.  But this allows us to add the ability to
+  // switch rule sets on the fly if we want.
+  if (mHTMLEditor) {
+    mHTMLEditor->RemoveEditActionListener(this);
+  }
+}
+
+NS_IMPL_ADDREF_INHERITED(HTMLEditRules, TextEditRules)
+NS_IMPL_RELEASE_INHERITED(HTMLEditRules, TextEditRules)
+NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(HTMLEditRules)
+  NS_INTERFACE_TABLE_INHERITED(HTMLEditRules, nsIEditActionListener)
+NS_INTERFACE_TABLE_TAIL_INHERITING(TextEditRules)
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(HTMLEditRules, TextEditRules,
+                                   mDocChangeRange, mUtilRange, mNewBlock,
+                                   mRangeItem)
+
+NS_IMETHODIMP
+HTMLEditRules::Init(TextEditor* aTextEditor)
+{
+  InitFields();
+
+  mHTMLEditor = static_cast<HTMLEditor*>(aTextEditor);
+
+  // call through to base class Init
+  nsresult rv = TextEditRules::Init(aTextEditor);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // cache any prefs we care about
+  static const char kPrefName[] =
+    "editor.html.typing.returnInEmptyListItemClosesList";
+  nsAdoptingCString returnInEmptyLIKillsList =
+    Preferences::GetCString(kPrefName);
+
+  // only when "false", becomes FALSE.  Otherwise (including empty), TRUE.
+  // XXX Why was this pref designed as a string and not bool?
+  mReturnInEmptyLIKillsList = !returnInEmptyLIKillsList.EqualsLiteral("false");
+
+  // make a utility range for use by the listenter
+  nsCOMPtr<nsINode> node = mHTMLEditor->GetRoot();
+  if (!node) {
+    node = mHTMLEditor->GetDocument();
+  }
+
+  NS_ENSURE_STATE(node);
+
+  mUtilRange = new nsRange(node);
+
+  // set up mDocChangeRange to be whole doc
+  // temporarily turn off rules sniffing
+  AutoLockRulesSniffing lockIt(this);
+  if (!mDocChangeRange) {
+    mDocChangeRange = new nsRange(node);
+  }
+
+  if (node->IsElement()) {
+    ErrorResult rv;
+    mDocChangeRange->SelectNode(*node, rv);
+    NS_ENSURE_TRUE(!rv.Failed(), rv.StealNSResult());
+    AdjustSpecialBreaks();
+  }
+
+  // add ourselves as a listener to edit actions
+  return mHTMLEditor->AddEditActionListener(this);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DetachEditor()
+{
+  if (mHTMLEditor) {
+    mHTMLEditor->RemoveEditActionListener(this);
+  }
+  mHTMLEditor = nullptr;
+  return TextEditRules::DetachEditor();
+}
+
+NS_IMETHODIMP
+HTMLEditRules::BeforeEdit(EditAction action,
+                          nsIEditor::EDirection aDirection)
+{
+  if (mLockRulesSniffing) {
+    return NS_OK;
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  AutoLockRulesSniffing lockIt(this);
+  mDidExplicitlySetInterline = false;
+
+  if (!mActionNesting) {
+    mActionNesting++;
+
+    // Clear our flag about if just deleted a range
+    mDidRangedDelete = false;
+
+    // Remember where our selection was before edit action took place:
+
+    // Get selection
+    RefPtr<Selection> selection = htmlEditor->GetSelection();
+
+    // Get the selection location
+    if (NS_WARN_IF(!selection) || !selection->RangeCount()) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    mRangeItem->startNode = selection->GetRangeAt(0)->GetStartParent();
+    mRangeItem->startOffset = selection->GetRangeAt(0)->StartOffset();
+    mRangeItem->endNode = selection->GetRangeAt(0)->GetEndParent();
+    mRangeItem->endOffset = selection->GetRangeAt(0)->EndOffset();
+    nsCOMPtr<nsINode> selStartNode = mRangeItem->startNode;
+    nsCOMPtr<nsINode> selEndNode = mRangeItem->endNode;
+
+    // Register with range updater to track this as we perturb the doc
+    htmlEditor->mRangeUpdater.RegisterRangeItem(mRangeItem);
+
+    // Clear deletion state bool
+    mDidDeleteSelection = false;
+
+    // Clear out mDocChangeRange and mUtilRange
+    if (mDocChangeRange) {
+      // Clear out our accounting of what changed
+      mDocChangeRange->Reset();
+    }
+    if (mUtilRange) {
+      // Ditto for mUtilRange.
+      mUtilRange->Reset();
+    }
+
+    // Remember current inline styles for deletion and normal insertion ops
+    if (action == EditAction::insertText ||
+        action == EditAction::insertIMEText ||
+        action == EditAction::deleteSelection ||
+        IsStyleCachePreservingAction(action)) {
+      nsCOMPtr<nsINode> selNode =
+        aDirection == nsIEditor::eNext ? selEndNode : selStartNode;
+      nsresult rv = CacheInlineStyles(GetAsDOMNode(selNode));
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // Stabilize the document against contenteditable count changes
+    nsCOMPtr<nsIDOMDocument> doc = htmlEditor->GetDOMDocument();
+    NS_ENSURE_TRUE(doc, NS_ERROR_NOT_INITIALIZED);
+    nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(doc);
+    NS_ENSURE_TRUE(htmlDoc, NS_ERROR_FAILURE);
+    if (htmlDoc->GetEditingState() == nsIHTMLDocument::eContentEditable) {
+      htmlDoc->ChangeContentEditableCount(nullptr, +1);
+      mRestoreContentEditableCount = true;
+    }
+
+    // Check that selection is in subtree defined by body node
+    ConfirmSelectionInBody();
+    // Let rules remember the top level action
+    mTheAction = action;
+  }
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+HTMLEditRules::AfterEdit(EditAction action,
+                         nsIEditor::EDirection aDirection)
+{
+  if (mLockRulesSniffing) {
+    return NS_OK;
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  AutoLockRulesSniffing lockIt(this);
+
+  MOZ_ASSERT(mActionNesting > 0);
+  nsresult rv = NS_OK;
+  mActionNesting--;
+  if (!mActionNesting) {
+    // Do all the tricky stuff
+    rv = AfterEditInner(action, aDirection);
+
+    // Free up selectionState range item
+    htmlEditor->mRangeUpdater.DropRangeItem(mRangeItem);
+
+    // Reset the contenteditable count to its previous value
+    if (mRestoreContentEditableCount) {
+      nsCOMPtr<nsIDOMDocument> doc = htmlEditor->GetDOMDocument();
+      NS_ENSURE_TRUE(doc, NS_ERROR_NOT_INITIALIZED);
+      nsCOMPtr<nsIHTMLDocument> htmlDoc = do_QueryInterface(doc);
+      NS_ENSURE_TRUE(htmlDoc, NS_ERROR_FAILURE);
+      if (htmlDoc->GetEditingState() == nsIHTMLDocument::eContentEditable) {
+        htmlDoc->ChangeContentEditableCount(nullptr, -1);
+      }
+      mRestoreContentEditableCount = false;
+    }
+  }
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::AfterEditInner(EditAction action,
+                              nsIEditor::EDirection aDirection)
+{
+  ConfirmSelectionInBody();
+  if (action == EditAction::ignore) {
+    return NS_OK;
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+  NS_ENSURE_STATE(selection);
+
+  nsCOMPtr<nsIDOMNode> rangeStartParent, rangeEndParent;
+  int32_t rangeStartOffset = 0, rangeEndOffset = 0;
+  // do we have a real range to act on?
+  bool bDamagedRange = false;
+  if (mDocChangeRange) {
+    mDocChangeRange->GetStartContainer(getter_AddRefs(rangeStartParent));
+    mDocChangeRange->GetEndContainer(getter_AddRefs(rangeEndParent));
+    mDocChangeRange->GetStartOffset(&rangeStartOffset);
+    mDocChangeRange->GetEndOffset(&rangeEndOffset);
+    if (rangeStartParent && rangeEndParent)
+      bDamagedRange = true;
+  }
+
+  if (bDamagedRange && !((action == EditAction::undo) ||
+                         (action == EditAction::redo))) {
+    // don't let any txns in here move the selection around behind our back.
+    // Note that this won't prevent explicit selection setting from working.
+    NS_ENSURE_STATE(mHTMLEditor);
+    AutoTransactionsConserveSelection dontSpazMySelection(mHTMLEditor);
+
+    // expand the "changed doc range" as needed
+    PromoteRange(*mDocChangeRange, action);
+
+    // if we did a ranged deletion or handling backspace key, make sure we have
+    // a place to put caret.
+    // Note we only want to do this if the overall operation was deletion,
+    // not if deletion was done along the way for EditAction::loadHTML, EditAction::insertText, etc.
+    // That's why this is here rather than DidDeleteSelection().
+    if (action == EditAction::deleteSelection && mDidRangedDelete) {
+      nsresult rv = InsertBRIfNeeded(selection);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // add in any needed <br>s, and remove any unneeded ones.
+    AdjustSpecialBreaks();
+
+    // merge any adjacent text nodes
+    if (action != EditAction::insertText &&
+        action != EditAction::insertIMEText) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->CollapseAdjacentTextNodes(mDocChangeRange);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // clean up any empty nodes in the selection
+    nsresult rv = RemoveEmptyNodes();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // attempt to transform any unneeded nbsp's into spaces after doing various operations
+    if (action == EditAction::insertText ||
+        action == EditAction::insertIMEText ||
+        action == EditAction::deleteSelection ||
+        action == EditAction::insertBreak ||
+        action == EditAction::htmlPaste ||
+        action == EditAction::loadHTML) {
+      rv = AdjustWhitespace(selection);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // also do this for original selection endpoints.
+      NS_ENSURE_STATE(mHTMLEditor);
+      NS_ENSURE_STATE(mRangeItem->startNode);
+      NS_ENSURE_STATE(mRangeItem->endNode);
+      WSRunObject(mHTMLEditor, mRangeItem->startNode,
+                  mRangeItem->startOffset).AdjustWhitespace();
+      // we only need to handle old selection endpoint if it was different from start
+      if (mRangeItem->startNode != mRangeItem->endNode ||
+          mRangeItem->startOffset != mRangeItem->endOffset) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        WSRunObject(mHTMLEditor, mRangeItem->endNode,
+                    mRangeItem->endOffset).AdjustWhitespace();
+      }
+    }
+
+    // if we created a new block, make sure selection lands in it
+    if (mNewBlock) {
+      rv = PinSelectionToNewBlock(selection);
+      mNewBlock = nullptr;
+    }
+
+    // adjust selection for insert text, html paste, and delete actions
+    if (action == EditAction::insertText ||
+        action == EditAction::insertIMEText ||
+        action == EditAction::deleteSelection ||
+        action == EditAction::insertBreak ||
+        action == EditAction::htmlPaste ||
+        action == EditAction::loadHTML) {
+      rv = AdjustSelection(selection, aDirection);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // check for any styles which were removed inappropriately
+    if (action == EditAction::insertText ||
+        action == EditAction::insertIMEText ||
+        action == EditAction::deleteSelection ||
+        IsStyleCachePreservingAction(action)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->mTypeInState->UpdateSelState(selection);
+      rv = ReapplyCachedStyles();
+      NS_ENSURE_SUCCESS(rv, rv);
+      ClearCachedStyles();
+    }
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+
+  nsresult rv =
+    mHTMLEditor->HandleInlineSpellCheck(action, selection,
+                                        GetAsDOMNode(mRangeItem->startNode),
+                                        mRangeItem->startOffset,
+                                        rangeStartParent, rangeStartOffset,
+                                        rangeEndParent, rangeEndOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // detect empty doc
+  rv = CreateBogusNodeIfNeeded(selection);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // adjust selection HINT if needed
+  if (!mDidExplicitlySetInterline) {
+    CheckInterlinePosition(*selection);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillDoAction(Selection* aSelection,
+                            RulesInfo* aInfo,
+                            bool* aCancel,
+                            bool* aHandled)
+{
+  MOZ_ASSERT(aInfo && aCancel && aHandled);
+
+  *aCancel = false;
+  *aHandled = false;
+
+  // my kingdom for dynamic cast
+  TextRulesInfo* info = static_cast<TextRulesInfo*>(aInfo);
+
+  // Deal with actions for which we don't need to check whether the selection is
+  // editable.
+  if (info->action == EditAction::outputText ||
+      info->action == EditAction::undo ||
+      info->action == EditAction::redo) {
+    return TextEditRules::WillDoAction(aSelection, aInfo, aCancel, aHandled);
+  }
+
+  // Nothing to do if there's no selection to act on
+  if (!aSelection) {
+    return NS_OK;
+  }
+  NS_ENSURE_TRUE(aSelection->RangeCount(), NS_OK);
+
+  RefPtr<nsRange> range = aSelection->GetRangeAt(0);
+  nsCOMPtr<nsINode> selStartNode = range->GetStartParent();
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (!mHTMLEditor->IsModifiableNode(selStartNode)) {
+    *aCancel = true;
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsINode> selEndNode = range->GetEndParent();
+
+  if (selStartNode != selEndNode) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsModifiableNode(selEndNode)) {
+      *aCancel = true;
+      return NS_OK;
+    }
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsModifiableNode(range->GetCommonAncestor())) {
+      *aCancel = true;
+      return NS_OK;
+    }
+  }
+
+  switch (info->action) {
+    case EditAction::insertText:
+    case EditAction::insertIMEText:
+      UndefineCaretBidiLevel(aSelection);
+      return WillInsertText(info->action, aSelection, aCancel, aHandled,
+                            info->inString, info->outString, info->maxLength);
+    case EditAction::loadHTML:
+      return WillLoadHTML(aSelection, aCancel);
+    case EditAction::insertBreak:
+      UndefineCaretBidiLevel(aSelection);
+      return WillInsertBreak(*aSelection, aCancel, aHandled);
+    case EditAction::deleteSelection:
+      return WillDeleteSelection(aSelection, info->collapsedAction,
+                                 info->stripWrappers, aCancel, aHandled);
+    case EditAction::makeList:
+      return WillMakeList(aSelection, info->blockType, info->entireList,
+                          info->bulletType, aCancel, aHandled);
+    case EditAction::indent:
+      return WillIndent(aSelection, aCancel, aHandled);
+    case EditAction::outdent:
+      return WillOutdent(*aSelection, aCancel, aHandled);
+    case EditAction::setAbsolutePosition:
+      return WillAbsolutePosition(*aSelection, aCancel, aHandled);
+    case EditAction::removeAbsolutePosition:
+      return WillRemoveAbsolutePosition(aSelection, aCancel, aHandled);
+    case EditAction::align:
+      return WillAlign(*aSelection, *info->alignType, aCancel, aHandled);
+    case EditAction::makeBasicBlock:
+      return WillMakeBasicBlock(*aSelection, *info->blockType, aCancel,
+                                aHandled);
+    case EditAction::removeList:
+      return WillRemoveList(aSelection, info->bOrdered, aCancel, aHandled);
+    case EditAction::makeDefListItem:
+      return WillMakeDefListItem(aSelection, info->blockType, info->entireList,
+                                 aCancel, aHandled);
+    case EditAction::insertElement:
+      WillInsert(*aSelection, aCancel);
+      return NS_OK;
+    case EditAction::decreaseZIndex:
+      return WillRelativeChangeZIndex(aSelection, -1, aCancel, aHandled);
+    case EditAction::increaseZIndex:
+      return WillRelativeChangeZIndex(aSelection, 1, aCancel, aHandled);
+    default:
+      return TextEditRules::WillDoAction(aSelection, aInfo,
+                                         aCancel, aHandled);
+  }
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidDoAction(Selection* aSelection,
+                           RulesInfo* aInfo,
+                           nsresult aResult)
+{
+  TextRulesInfo* info = static_cast<TextRulesInfo*>(aInfo);
+  switch (info->action) {
+    case EditAction::insertBreak:
+      return DidInsertBreak(aSelection, aResult);
+    case EditAction::deleteSelection:
+      return DidDeleteSelection(aSelection, info->collapsedAction, aResult);
+    case EditAction::makeBasicBlock:
+    case EditAction::indent:
+    case EditAction::outdent:
+    case EditAction::align:
+      return DidMakeBasicBlock(aSelection, aInfo, aResult);
+    case EditAction::setAbsolutePosition: {
+      nsresult rv = DidMakeBasicBlock(aSelection, aInfo, aResult);
+      NS_ENSURE_SUCCESS(rv, rv);
+      return DidAbsolutePosition();
+    }
+    default:
+      // pass through to TextEditRules
+      return TextEditRules::DidDoAction(aSelection, aInfo, aResult);
+  }
+}
+
+nsresult
+HTMLEditRules::GetListState(bool* aMixed,
+                            bool* aOL,
+                            bool* aUL,
+                            bool* aDL)
+{
+  NS_ENSURE_TRUE(aMixed && aOL && aUL && aDL, NS_ERROR_NULL_POINTER);
+  *aMixed = false;
+  *aOL = false;
+  *aUL = false;
+  *aDL = false;
+  bool bNonList = false;
+
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  nsresult rv = GetListActionNodes(arrayOfNodes, EntireList::no,
+                                   TouchContent::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Examine list type for nodes in selection.
+  for (const auto& curNode : arrayOfNodes) {
+    if (!curNode->IsElement()) {
+      bNonList = true;
+    } else if (curNode->IsHTMLElement(nsGkAtoms::ul)) {
+      *aUL = true;
+    } else if (curNode->IsHTMLElement(nsGkAtoms::ol)) {
+      *aOL = true;
+    } else if (curNode->IsHTMLElement(nsGkAtoms::li)) {
+      if (dom::Element* parent = curNode->GetParentElement()) {
+        if (parent->IsHTMLElement(nsGkAtoms::ul)) {
+          *aUL = true;
+        } else if (parent->IsHTMLElement(nsGkAtoms::ol)) {
+          *aOL = true;
+        }
+      }
+    } else if (curNode->IsAnyOfHTMLElements(nsGkAtoms::dl,
+                                            nsGkAtoms::dt,
+                                            nsGkAtoms::dd)) {
+      *aDL = true;
+    } else {
+      bNonList = true;
+    }
+  }
+
+  // hokey arithmetic with booleans
+  if ((*aUL + *aOL + *aDL + bNonList) > 1) {
+    *aMixed = true;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::GetListItemState(bool* aMixed,
+                                bool* aLI,
+                                bool* aDT,
+                                bool* aDD)
+{
+  NS_ENSURE_TRUE(aMixed && aLI && aDT && aDD, NS_ERROR_NULL_POINTER);
+  *aMixed = false;
+  *aLI = false;
+  *aDT = false;
+  *aDD = false;
+  bool bNonList = false;
+
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  nsresult rv = GetListActionNodes(arrayOfNodes, EntireList::no,
+                                   TouchContent::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // examine list type for nodes in selection
+  for (const auto& node : arrayOfNodes) {
+    if (!node->IsElement()) {
+      bNonList = true;
+    } else if (node->IsAnyOfHTMLElements(nsGkAtoms::ul,
+                                         nsGkAtoms::ol,
+                                         nsGkAtoms::li)) {
+      *aLI = true;
+    } else if (node->IsHTMLElement(nsGkAtoms::dt)) {
+      *aDT = true;
+    } else if (node->IsHTMLElement(nsGkAtoms::dd)) {
+      *aDD = true;
+    } else if (node->IsHTMLElement(nsGkAtoms::dl)) {
+      // need to look inside dl and see which types of items it has
+      bool bDT, bDD;
+      GetDefinitionListItemTypes(node->AsElement(), &bDT, &bDD);
+      *aDT |= bDT;
+      *aDD |= bDD;
+    } else {
+      bNonList = true;
+    }
+  }
+
+  // hokey arithmetic with booleans
+  if (*aDT + *aDD + bNonList > 1) {
+    *aMixed = true;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::GetAlignment(bool* aMixed,
+                            nsIHTMLEditor::EAlignment* aAlign)
+{
+  MOZ_ASSERT(aMixed && aAlign);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // For now, just return first alignment.  We'll lie about if it's mixed.
+  // This is for efficiency given that our current ui doesn't care if it's
+  // mixed.
+  // cmanske: NOT TRUE! We would like to pay attention to mixed state in Format
+  // | Align submenu!
+
+  // This routine assumes that alignment is done ONLY via divs
+
+  // Default alignment is left
+  *aMixed = false;
+  *aAlign = nsIHTMLEditor::eLeft;
+
+  // Get selection
+  NS_ENSURE_STATE(htmlEditor->GetSelection());
+  OwningNonNull<Selection> selection = *htmlEditor->GetSelection();
+
+  // Get selection location
+  NS_ENSURE_TRUE(htmlEditor->GetRoot(), NS_ERROR_FAILURE);
+  OwningNonNull<Element> root = *htmlEditor->GetRoot();
+
+  int32_t rootOffset = root->GetParentNode() ?
+                       root->GetParentNode()->IndexOf(root) : -1;
+
+  NS_ENSURE_STATE(selection->GetRangeAt(0) &&
+                  selection->GetRangeAt(0)->GetStartParent());
+  OwningNonNull<nsINode> parent = *selection->GetRangeAt(0)->GetStartParent();
+  int32_t offset = selection->GetRangeAt(0)->StartOffset();
+
+  // Is the selection collapsed?
+  nsCOMPtr<nsINode> nodeToExamine;
+  if (selection->Collapsed() || parent->GetAsText()) {
+    // If selection is collapsed, we want to look at 'parent' and its ancestors
+    // for divs with alignment on them.  If we are in a text node, then that is
+    // the node of interest.
+    nodeToExamine = parent;
+  } else if (parent->IsHTMLElement(nsGkAtoms::html) && offset == rootOffset) {
+    // If we have selected the body, let's look at the first editable node
+    nodeToExamine = htmlEditor->GetNextNode(parent, offset, true);
+  } else {
+    nsTArray<RefPtr<nsRange>> arrayOfRanges;
+    GetPromotedRanges(selection, arrayOfRanges, EditAction::align);
+
+    // Use these ranges to construct a list of nodes to act on.
+    nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+    nsresult rv = GetNodesForOperation(arrayOfRanges, arrayOfNodes,
+                                       EditAction::align, TouchContent::no);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nodeToExamine = arrayOfNodes.SafeElementAt(0);
+  }
+
+  NS_ENSURE_TRUE(nodeToExamine, NS_ERROR_NULL_POINTER);
+
+  NS_NAMED_LITERAL_STRING(typeAttrName, "align");
+  nsCOMPtr<Element> blockParent = htmlEditor->GetBlock(*nodeToExamine);
+
+  NS_ENSURE_TRUE(blockParent, NS_ERROR_FAILURE);
+
+  if (htmlEditor->IsCSSEnabled() &&
+      htmlEditor->mCSSEditUtils->IsCSSEditableProperty(blockParent, nullptr,
+                                                        &typeAttrName)) {
+    // We are in CSS mode and we know how to align this element with CSS
+    nsAutoString value;
+    // Let's get the value(s) of text-align or margin-left/margin-right
+    htmlEditor->mCSSEditUtils->GetCSSEquivalentToHTMLInlineStyleSet(
+        blockParent, nullptr, &typeAttrName, value, CSSEditUtils::eComputed);
+    if (value.EqualsLiteral("center") ||
+        value.EqualsLiteral("-moz-center") ||
+        value.EqualsLiteral("auto auto")) {
+      *aAlign = nsIHTMLEditor::eCenter;
+      return NS_OK;
+    }
+    if (value.EqualsLiteral("right") ||
+        value.EqualsLiteral("-moz-right") ||
+        value.EqualsLiteral("auto 0px")) {
+      *aAlign = nsIHTMLEditor::eRight;
+      return NS_OK;
+    }
+    if (value.EqualsLiteral("justify")) {
+      *aAlign = nsIHTMLEditor::eJustify;
+      return NS_OK;
+    }
+    *aAlign = nsIHTMLEditor::eLeft;
+    return NS_OK;
+  }
+
+  // Check up the ladder for divs with alignment
+  bool isFirstNodeToExamine = true;
+  for (; nodeToExamine; nodeToExamine = nodeToExamine->GetParentNode()) {
+    if (!isFirstNodeToExamine &&
+        nodeToExamine->IsHTMLElement(nsGkAtoms::table)) {
+      // The node to examine is a table and this is not the first node we
+      // examine; let's break here to materialize the 'inline-block' behaviour
+      // of html tables regarding to text alignment
+      return NS_OK;
+    }
+    if (HTMLEditUtils::SupportsAlignAttr(GetAsDOMNode(nodeToExamine))) {
+      // Check for alignment
+      nsAutoString typeAttrVal;
+      nodeToExamine->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::align,
+                                          typeAttrVal);
+      ToLowerCase(typeAttrVal);
+      if (!typeAttrVal.IsEmpty()) {
+        if (typeAttrVal.EqualsLiteral("center")) {
+          *aAlign = nsIHTMLEditor::eCenter;
+        } else if (typeAttrVal.EqualsLiteral("right")) {
+          *aAlign = nsIHTMLEditor::eRight;
+        } else if (typeAttrVal.EqualsLiteral("justify")) {
+          *aAlign = nsIHTMLEditor::eJustify;
+        } else {
+          *aAlign = nsIHTMLEditor::eLeft;
+        }
+        return NS_OK;
+      }
+    }
+    isFirstNodeToExamine = false;
+  }
+  return NS_OK;
+}
+
+static nsIAtom& MarginPropertyAtomForIndent(CSSEditUtils& aHTMLCSSUtils,
+                                            nsINode& aNode)
+{
+  nsAutoString direction;
+  aHTMLCSSUtils.GetComputedProperty(aNode, *nsGkAtoms::direction, direction);
+  return direction.EqualsLiteral("rtl") ?
+    *nsGkAtoms::marginRight : *nsGkAtoms::marginLeft;
+}
+
+nsresult
+HTMLEditRules::GetIndentState(bool* aCanIndent,
+                              bool* aCanOutdent)
+{
+  // XXX Looks like that this is implementation of
+  //     nsIHTMLEditor::getIndentState() however nobody calls this method
+  //     even with the interface method.
+  NS_ENSURE_TRUE(aCanIndent && aCanOutdent, NS_ERROR_FAILURE);
+  *aCanIndent = true;
+  *aCanOutdent = false;
+
+  // get selection
+  NS_ENSURE_STATE(mHTMLEditor && mHTMLEditor->GetSelection());
+  OwningNonNull<Selection> selection = *mHTMLEditor->GetSelection();
+
+  // contruct a list of nodes to act on.
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  nsresult rv = GetNodesFromSelection(*selection, EditAction::indent,
+                                      arrayOfNodes, TouchContent::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // examine nodes in selection for blockquotes or list elements;
+  // these we can outdent.  Note that we return true for canOutdent
+  // if *any* of the selection is outdentable, rather than all of it.
+  NS_ENSURE_STATE(mHTMLEditor);
+  bool useCSS = mHTMLEditor->IsCSSEnabled();
+  for (auto& curNode : Reversed(arrayOfNodes)) {
+    if (HTMLEditUtils::IsNodeThatCanOutdent(GetAsDOMNode(curNode))) {
+      *aCanOutdent = true;
+      break;
+    } else if (useCSS) {
+      // we are in CSS mode, indentation is done using the margin-left (or margin-right) property
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsIAtom& marginProperty =
+        MarginPropertyAtomForIndent(*mHTMLEditor->mCSSEditUtils, curNode);
+      nsAutoString value;
+      // retrieve its specified value
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->mCSSEditUtils->GetSpecifiedProperty(*curNode,
+                                                       marginProperty, value);
+      float f;
+      nsCOMPtr<nsIAtom> unit;
+      // get its number part and its unit
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->mCSSEditUtils->ParseLength(value, &f, getter_AddRefs(unit));
+      // if the number part is strictly positive, outdent is possible
+      if (0 < f) {
+        *aCanOutdent = true;
+        break;
+      }
+    }
+  }
+
+  if (!*aCanOutdent) {
+    // if we haven't found something to outdent yet, also check the parents
+    // of selection endpoints.  We might have a blockquote or list item
+    // in the parent hierarchy.
+
+    // gather up info we need for test
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<nsIDOMNode> parent, tmp, root = do_QueryInterface(mHTMLEditor->GetRoot());
+    NS_ENSURE_TRUE(root, NS_ERROR_NULL_POINTER);
+    int32_t selOffset;
+    NS_ENSURE_STATE(mHTMLEditor);
+    RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+    NS_ENSURE_TRUE(selection, NS_ERROR_NULL_POINTER);
+
+    // test start parent hierarchy
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->GetStartNodeAndOffset(selection, getter_AddRefs(parent),
+                                            &selOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    while (parent && parent != root) {
+      if (HTMLEditUtils::IsNodeThatCanOutdent(parent)) {
+        *aCanOutdent = true;
+        break;
+      }
+      tmp = parent;
+      tmp->GetParentNode(getter_AddRefs(parent));
+    }
+
+    // test end parent hierarchy
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->GetEndNodeAndOffset(selection, getter_AddRefs(parent),
+                                          &selOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    while (parent && parent != root) {
+      if (HTMLEditUtils::IsNodeThatCanOutdent(parent)) {
+        *aCanOutdent = true;
+        break;
+      }
+      tmp = parent;
+      tmp->GetParentNode(getter_AddRefs(parent));
+    }
+  }
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::GetParagraphState(bool* aMixed,
+                                 nsAString& outFormat)
+{
+  // This routine is *heavily* tied to our ui choices in the paragraph
+  // style popup.  I can't see a way around that.
+  NS_ENSURE_TRUE(aMixed, NS_ERROR_NULL_POINTER);
+  *aMixed = true;
+  outFormat.Truncate(0);
+
+  bool bMixed = false;
+  // using "x" as an uninitialized value, since "" is meaningful
+  nsAutoString formatStr(NS_LITERAL_STRING("x"));
+
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  nsresult rv = GetParagraphFormatNodes(arrayOfNodes, TouchContent::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // post process list.  We need to replace any block nodes that are not format
+  // nodes with their content.  This is so we only have to look "up" the hierarchy
+  // to find format nodes, instead of both up and down.
+  for (int32_t i = arrayOfNodes.Length() - 1; i >= 0; i--) {
+    auto& curNode = arrayOfNodes[i];
+    nsAutoString format;
+    // if it is a known format node we have it easy
+    if (IsBlockNode(curNode) && !HTMLEditUtils::IsFormatNode(curNode)) {
+      // arrayOfNodes.RemoveObject(curNode);
+      rv = AppendInnerFormatNodes(arrayOfNodes, curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // we might have an empty node list.  if so, find selection parent
+  // and put that on the list
+  if (arrayOfNodes.IsEmpty()) {
+    nsCOMPtr<nsINode> selNode;
+    int32_t selOffset;
+    NS_ENSURE_STATE(mHTMLEditor);
+    RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+    NS_ENSURE_STATE(selection);
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->GetStartNodeAndOffset(selection, getter_AddRefs(selNode),
+                                            &selOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_TRUE(selNode, NS_ERROR_NULL_POINTER);
+    arrayOfNodes.AppendElement(*selNode);
+  }
+
+  // remember root node
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIDOMElement> rootElem = do_QueryInterface(mHTMLEditor->GetRoot());
+  NS_ENSURE_TRUE(rootElem, NS_ERROR_NULL_POINTER);
+
+  // loop through the nodes in selection and examine their paragraph format
+  for (auto& curNode : Reversed(arrayOfNodes)) {
+    nsAutoString format;
+    // if it is a known format node we have it easy
+    if (HTMLEditUtils::IsFormatNode(curNode)) {
+      GetFormatString(GetAsDOMNode(curNode), format);
+    } else if (IsBlockNode(curNode)) {
+      // this is a div or some other non-format block.
+      // we should ignore it.  Its children were appended to this list
+      // by AppendInnerFormatNodes() call above.  We will get needed
+      // info when we examine them instead.
+      continue;
+    } else {
+      nsCOMPtr<nsIDOMNode> node, tmp = GetAsDOMNode(curNode);
+      tmp->GetParentNode(getter_AddRefs(node));
+      while (node) {
+        if (node == rootElem) {
+          format.Truncate(0);
+          break;
+        } else if (HTMLEditUtils::IsFormatNode(node)) {
+          GetFormatString(node, format);
+          break;
+        }
+        // else keep looking up
+        tmp = node;
+        tmp->GetParentNode(getter_AddRefs(node));
+      }
+    }
+
+    // if this is the first node, we've found, remember it as the format
+    if (formatStr.EqualsLiteral("x")) {
+      formatStr = format;
+    }
+    // else make sure it matches previously found format
+    else if (format != formatStr) {
+      bMixed = true;
+      break;
+    }
+  }
+
+  *aMixed = bMixed;
+  outFormat = formatStr;
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::AppendInnerFormatNodes(nsTArray<OwningNonNull<nsINode>>& aArray,
+                                      nsINode* aNode)
+{
+  MOZ_ASSERT(aNode);
+
+  // we only need to place any one inline inside this node onto
+  // the list.  They are all the same for purposes of determining
+  // paragraph style.  We use foundInline to track this as we are
+  // going through the children in the loop below.
+  bool foundInline = false;
+  for (nsIContent* child = aNode->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+    bool isBlock = IsBlockNode(*child);
+    bool isFormat = HTMLEditUtils::IsFormatNode(child);
+    if (isBlock && !isFormat) {
+      // if it's a div, etc., recurse
+      AppendInnerFormatNodes(aArray, child);
+    } else if (isFormat) {
+      aArray.AppendElement(*child);
+    } else if (!foundInline) {
+      // if this is the first inline we've found, use it
+      foundInline = true;
+      aArray.AppendElement(*child);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::GetFormatString(nsIDOMNode* aNode,
+                               nsAString& outFormat)
+{
+  NS_ENSURE_TRUE(aNode, NS_ERROR_NULL_POINTER);
+
+  if (HTMLEditUtils::IsFormatNode(aNode)) {
+    nsCOMPtr<nsIAtom> atom = EditorBase::GetTag(aNode);
+    atom->ToString(outFormat);
+  } else {
+    outFormat.Truncate();
+  }
+  return NS_OK;
+}
+
+void
+HTMLEditRules::WillInsert(Selection& aSelection,
+                          bool* aCancel)
+{
+  MOZ_ASSERT(aCancel);
+
+  TextEditRules::WillInsert(aSelection, aCancel);
+
+  NS_ENSURE_TRUE_VOID(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Adjust selection to prevent insertion after a moz-BR.  This next only
+  // works for collapsed selections right now, because selection is a pain to
+  // work with when not collapsed.  (no good way to extend start or end of
+  // selection), so we ignore those types of selections.
+  if (!aSelection.Collapsed()) {
+    return;
+  }
+
+  // If we are after a mozBR in the same block, then move selection to be
+  // before it
+  NS_ENSURE_TRUE_VOID(aSelection.GetRangeAt(0) &&
+                      aSelection.GetRangeAt(0)->GetStartParent());
+  OwningNonNull<nsINode> selNode = *aSelection.GetRangeAt(0)->GetStartParent();
+  int32_t selOffset = aSelection.GetRangeAt(0)->StartOffset();
+
+  // Get prior node
+  nsCOMPtr<nsIContent> priorNode = htmlEditor->GetPriorHTMLNode(selNode,
+                                                                selOffset);
+  if (priorNode && TextEditUtils::IsMozBR(priorNode)) {
+    nsCOMPtr<Element> block1 = htmlEditor->GetBlock(selNode);
+    nsCOMPtr<Element> block2 = htmlEditor->GetBlockNodeParent(priorNode);
+
+    if (block1 && block1 == block2) {
+      // If we are here then the selection is right after a mozBR that is in
+      // the same block as the selection.  We need to move the selection start
+      // to be before the mozBR.
+      selNode = priorNode->GetParentNode();
+      selOffset = selNode->IndexOf(priorNode);
+      nsresult rv = aSelection.Collapse(selNode, selOffset);
+      NS_ENSURE_SUCCESS_VOID(rv);
+    }
+  }
+
+  if (mDidDeleteSelection &&
+      (mTheAction == EditAction::insertText ||
+       mTheAction == EditAction::insertIMEText ||
+       mTheAction == EditAction::deleteSelection)) {
+    nsresult rv = ReapplyCachedStyles();
+    NS_ENSURE_SUCCESS_VOID(rv);
+  }
+  // For most actions we want to clear the cached styles, but there are
+  // exceptions
+  if (!IsStyleCachePreservingAction(mTheAction)) {
+    ClearCachedStyles();
+  }
+}
+
+nsresult
+HTMLEditRules::WillInsertText(EditAction aAction,
+                              Selection* aSelection,
+                              bool* aCancel,
+                              bool* aHandled,
+                              const nsAString* inString,
+                              nsAString* outString,
+                              int32_t aMaxLength)
+{
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  if (inString->IsEmpty() && aAction != EditAction::insertIMEText) {
+    // HACK: this is a fix for bug 19395
+    // I can't outlaw all empty insertions
+    // because IME transaction depend on them
+    // There is more work to do to make the
+    // world safe for IME.
+    *aCancel = true;
+    *aHandled = false;
+    return NS_OK;
+  }
+
+  // initialize out param
+  *aCancel = false;
+  *aHandled = true;
+  // If the selection isn't collapsed, delete it.  Don't delete existing inline
+  // tags, because we're hopefully going to insert text (bug 787432).
+  if (!aSelection->Collapsed()) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->DeleteSelection(nsIEditor::eNone, nsIEditor::eNoStrip);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  WillInsert(*aSelection, aCancel);
+  // initialize out param
+  // we want to ignore result of WillInsert()
+  *aCancel = false;
+
+  // we need to get the doc
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIDocument> doc = mHTMLEditor->GetDocument();
+  NS_ENSURE_STATE(doc);
+
+  // for every property that is set, insert a new inline style node
+  nsresult rv = CreateStyleForInsertText(*aSelection, *doc);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // get the (collapsed) selection location
+  NS_ENSURE_STATE(mHTMLEditor);
+  NS_ENSURE_STATE(aSelection->GetRangeAt(0));
+  nsCOMPtr<nsINode> selNode = aSelection->GetRangeAt(0)->GetStartParent();
+  int32_t selOffset = aSelection->GetRangeAt(0)->StartOffset();
+  NS_ENSURE_STATE(selNode);
+
+  // dont put text in places that can't have it
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (!mHTMLEditor->IsTextNode(selNode) &&
+      (!mHTMLEditor || !mHTMLEditor->CanContainTag(*selNode,
+                                                   *nsGkAtoms::textTagName))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (aAction == EditAction::insertIMEText) {
+    // Right now the WSRunObject code bails on empty strings, but IME needs
+    // the InsertTextImpl() call to still happen since empty strings are meaningful there.
+    NS_ENSURE_STATE(mHTMLEditor);
+    // If there is one or more IME selections, its minimum offset should be
+    // the insertion point.
+    int32_t IMESelectionOffset =
+      mHTMLEditor->GetIMESelectionStartOffsetIn(selNode);
+    if (IMESelectionOffset >= 0) {
+      selOffset = IMESelectionOffset;
+    }
+    if (inString->IsEmpty()) {
+      rv = mHTMLEditor->InsertTextImpl(*inString, address_of(selNode),
+                                       &selOffset, doc);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      WSRunObject wsObj(mHTMLEditor, selNode, selOffset);
+      rv = wsObj.InsertText(*inString, address_of(selNode), &selOffset, doc);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+  }
+  // aAction == kInsertText
+  else {
+    // find where we are
+    nsCOMPtr<nsINode> curNode = selNode;
+    int32_t curOffset = selOffset;
+
+    // is our text going to be PREformatted?
+    // We remember this so that we know how to handle tabs.
+    bool isPRE;
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->IsPreformatted(GetAsDOMNode(selNode), &isPRE);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // turn off the edit listener: we know how to
+    // build the "doc changed range" ourselves, and it's
+    // must faster to do it once here than to track all
+    // the changes one at a time.
+    AutoLockListener lockit(&mListenerEnabled);
+
+    // don't spaz my selection in subtransactions
+    NS_ENSURE_STATE(mHTMLEditor);
+    AutoTransactionsConserveSelection dontSpazMySelection(mHTMLEditor);
+    nsAutoString tString(*inString);
+    const char16_t *unicodeBuf = tString.get();
+    int32_t pos = 0;
+    NS_NAMED_LITERAL_STRING(newlineStr, LFSTR);
+
+    // for efficiency, break out the pre case separately.  This is because
+    // its a lot cheaper to search the input string for only newlines than
+    // it is to search for both tabs and newlines.
+    if (isPRE || IsPlaintextEditor()) {
+      while (unicodeBuf && pos != -1 &&
+             pos < static_cast<int32_t>(inString->Length())) {
+        int32_t oldPos = pos;
+        int32_t subStrLen;
+        pos = tString.FindChar(nsCRT::LF, oldPos);
+
+        if (pos != -1) {
+          subStrLen = pos - oldPos;
+          // if first char is newline, then use just it
+          if (!subStrLen) {
+            subStrLen = 1;
+          }
+        } else {
+          subStrLen = tString.Length() - oldPos;
+          pos = tString.Length();
+        }
+
+        nsDependentSubstring subStr(tString, oldPos, subStrLen);
+
+        // is it a return?
+        if (subStr.Equals(newlineStr)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          nsCOMPtr<Element> br =
+            mHTMLEditor->CreateBRImpl(address_of(curNode), &curOffset,
+                                      nsIEditor::eNone);
+          NS_ENSURE_STATE(br);
+          pos++;
+        } else {
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->InsertTextImpl(subStr, address_of(curNode),
+                                           &curOffset, doc);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      }
+    } else {
+      NS_NAMED_LITERAL_STRING(tabStr, "\t");
+      NS_NAMED_LITERAL_STRING(spacesStr, "    ");
+      char specialChars[] = {TAB, nsCRT::LF, 0};
+      while (unicodeBuf && pos != -1 &&
+             pos < static_cast<int32_t>(inString->Length())) {
+        int32_t oldPos = pos;
+        int32_t subStrLen;
+        pos = tString.FindCharInSet(specialChars, oldPos);
+
+        if (pos != -1) {
+          subStrLen = pos - oldPos;
+          // if first char is newline, then use just it
+          if (!subStrLen) {
+            subStrLen = 1;
+          }
+        } else {
+          subStrLen = tString.Length() - oldPos;
+          pos = tString.Length();
+        }
+
+        nsDependentSubstring subStr(tString, oldPos, subStrLen);
+        NS_ENSURE_STATE(mHTMLEditor);
+        WSRunObject wsObj(mHTMLEditor, curNode, curOffset);
+
+        // is it a tab?
+        if (subStr.Equals(tabStr)) {
+          rv =
+            wsObj.InsertText(spacesStr, address_of(curNode), &curOffset, doc);
+          NS_ENSURE_SUCCESS(rv, rv);
+          pos++;
+        }
+        // is it a return?
+        else if (subStr.Equals(newlineStr)) {
+          nsCOMPtr<Element> br = wsObj.InsertBreak(address_of(curNode),
+                                                   &curOffset,
+                                                   nsIEditor::eNone);
+          NS_ENSURE_TRUE(br, NS_ERROR_FAILURE);
+          pos++;
+        } else {
+          rv = wsObj.InsertText(subStr, address_of(curNode), &curOffset, doc);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      }
+    }
+    aSelection->SetInterlinePosition(false);
+    if (curNode) aSelection->Collapse(curNode, curOffset);
+    // manually update the doc changed range so that AfterEdit will clean up
+    // the correct portion of the document.
+    if (!mDocChangeRange) {
+      mDocChangeRange = new nsRange(selNode);
+    }
+    rv = mDocChangeRange->SetStart(selNode, selOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (curNode) {
+      rv = mDocChangeRange->SetEnd(curNode, curOffset);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      rv = mDocChangeRange->SetEnd(selNode, selOffset);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillLoadHTML(Selection* aSelection,
+                            bool* aCancel)
+{
+  NS_ENSURE_TRUE(aSelection && aCancel, NS_ERROR_NULL_POINTER);
+
+  *aCancel = false;
+
+  // Delete mBogusNode if it exists. If we really need one,
+  // it will be added during post-processing in AfterEditInner().
+
+  if (mBogusNode) {
+    mTextEditor->DeleteNode(mBogusNode);
+    mBogusNode = nullptr;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillInsertBreak(Selection& aSelection,
+                               bool* aCancel,
+                               bool* aHandled)
+{
+  MOZ_ASSERT(aCancel && aHandled);
+  *aCancel = false;
+  *aHandled = false;
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // If the selection isn't collapsed, delete it.
+  if (!aSelection.Collapsed()) {
+    nsresult rv =
+      htmlEditor->DeleteSelection(nsIEditor::eNone, nsIEditor::eStrip);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  WillInsert(aSelection, aCancel);
+
+  // Initialize out param.  We want to ignore result of WillInsert().
+  *aCancel = false;
+
+  // Split any mailcites in the way.  Should we abort this if we encounter
+  // table cell boundaries?
+  if (IsMailEditor()) {
+    nsresult rv = SplitMailCites(&aSelection, aHandled);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (*aHandled) {
+      return NS_OK;
+    }
+  }
+
+  // Smart splitting rules
+  NS_ENSURE_TRUE(aSelection.GetRangeAt(0) &&
+                 aSelection.GetRangeAt(0)->GetStartParent(),
+                 NS_ERROR_FAILURE);
+  OwningNonNull<nsINode> node = *aSelection.GetRangeAt(0)->GetStartParent();
+  int32_t offset = aSelection.GetRangeAt(0)->StartOffset();
+
+  // Do nothing if the node is read-only
+  if (!htmlEditor->IsModifiableNode(node)) {
+    *aCancel = true;
+    return NS_OK;
+  }
+
+  // Identify the block
+  nsCOMPtr<Element> blockParent = htmlEditor->GetBlock(node);
+  NS_ENSURE_TRUE(blockParent, NS_ERROR_FAILURE);
+
+  // If the active editing host is an inline element, or if the active editing
+  // host is the block parent itself, just append a br.
+  nsCOMPtr<Element> host = htmlEditor->GetActiveEditingHost();
+  if (!EditorUtils::IsDescendantOf(blockParent, host)) {
+    nsresult rv = StandardBreakImpl(node, offset, aSelection);
+    NS_ENSURE_SUCCESS(rv, rv);
+    *aHandled = true;
+    return NS_OK;
+  }
+
+  // If block is empty, populate with br.  (For example, imagine a div that
+  // contains the word "text".  The user selects "text" and types return.
+  // "Text" is deleted leaving an empty block.  We want to put in one br to
+  // make block have a line.  Then code further below will put in a second br.)
+  bool isEmpty;
+  IsEmptyBlock(*blockParent, &isEmpty);
+  if (isEmpty) {
+    nsCOMPtr<Element> br = htmlEditor->CreateBR(blockParent,
+                                                blockParent->Length());
+    NS_ENSURE_STATE(br);
+  }
+
+  nsCOMPtr<Element> listItem = IsInListItem(blockParent);
+  if (listItem && listItem != host) {
+    ReturnInListItem(aSelection, *listItem, node, offset);
+    *aHandled = true;
+    return NS_OK;
+  } else if (HTMLEditUtils::IsHeader(*blockParent)) {
+    // Headers: close (or split) header
+    ReturnInHeader(aSelection, *blockParent, node, offset);
+    *aHandled = true;
+    return NS_OK;
+  } else if (blockParent->IsHTMLElement(nsGkAtoms::p)) {
+    // Paragraphs: special rules to look for <br>s
+    nsresult rv =
+      ReturnInParagraph(&aSelection, GetAsDOMNode(blockParent),
+                        GetAsDOMNode(node), offset, aCancel, aHandled);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Fall through, we may not have handled it in ReturnInParagraph()
+  }
+
+  // If not already handled then do the standard thing
+  if (!(*aHandled)) {
+    *aHandled = true;
+    return StandardBreakImpl(node, offset, aSelection);
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::StandardBreakImpl(nsINode& aNode,
+                                 int32_t aOffset,
+                                 Selection& aSelection)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  nsCOMPtr<Element> brNode;
+  bool bAfterBlock = false;
+  bool bBeforeBlock = false;
+  nsCOMPtr<nsINode> node = &aNode;
+
+  if (IsPlaintextEditor()) {
+    brNode = htmlEditor->CreateBR(node, aOffset);
+    NS_ENSURE_STATE(brNode);
+  } else {
+    WSRunObject wsObj(htmlEditor, node, aOffset);
+    int32_t visOffset = 0;
+    WSType wsType;
+    nsCOMPtr<nsINode> visNode;
+    wsObj.PriorVisibleNode(node, aOffset, address_of(visNode),
+                           &visOffset, &wsType);
+    if (wsType & WSType::block) {
+      bAfterBlock = true;
+    }
+    wsObj.NextVisibleNode(node, aOffset, address_of(visNode),
+                          &visOffset, &wsType);
+    if (wsType & WSType::block) {
+      bBeforeBlock = true;
+    }
+    nsCOMPtr<nsIDOMNode> linkDOMNode;
+    if (htmlEditor->IsInLink(GetAsDOMNode(node), address_of(linkDOMNode))) {
+      // Split the link
+      nsCOMPtr<Element> linkNode = do_QueryInterface(linkDOMNode);
+      NS_ENSURE_STATE(linkNode || !linkDOMNode);
+      nsCOMPtr<nsINode> linkParent = linkNode->GetParentNode();
+      aOffset = htmlEditor->SplitNodeDeep(*linkNode, *node->AsContent(),
+                                          aOffset,
+                                          HTMLEditor::EmptyContainers::no);
+      NS_ENSURE_STATE(aOffset != -1);
+      node = linkParent;
+    }
+    brNode = wsObj.InsertBreak(address_of(node), &aOffset, nsIEditor::eNone);
+    NS_ENSURE_TRUE(brNode, NS_ERROR_FAILURE);
+  }
+  node = brNode->GetParentNode();
+  NS_ENSURE_TRUE(node, NS_ERROR_NULL_POINTER);
+  int32_t offset = node->IndexOf(brNode);
+  if (bAfterBlock && bBeforeBlock) {
+    // We just placed a br between block boundaries.  This is the one case
+    // where we want the selection to be before the br we just placed, as the
+    // br will be on a new line, rather than at end of prior line.
+    aSelection.SetInterlinePosition(true);
+    nsresult rv = aSelection.Collapse(node, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    WSRunObject wsObj(htmlEditor, node, offset + 1);
+    nsCOMPtr<nsINode> secondBR;
+    int32_t visOffset = 0;
+    WSType wsType;
+    wsObj.NextVisibleNode(node, offset + 1, address_of(secondBR),
+                          &visOffset, &wsType);
+    if (wsType == WSType::br) {
+      // The next thing after the break we inserted is another break.  Move the
+      // second break to be the first break's sibling.  This will prevent them
+      // from being in different inline nodes, which would break
+      // SetInterlinePosition().  It will also assure that if the user clicks
+      // away and then clicks back on their new blank line, they will still get
+      // the style from the line above.
+      nsCOMPtr<nsINode> brParent = secondBR->GetParentNode();
+      int32_t brOffset = brParent ? brParent->IndexOf(secondBR) : -1;
+      if (brParent != node || brOffset != offset + 1) {
+        nsresult rv =
+          htmlEditor->MoveNode(secondBR->AsContent(), node, offset + 1);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+    // SetInterlinePosition(true) means we want the caret to stick to the
+    // content on the "right".  We want the caret to stick to whatever is past
+    // the break.  This is because the break is on the same line we were on,
+    // but the next content will be on the following line.
+
+    // An exception to this is if the break has a next sibling that is a block
+    // node.  Then we stick to the left to avoid an uber caret.
+    nsCOMPtr<nsIContent> siblingNode = brNode->GetNextSibling();
+    if (siblingNode && IsBlockNode(*siblingNode)) {
+      aSelection.SetInterlinePosition(false);
+    } else {
+      aSelection.SetInterlinePosition(true);
+    }
+    nsresult rv = aSelection.Collapse(node, offset + 1);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::DidInsertBreak(Selection* aSelection,
+                              nsresult aResult)
+{
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::SplitMailCites(Selection* aSelection,
+                              bool* aHandled)
+{
+  NS_ENSURE_TRUE(aSelection && aHandled, NS_ERROR_NULL_POINTER);
+  nsCOMPtr<nsIContent> leftCite, rightCite;
+  nsCOMPtr<nsINode> selNode;
+  nsCOMPtr<Element> citeNode;
+  int32_t selOffset;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(aSelection, getter_AddRefs(selNode),
+                                       &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  citeNode = GetTopEnclosingMailCite(*selNode);
+  if (citeNode) {
+    // If our selection is just before a break, nudge it to be
+    // just after it.  This does two things for us.  It saves us the trouble of having to add
+    // a break here ourselves to preserve the "blockness" of the inline span mailquote
+    // (in the inline case), and :
+    // it means the break won't end up making an empty line that happens to be inside a
+    // mailquote (in either inline or block case).
+    // The latter can confuse a user if they click there and start typing,
+    // because being in the mailquote may affect wrapping behavior, or font color, etc.
+    NS_ENSURE_STATE(mHTMLEditor);
+    WSRunObject wsObj(mHTMLEditor, selNode, selOffset);
+    nsCOMPtr<nsINode> visNode;
+    int32_t visOffset=0;
+    WSType wsType;
+    wsObj.NextVisibleNode(selNode, selOffset, address_of(visNode),
+                          &visOffset, &wsType);
+    if (wsType == WSType::br) {
+      // ok, we are just before a break.  is it inside the mailquote?
+      if (visNode != citeNode && citeNode->Contains(visNode)) {
+        // it is.  so lets reset our selection to be just after it.
+        NS_ENSURE_STATE(mHTMLEditor);
+        selNode = mHTMLEditor->GetNodeLocation(visNode, &selOffset);
+        ++selOffset;
+      }
+    }
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    NS_ENSURE_STATE(selNode->IsContent());
+    int32_t newOffset = mHTMLEditor->SplitNodeDeep(*citeNode,
+        *selNode->AsContent(), selOffset, HTMLEditor::EmptyContainers::no,
+        getter_AddRefs(leftCite), getter_AddRefs(rightCite));
+    NS_ENSURE_STATE(newOffset != -1);
+
+    // Add an invisible <br> to the end of the left part if it was a <span> of
+    // style="display: block". This is important, since when serialising the
+    // cite to plain text, the span which caused the visual break is discarded.
+    // So the added <br> will guarantee that the serialiser will insert a
+    // break where the user saw one.
+    if (leftCite &&
+        leftCite->IsHTMLElement(nsGkAtoms::span) &&
+        leftCite->GetPrimaryFrame()->IsFrameOfType(nsIFrame::eBlockFrame)) {
+       nsCOMPtr<nsINode> lastChild = leftCite->GetLastChild();
+       if (lastChild && !lastChild->IsHTMLElement(nsGkAtoms::br)) {
+         // We ignore the result here.
+         nsCOMPtr<Element> invisBR =
+           mHTMLEditor->CreateBR(leftCite, leftCite->Length());
+      }
+    }
+
+    selNode = citeNode->GetParentNode();
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> brNode = mHTMLEditor->CreateBR(selNode, newOffset);
+    NS_ENSURE_STATE(brNode);
+
+    // want selection before the break, and on same line
+    aSelection->SetInterlinePosition(true);
+    rv = aSelection->Collapse(selNode, newOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // if citeNode wasn't a block, we might also want another break before it.
+    // We need to examine the content both before the br we just added and also
+    // just after it.  If we don't have another br or block boundary adjacent,
+    // then we will need a 2nd br added to achieve blank line that user expects.
+    if (IsInlineNode(*citeNode)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      WSRunObject wsObj(mHTMLEditor, selNode, newOffset);
+      nsCOMPtr<nsINode> visNode;
+      int32_t visOffset=0;
+      WSType wsType;
+      wsObj.PriorVisibleNode(selNode, newOffset, address_of(visNode),
+                             &visOffset, &wsType);
+      if (wsType == WSType::normalWS || wsType == WSType::text ||
+          wsType == WSType::special) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        WSRunObject wsObjAfterBR(mHTMLEditor, selNode, newOffset+1);
+        wsObjAfterBR.NextVisibleNode(selNode, newOffset + 1,
+                                     address_of(visNode), &visOffset, &wsType);
+        if (wsType == WSType::normalWS || wsType == WSType::text ||
+            wsType == WSType::special ||
+            // In case we're at the very end.
+            wsType == WSType::thisBlock) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          brNode = mHTMLEditor->CreateBR(selNode, newOffset);
+          NS_ENSURE_STATE(brNode);
+        }
+      }
+    }
+
+    // delete any empty cites
+    bool bEmptyCite = false;
+    if (leftCite) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->IsEmptyNode(leftCite, &bEmptyCite, true, false);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+      if (bEmptyCite) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->DeleteNode(leftCite);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      }
+    }
+
+    if (rightCite) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->IsEmptyNode(rightCite, &bEmptyCite, true, false);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+      if (bEmptyCite) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->DeleteNode(rightCite);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      }
+    }
+    *aHandled = true;
+  }
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::WillDeleteSelection(Selection* aSelection,
+                                   nsIEditor::EDirection aAction,
+                                   nsIEditor::EStripWrappers aStripWrappers,
+                                   bool* aCancel,
+                                   bool* aHandled)
+{
+  MOZ_ASSERT(aStripWrappers == nsIEditor::eStrip ||
+             aStripWrappers == nsIEditor::eNoStrip);
+
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  // Initialize out params
+  *aCancel = false;
+  *aHandled = false;
+
+  // Remember that we did a selection deletion.  Used by CreateStyleForInsertText()
+  mDidDeleteSelection = true;
+
+  // If there is only bogus content, cancel the operation
+  if (mBogusNode) {
+    *aCancel = true;
+    return NS_OK;
+  }
+
+  // First check for table selection mode.  If so, hand off to table editor.
+  nsCOMPtr<nsIDOMElement> cell;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetFirstSelectedCell(nullptr, getter_AddRefs(cell));
+  if (NS_SUCCEEDED(rv) && cell) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->DeleteTableCellContents();
+    *aHandled = true;
+    return rv;
+  }
+  cell = nullptr;
+
+  // origCollapsed is used later to determine whether we should join blocks. We
+  // don't really care about bCollapsed because it will be modified by
+  // ExtendSelectionForDelete later. JoinBlocks should happen if the original
+  // selection is collapsed and the cursor is at the end of a block element, in
+  // which case ExtendSelectionForDelete would always make the selection not
+  // collapsed.
+  bool bCollapsed = aSelection->Collapsed();
+  bool join = false;
+  bool origCollapsed = bCollapsed;
+
+  nsCOMPtr<nsINode> selNode;
+  int32_t selOffset;
+
+  NS_ENSURE_STATE(aSelection->GetRangeAt(0));
+  nsCOMPtr<nsINode> startNode = aSelection->GetRangeAt(0)->GetStartParent();
+  int32_t startOffset = aSelection->GetRangeAt(0)->StartOffset();
+  NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
+
+  if (bCollapsed) {
+    // If we are inside an empty block, delete it.
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> host = mHTMLEditor->GetActiveEditingHost();
+    NS_ENSURE_TRUE(host, NS_ERROR_FAILURE);
+    rv = CheckForEmptyBlock(startNode, host, aSelection, aAction, aHandled);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (*aHandled) {
+      return NS_OK;
+    }
+
+    // Test for distance between caret and text that will be deleted
+    rv = CheckBidiLevelForDeletion(aSelection, GetAsDOMNode(startNode),
+                                   startOffset, aAction, aCancel);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (*aCancel) {
+      return NS_OK;
+    }
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->ExtendSelectionForDelete(aSelection, &aAction);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // We should delete nothing.
+    if (aAction == nsIEditor::eNone) {
+      return NS_OK;
+    }
+
+    // ExtendSelectionForDelete() may have changed the selection, update it
+    NS_ENSURE_STATE(aSelection->GetRangeAt(0));
+    startNode = aSelection->GetRangeAt(0)->GetStartParent();
+    startOffset = aSelection->GetRangeAt(0)->StartOffset();
+    NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
+
+    bCollapsed = aSelection->Collapsed();
+  }
+
+  if (bCollapsed) {
+    // What's in the direction we are deleting?
+    NS_ENSURE_STATE(mHTMLEditor);
+    WSRunObject wsObj(mHTMLEditor, startNode, startOffset);
+    nsCOMPtr<nsINode> visNode;
+    int32_t visOffset;
+    WSType wsType;
+
+    // Find next visible node
+    if (aAction == nsIEditor::eNext) {
+      wsObj.NextVisibleNode(startNode, startOffset, address_of(visNode),
+                            &visOffset, &wsType);
+    } else {
+      wsObj.PriorVisibleNode(startNode, startOffset, address_of(visNode),
+                             &visOffset, &wsType);
+    }
+
+    if (!visNode) {
+      // Can't find anything to delete!
+      *aCancel = true;
+      // XXX This is the result of mHTMLEditor->GetFirstSelectedCell().
+      //     The value could be both an error and NS_OK.
+      return rv;
+    }
+
+    if (wsType == WSType::normalWS) {
+      // We found some visible ws to delete.  Let ws code handle it.
+      *aHandled = true;
+      if (aAction == nsIEditor::eNext) {
+        rv = wsObj.DeleteWSForward();
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      } else {
+        rv = wsObj.DeleteWSBackward();
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      }
+      return InsertBRIfNeeded(aSelection);
+    }
+
+    if (wsType == WSType::text) {
+      // Found normal text to delete.
+      OwningNonNull<Text> nodeAsText = *visNode->GetAsText();
+      int32_t so = visOffset;
+      int32_t eo = visOffset + 1;
+      if (aAction == nsIEditor::ePrevious) {
+        if (!so) {
+          return NS_ERROR_UNEXPECTED;
+        }
+        so--;
+        eo--;
+        // Bug 1068979: delete both codepoints if surrogate pair
+        if (so > 0) {
+          const nsTextFragment *text = nodeAsText->GetText();
+          if (NS_IS_LOW_SURROGATE(text->CharAt(so)) &&
+              NS_IS_HIGH_SURROGATE(text->CharAt(so - 1))) {
+            so--;
+          }
+        }
+      } else {
+        RefPtr<nsRange> range = aSelection->GetRangeAt(0);
+        NS_ENSURE_STATE(range);
+
+        NS_ASSERTION(range->GetStartParent() == visNode,
+                     "selection start not in visNode");
+        NS_ASSERTION(range->GetEndParent() == visNode,
+                     "selection end not in visNode");
+
+        so = range->StartOffset();
+        eo = range->EndOffset();
+      }
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = WSRunObject::PrepareToDeleteRange(mHTMLEditor, address_of(visNode),
+                                             &so, address_of(visNode), &eo);
+      NS_ENSURE_SUCCESS(rv, rv);
+      NS_ENSURE_STATE(mHTMLEditor);
+      *aHandled = true;
+      rv = mHTMLEditor->DeleteText(nodeAsText, std::min(so, eo),
+                                   DeprecatedAbs(eo - so));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // XXX When Backspace key is pressed, Chromium removes following empty
+      //     text nodes when removing the last character of the non-empty text
+      //     node.  However, Edge never removes empty text nodes even if
+      //     selection is in the following empty text node(s).  For now, we
+      //     should keep our traditional behavior same as Edge for backward
+      //     compatibility.
+      // XXX When Delete key is pressed, Edge removes all preceding empty
+      //     text nodes when removing the first character of the non-empty
+      //     text node.  Chromium removes only selected empty text node and
+      //     following empty text nodes and the first character of the
+      //     non-empty text node.  For now, we should keep our traditional
+      //     behavior same as Chromium for backward compatibility.
+
+      DeleteNodeIfCollapsedText(nodeAsText);
+
+      rv = InsertBRIfNeeded(aSelection);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Remember that we did a ranged delete for the benefit of
+      // AfterEditInner().
+      mDidRangedDelete = true;
+
+      return NS_OK;
+    }
+
+    if (wsType == WSType::special || wsType == WSType::br ||
+        visNode->IsHTMLElement(nsGkAtoms::hr)) {
+      // Short circuit for invisible breaks.  delete them and recurse.
+      if (visNode->IsHTMLElement(nsGkAtoms::br) &&
+          (!mHTMLEditor || !mHTMLEditor->IsVisBreak(visNode))) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->DeleteNode(visNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        return WillDeleteSelection(aSelection, aAction, aStripWrappers,
+                                   aCancel, aHandled);
+      }
+
+      // Special handling for backspace when positioned after <hr>
+      if (aAction == nsIEditor::ePrevious &&
+          visNode->IsHTMLElement(nsGkAtoms::hr)) {
+        // Only if the caret is positioned at the end-of-hr-line position, we
+        // want to delete the <hr>.
+        //
+        // In other words, we only want to delete, if our selection position
+        // (indicated by startNode and startOffset) is the position directly
+        // after the <hr>, on the same line as the <hr>.
+        //
+        // To detect this case we check:
+        // startNode == parentOfVisNode
+        // and
+        // startOffset -1 == visNodeOffsetToVisNodeParent
+        // and
+        // interline position is false (left)
+        //
+        // In any other case we set the position to startnode -1 and
+        // interlineposition to false, only moving the caret to the
+        // end-of-hr-line position.
+        bool moveOnly = true;
+
+        selNode = visNode->GetParentNode();
+        selOffset = selNode ? selNode->IndexOf(visNode) : -1;
+
+        bool interLineIsRight;
+        rv = aSelection->GetInterlinePosition(&interLineIsRight);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        if (startNode == selNode && startOffset - 1 == selOffset &&
+            !interLineIsRight) {
+          moveOnly = false;
+        }
+
+        if (moveOnly) {
+          // Go to the position after the <hr>, but to the end of the <hr> line
+          // by setting the interline position to left.
+          ++selOffset;
+          aSelection->Collapse(selNode, selOffset);
+          aSelection->SetInterlinePosition(false);
+          mDidExplicitlySetInterline = true;
+          *aHandled = true;
+
+          // There is one exception to the move only case.  If the <hr> is
+          // followed by a <br> we want to delete the <br>.
+
+          WSType otherWSType;
+          nsCOMPtr<nsINode> otherNode;
+          int32_t otherOffset;
+
+          wsObj.NextVisibleNode(startNode, startOffset, address_of(otherNode),
+                                &otherOffset, &otherWSType);
+
+          if (otherWSType == WSType::br) {
+            // Delete the <br>
+
+            NS_ENSURE_STATE(mHTMLEditor);
+            nsCOMPtr<nsIContent> otherContent(do_QueryInterface(otherNode));
+            rv = WSRunObject::PrepareToDeleteNode(mHTMLEditor, otherContent);
+            NS_ENSURE_SUCCESS(rv, rv);
+            NS_ENSURE_STATE(mHTMLEditor);
+            rv = mHTMLEditor->DeleteNode(otherNode);
+            NS_ENSURE_SUCCESS(rv, rv);
+          }
+
+          return NS_OK;
+        }
+        // Else continue with normal delete code
+      }
+
+      // Found break or image, or hr.
+      NS_ENSURE_STATE(mHTMLEditor);
+      NS_ENSURE_STATE(visNode->IsContent());
+      rv = WSRunObject::PrepareToDeleteNode(mHTMLEditor, visNode->AsContent());
+      NS_ENSURE_SUCCESS(rv, rv);
+      // Remember sibling to visnode, if any
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<nsIContent> sibling = mHTMLEditor->GetPriorHTMLSibling(visNode);
+      // Delete the node, and join like nodes if appropriate
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(visNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      // We did something, so let's say so.
+      *aHandled = true;
+      // Is there a prior node and are they siblings?
+      nsCOMPtr<nsINode> stepbrother;
+      if (sibling) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        stepbrother = mHTMLEditor->GetNextHTMLSibling(sibling);
+      }
+      // Are they both text nodes?  If so, join them!
+      if (startNode == stepbrother && startNode->GetAsText() &&
+          sibling->GetAsText()) {
+        EditorDOMPoint pt = JoinNodesSmart(*sibling, *startNode->AsContent());
+        NS_ENSURE_STATE(pt.node);
+        // Fix up selection
+        rv = aSelection->Collapse(pt.node, pt.offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      rv = InsertBRIfNeeded(aSelection);
+      NS_ENSURE_SUCCESS(rv, rv);
+      return NS_OK;
+    }
+
+    if (wsType == WSType::otherBlock) {
+      // Make sure it's not a table element.  If so, cancel the operation
+      // (translation: users cannot backspace or delete across table cells)
+      if (HTMLEditUtils::IsTableElement(visNode)) {
+        *aCancel = true;
+        return NS_OK;
+      }
+
+      // Next to a block.  See if we are between a block and a br.  If so, we
+      // really want to delete the br.  Else join content at selection to the
+      // block.
+      bool bDeletedBR = false;
+      WSType otherWSType;
+      nsCOMPtr<nsINode> otherNode;
+      int32_t otherOffset;
+
+      // Find node in other direction
+      if (aAction == nsIEditor::eNext) {
+        wsObj.PriorVisibleNode(startNode, startOffset, address_of(otherNode),
+                               &otherOffset, &otherWSType);
+      } else {
+        wsObj.NextVisibleNode(startNode, startOffset, address_of(otherNode),
+                              &otherOffset, &otherWSType);
+      }
+
+      // First find the adjacent node in the block
+      nsCOMPtr<nsIContent> leafNode;
+      nsCOMPtr<nsINode> leftNode, rightNode;
+      if (aAction == nsIEditor::ePrevious) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        leafNode = mHTMLEditor->GetLastEditableLeaf(*visNode);
+        leftNode = leafNode;
+        rightNode = startNode;
+      } else {
+        NS_ENSURE_STATE(mHTMLEditor);
+        leafNode = mHTMLEditor->GetFirstEditableLeaf(*visNode);
+        leftNode = startNode;
+        rightNode = leafNode;
+      }
+
+      if (otherNode->IsHTMLElement(nsGkAtoms::br)) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->DeleteNode(otherNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // XXX Only in this case, setting "handled" to true only when it
+        //     succeeds?
+        *aHandled = true;
+        bDeletedBR = true;
+      }
+
+      // Don't cross table boundaries
+      if (leftNode && rightNode &&
+          InDifferentTableElements(leftNode, rightNode)) {
+        return NS_OK;
+      }
+
+      if (bDeletedBR) {
+        // Put selection at edge of block and we are done.
+        NS_ENSURE_STATE(leafNode);
+        EditorDOMPoint newSel = GetGoodSelPointForNode(*leafNode, aAction);
+        NS_ENSURE_STATE(newSel.node);
+        aSelection->Collapse(newSel.node, newSel.offset);
+        return NS_OK;
+      }
+
+      // Else we are joining content to block
+
+      nsCOMPtr<nsINode> selPointNode = startNode;
+      int32_t selPointOffset = startOffset;
+      {
+        NS_ENSURE_STATE(mHTMLEditor);
+        AutoTrackDOMPoint tracker(mHTMLEditor->mRangeUpdater,
+                                  address_of(selPointNode), &selPointOffset);
+        NS_ENSURE_STATE(leftNode && leftNode->IsContent() &&
+                        rightNode && rightNode->IsContent());
+        *aHandled = true;
+        rv = JoinBlocks(*leftNode->AsContent(), *rightNode->AsContent(),
+                        aCancel);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      aSelection->Collapse(selPointNode, selPointOffset);
+      return NS_OK;
+    }
+
+    if (wsType == WSType::thisBlock) {
+      // At edge of our block.  Look beside it and see if we can join to an
+      // adjacent block
+
+      // Make sure it's not a table element.  If so, cancel the operation
+      // (translation: users cannot backspace or delete across table cells)
+      if (HTMLEditUtils::IsTableElement(visNode)) {
+        *aCancel = true;
+        return NS_OK;
+      }
+
+      // First find the relevant nodes
+      nsCOMPtr<nsINode> leftNode, rightNode;
+      if (aAction == nsIEditor::ePrevious) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        leftNode = mHTMLEditor->GetPriorHTMLNode(visNode);
+        rightNode = startNode;
+      } else {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rightNode = mHTMLEditor->GetNextHTMLNode(visNode);
+        leftNode = startNode;
+      }
+
+      // Nothing to join
+      if (!leftNode || !rightNode) {
+        *aCancel = true;
+        return NS_OK;
+      }
+
+      // Don't cross table boundaries -- cancel it
+      if (InDifferentTableElements(leftNode, rightNode)) {
+        *aCancel = true;
+        return NS_OK;
+      }
+
+      nsCOMPtr<nsINode> selPointNode = startNode;
+      int32_t selPointOffset = startOffset;
+      {
+        NS_ENSURE_STATE(mHTMLEditor);
+        AutoTrackDOMPoint tracker(mHTMLEditor->mRangeUpdater,
+                                  address_of(selPointNode), &selPointOffset);
+        NS_ENSURE_STATE(leftNode->IsContent() && rightNode->IsContent());
+        *aHandled = true;
+        rv = JoinBlocks(*leftNode->AsContent(), *rightNode->AsContent(),
+                        aCancel);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      aSelection->Collapse(selPointNode, selPointOffset);
+      return NS_OK;
+    }
+  }
+
+
+  // Else we have a non-collapsed selection.  First adjust the selection.
+  rv = ExpandSelectionForDeletion(*aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Remember that we did a ranged delete for the benefit of AfterEditInner().
+  mDidRangedDelete = true;
+
+  // Refresh start and end points
+  NS_ENSURE_STATE(aSelection->GetRangeAt(0));
+  startNode = aSelection->GetRangeAt(0)->GetStartParent();
+  startOffset = aSelection->GetRangeAt(0)->StartOffset();
+  NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
+  nsCOMPtr<nsINode> endNode = aSelection->GetRangeAt(0)->GetEndParent();
+  int32_t endOffset = aSelection->GetRangeAt(0)->EndOffset();
+  NS_ENSURE_TRUE(endNode, NS_ERROR_FAILURE);
+
+  // Figure out if the endpoints are in nodes that can be merged.  Adjust
+  // surrounding whitespace in preparation to delete selection.
+  if (!IsPlaintextEditor()) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    AutoTransactionsConserveSelection dontSpazMySelection(mHTMLEditor);
+    rv = WSRunObject::PrepareToDeleteRange(mHTMLEditor,
+                                           address_of(startNode), &startOffset,
+                                           address_of(endNode), &endOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  {
+    // Track location of where we are deleting
+    NS_ENSURE_STATE(mHTMLEditor);
+    AutoTrackDOMPoint startTracker(mHTMLEditor->mRangeUpdater,
+                                   address_of(startNode), &startOffset);
+    AutoTrackDOMPoint endTracker(mHTMLEditor->mRangeUpdater,
+                                 address_of(endNode), &endOffset);
+    // We are handling all ranged deletions directly now.
+    *aHandled = true;
+
+    if (endNode == startNode) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteSelectionImpl(aAction, aStripWrappers);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      // Figure out mailcite ancestors
+      nsCOMPtr<Element> startCiteNode = GetTopEnclosingMailCite(*startNode);
+      nsCOMPtr<Element> endCiteNode = GetTopEnclosingMailCite(*endNode);
+
+      // If we only have a mailcite at one of the two endpoints, set the
+      // directionality of the deletion so that the selection will end up
+      // outside the mailcite.
+      if (startCiteNode && !endCiteNode) {
+        aAction = nsIEditor::eNext;
+      } else if (!startCiteNode && endCiteNode) {
+        aAction = nsIEditor::ePrevious;
+      }
+
+      // Figure out block parents
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<Element> leftParent = mHTMLEditor->GetBlock(*startNode);
+      nsCOMPtr<Element> rightParent = mHTMLEditor->GetBlock(*endNode);
+
+      // Are endpoint block parents the same?  Use default deletion
+      if (leftParent && leftParent == rightParent) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        mHTMLEditor->DeleteSelectionImpl(aAction, aStripWrappers);
+      } else {
+        // Deleting across blocks.  Are the blocks of same type?
+        NS_ENSURE_STATE(leftParent && rightParent);
+
+        // Are the blocks siblings?
+        nsCOMPtr<nsINode> leftBlockParent = leftParent->GetParentNode();
+        nsCOMPtr<nsINode> rightBlockParent = rightParent->GetParentNode();
+
+        // MOOSE: this could conceivably screw up a table.. fix me.
+        NS_ENSURE_STATE(mHTMLEditor);
+        if (leftBlockParent == rightBlockParent &&
+            mHTMLEditor->NodesSameType(GetAsDOMNode(leftParent),
+                                       GetAsDOMNode(rightParent)) &&
+            // XXX What's special about these three types of block?
+            (leftParent->IsHTMLElement(nsGkAtoms::p) ||
+             HTMLEditUtils::IsListItem(leftParent) ||
+             HTMLEditUtils::IsHeader(*leftParent))) {
+          // First delete the selection
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->DeleteSelectionImpl(aAction, aStripWrappers);
+          NS_ENSURE_SUCCESS(rv, rv);
+          // Join blocks
+          NS_ENSURE_STATE(mHTMLEditor);
+          EditorDOMPoint pt =
+            mHTMLEditor->JoinNodeDeep(*leftParent, *rightParent);
+          NS_ENSURE_STATE(pt.node);
+          // Fix up selection
+          rv = aSelection->Collapse(pt.node, pt.offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          return NS_OK;
+        }
+
+        // Else blocks not same type, or not siblings.  Delete everything
+        // except table elements.
+        join = true;
+
+        uint32_t rangeCount = aSelection->RangeCount();
+        for (uint32_t rangeIdx = 0; rangeIdx < rangeCount; ++rangeIdx) {
+          OwningNonNull<nsRange> range = *aSelection->GetRangeAt(rangeIdx);
+
+          // Build a list of nodes in the range
+          nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+          TrivialFunctor functor;
+          DOMSubtreeIterator iter;
+          nsresult rv = iter.Init(*range);
+          NS_ENSURE_SUCCESS(rv, rv);
+          iter.AppendList(functor, arrayOfNodes);
+
+          // Now that we have the list, delete non-table elements
+          int32_t listCount = arrayOfNodes.Length();
+          for (int32_t j = 0; j < listCount; j++) {
+            nsCOMPtr<nsINode> somenode = do_QueryInterface(arrayOfNodes[0]);
+            NS_ENSURE_STATE(somenode);
+            DeleteNonTableElements(somenode);
+            arrayOfNodes.RemoveElementAt(0);
+            // If something visible is deleted, no need to join.  Visible means
+            // all nodes except non-visible textnodes and breaks.
+            if (join && origCollapsed) {
+              if (!somenode->IsContent()) {
+                join = false;
+                continue;
+              }
+              nsCOMPtr<nsIContent> content = somenode->AsContent();
+              if (content->NodeType() == nsIDOMNode::TEXT_NODE) {
+                NS_ENSURE_STATE(mHTMLEditor);
+                mHTMLEditor->IsVisTextNode(content, &join, true);
+              } else {
+                NS_ENSURE_STATE(mHTMLEditor);
+                join = content->IsHTMLElement(nsGkAtoms::br) &&
+                       !mHTMLEditor->IsVisBreak(somenode);
+              }
+            }
+          }
+        }
+
+        // Check endpoints for possible text deletion.  We can assume that if
+        // text node is found, we can delete to end or to begining as
+        // appropriate, since the case where both sel endpoints in same text
+        // node was already handled (we wouldn't be here)
+        if (startNode->GetAsText() &&
+            startNode->Length() > static_cast<uint32_t>(startOffset)) {
+          // Delete to last character
+          OwningNonNull<nsGenericDOMDataNode> dataNode =
+            *static_cast<nsGenericDOMDataNode*>(startNode.get());
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->DeleteText(dataNode, startOffset,
+                                       startNode->Length() - startOffset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+        if (endNode->GetAsText() && endOffset) {
+          // Delete to first character
+          NS_ENSURE_STATE(mHTMLEditor);
+          OwningNonNull<nsGenericDOMDataNode> dataNode =
+            *static_cast<nsGenericDOMDataNode*>(endNode.get());
+          rv = mHTMLEditor->DeleteText(dataNode, 0, endOffset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+
+        if (join) {
+          rv = JoinBlocks(*leftParent, *rightParent, aCancel);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      }
+    }
+  }
+
+  // We might have left only collapsed whitespace in the start/end nodes
+  {
+    AutoTrackDOMPoint startTracker(mHTMLEditor->mRangeUpdater,
+                                   address_of(startNode), &startOffset);
+    AutoTrackDOMPoint endTracker(mHTMLEditor->mRangeUpdater,
+                                 address_of(endNode), &endOffset);
+
+    DeleteNodeIfCollapsedText(*startNode);
+    DeleteNodeIfCollapsedText(*endNode);
+  }
+
+  // If we're joining blocks: if deleting forward the selection should be
+  // collapsed to the end of the selection, if deleting backward the selection
+  // should be collapsed to the beginning of the selection. But if we're not
+  // joining then the selection should collapse to the beginning of the
+  // selection if we'redeleting forward, because the end of the selection will
+  // still be in the next block. And same thing for deleting backwards
+  // (selection should collapse to the end, because the beginning will still be
+  // in the first block). See Bug 507936
+  if (aAction == (join ? nsIEditor::eNext : nsIEditor::ePrevious)) {
+    rv = aSelection->Collapse(endNode, endOffset);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  } else {
+    rv = aSelection->Collapse(startNode, startOffset);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+/**
+ * If aNode is a text node that contains only collapsed whitespace, delete it.
+ * It doesn't serve any useful purpose, and we don't want it to confuse code
+ * that doesn't correctly skip over it.
+ *
+ * If deleting the node fails (like if it's not editable), the caller should
+ * proceed as usual, so don't return any errors.
+ */
+void
+HTMLEditRules::DeleteNodeIfCollapsedText(nsINode& aNode)
+{
+  if (!aNode.GetAsText()) {
+    return;
+  }
+  bool empty;
+  nsresult rv = mHTMLEditor->IsVisTextNode(aNode.AsContent(), &empty, false);
+  NS_ENSURE_SUCCESS_VOID(rv);
+  if (empty) {
+    mHTMLEditor->DeleteNode(&aNode);
+  }
+}
+
+
+/**
+ * InsertBRIfNeeded() determines if a br is needed for current selection to not
+ * be spastic.  If so, it inserts one.  Callers responsibility to only call
+ * with collapsed selection.
+ *
+ * @param aSelection        The collapsed selection.
+ */
+nsresult
+HTMLEditRules::InsertBRIfNeeded(Selection* aSelection)
+{
+  NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
+
+  // get selection
+  nsCOMPtr<nsINode> node;
+  int32_t offset;
+  nsresult rv =
+    mTextEditor->GetStartNodeAndOffset(aSelection,
+                                       getter_AddRefs(node), &offset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_TRUE(node, NS_ERROR_FAILURE);
+
+  // inline elements don't need any br
+  if (!IsBlockNode(*node)) {
+    return NS_OK;
+  }
+
+  // examine selection
+  NS_ENSURE_STATE(mHTMLEditor);
+  WSRunObject wsObj(mHTMLEditor, node, offset);
+  if (((wsObj.mStartReason & WSType::block) ||
+       (wsObj.mStartReason & WSType::br)) &&
+      (wsObj.mEndReason & WSType::block)) {
+    // if we are tucked between block boundaries then insert a br
+    // first check that we are allowed to
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (mHTMLEditor->CanContainTag(*node, *nsGkAtoms::br)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<Element> br =
+        mHTMLEditor->CreateBR(node, offset, nsIEditor::ePrevious);
+      return br ? NS_OK : NS_ERROR_FAILURE;
+    }
+  }
+  return NS_OK;
+}
+
+/**
+ * GetGoodSelPointForNode() finds where at a node you would want to set the
+ * selection if you were trying to have a caret next to it.  Always returns a
+ * valid value (unless mHTMLEditor has gone away).
+ *
+ * @param aNode         The node
+ * @param aAction       Which edge to find:
+ *                        eNext/eNextWord/eToEndOfLine indicates beginning,
+ *                        ePrevious/PreviousWord/eToBeginningOfLine ending.
+ */
+EditorDOMPoint
+HTMLEditRules::GetGoodSelPointForNode(nsINode& aNode,
+                                      nsIEditor::EDirection aAction)
+{
+  MOZ_ASSERT(aAction == nsIEditor::eNext ||
+             aAction == nsIEditor::eNextWord ||
+             aAction == nsIEditor::ePrevious ||
+             aAction == nsIEditor::ePreviousWord ||
+             aAction == nsIEditor::eToBeginningOfLine ||
+             aAction == nsIEditor::eToEndOfLine);
+
+  bool isPreviousAction = (aAction == nsIEditor::ePrevious ||
+                           aAction == nsIEditor::ePreviousWord ||
+                           aAction == nsIEditor::eToBeginningOfLine);
+
+  NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+  if (aNode.GetAsText() || mHTMLEditor->IsContainer(&aNode) ||
+      NS_WARN_IF(!aNode.GetParentNode())) {
+    return EditorDOMPoint(&aNode, isPreviousAction ? aNode.Length() : 0);
+  }
+
+  EditorDOMPoint ret;
+  ret.node = aNode.GetParentNode();
+  ret.offset = ret.node ? ret.node->IndexOf(&aNode) : -1;
+  NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+  if ((!aNode.IsHTMLElement(nsGkAtoms::br) ||
+       mHTMLEditor->IsVisBreak(&aNode)) && isPreviousAction) {
+    ret.offset++;
+  }
+  return ret;
+}
+
+
+/**
+ * This method is used to join two block elements.  The right element is always
+ * joined to the left element.  If the elements are the same type and not
+ * nested within each other, JoinNodesSmart is called (example, joining two
+ * list items together into one).  If the elements are not the same type, or
+ * one is a descendant of the other, we instead destroy the right block placing
+ * its children into leftblock.  DTD containment rules are followed throughout.
+ */
+nsresult
+HTMLEditRules::JoinBlocks(nsIContent& aLeftNode,
+                          nsIContent& aRightNode,
+                          bool* aCanceled)
+{
+  MOZ_ASSERT(aCanceled);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  nsCOMPtr<Element> leftBlock = htmlEditor->GetBlock(aLeftNode);
+  nsCOMPtr<Element> rightBlock = htmlEditor->GetBlock(aRightNode);
+
+  // Sanity checks
+  NS_ENSURE_TRUE(leftBlock && rightBlock, NS_ERROR_NULL_POINTER);
+  NS_ENSURE_STATE(leftBlock != rightBlock);
+
+  if (HTMLEditUtils::IsTableElement(leftBlock) ||
+      HTMLEditUtils::IsTableElement(rightBlock)) {
+    // Do not try to merge table elements
+    *aCanceled = true;
+    return NS_OK;
+  }
+
+  // Make sure we don't try to move things into HR's, which look like blocks
+  // but aren't containers
+  if (leftBlock->IsHTMLElement(nsGkAtoms::hr)) {
+    leftBlock = htmlEditor->GetBlockNodeParent(leftBlock);
+  }
+  if (rightBlock->IsHTMLElement(nsGkAtoms::hr)) {
+    rightBlock = htmlEditor->GetBlockNodeParent(rightBlock);
+  }
+  NS_ENSURE_STATE(leftBlock && rightBlock);
+
+  // Bail if both blocks the same
+  if (leftBlock == rightBlock) {
+    *aCanceled = true;
+    return NS_OK;
+  }
+
+  // Joining a list item to its parent is a NOP.
+  if (HTMLEditUtils::IsList(leftBlock) &&
+      HTMLEditUtils::IsListItem(rightBlock) &&
+      rightBlock->GetParentNode() == leftBlock) {
+    return NS_OK;
+  }
+
+  // Special rule here: if we are trying to join list items, and they are in
+  // different lists, join the lists instead.
+  bool mergeLists = false;
+  nsIAtom* existingList = nsGkAtoms::_empty;
+  int32_t offset;
+  nsCOMPtr<Element> leftList, rightList;
+  if (HTMLEditUtils::IsListItem(leftBlock) &&
+      HTMLEditUtils::IsListItem(rightBlock)) {
+    leftList = leftBlock->GetParentElement();
+    rightList = rightBlock->GetParentElement();
+    if (leftList && rightList && leftList != rightList &&
+        !EditorUtils::IsDescendantOf(leftList, rightBlock, &offset) &&
+        !EditorUtils::IsDescendantOf(rightList, leftBlock, &offset)) {
+      // There are some special complications if the lists are descendants of
+      // the other lists' items.  Note that it is okay for them to be
+      // descendants of the other lists themselves, which is the usual case for
+      // sublists in our implementation.
+      leftBlock = leftList;
+      rightBlock = rightList;
+      mergeLists = true;
+      existingList = leftList->NodeInfo()->NameAtom();
+    }
+  }
+
+  AutoTransactionsConserveSelection dontSpazMySelection(htmlEditor);
+
+  int32_t rightOffset = 0;
+  int32_t leftOffset = -1;
+
+  // offset below is where you find yourself in rightBlock when you traverse
+  // upwards from leftBlock
+  if (EditorUtils::IsDescendantOf(leftBlock, rightBlock, &rightOffset)) {
+    // Tricky case.  Left block is inside right block.  Do ws adjustment.  This
+    // just destroys non-visible ws at boundaries we will be joining.
+    rightOffset++;
+    nsresult rv = WSRunObject::ScrubBlockBoundary(htmlEditor,
+                                                  WSRunObject::kBlockEnd,
+                                                  leftBlock);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    {
+      // We can't just track rightBlock because it's an Element.
+      nsCOMPtr<nsINode> trackingRightBlock(rightBlock);
+      AutoTrackDOMPoint tracker(htmlEditor->mRangeUpdater,
+                                address_of(trackingRightBlock), &rightOffset);
+      rv = WSRunObject::ScrubBlockBoundary(htmlEditor,
+                                           WSRunObject::kAfterBlock,
+                                           rightBlock, rightOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (trackingRightBlock->IsElement()) {
+        rightBlock = trackingRightBlock->AsElement();
+      } else {
+        NS_ENSURE_STATE(trackingRightBlock->GetParentElement());
+        rightBlock = trackingRightBlock->GetParentElement();
+      }
+    }
+    // Do br adjustment.
+    nsCOMPtr<Element> brNode =
+      CheckForInvisibleBR(*leftBlock, BRLocation::blockEnd);
+    if (mergeLists) {
+      // The idea here is to take all children in rightList that are past
+      // offset, and pull them into leftlist.
+      for (nsCOMPtr<nsIContent> child = rightList->GetChildAt(offset);
+           child; child = rightList->GetChildAt(rightOffset)) {
+        rv = htmlEditor->MoveNode(child, leftList, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    } else {
+      MoveBlock(*leftBlock, *rightBlock, leftOffset, rightOffset);
+    }
+    if (brNode) {
+      htmlEditor->DeleteNode(brNode);
+    }
+  // Offset below is where you find yourself in leftBlock when you traverse
+  // upwards from rightBlock
+  } else if (EditorUtils::IsDescendantOf(rightBlock, leftBlock, &leftOffset)) {
+    // Tricky case.  Right block is inside left block.  Do ws adjustment.  This
+    // just destroys non-visible ws at boundaries we will be joining.
+    nsresult rv = WSRunObject::ScrubBlockBoundary(htmlEditor,
+                                                  WSRunObject::kBlockStart,
+                                                  rightBlock);
+    NS_ENSURE_SUCCESS(rv, rv);
+    {
+      // We can't just track leftBlock because it's an Element, so track
+      // something else.
+      nsCOMPtr<nsINode> trackingLeftBlock(leftBlock);
+      AutoTrackDOMPoint tracker(htmlEditor->mRangeUpdater,
+                                address_of(trackingLeftBlock), &leftOffset);
+      rv = WSRunObject::ScrubBlockBoundary(htmlEditor,
+                                           WSRunObject::kBeforeBlock,
+                                           leftBlock, leftOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (trackingLeftBlock->IsElement()) {
+        leftBlock = trackingLeftBlock->AsElement();
+      } else {
+        NS_ENSURE_STATE(trackingLeftBlock->GetParentElement());
+        leftBlock = trackingLeftBlock->GetParentElement();
+      }
+    }
+    // Do br adjustment.
+    nsCOMPtr<Element> brNode =
+      CheckForInvisibleBR(*leftBlock, BRLocation::beforeBlock, leftOffset);
+    if (mergeLists) {
+      MoveContents(*rightList, *leftList, &leftOffset);
+    } else {
+      // Left block is a parent of right block, and the parent of the previous
+      // visible content.  Right block is a child and contains the contents we
+      // want to move.
+
+      int32_t previousContentOffset;
+      nsCOMPtr<nsINode> previousContentParent;
+
+      if (&aLeftNode == leftBlock) {
+        // We are working with valid HTML, aLeftNode is a block node, and is
+        // therefore allowed to contain rightBlock.  This is the simple case,
+        // we will simply move the content in rightBlock out of its block.
+        previousContentParent = leftBlock;
+        previousContentOffset = leftOffset;
+      } else {
+        // We try to work as well as possible with HTML that's already invalid.
+        // Although "right block" is a block, and a block must not be contained
+        // in inline elements, reality is that broken documents do exist.  The
+        // DIRECT parent of "left NODE" might be an inline element.  Previous
+        // versions of this code skipped inline parents until the first block
+        // parent was found (and used "left block" as the destination).
+        // However, in some situations this strategy moves the content to an
+        // unexpected position.  (see bug 200416) The new idea is to make the
+        // moving content a sibling, next to the previous visible content.
+
+        previousContentParent = aLeftNode.GetParentNode();
+        previousContentOffset = previousContentParent ?
+          previousContentParent->IndexOf(&aLeftNode) : -1;
+
+        // We want to move our content just after the previous visible node.
+        previousContentOffset++;
+      }
+
+      // Because we don't want the moving content to receive the style of the
+      // previous content, we split the previous content's style.
+
+      nsCOMPtr<Element> editorRoot = htmlEditor->GetEditorRoot();
+      if (!editorRoot || &aLeftNode != editorRoot) {
+        nsCOMPtr<nsIContent> splittedPreviousContent;
+        rv = htmlEditor->SplitStyleAbovePoint(
+                           address_of(previousContentParent),
+                           &previousContentOffset,
+                           nullptr, nullptr, nullptr,
+                           getter_AddRefs(splittedPreviousContent));
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        if (splittedPreviousContent) {
+          previousContentParent = splittedPreviousContent->GetParentNode();
+          previousContentOffset = previousContentParent ?
+            previousContentParent->IndexOf(splittedPreviousContent) : -1;
+        }
+      }
+
+      NS_ENSURE_TRUE(previousContentParent, NS_ERROR_NULL_POINTER);
+
+      rv = MoveBlock(*previousContentParent->AsElement(), *rightBlock,
+                     previousContentOffset, rightOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    if (brNode) {
+      htmlEditor->DeleteNode(brNode);
+    }
+  } else {
+    // Normal case.  Blocks are siblings, or at least close enough.  An example
+    // of the latter is <p>paragraph</p><ul><li>one<li>two<li>three</ul>.  The
+    // first li and the p are not true siblings, but we still want to join them
+    // if you backspace from li into p.
+
+    // Adjust whitespace at block boundaries
+    nsresult rv =
+      WSRunObject::PrepareToJoinBlocks(htmlEditor, leftBlock, rightBlock);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Do br adjustment.
+    nsCOMPtr<Element> brNode =
+      CheckForInvisibleBR(*leftBlock, BRLocation::blockEnd);
+    if (mergeLists || leftBlock->NodeInfo()->NameAtom() ==
+                      rightBlock->NodeInfo()->NameAtom()) {
+      // Nodes are same type.  merge them.
+      EditorDOMPoint pt = JoinNodesSmart(*leftBlock, *rightBlock);
+      if (pt.node && mergeLists) {
+        nsCOMPtr<Element> newBlock;
+        ConvertListType(rightBlock, getter_AddRefs(newBlock),
+                        existingList, nsGkAtoms::li);
+      }
+    } else {
+      // Nodes are dissimilar types.
+      rv = MoveBlock(*leftBlock, *rightBlock, leftOffset, rightOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    if (brNode) {
+      rv = htmlEditor->DeleteNode(brNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+
+/**
+ * Moves the content from aRightBlock starting from aRightOffset into
+ * aLeftBlock at aLeftOffset. Note that the "block" might merely be inline
+ * nodes between <br>s, or between blocks, etc.  DTD containment rules are
+ * followed throughout.
+ */
+nsresult
+HTMLEditRules::MoveBlock(Element& aLeftBlock,
+                         Element& aRightBlock,
+                         int32_t aLeftOffset,
+                         int32_t aRightOffset)
+{
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  // GetNodesFromPoint is the workhorse that figures out what we wnat to move.
+  nsresult rv = GetNodesFromPoint(EditorDOMPoint(&aRightBlock, aRightOffset),
+                                  EditAction::makeList, arrayOfNodes,
+                                  TouchContent::yes);
+  NS_ENSURE_SUCCESS(rv, rv);
+  for (uint32_t i = 0; i < arrayOfNodes.Length(); i++) {
+    // get the node to act on
+    if (IsBlockNode(arrayOfNodes[i])) {
+      // For block nodes, move their contents only, then delete block.
+      rv = MoveContents(*arrayOfNodes[i]->AsElement(), aLeftBlock,
+                        &aLeftOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(arrayOfNodes[i]);
+    } else {
+      // Otherwise move the content as is, checking against the DTD.
+      rv = MoveNodeSmart(*arrayOfNodes[i]->AsContent(), aLeftBlock,
+                         &aLeftOffset);
+    }
+  }
+
+  // XXX We're only checking return value of the last iteration
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+/**
+ * This method is used to move node aNode to (aDestElement, aInOutDestOffset).
+ * DTD containment rules are followed throughout.  aInOutDestOffset is updated
+ * to point _after_ inserted content.
+ */
+nsresult
+HTMLEditRules::MoveNodeSmart(nsIContent& aNode,
+                             Element& aDestElement,
+                             int32_t* aInOutDestOffset)
+{
+  MOZ_ASSERT(aInOutDestOffset);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Check if this node can go into the destination node
+  if (htmlEditor->CanContain(aDestElement, aNode)) {
+    // If it can, move it there
+    nsresult rv =
+      htmlEditor->MoveNode(&aNode, &aDestElement, *aInOutDestOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (*aInOutDestOffset != -1) {
+      (*aInOutDestOffset)++;
+    }
+  } else {
+    // If it can't, move its children (if any), and then delete it.
+    if (aNode.IsElement()) {
+      nsresult rv =
+        MoveContents(*aNode.AsElement(), aDestElement, aInOutDestOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    nsresult rv = htmlEditor->DeleteNode(&aNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+/**
+ * Moves the _contents_ of aElement to (aDestElement, aInOutDestOffset).  DTD
+ * containment rules are followed throughout.  aInOutDestOffset is updated to
+ * point _after_ inserted content.
+ */
+nsresult
+HTMLEditRules::MoveContents(Element& aElement,
+                            Element& aDestElement,
+                            int32_t* aInOutDestOffset)
+{
+  MOZ_ASSERT(aInOutDestOffset);
+
+  NS_ENSURE_TRUE(&aElement != &aDestElement, NS_ERROR_ILLEGAL_VALUE);
+
+  while (aElement.GetFirstChild()) {
+    nsresult rv = MoveNodeSmart(*aElement.GetFirstChild(), aDestElement,
+                                aInOutDestOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::DeleteNonTableElements(nsINode* aNode)
+{
+  MOZ_ASSERT(aNode);
+  if (!HTMLEditUtils::IsTableElementButNotTable(aNode)) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    return mHTMLEditor->DeleteNode(aNode->AsDOMNode());
+  }
+
+  for (int32_t i = aNode->GetChildCount() - 1; i >= 0; --i) {
+    nsresult rv = DeleteNonTableElements(aNode->GetChildAt(i));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::DidDeleteSelection(Selection* aSelection,
+                                  nsIEditor::EDirection aDir,
+                                  nsresult aResult)
+{
+  if (!aSelection) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  // find where we are
+  nsCOMPtr<nsINode> startNode;
+  int32_t startOffset;
+  nsresult rv = mTextEditor->GetStartNodeAndOffset(aSelection,
+                                                   getter_AddRefs(startNode),
+                                                   &startOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_TRUE(startNode, NS_ERROR_FAILURE);
+
+  // find any enclosing mailcite
+  nsCOMPtr<Element> citeNode = GetTopEnclosingMailCite(*startNode);
+  if (citeNode) {
+    bool isEmpty = true, seenBR = false;
+    NS_ENSURE_STATE(mHTMLEditor);
+    mHTMLEditor->IsEmptyNodeImpl(citeNode, &isEmpty, true, true, false,
+                                 &seenBR);
+    if (isEmpty) {
+      int32_t offset;
+      nsCOMPtr<nsINode> parent = EditorBase::GetNodeLocation(citeNode, &offset);
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(citeNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (parent && seenBR) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        nsCOMPtr<Element> brNode = mHTMLEditor->CreateBR(parent, offset);
+        NS_ENSURE_STATE(brNode);
+        aSelection->Collapse(parent, offset);
+      }
+    }
+  }
+
+  // call through to base class
+  return TextEditRules::DidDeleteSelection(aSelection, aDir, aResult);
+}
+
+nsresult
+HTMLEditRules::WillMakeList(Selection* aSelection,
+                            const nsAString* aListType,
+                            bool aEntireList,
+                            const nsAString* aBulletType,
+                            bool* aCancel,
+                            bool* aHandled,
+                            const nsAString* aItemType)
+{
+  if (!aSelection || !aListType || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  OwningNonNull<nsIAtom> listType = NS_Atomize(*aListType);
+
+  WillInsert(*aSelection, aCancel);
+
+  // initialize out param
+  // we want to ignore result of WillInsert()
+  *aCancel = false;
+  *aHandled = false;
+
+  // deduce what tag to use for list items
+  nsCOMPtr<nsIAtom> itemType;
+  if (aItemType) {
+    itemType = NS_Atomize(*aItemType);
+    NS_ENSURE_TRUE(itemType, NS_ERROR_OUT_OF_MEMORY);
+  } else if (listType == nsGkAtoms::dl) {
+    itemType = nsGkAtoms::dd;
+  } else {
+    itemType = nsGkAtoms::li;
+  }
+
+  // convert the selection ranges into "promoted" selection ranges:
+  // this basically just expands the range to include the immediate
+  // block parent, and then further expands to include any ancestors
+  // whose children are all in the range
+
+  *aHandled = true;
+
+  nsresult rv = NormalizeSelection(aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  rv = GetListActionNodes(arrayOfNodes,
+                          aEntireList ? EntireList::yes : EntireList::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // check if all our nodes are <br>s, or empty inlines
+  bool bOnlyBreaks = true;
+  for (auto& curNode : arrayOfNodes) {
+    // if curNode is not a Break or empty inline, we're done
+    if (!TextEditUtils::IsBreak(curNode) &&
+        !IsEmptyInline(curNode)) {
+      bOnlyBreaks = false;
+      break;
+    }
+  }
+
+  // if no nodes, we make empty list.  Ditto if the user tried to make a list
+  // of some # of breaks.
+  if (arrayOfNodes.IsEmpty() || bOnlyBreaks) {
+    // if only breaks, delete them
+    if (bOnlyBreaks) {
+      for (auto& node : arrayOfNodes) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->DeleteNode(node);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+
+    // get selection location
+    NS_ENSURE_STATE(aSelection->RangeCount());
+    nsCOMPtr<nsINode> parent = aSelection->GetRangeAt(0)->GetStartParent();
+    int32_t offset = aSelection->GetRangeAt(0)->StartOffset();
+    NS_ENSURE_STATE(parent);
+
+    // make sure we can put a list here
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->CanContainTag(*parent, listType)) {
+      *aCancel = true;
+      return NS_OK;
+    }
+    rv = SplitAsNeeded(listType, parent, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> theList =
+      mHTMLEditor->CreateNode(listType, parent, offset);
+    NS_ENSURE_STATE(theList);
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> theListItem =
+      mHTMLEditor->CreateNode(itemType, theList, 0);
+    NS_ENSURE_STATE(theListItem);
+
+    // remember our new block for postprocessing
+    mNewBlock = theListItem;
+    // put selection in new list item
+    *aHandled = true;
+    rv = aSelection->Collapse(theListItem, 0);
+    // Don't restore the selection
+    selectionRestorer.Abort();
+    return rv;
+  }
+
+  // if there is only one node in the array, and it is a list, div, or
+  // blockquote, then look inside of it until we find inner list or content.
+
+  LookInsideDivBQandList(arrayOfNodes);
+
+  // Ok, now go through all the nodes and put then in the list,
+  // or whatever is approriate.  Wohoo!
+
+  uint32_t listCount = arrayOfNodes.Length();
+  nsCOMPtr<nsINode> curParent;
+  nsCOMPtr<Element> curList, prevListItem;
+
+  for (uint32_t i = 0; i < listCount; i++) {
+    // here's where we actually figure out what to do
+    nsCOMPtr<Element> newBlock;
+    NS_ENSURE_STATE(arrayOfNodes[i]->IsContent());
+    OwningNonNull<nsIContent> curNode = *arrayOfNodes[i]->AsContent();
+    int32_t offset;
+    curParent = EditorBase::GetNodeLocation(curNode, &offset);
+
+    // make sure we don't assemble content that is in different table cells
+    // into the same list.  respect table cell boundaries when listifying.
+    if (curList && InDifferentTableElements(curList, curNode)) {
+      curList = nullptr;
+    }
+
+    // if curNode is a Break, delete it, and quit remembering prev list item
+    if (TextEditUtils::IsBreak(curNode)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      prevListItem = nullptr;
+      continue;
+    } else if (IsEmptyInline(curNode)) {
+      // if curNode is an empty inline container, delete it
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      continue;
+    }
+
+    if (HTMLEditUtils::IsList(curNode)) {
+      // do we have a curList already?
+      if (curList && !EditorUtils::IsDescendantOf(curNode, curList)) {
+        // move all of our children into curList.  cheezy way to do it: move
+        // whole list and then RemoveContainer() on the list.  ConvertListType
+        // first: that routine handles converting the list item types, if
+        // needed
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, curList, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        rv = ConvertListType(curNode->AsElement(), getter_AddRefs(newBlock),
+                             listType, itemType);
+        NS_ENSURE_SUCCESS(rv, rv);
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->RemoveBlockContainer(*newBlock);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } else {
+        // replace list with new list type
+        rv = ConvertListType(curNode->AsElement(), getter_AddRefs(newBlock),
+                             listType, itemType);
+        NS_ENSURE_SUCCESS(rv, rv);
+        curList = newBlock;
+      }
+      prevListItem = nullptr;
+      continue;
+    }
+
+    if (HTMLEditUtils::IsListItem(curNode)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      if (!curParent->IsHTMLElement(listType)) {
+        // list item is in wrong type of list. if we don't have a curList,
+        // split the old list and make a new list of correct type.
+        if (!curList || EditorUtils::IsDescendantOf(curNode, curList)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          NS_ENSURE_STATE(curParent->IsContent());
+          ErrorResult rv;
+          nsCOMPtr<nsIContent> splitNode =
+            mHTMLEditor->SplitNode(*curParent->AsContent(), offset, rv);
+          NS_ENSURE_TRUE(!rv.Failed(), rv.StealNSResult());
+          newBlock = splitNode ? splitNode->AsElement() : nullptr;
+          int32_t offset;
+          nsCOMPtr<nsINode> parent = EditorBase::GetNodeLocation(curParent,
+                                                                 &offset);
+          NS_ENSURE_STATE(mHTMLEditor);
+          curList = mHTMLEditor->CreateNode(listType, parent, offset);
+          NS_ENSURE_STATE(curList);
+        }
+        // move list item to new list
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, curList, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // convert list item type if needed
+        NS_ENSURE_STATE(mHTMLEditor);
+        if (!curNode->IsHTMLElement(itemType)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          newBlock = mHTMLEditor->ReplaceContainer(curNode->AsElement(),
+                                                   itemType);
+          NS_ENSURE_STATE(newBlock);
+        }
+      } else {
+        // item is in right type of list.  But we might still have to move it.
+        // and we might need to convert list item types.
+        if (!curList) {
+          curList = curParent->AsElement();
+        } else if (curParent != curList) {
+          // move list item to new list
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->MoveNode(curNode, curList, -1);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+        NS_ENSURE_STATE(mHTMLEditor);
+        if (!curNode->IsHTMLElement(itemType)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          newBlock = mHTMLEditor->ReplaceContainer(curNode->AsElement(),
+                                                   itemType);
+          NS_ENSURE_STATE(newBlock);
+        }
+      }
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<nsIDOMElement> curElement = do_QueryInterface(curNode);
+      NS_NAMED_LITERAL_STRING(typestr, "type");
+      if (aBulletType && !aBulletType->IsEmpty()) {
+        rv = mHTMLEditor->SetAttribute(curElement, typestr, *aBulletType);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      } else {
+        rv = mHTMLEditor->RemoveAttribute(curElement, typestr);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return rv;
+        }
+      }
+      continue;
+    }
+
+    // if we hit a div clear our prevListItem, insert divs contents
+    // into our node array, and remove the div
+    if (curNode->IsHTMLElement(nsGkAtoms::div)) {
+      prevListItem = nullptr;
+      int32_t j = i + 1;
+      GetInnerContent(*curNode, arrayOfNodes, &j);
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->RemoveContainer(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      listCount = arrayOfNodes.Length();
+      continue;
+    }
+
+    // need to make a list to put things in if we haven't already,
+    if (!curList) {
+      rv = SplitAsNeeded(listType, curParent, offset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      NS_ENSURE_STATE(mHTMLEditor);
+      curList = mHTMLEditor->CreateNode(listType, curParent, offset);
+      // remember our new block for postprocessing
+      mNewBlock = curList;
+      // curList is now the correct thing to put curNode in
+      prevListItem = nullptr;
+    }
+
+    // if curNode isn't a list item, we must wrap it in one
+    nsCOMPtr<Element> listItem;
+    if (!HTMLEditUtils::IsListItem(curNode)) {
+      if (IsInlineNode(curNode) && prevListItem) {
+        // this is a continuation of some inline nodes that belong together in
+        // the same list item.  use prevListItem
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, prevListItem, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } else {
+        // don't wrap li around a paragraph.  instead replace paragraph with li
+        if (curNode->IsHTMLElement(nsGkAtoms::p)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          listItem = mHTMLEditor->ReplaceContainer(curNode->AsElement(),
+                                                   itemType);
+          NS_ENSURE_STATE(listItem);
+        } else {
+          NS_ENSURE_STATE(mHTMLEditor);
+          listItem = mHTMLEditor->InsertContainerAbove(curNode, itemType);
+          NS_ENSURE_STATE(listItem);
+        }
+        if (IsInlineNode(curNode)) {
+          prevListItem = listItem;
+        } else {
+          prevListItem = nullptr;
+        }
+      }
+    } else {
+      listItem = curNode->AsElement();
+    }
+
+    if (listItem) {
+      // if we made a new list item, deal with it: tuck the listItem into the
+      // end of the active list
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->MoveNode(listItem, curList, -1);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::WillRemoveList(Selection* aSelection,
+                              bool aOrdered,
+                              bool* aCancel,
+                              bool* aHandled)
+{
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  // initialize out param
+  *aCancel = false;
+  *aHandled = true;
+
+  nsresult rv = NormalizeSelection(aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+
+  nsTArray<RefPtr<nsRange>> arrayOfRanges;
+  GetPromotedRanges(*aSelection, arrayOfRanges, EditAction::makeList);
+
+  // use these ranges to contruct a list of nodes to act on.
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  rv = GetListActionNodes(arrayOfNodes, EntireList::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Remove all non-editable nodes.  Leave them be.
+  for (int32_t i = arrayOfNodes.Length() - 1; i >= 0; i--) {
+    OwningNonNull<nsINode> testNode = arrayOfNodes[i];
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsEditable(testNode)) {
+      arrayOfNodes.RemoveElementAt(i);
+    }
+  }
+
+  // Only act on lists or list items in the array
+  for (auto& curNode : arrayOfNodes) {
+    // here's where we actually figure out what to do
+    if (HTMLEditUtils::IsListItem(curNode)) {
+      // unlist this listitem
+      bool bOutOfList;
+      do {
+        rv = PopListItem(GetAsDOMNode(curNode), &bOutOfList);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } while (!bOutOfList); // keep popping it out until it's not in a list anymore
+    } else if (HTMLEditUtils::IsList(curNode)) {
+      // node is a list, move list items out
+      rv = RemoveListStructure(*curNode->AsElement());
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillMakeDefListItem(Selection* aSelection,
+                                   const nsAString *aItemType,
+                                   bool aEntireList,
+                                   bool* aCancel,
+                                   bool* aHandled)
+{
+  // for now we let WillMakeList handle this
+  NS_NAMED_LITERAL_STRING(listType, "dl");
+  return WillMakeList(aSelection, &listType, aEntireList, nullptr, aCancel, aHandled, aItemType);
+}
+
+nsresult
+HTMLEditRules::WillMakeBasicBlock(Selection& aSelection,
+                                  const nsAString& aBlockType,
+                                  bool* aCancel,
+                                  bool* aHandled)
+{
+  MOZ_ASSERT(aCancel && aHandled);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  OwningNonNull<nsIAtom> blockType = NS_Atomize(aBlockType);
+
+  WillInsert(aSelection, aCancel);
+  // We want to ignore result of WillInsert()
+  *aCancel = false;
+  *aHandled = false;
+
+  nsresult rv = NormalizeSelection(&aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  AutoSelectionRestorer selectionRestorer(&aSelection, htmlEditor);
+  AutoTransactionsConserveSelection dontSpazMySelection(htmlEditor);
+  *aHandled = true;
+
+  // Contruct a list of nodes to act on.
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  rv = GetNodesFromSelection(aSelection, EditAction::makeBasicBlock,
+                             arrayOfNodes);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Remove all non-editable nodes.  Leave them be.
+  for (int32_t i = arrayOfNodes.Length() - 1; i >= 0; i--) {
+    if (!htmlEditor->IsEditable(arrayOfNodes[i])) {
+      arrayOfNodes.RemoveElementAt(i);
+    }
+  }
+
+  // If nothing visible in list, make an empty block
+  if (ListIsEmptyLine(arrayOfNodes)) {
+    // Get selection location
+    NS_ENSURE_STATE(aSelection.GetRangeAt(0) &&
+                    aSelection.GetRangeAt(0)->GetStartParent());
+    OwningNonNull<nsINode> parent =
+      *aSelection.GetRangeAt(0)->GetStartParent();
+    int32_t offset = aSelection.GetRangeAt(0)->StartOffset();
+
+    if (blockType == nsGkAtoms::normal ||
+        blockType == nsGkAtoms::_empty) {
+      // We are removing blocks (going to "body text")
+      NS_ENSURE_TRUE(htmlEditor->GetBlock(parent), NS_ERROR_NULL_POINTER);
+      OwningNonNull<Element> curBlock = *htmlEditor->GetBlock(parent);
+      if (HTMLEditUtils::IsFormatNode(curBlock)) {
+        // If the first editable node after selection is a br, consume it.
+        // Otherwise it gets pushed into a following block after the split,
+        // which is visually bad.
+        nsCOMPtr<nsIContent> brNode =
+          htmlEditor->GetNextHTMLNode(parent, offset);
+        if (brNode && brNode->IsHTMLElement(nsGkAtoms::br)) {
+          rv = htmlEditor->DeleteNode(brNode);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+        // Do the splits!
+        offset = htmlEditor->SplitNodeDeep(curBlock, *parent->AsContent(),
+                                            offset,
+                                            HTMLEditor::EmptyContainers::no);
+        NS_ENSURE_STATE(offset != -1);
+        // Put a br at the split point
+        brNode = htmlEditor->CreateBR(curBlock->GetParentNode(), offset);
+        NS_ENSURE_STATE(brNode);
+        // Put selection at the split point
+        *aHandled = true;
+        rv = aSelection.Collapse(curBlock->GetParentNode(), offset);
+        // Don't restore the selection
+        selectionRestorer.Abort();
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      // Else nothing to do!
+    } else {
+      // We are making a block.  Consume a br, if needed.
+      nsCOMPtr<nsIContent> brNode =
+        htmlEditor->GetNextHTMLNode(parent, offset, true);
+      if (brNode && brNode->IsHTMLElement(nsGkAtoms::br)) {
+        rv = htmlEditor->DeleteNode(brNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // We don't need to act on this node any more
+        arrayOfNodes.RemoveElement(brNode);
+      }
+      // Make sure we can put a block here
+      rv = SplitAsNeeded(blockType, parent, offset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      nsCOMPtr<Element> block =
+        htmlEditor->CreateNode(blockType, parent, offset);
+      NS_ENSURE_STATE(block);
+      // Remember our new block for postprocessing
+      mNewBlock = block;
+      // Delete anything that was in the list of nodes
+      while (!arrayOfNodes.IsEmpty()) {
+        OwningNonNull<nsINode> curNode = arrayOfNodes[0];
+        rv = htmlEditor->DeleteNode(curNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        arrayOfNodes.RemoveElementAt(0);
+      }
+      // Put selection in new block
+      *aHandled = true;
+      rv = aSelection.Collapse(block, 0);
+      // Don't restore the selection
+      selectionRestorer.Abort();
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    return NS_OK;
+  }
+  // Okay, now go through all the nodes and make the right kind of blocks, or
+  // whatever is approriate.  Woohoo!  Note: blockquote is handled a little
+  // differently.
+  if (blockType == nsGkAtoms::blockquote) {
+    rv = MakeBlockquote(arrayOfNodes);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else if (blockType == nsGkAtoms::normal ||
+             blockType == nsGkAtoms::_empty) {
+    rv = RemoveBlockStyle(arrayOfNodes);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    rv = ApplyBlockStyle(arrayOfNodes, blockType);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::DidMakeBasicBlock(Selection* aSelection,
+                                 RulesInfo* aInfo,
+                                 nsresult aResult)
+{
+  NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
+  // check for empty block.  if so, put a moz br in it.
+  if (!aSelection->Collapsed()) {
+    return NS_OK;
+  }
+
+  NS_ENSURE_STATE(aSelection->GetRangeAt(0) &&
+                  aSelection->GetRangeAt(0)->GetStartParent());
+  nsresult rv =
+    InsertMozBRIfNeeded(*aSelection->GetRangeAt(0)->GetStartParent());
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillIndent(Selection* aSelection,
+                          bool* aCancel,
+                          bool* aHandled)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (mHTMLEditor->IsCSSEnabled()) {
+    nsresult rv = WillCSSIndent(aSelection, aCancel, aHandled);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  } else {
+    nsresult rv = WillHTMLIndent(aSelection, aCancel, aHandled);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillCSSIndent(Selection* aSelection,
+                             bool* aCancel,
+                             bool* aHandled)
+{
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  WillInsert(*aSelection, aCancel);
+
+  // initialize out param
+  // we want to ignore result of WillInsert()
+  *aCancel = false;
+  *aHandled = true;
+
+  nsresult rv = NormalizeSelection(aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+  nsTArray<OwningNonNull<nsRange>> arrayOfRanges;
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+
+  // short circuit: detect case of collapsed selection inside an <li>.
+  // just sublist that <li>.  This prevents bug 97797.
+
+  nsCOMPtr<Element> liNode;
+  if (aSelection->Collapsed()) {
+    nsCOMPtr<nsINode> node;
+    int32_t offset;
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->GetStartNodeAndOffset(aSelection,
+                                         getter_AddRefs(node), &offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<Element> block = mHTMLEditor->GetBlock(*node);
+    if (block && HTMLEditUtils::IsListItem(block)) {
+      liNode = block;
+    }
+  }
+
+  if (liNode) {
+    arrayOfNodes.AppendElement(*liNode);
+  } else {
+    // convert the selection ranges into "promoted" selection ranges:
+    // this basically just expands the range to include the immediate
+    // block parent, and then further expands to include any ancestors
+    // whose children are all in the range
+    rv = GetNodesFromSelection(*aSelection, EditAction::indent, arrayOfNodes);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // if nothing visible in list, make an empty block
+  if (ListIsEmptyLine(arrayOfNodes)) {
+    // get selection location
+    NS_ENSURE_STATE(aSelection->RangeCount());
+    nsCOMPtr<nsINode> parent = aSelection->GetRangeAt(0)->GetStartParent();
+    int32_t offset = aSelection->GetRangeAt(0)->StartOffset();
+    NS_ENSURE_STATE(parent);
+
+    // make sure we can put a block here
+    rv = SplitAsNeeded(*nsGkAtoms::div, parent, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> theBlock = mHTMLEditor->CreateNode(nsGkAtoms::div,
+                                                         parent, offset);
+    NS_ENSURE_STATE(theBlock);
+    // remember our new block for postprocessing
+    mNewBlock = theBlock;
+    ChangeIndentation(*theBlock, Change::plus);
+    // delete anything that was in the list of nodes
+    while (!arrayOfNodes.IsEmpty()) {
+      OwningNonNull<nsINode> curNode = arrayOfNodes[0];
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      arrayOfNodes.RemoveElementAt(0);
+    }
+    // put selection in new block
+    *aHandled = true;
+    rv = aSelection->Collapse(theBlock, 0);
+    // Don't restore the selection
+    selectionRestorer.Abort();
+    return rv;
+  }
+
+  // Ok, now go through all the nodes and put them in a blockquote,
+  // or whatever is appropriate.  Wohoo!
+  nsCOMPtr<nsINode> curParent;
+  nsCOMPtr<Element> curList, curQuote;
+  nsCOMPtr<nsIContent> sibling;
+  int32_t listCount = arrayOfNodes.Length();
+  for (int32_t i = 0; i < listCount; i++) {
+    // here's where we actually figure out what to do
+    NS_ENSURE_STATE(arrayOfNodes[i]->IsContent());
+    nsCOMPtr<nsIContent> curNode = arrayOfNodes[i]->AsContent();
+
+    // Ignore all non-editable nodes.  Leave them be.
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsEditable(curNode)) {
+      continue;
+    }
+
+    curParent = curNode->GetParentNode();
+    int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+    // some logic for putting list items into nested lists...
+    if (HTMLEditUtils::IsList(curParent)) {
+      sibling = nullptr;
+
+      // Check for whether we should join a list that follows curNode.
+      // We do this if the next element is a list, and the list is of the
+      // same type (li/ol) as curNode was a part it.
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetNextHTMLSibling(curNode);
+      if (sibling && HTMLEditUtils::IsList(sibling) &&
+          curParent->NodeInfo()->NameAtom() ==
+            sibling->NodeInfo()->NameAtom() &&
+          curParent->NodeInfo()->NamespaceID() ==
+            sibling->NodeInfo()->NamespaceID()) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, sibling, 0);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+      // Check for whether we should join a list that preceeds curNode.
+      // We do this if the previous element is a list, and the list is of
+      // the same type (li/ol) as curNode was a part of.
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetPriorHTMLSibling(curNode);
+      if (sibling && HTMLEditUtils::IsList(sibling) &&
+          curParent->NodeInfo()->NameAtom() ==
+            sibling->NodeInfo()->NameAtom() &&
+          curParent->NodeInfo()->NamespaceID() ==
+            sibling->NodeInfo()->NamespaceID()) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, sibling, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+      sibling = nullptr;
+
+      // check to see if curList is still appropriate.  Which it is if
+      // curNode is still right after it in the same list.
+      if (curList) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        sibling = mHTMLEditor->GetPriorHTMLSibling(curNode);
+      }
+
+      if (!curList || (sibling && sibling != curList)) {
+        // create a new nested list of correct type
+        rv =
+          SplitAsNeeded(*curParent->NodeInfo()->NameAtom(), curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        NS_ENSURE_STATE(mHTMLEditor);
+        curList = mHTMLEditor->CreateNode(curParent->NodeInfo()->NameAtom(),
+                                          curParent, offset);
+        NS_ENSURE_STATE(curList);
+        // curList is now the correct thing to put curNode in
+        // remember our new block for postprocessing
+        mNewBlock = curList;
+      }
+      // tuck the node into the end of the active list
+      uint32_t listLen = curList->Length();
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->MoveNode(curNode, curList, listLen);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    // Not a list item.
+    else {
+      if (curNode && IsBlockNode(*curNode)) {
+        ChangeIndentation(*curNode->AsElement(), Change::plus);
+        curQuote = nullptr;
+      } else {
+        if (!curQuote) {
+          // First, check that our element can contain a div.
+          if (!mTextEditor->CanContainTag(*curParent, *nsGkAtoms::div)) {
+            return NS_OK; // cancelled
+          }
+
+          rv = SplitAsNeeded(*nsGkAtoms::div, curParent, offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          NS_ENSURE_STATE(mHTMLEditor);
+          curQuote = mHTMLEditor->CreateNode(nsGkAtoms::div, curParent,
+                                             offset);
+          NS_ENSURE_STATE(curQuote);
+          ChangeIndentation(*curQuote, Change::plus);
+          // remember our new block for postprocessing
+          mNewBlock = curQuote;
+          // curQuote is now the correct thing to put curNode in
+        }
+
+        // tuck the node into the end of the active blockquote
+        uint32_t quoteLen = curQuote->Length();
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, curQuote, quoteLen);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillHTMLIndent(Selection* aSelection,
+                              bool* aCancel,
+                              bool* aHandled)
+{
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  WillInsert(*aSelection, aCancel);
+
+  // initialize out param
+  // we want to ignore result of WillInsert()
+  *aCancel = false;
+  *aHandled = true;
+
+  nsresult rv = NormalizeSelection(aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+
+  // convert the selection ranges into "promoted" selection ranges:
+  // this basically just expands the range to include the immediate
+  // block parent, and then further expands to include any ancestors
+  // whose children are all in the range
+
+  nsTArray<RefPtr<nsRange>> arrayOfRanges;
+  GetPromotedRanges(*aSelection, arrayOfRanges, EditAction::indent);
+
+  // use these ranges to contruct a list of nodes to act on.
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  rv = GetNodesForOperation(arrayOfRanges, arrayOfNodes, EditAction::indent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // if nothing visible in list, make an empty block
+  if (ListIsEmptyLine(arrayOfNodes)) {
+    // get selection location
+    NS_ENSURE_STATE(aSelection->RangeCount());
+    nsCOMPtr<nsINode> parent = aSelection->GetRangeAt(0)->GetStartParent();
+    int32_t offset = aSelection->GetRangeAt(0)->StartOffset();
+    NS_ENSURE_STATE(parent);
+
+    // make sure we can put a block here
+    rv = SplitAsNeeded(*nsGkAtoms::blockquote, parent, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> theBlock = mHTMLEditor->CreateNode(nsGkAtoms::blockquote,
+                                                         parent, offset);
+    NS_ENSURE_STATE(theBlock);
+    // remember our new block for postprocessing
+    mNewBlock = theBlock;
+    // delete anything that was in the list of nodes
+    while (!arrayOfNodes.IsEmpty()) {
+      OwningNonNull<nsINode> curNode = arrayOfNodes[0];
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->DeleteNode(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      arrayOfNodes.RemoveElementAt(0);
+    }
+    // put selection in new block
+    *aHandled = true;
+    rv = aSelection->Collapse(theBlock, 0);
+    // Don't restore the selection
+    selectionRestorer.Abort();
+    return rv;
+  }
+
+  // Ok, now go through all the nodes and put them in a blockquote,
+  // or whatever is appropriate.  Wohoo!
+  nsCOMPtr<nsINode> curParent;
+  nsCOMPtr<nsIContent> sibling;
+  nsCOMPtr<Element> curList, curQuote, indentedLI;
+  int32_t listCount = arrayOfNodes.Length();
+  for (int32_t i = 0; i < listCount; i++) {
+    // here's where we actually figure out what to do
+    NS_ENSURE_STATE(arrayOfNodes[i]->IsContent());
+    nsCOMPtr<nsIContent> curNode = arrayOfNodes[i]->AsContent();
+
+    // Ignore all non-editable nodes.  Leave them be.
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsEditable(curNode)) {
+      continue;
+    }
+
+    curParent = curNode->GetParentNode();
+    int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+    // some logic for putting list items into nested lists...
+    if (HTMLEditUtils::IsList(curParent)) {
+      sibling = nullptr;
+
+      // Check for whether we should join a list that follows curNode.
+      // We do this if the next element is a list, and the list is of the
+      // same type (li/ol) as curNode was a part it.
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetNextHTMLSibling(curNode);
+      if (sibling && HTMLEditUtils::IsList(sibling) &&
+          curParent->NodeInfo()->NameAtom() ==
+            sibling->NodeInfo()->NameAtom() &&
+          curParent->NodeInfo()->NamespaceID() ==
+            sibling->NodeInfo()->NamespaceID()) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, sibling, 0);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+
+      // Check for whether we should join a list that preceeds curNode.
+      // We do this if the previous element is a list, and the list is of
+      // the same type (li/ol) as curNode was a part of.
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetPriorHTMLSibling(curNode);
+      if (sibling && HTMLEditUtils::IsList(sibling) &&
+          curParent->NodeInfo()->NameAtom() ==
+            sibling->NodeInfo()->NameAtom() &&
+          curParent->NodeInfo()->NamespaceID() ==
+            sibling->NodeInfo()->NamespaceID()) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, sibling, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+
+      sibling = nullptr;
+
+      // check to see if curList is still appropriate.  Which it is if
+      // curNode is still right after it in the same list.
+      if (curList) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        sibling = mHTMLEditor->GetPriorHTMLSibling(curNode);
+      }
+
+      if (!curList || (sibling && sibling != curList)) {
+        // create a new nested list of correct type
+        rv =
+          SplitAsNeeded(*curParent->NodeInfo()->NameAtom(), curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        NS_ENSURE_STATE(mHTMLEditor);
+        curList = mHTMLEditor->CreateNode(curParent->NodeInfo()->NameAtom(),
+                                          curParent, offset);
+        NS_ENSURE_STATE(curList);
+        // curList is now the correct thing to put curNode in
+        // remember our new block for postprocessing
+        mNewBlock = curList;
+      }
+      // tuck the node into the end of the active list
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->MoveNode(curNode, curList, -1);
+      NS_ENSURE_SUCCESS(rv, rv);
+      // forget curQuote, if any
+      curQuote = nullptr;
+    }
+    // Not a list item, use blockquote?
+    else {
+      // if we are inside a list item, we don't want to blockquote, we want
+      // to sublist the list item.  We may have several nodes listed in the
+      // array of nodes to act on, that are in the same list item.  Since
+      // we only want to indent that li once, we must keep track of the most
+      // recent indented list item, and not indent it if we find another node
+      // to act on that is still inside the same li.
+      nsCOMPtr<Element> listItem = IsInListItem(curNode);
+      if (listItem) {
+        if (indentedLI == listItem) {
+          // already indented this list item
+          continue;
+        }
+        curParent = listItem->GetParentNode();
+        offset = curParent ? curParent->IndexOf(listItem) : -1;
+        // check to see if curList is still appropriate.  Which it is if
+        // curNode is still right after it in the same list.
+        if (curList) {
+          sibling = nullptr;
+          NS_ENSURE_STATE(mHTMLEditor);
+          sibling = mHTMLEditor->GetPriorHTMLSibling(curNode);
+        }
+
+        if (!curList || (sibling && sibling != curList)) {
+          // create a new nested list of correct type
+          rv = SplitAsNeeded(*curParent->NodeInfo()->NameAtom(), curParent,
+                             offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          NS_ENSURE_STATE(mHTMLEditor);
+          curList = mHTMLEditor->CreateNode(curParent->NodeInfo()->NameAtom(),
+                                            curParent, offset);
+          NS_ENSURE_STATE(curList);
+        }
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(listItem, curList, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // remember we indented this li
+        indentedLI = listItem;
+      } else {
+        // need to make a blockquote to put things in if we haven't already,
+        // or if this node doesn't go in blockquote we used earlier.
+        // One reason it might not go in prio blockquote is if we are now
+        // in a different table cell.
+        if (curQuote && InDifferentTableElements(curQuote, curNode)) {
+          curQuote = nullptr;
+        }
+
+        if (!curQuote) {
+          // First, check that our element can contain a blockquote.
+          if (!mTextEditor->CanContainTag(*curParent, *nsGkAtoms::blockquote)) {
+            return NS_OK; // cancelled
+          }
+
+          rv = SplitAsNeeded(*nsGkAtoms::blockquote, curParent, offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          NS_ENSURE_STATE(mHTMLEditor);
+          curQuote = mHTMLEditor->CreateNode(nsGkAtoms::blockquote, curParent,
+                                             offset);
+          NS_ENSURE_STATE(curQuote);
+          // remember our new block for postprocessing
+          mNewBlock = curQuote;
+          // curQuote is now the correct thing to put curNode in
+        }
+
+        // tuck the node into the end of the active blockquote
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->MoveNode(curNode, curQuote, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // forget curList, if any
+        curList = nullptr;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::WillOutdent(Selection& aSelection,
+                           bool* aCancel,
+                           bool* aHandled)
+{
+  MOZ_ASSERT(aCancel && aHandled);
+  *aCancel = false;
+  *aHandled = true;
+  nsCOMPtr<nsIContent> rememberedLeftBQ, rememberedRightBQ;
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+  bool useCSS = htmlEditor->IsCSSEnabled();
+
+  nsresult rv = NormalizeSelection(&aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Some scoping for selection resetting - we may need to tweak it
+  {
+    AutoSelectionRestorer selectionRestorer(&aSelection, htmlEditor);
+
+    // Convert the selection ranges into "promoted" selection ranges: this
+    // basically just expands the range to include the immediate block parent,
+    // and then further expands to include any ancestors whose children are all
+    // in the range
+    nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+    rv = GetNodesFromSelection(aSelection, EditAction::outdent, arrayOfNodes);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Okay, now go through all the nodes and remove a level of blockquoting,
+    // or whatever is appropriate.  Wohoo!
+
+    nsCOMPtr<Element> curBlockQuote;
+    nsCOMPtr<nsIContent> firstBQChild, lastBQChild;
+    bool curBlockQuoteIsIndentedWithCSS = false;
+    for (uint32_t i = 0; i < arrayOfNodes.Length(); i++) {
+      if (!arrayOfNodes[i]->IsContent()) {
+        continue;
+      }
+      OwningNonNull<nsIContent> curNode = *arrayOfNodes[i]->AsContent();
+
+      // Here's where we actually figure out what to do
+      nsCOMPtr<nsINode> curParent = curNode->GetParentNode();
+      int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+      // Is it a blockquote?
+      if (curNode->IsHTMLElement(nsGkAtoms::blockquote)) {
+        // If it is a blockquote, remove it.  So we need to finish up dealng
+        // with any curBlockQuote first.
+        if (curBlockQuote) {
+          rv = OutdentPartOfBlock(*curBlockQuote, *firstBQChild, *lastBQChild,
+                                  curBlockQuoteIsIndentedWithCSS,
+                                  getter_AddRefs(rememberedLeftBQ),
+                                  getter_AddRefs(rememberedRightBQ));
+          NS_ENSURE_SUCCESS(rv, rv);
+          curBlockQuote = nullptr;
+          firstBQChild = nullptr;
+          lastBQChild = nullptr;
+          curBlockQuoteIsIndentedWithCSS = false;
+        }
+        rv = htmlEditor->RemoveBlockContainer(curNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+      // Is it a block with a 'margin' property?
+      if (useCSS && IsBlockNode(curNode)) {
+        nsIAtom& marginProperty =
+          MarginPropertyAtomForIndent(*htmlEditor->mCSSEditUtils, curNode);
+        nsAutoString value;
+        htmlEditor->mCSSEditUtils->GetSpecifiedProperty(curNode,
+                                                         marginProperty,
+                                                         value);
+        float f;
+        nsCOMPtr<nsIAtom> unit;
+        NS_ENSURE_STATE(htmlEditor);
+        htmlEditor->mCSSEditUtils->ParseLength(value, &f,
+                                               getter_AddRefs(unit));
+        if (f > 0) {
+          ChangeIndentation(*curNode->AsElement(), Change::minus);
+          continue;
+        }
+      }
+      // Is it a list item?
+      if (HTMLEditUtils::IsListItem(curNode)) {
+        // If it is a list item, that means we are not outdenting whole list.
+        // So we need to finish up dealing with any curBlockQuote, and then pop
+        // this list item.
+        if (curBlockQuote) {
+          rv = OutdentPartOfBlock(*curBlockQuote, *firstBQChild, *lastBQChild,
+                                  curBlockQuoteIsIndentedWithCSS,
+                                  getter_AddRefs(rememberedLeftBQ),
+                                  getter_AddRefs(rememberedRightBQ));
+          NS_ENSURE_SUCCESS(rv, rv);
+          curBlockQuote = nullptr;
+          firstBQChild = nullptr;
+          lastBQChild = nullptr;
+          curBlockQuoteIsIndentedWithCSS = false;
+        }
+        bool unused;
+        rv = PopListItem(GetAsDOMNode(curNode), &unused);
+        NS_ENSURE_SUCCESS(rv, rv);
+        continue;
+      }
+      // Do we have a blockquote that we are already committed to removing?
+      if (curBlockQuote) {
+        // If so, is this node a descendant?
+        if (EditorUtils::IsDescendantOf(curNode, curBlockQuote)) {
+          lastBQChild = curNode;
+          // Then we don't need to do anything different for this node
+          continue;
+        }
+        // Otherwise, we have progressed beyond end of curBlockQuote, so
+        // let's handle it now.  We need to remove the portion of
+        // curBlockQuote that contains [firstBQChild - lastBQChild].
+        rv = OutdentPartOfBlock(*curBlockQuote, *firstBQChild, *lastBQChild,
+                                curBlockQuoteIsIndentedWithCSS,
+                                getter_AddRefs(rememberedLeftBQ),
+                                getter_AddRefs(rememberedRightBQ));
+        NS_ENSURE_SUCCESS(rv, rv);
+        curBlockQuote = nullptr;
+        firstBQChild = nullptr;
+        lastBQChild = nullptr;
+        curBlockQuoteIsIndentedWithCSS = false;
+        // Fall out and handle curNode
+      }
+
+      // Are we inside a blockquote?
+      OwningNonNull<nsINode> n = curNode;
+      curBlockQuoteIsIndentedWithCSS = false;
+      // Keep looking up the hierarchy as long as we don't hit the body or the
+      // active editing host or a table element (other than an entire table)
+      while (!n->IsHTMLElement(nsGkAtoms::body) && 
+             htmlEditor->IsDescendantOfEditorRoot(n) &&
+             (n->IsHTMLElement(nsGkAtoms::table) ||
+              !HTMLEditUtils::IsTableElement(n))) {
+        if (!n->GetParentNode()) {
+          break;
+        }
+        n = *n->GetParentNode();
+        if (n->IsHTMLElement(nsGkAtoms::blockquote)) {
+          // If so, remember it and the first node we are taking out of it.
+          curBlockQuote = n->AsElement();
+          firstBQChild = curNode;
+          lastBQChild = curNode;
+          break;
+        } else if (useCSS) {
+          nsIAtom& marginProperty =
+            MarginPropertyAtomForIndent(*htmlEditor->mCSSEditUtils, curNode);
+          nsAutoString value;
+          htmlEditor->mCSSEditUtils->GetSpecifiedProperty(*n, marginProperty,
+                                                           value);
+          float f;
+          nsCOMPtr<nsIAtom> unit;
+          htmlEditor->mCSSEditUtils->ParseLength(value, &f, getter_AddRefs(unit));
+          if (f > 0 && !(HTMLEditUtils::IsList(curParent) &&
+                         HTMLEditUtils::IsList(curNode))) {
+            curBlockQuote = n->AsElement();
+            firstBQChild = curNode;
+            lastBQChild = curNode;
+            curBlockQuoteIsIndentedWithCSS = true;
+            break;
+          }
+        }
+      }
+
+      if (!curBlockQuote) {
+        // Couldn't find enclosing blockquote.  Handle list cases.
+        if (HTMLEditUtils::IsList(curParent)) {
+          // Move node out of list
+          if (HTMLEditUtils::IsList(curNode)) {
+            // Just unwrap this sublist
+            rv = htmlEditor->RemoveBlockContainer(curNode);
+            NS_ENSURE_SUCCESS(rv, rv);
+          }
+          // handled list item case above
+        } else if (HTMLEditUtils::IsList(curNode)) {
+          // node is a list, but parent is non-list: move list items out
+          nsCOMPtr<nsIContent> child = curNode->GetLastChild();
+          while (child) {
+            if (HTMLEditUtils::IsListItem(child)) {
+              bool unused;
+              rv = PopListItem(GetAsDOMNode(child), &unused);
+              NS_ENSURE_SUCCESS(rv, rv);
+            } else if (HTMLEditUtils::IsList(child)) {
+              // We have an embedded list, so move it out from under the parent
+              // list. Be sure to put it after the parent list because this
+              // loop iterates backwards through the parent's list of children.
+
+              rv = htmlEditor->MoveNode(child, curParent, offset + 1);
+              NS_ENSURE_SUCCESS(rv, rv);
+            } else {
+              // Delete any non-list items for now
+              rv = htmlEditor->DeleteNode(child);
+              NS_ENSURE_SUCCESS(rv, rv);
+            }
+            child = curNode->GetLastChild();
+          }
+          // Delete the now-empty list
+          rv = htmlEditor->RemoveBlockContainer(curNode);
+          NS_ENSURE_SUCCESS(rv, rv);
+        } else if (useCSS) {
+          nsCOMPtr<Element> element;
+          if (curNode->GetAsText()) {
+            // We want to outdent the parent of text nodes
+            element = curNode->GetParentElement();
+          } else if (curNode->IsElement()) {
+            element = curNode->AsElement();
+          }
+          if (element) {
+            ChangeIndentation(*element, Change::minus);
+          }
+        }
+      }
+    }
+    if (curBlockQuote) {
+      // We have a blockquote we haven't finished handling
+      rv = OutdentPartOfBlock(*curBlockQuote, *firstBQChild, *lastBQChild,
+                              curBlockQuoteIsIndentedWithCSS,
+                              getter_AddRefs(rememberedLeftBQ),
+                              getter_AddRefs(rememberedRightBQ));
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  // Make sure selection didn't stick to last piece of content in old bq (only
+  // a problem for collapsed selections)
+  if (rememberedLeftBQ || rememberedRightBQ) {
+    if (aSelection.Collapsed()) {
+      // Push selection past end of rememberedLeftBQ
+      NS_ENSURE_TRUE(aSelection.GetRangeAt(0), NS_OK);
+      nsCOMPtr<nsINode> startNode = aSelection.GetRangeAt(0)->GetStartParent();
+      int32_t startOffset = aSelection.GetRangeAt(0)->StartOffset();
+      if (rememberedLeftBQ &&
+          (startNode == rememberedLeftBQ ||
+           EditorUtils::IsDescendantOf(startNode, rememberedLeftBQ))) {
+        // Selection is inside rememberedLeftBQ - push it past it.
+        startNode = rememberedLeftBQ->GetParentNode();
+        startOffset = startNode ? 1 + startNode->IndexOf(rememberedLeftBQ) : 0;
+        aSelection.Collapse(startNode, startOffset);
+      }
+      // And pull selection before beginning of rememberedRightBQ
+      startNode = aSelection.GetRangeAt(0)->GetStartParent();
+      startOffset = aSelection.GetRangeAt(0)->StartOffset();
+      if (rememberedRightBQ &&
+          (startNode == rememberedRightBQ ||
+           EditorUtils::IsDescendantOf(startNode, rememberedRightBQ))) {
+        // Selection is inside rememberedRightBQ - push it before it.
+        startNode = rememberedRightBQ->GetParentNode();
+        startOffset = startNode ? startNode->IndexOf(rememberedRightBQ) : -1;
+        aSelection.Collapse(startNode, startOffset);
+      }
+    }
+    return NS_OK;
+  }
+  return NS_OK;
+}
+
+
+/**
+ * RemovePartOfBlock() splits aBlock and move aStartChild to aEndChild out of
+ * aBlock.
+ */
+nsresult
+HTMLEditRules::RemovePartOfBlock(Element& aBlock,
+                                 nsIContent& aStartChild,
+                                 nsIContent& aEndChild)
+{
+  SplitBlock(aBlock, aStartChild, aEndChild);
+  // Get rid of part of blockquote we are outdenting
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv = mHTMLEditor->RemoveBlockContainer(aBlock);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+void
+HTMLEditRules::SplitBlock(Element& aBlock,
+                          nsIContent& aStartChild,
+                          nsIContent& aEndChild,
+                          nsIContent** aOutLeftNode,
+                          nsIContent** aOutRightNode,
+                          nsIContent** aOutMiddleNode)
+{
+  // aStartChild and aEndChild must be exclusive descendants of aBlock
+  MOZ_ASSERT(EditorUtils::IsDescendantOf(&aStartChild, &aBlock) &&
+             EditorUtils::IsDescendantOf(&aEndChild, &aBlock));
+  NS_ENSURE_TRUE_VOID(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Get split point location
+  OwningNonNull<nsIContent> startParent = *aStartChild.GetParent();
+  int32_t startOffset = startParent->IndexOf(&aStartChild);
+
+  // Do the splits!
+  nsCOMPtr<nsIContent> newMiddleNode1;
+  htmlEditor->SplitNodeDeep(aBlock, startParent, startOffset,
+                            HTMLEditor::EmptyContainers::no,
+                            aOutLeftNode, getter_AddRefs(newMiddleNode1));
+
+  // Get split point location
+  OwningNonNull<nsIContent> endParent = *aEndChild.GetParent();
+  // +1 because we want to be after the child
+  int32_t endOffset = 1 + endParent->IndexOf(&aEndChild);
+
+  // Do the splits!
+  nsCOMPtr<nsIContent> newMiddleNode2;
+  htmlEditor->SplitNodeDeep(aBlock, endParent, endOffset,
+                            HTMLEditor::EmptyContainers::no,
+                            getter_AddRefs(newMiddleNode2), aOutRightNode);
+
+  if (aOutMiddleNode) {
+    if (newMiddleNode2) {
+      newMiddleNode2.forget(aOutMiddleNode);
+    } else {
+      newMiddleNode1.forget(aOutMiddleNode);
+    }
+  }
+}
+
+nsresult
+HTMLEditRules::OutdentPartOfBlock(Element& aBlock,
+                                  nsIContent& aStartChild,
+                                  nsIContent& aEndChild,
+                                  bool aIsBlockIndentedWithCSS,
+                                  nsIContent** aOutLeftNode,
+                                  nsIContent** aOutRightNode)
+{
+  MOZ_ASSERT(aOutLeftNode && aOutRightNode);
+
+  nsCOMPtr<nsIContent> middleNode;
+  SplitBlock(aBlock, aStartChild, aEndChild, aOutLeftNode, aOutRightNode,
+             getter_AddRefs(middleNode));
+
+  NS_ENSURE_STATE(middleNode);
+
+  if (!aIsBlockIndentedWithCSS) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv = mHTMLEditor->RemoveBlockContainer(*middleNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else if (middleNode->IsElement()) {
+    // We do nothing if middleNode isn't an element
+    nsresult rv = ChangeIndentation(*middleNode->AsElement(), Change::minus);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+/**
+ * ConvertListType() converts list type and list item type.
+ */
+nsresult
+HTMLEditRules::ConvertListType(Element* aList,
+                               Element** aOutList,
+                               nsIAtom* aListType,
+                               nsIAtom* aItemType)
+{
+  MOZ_ASSERT(aList);
+  MOZ_ASSERT(aOutList);
+  MOZ_ASSERT(aListType);
+  MOZ_ASSERT(aItemType);
+
+  nsCOMPtr<nsINode> child = aList->GetFirstChild();
+  while (child) {
+    if (child->IsElement()) {
+      dom::Element* element = child->AsElement();
+      if (HTMLEditUtils::IsListItem(element) &&
+          !element->IsHTMLElement(aItemType)) {
+        child = mHTMLEditor->ReplaceContainer(element, aItemType);
+        NS_ENSURE_STATE(child);
+      } else if (HTMLEditUtils::IsList(element) &&
+                 !element->IsHTMLElement(aListType)) {
+        nsCOMPtr<dom::Element> temp;
+        nsresult rv = ConvertListType(child->AsElement(), getter_AddRefs(temp),
+                                      aListType, aItemType);
+        NS_ENSURE_SUCCESS(rv, rv);
+        child = temp.forget();
+      }
+    }
+    child = child->GetNextSibling();
+  }
+
+  if (aList->IsHTMLElement(aListType)) {
+    nsCOMPtr<dom::Element> list = aList->AsElement();
+    list.forget(aOutList);
+    return NS_OK;
+  }
+
+  *aOutList = mHTMLEditor->ReplaceContainer(aList, aListType).take();
+  NS_ENSURE_STATE(aOutList);
+
+  return NS_OK;
+}
+
+
+/**
+ * CreateStyleForInsertText() takes care of clearing and setting appropriate
+ * style nodes for text insertion.
+ */
+nsresult
+HTMLEditRules::CreateStyleForInsertText(Selection& aSelection,
+                                        nsIDocument& aDoc)
+{
+  MOZ_ASSERT(mHTMLEditor->mTypeInState);
+
+  bool weDidSomething = false;
+  NS_ENSURE_STATE(aSelection.GetRangeAt(0));
+  nsCOMPtr<nsINode> node = aSelection.GetRangeAt(0)->GetStartParent();
+  int32_t offset = aSelection.GetRangeAt(0)->StartOffset();
+
+  // next examine our present style and make sure default styles are either
+  // present or explicitly overridden.  If neither, add the default style to
+  // the TypeInState
+  int32_t length = mHTMLEditor->mDefaultStyles.Length();
+  for (int32_t j = 0; j < length; j++) {
+    PropItem* propItem = mHTMLEditor->mDefaultStyles[j];
+    MOZ_ASSERT(propItem);
+    bool bFirst, bAny, bAll;
+
+    // GetInlineProperty also examine TypeInState.  The only gotcha here is
+    // that a cleared property looks like an unset property.  For now I'm
+    // assuming that's not a problem: that default styles will always be
+    // multivalue styles (like font face or size) where clearing the style
+    // means we want to go back to the default.  If we ever wanted a "toggle"
+    // style like bold for a default, though, I'll have to add code to detect
+    // the difference between unset and explicitly cleared, else user would
+    // never be able to unbold, for instance.
+    nsAutoString curValue;
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->GetInlinePropertyBase(*propItem->tag, &propItem->attr,
+                                         nullptr, &bFirst, &bAny, &bAll,
+                                         &curValue, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (!bAny) {
+      // no style set for this prop/attr
+      mHTMLEditor->mTypeInState->SetProp(propItem->tag, propItem->attr,
+                                         propItem->value);
+    }
+  }
+
+  nsCOMPtr<Element> rootElement = aDoc.GetRootElement();
+  NS_ENSURE_STATE(rootElement);
+
+  // process clearing any styles first
+  nsAutoPtr<PropItem> item(mHTMLEditor->mTypeInState->TakeClearProperty());
+  while (item && node != rootElement) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->ClearStyle(address_of(node), &offset,
+                              item->tag, &item->attr);
+    NS_ENSURE_SUCCESS(rv, rv);
+    item = mHTMLEditor->mTypeInState->TakeClearProperty();
+    weDidSomething = true;
+  }
+
+  // then process setting any styles
+  int32_t relFontSize = mHTMLEditor->mTypeInState->TakeRelativeFontSize();
+  item = mHTMLEditor->mTypeInState->TakeSetProperty();
+
+  if (item || relFontSize) {
+    // we have at least one style to add; make a new text node to insert style
+    // nodes above.
+    if (RefPtr<Text> text = node->GetAsText()) {
+      // if we are in a text node, split it
+      NS_ENSURE_STATE(mHTMLEditor);
+      offset = mHTMLEditor->SplitNodeDeep(*text, *text, offset);
+      NS_ENSURE_STATE(offset != -1);
+      node = node->GetParentNode();
+    }
+    if (!mHTMLEditor->IsContainer(node)) {
+      return NS_OK;
+    }
+    OwningNonNull<Text> newNode = aDoc.CreateTextNode(EmptyString());
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv = mHTMLEditor->InsertNode(*newNode, *node, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    node = newNode;
+    offset = 0;
+    weDidSomething = true;
+
+    if (relFontSize) {
+      // dir indicated bigger versus smaller.  1 = bigger, -1 = smaller
+      HTMLEditor::FontSize dir = relFontSize > 0 ?
+        HTMLEditor::FontSize::incr : HTMLEditor::FontSize::decr;
+      for (int32_t j = 0; j < DeprecatedAbs(relFontSize); j++) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->RelativeFontChangeOnTextNode(dir, newNode, 0, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+
+    while (item) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->SetInlinePropertyOnNode(*node->AsContent(),
+                                                *item->tag, &item->attr,
+                                                item->value);
+      NS_ENSURE_SUCCESS(rv, rv);
+      item = mHTMLEditor->mTypeInState->TakeSetProperty();
+    }
+  }
+  if (weDidSomething) {
+    return aSelection.Collapse(node, offset);
+  }
+
+  return NS_OK;
+}
+
+
+/**
+ * Figure out if aNode is (or is inside) an empty block.  A block can have
+ * children and still be considered empty, if the children are empty or
+ * non-editable.
+ */
+nsresult
+HTMLEditRules::IsEmptyBlock(Element& aNode,
+                            bool* aOutIsEmptyBlock,
+                            MozBRCounts aMozBRCounts)
+{
+  MOZ_ASSERT(aOutIsEmptyBlock);
+  *aOutIsEmptyBlock = true;
+
+  NS_ENSURE_TRUE(IsBlockNode(aNode), NS_ERROR_NULL_POINTER);
+
+  return mHTMLEditor->IsEmptyNode(aNode.AsDOMNode(), aOutIsEmptyBlock,
+                                  aMozBRCounts == MozBRCounts::yes ? false
+                                                                   : true);
+}
+
+
+nsresult
+HTMLEditRules::WillAlign(Selection& aSelection,
+                         const nsAString& aAlignType,
+                         bool* aCancel,
+                         bool* aHandled)
+{
+  MOZ_ASSERT(aCancel && aHandled);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  WillInsert(aSelection, aCancel);
+
+  // Initialize out param.  We want to ignore result of WillInsert().
+  *aCancel = false;
+  *aHandled = false;
+
+  nsresult rv = NormalizeSelection(&aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  AutoSelectionRestorer selectionRestorer(&aSelection, htmlEditor);
+
+  // Convert the selection ranges into "promoted" selection ranges: This
+  // basically just expands the range to include the immediate block parent,
+  // and then further expands to include any ancestors whose children are all
+  // in the range
+  *aHandled = true;
+  nsTArray<OwningNonNull<nsINode>> nodeArray;
+  rv = GetNodesFromSelection(aSelection, EditAction::align, nodeArray);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // If we don't have any nodes, or we have only a single br, then we are
+  // creating an empty alignment div.  We have to do some different things for
+  // these.
+  bool emptyDiv = nodeArray.IsEmpty();
+  if (nodeArray.Length() == 1) {
+    OwningNonNull<nsINode> node = nodeArray[0];
+
+    if (HTMLEditUtils::SupportsAlignAttr(GetAsDOMNode(node))) {
+      // The node is a table element, an hr, a paragraph, a div or a section
+      // header; in HTML 4, it can directly carry the ALIGN attribute and we
+      // don't need to make a div! If we are in CSS mode, all the work is done
+      // in AlignBlock
+      rv = AlignBlock(*node->AsElement(), aAlignType, ContentsOnly::yes);
+      NS_ENSURE_SUCCESS(rv, rv);
+      return NS_OK;
+    }
+
+    if (TextEditUtils::IsBreak(node)) {
+      // The special case emptyDiv code (below) that consumes BRs can cause
+      // tables to split if the start node of the selection is not in a table
+      // cell or caption, for example parent is a <tr>.  Avoid this unnecessary
+      // splitting if possible by leaving emptyDiv FALSE so that we fall
+      // through to the normal case alignment code.
+      //
+      // XXX: It seems a little error prone for the emptyDiv special case code
+      // to assume that the start node of the selection is the parent of the
+      // single node in the nodeArray, as the paragraph above points out. Do we
+      // rely on the selection start node because of the fact that nodeArray
+      // can be empty?  We should probably revisit this issue. - kin
+
+      NS_ENSURE_STATE(aSelection.GetRangeAt(0) &&
+                      aSelection.GetRangeAt(0)->GetStartParent());
+      OwningNonNull<nsINode> parent =
+        *aSelection.GetRangeAt(0)->GetStartParent();
+
+      emptyDiv = !HTMLEditUtils::IsTableElement(parent) ||
+                 HTMLEditUtils::IsTableCellOrCaption(parent);
+    }
+  }
+  if (emptyDiv) {
+    nsCOMPtr<nsINode> parent =
+      aSelection.GetRangeAt(0) ? aSelection.GetRangeAt(0)->GetStartParent()
+                               : nullptr;
+    NS_ENSURE_STATE(parent);
+    int32_t offset = aSelection.GetRangeAt(0)->StartOffset();
+
+    rv = SplitAsNeeded(*nsGkAtoms::div, parent, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Consume a trailing br, if any.  This is to keep an alignment from
+    // creating extra lines, if possible.
+    nsCOMPtr<nsIContent> brContent =
+      htmlEditor->GetNextHTMLNode(parent, offset);
+    if (brContent && TextEditUtils::IsBreak(brContent)) {
+      // Making use of html structure... if next node after where we are
+      // putting our div is not a block, then the br we found is in same block
+      // we are, so it's safe to consume it.
+      nsCOMPtr<nsIContent> sibling = htmlEditor->GetNextHTMLSibling(parent,
+                                                                    offset);
+      if (sibling && !IsBlockNode(*sibling)) {
+        rv = htmlEditor->DeleteNode(brContent);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+    nsCOMPtr<Element> div = htmlEditor->CreateNode(nsGkAtoms::div, parent,
+                                                   offset);
+    NS_ENSURE_STATE(div);
+    // Remember our new block for postprocessing
+    mNewBlock = div;
+    // Set up the alignment on the div, using HTML or CSS
+    rv = AlignBlock(*div, aAlignType, ContentsOnly::yes);
+    NS_ENSURE_SUCCESS(rv, rv);
+    *aHandled = true;
+    // Put in a moz-br so that it won't get deleted
+    rv = CreateMozBR(div->AsDOMNode(), 0);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aSelection.Collapse(div, 0);
+    // Don't restore the selection
+    selectionRestorer.Abort();
+    NS_ENSURE_SUCCESS(rv, rv);
+    return NS_OK;
+  }
+
+  // Next we detect all the transitions in the array, where a transition
+  // means that adjacent nodes in the array don't have the same parent.
+
+  nsTArray<bool> transitionList;
+  MakeTransitionList(nodeArray, transitionList);
+
+  // Okay, now go through all the nodes and give them an align attrib or put
+  // them in a div, or whatever is appropriate.  Woohoo!
+
+  nsCOMPtr<Element> curDiv;
+  bool useCSS = htmlEditor->IsCSSEnabled();
+  for (size_t i = 0; i < nodeArray.Length(); i++) {
+    auto& curNode = nodeArray[i];
+    // Here's where we actually figure out what to do
+
+    // Ignore all non-editable nodes.  Leave them be.
+    if (!htmlEditor->IsEditable(curNode)) {
+      continue;
+    }
+
+    // The node is a table element, an hr, a paragraph, a div or a section
+    // header; in HTML 4, it can directly carry the ALIGN attribute and we
+    // don't need to nest it, just set the alignment.  In CSS, assign the
+    // corresponding CSS styles in AlignBlock
+    if (HTMLEditUtils::SupportsAlignAttr(GetAsDOMNode(curNode))) {
+      rv = AlignBlock(*curNode->AsElement(), aAlignType, ContentsOnly::no);
+      NS_ENSURE_SUCCESS(rv, rv);
+      // Clear out curDiv so that we don't put nodes after this one into it
+      curDiv = nullptr;
+      continue;
+    }
+
+    nsCOMPtr<nsINode> curParent = curNode->GetParentNode();
+    int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+    // Skip insignificant formatting text nodes to prevent unnecessary
+    // structure splitting!
+    bool isEmptyTextNode = false;
+    if (curNode->GetAsText() &&
+        ((HTMLEditUtils::IsTableElement(curParent) &&
+          !HTMLEditUtils::IsTableCellOrCaption(*curParent)) ||
+         HTMLEditUtils::IsList(curParent) ||
+         (NS_SUCCEEDED(htmlEditor->IsEmptyNode(curNode, &isEmptyTextNode)) &&
+          isEmptyTextNode))) {
+      continue;
+    }
+
+    // If it's a list item, or a list inside a list, forget any "current" div,
+    // and instead put divs inside the appropriate block (td, li, etc.)
+    if (HTMLEditUtils::IsListItem(curNode) ||
+        HTMLEditUtils::IsList(curNode)) {
+      rv = RemoveAlignment(GetAsDOMNode(curNode), aAlignType, true);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (useCSS) {
+        htmlEditor->mCSSEditUtils->SetCSSEquivalentToHTMLStyle(
+            curNode->AsElement(), nullptr, &NS_LITERAL_STRING("align"),
+            &aAlignType, false);
+        curDiv = nullptr;
+        continue;
+      }
+      if (HTMLEditUtils::IsList(curParent)) {
+        // If we don't use CSS, add a contraint to list element: they have to
+        // be inside another list, i.e., >= second level of nesting
+        rv = AlignInnerBlocks(*curNode, &aAlignType);
+        NS_ENSURE_SUCCESS(rv, rv);
+        curDiv = nullptr;
+        continue;
+      }
+      // Clear out curDiv so that we don't put nodes after this one into it
+    }
+
+    // Need to make a div to put things in if we haven't already, or if this
+    // node doesn't go in div we used earlier.
+    if (!curDiv || transitionList[i]) {
+      // First, check that our element can contain a div.
+      if (!mTextEditor->CanContainTag(*curParent, *nsGkAtoms::div)) {
+        // Cancelled
+        return NS_OK;
+      }
+
+      rv = SplitAsNeeded(*nsGkAtoms::div, curParent, offset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      curDiv = htmlEditor->CreateNode(nsGkAtoms::div, curParent, offset);
+      NS_ENSURE_STATE(curDiv);
+      // Remember our new block for postprocessing
+      mNewBlock = curDiv;
+      // Set up the alignment on the div
+      rv = AlignBlock(*curDiv, aAlignType, ContentsOnly::yes);
+    }
+
+    NS_ENSURE_STATE(curNode->IsContent());
+
+    // Tuck the node into the end of the active div
+    rv = htmlEditor->MoveNode(curNode->AsContent(), curDiv, -1);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+
+/**
+ * AlignInnerBlocks() aligns inside table cells or list items.
+ */
+nsresult
+HTMLEditRules::AlignInnerBlocks(nsINode& aNode,
+                                const nsAString* alignType)
+{
+  NS_ENSURE_TRUE(alignType, NS_ERROR_NULL_POINTER);
+
+  // Gather list of table cells or list items
+  nsTArray<OwningNonNull<nsINode>> nodeArray;
+  TableCellAndListItemFunctor functor;
+  DOMIterator iter(aNode);
+  iter.AppendList(functor, nodeArray);
+
+  // Now that we have the list, align their contents as requested
+  for (auto& node : nodeArray) {
+    nsresult rv = AlignBlockContents(GetAsDOMNode(node), alignType);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+
+/**
+ * AlignBlockContents() aligns contents of a block element.
+ */
+nsresult
+HTMLEditRules::AlignBlockContents(nsIDOMNode* aNode,
+                                  const nsAString* alignType)
+{
+  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+  NS_ENSURE_TRUE(node && alignType, NS_ERROR_NULL_POINTER);
+  nsCOMPtr<nsIContent> firstChild, lastChild;
+  nsCOMPtr<Element> divNode;
+
+  bool useCSS = mHTMLEditor->IsCSSEnabled();
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  firstChild = mHTMLEditor->GetFirstEditableChild(*node);
+  NS_ENSURE_STATE(mHTMLEditor);
+  lastChild = mHTMLEditor->GetLastEditableChild(*node);
+  NS_NAMED_LITERAL_STRING(attr, "align");
+  if (!firstChild) {
+    // this cell has no content, nothing to align
+  } else if (firstChild == lastChild &&
+             firstChild->IsHTMLElement(nsGkAtoms::div)) {
+    // the cell already has a div containing all of its content: just
+    // act on this div.
+    nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(firstChild);
+    if (useCSS) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->SetAttributeOrEquivalent(divElem, attr,
+                                                          *alignType, false);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+  } else {
+    // else we need to put in a div, set the alignment, and toss in all the children
+    NS_ENSURE_STATE(mHTMLEditor);
+    divNode = mHTMLEditor->CreateNode(nsGkAtoms::div, node, 0);
+    NS_ENSURE_STATE(divNode);
+    // set up the alignment on the div
+    nsCOMPtr<nsIDOMElement> divElem = do_QueryInterface(divNode);
+    if (useCSS) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv =
+        mHTMLEditor->SetAttributeOrEquivalent(divElem, attr, *alignType, false);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->SetAttribute(divElem, attr, *alignType);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+    // tuck the children into the end of the active div
+    while (lastChild && (lastChild != divNode)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->MoveNode(lastChild, divNode, 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+      NS_ENSURE_STATE(mHTMLEditor);
+      lastChild = mHTMLEditor->GetLastEditableChild(*node);
+    }
+  }
+  return NS_OK;
+}
+
+/**
+ * CheckForEmptyBlock() is called by WillDeleteSelection() to detect and handle
+ * case of deleting from inside an empty block.
+ */
+nsresult
+HTMLEditRules::CheckForEmptyBlock(nsINode* aStartNode,
+                                  Element* aBodyNode,
+                                  Selection* aSelection,
+                                  nsIEditor::EDirection aAction,
+                                  bool* aHandled)
+{
+  // If the editing host is an inline element, bail out early.
+  if (aBodyNode && IsInlineNode(*aBodyNode)) {
+    return NS_OK;
+  }
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // If we are inside an empty block, delete it.  Note: do NOT delete table
+  // elements this way.
+  nsCOMPtr<Element> block = htmlEditor->GetBlock(*aStartNode);
+  bool bIsEmptyNode;
+  nsCOMPtr<Element> emptyBlock;
+  if (block && block != aBodyNode) {
+    // Efficiency hack, avoiding IsEmptyNode() call when in body
+    nsresult rv = htmlEditor->IsEmptyNode(block, &bIsEmptyNode, true, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+    while (block && bIsEmptyNode && !HTMLEditUtils::IsTableElement(block) &&
+           block != aBodyNode) {
+      emptyBlock = block;
+      block = htmlEditor->GetBlockNodeParent(emptyBlock);
+      if (block) {
+        rv = htmlEditor->IsEmptyNode(block, &bIsEmptyNode, true, false);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+  }
+
+  if (emptyBlock && emptyBlock->IsEditable()) {
+    nsCOMPtr<nsINode> blockParent = emptyBlock->GetParentNode();
+    NS_ENSURE_TRUE(blockParent, NS_ERROR_FAILURE);
+    int32_t offset = blockParent->IndexOf(emptyBlock);
+
+    if (HTMLEditUtils::IsListItem(emptyBlock)) {
+      // Are we the first list item in the list?
+      bool bIsFirst;
+      NS_ENSURE_STATE(htmlEditor);
+      nsresult rv =
+        htmlEditor->IsFirstEditableChild(GetAsDOMNode(emptyBlock), &bIsFirst);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (bIsFirst) {
+        nsCOMPtr<nsINode> listParent = blockParent->GetParentNode();
+        NS_ENSURE_TRUE(listParent, NS_ERROR_FAILURE);
+        int32_t listOffset = listParent->IndexOf(blockParent);
+        // If we are a sublist, skip the br creation
+        if (!HTMLEditUtils::IsList(listParent)) {
+          // Create a br before list
+          NS_ENSURE_STATE(htmlEditor);
+          nsCOMPtr<Element> br =
+            htmlEditor->CreateBR(listParent, listOffset);
+          NS_ENSURE_STATE(br);
+          // Adjust selection to be right before it
+          rv = aSelection->Collapse(listParent, listOffset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+        // Else just let selection percolate up.  We'll adjust it in
+        // AfterEdit()
+      }
+    } else {
+      if (aAction == nsIEditor::eNext || aAction == nsIEditor::eNextWord ||
+          aAction == nsIEditor::eToEndOfLine) {
+        // Move to the start of the next node, if any
+        nsCOMPtr<nsIContent> nextNode = htmlEditor->GetNextNode(blockParent,
+                                                                offset + 1, true);
+        if (nextNode) {
+          EditorDOMPoint pt = GetGoodSelPointForNode(*nextNode, aAction);
+          nsresult rv = aSelection->Collapse(pt.node, pt.offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        } else {
+          // Adjust selection to be right after it.
+          nsresult rv = aSelection->Collapse(blockParent, offset + 1);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      } else if (aAction == nsIEditor::ePrevious ||
+                 aAction == nsIEditor::ePreviousWord ||
+                 aAction == nsIEditor::eToBeginningOfLine) {
+        // Move to the end of the previous node
+        nsCOMPtr<nsIContent> priorNode = htmlEditor->GetPriorNode(blockParent,
+                                                                  offset,
+                                                                  true);
+        if (priorNode) {
+          EditorDOMPoint pt = GetGoodSelPointForNode(*priorNode, aAction);
+          nsresult rv = aSelection->Collapse(pt.node, pt.offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        } else {
+          nsresult rv = aSelection->Collapse(blockParent, offset + 1);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      } else if (aAction != nsIEditor::eNone) {
+        NS_RUNTIMEABORT("CheckForEmptyBlock doesn't support this action yet");
+      }
+    }
+    NS_ENSURE_STATE(htmlEditor);
+    *aHandled = true;
+    nsresult rv = htmlEditor->DeleteNode(emptyBlock);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+Element*
+HTMLEditRules::CheckForInvisibleBR(Element& aBlock,
+                                   BRLocation aWhere,
+                                   int32_t aOffset)
+{
+  nsCOMPtr<nsINode> testNode;
+  int32_t testOffset = 0;
+
+  if (aWhere == BRLocation::blockEnd) {
+    // No block crossing
+    nsCOMPtr<nsIContent> rightmostNode =
+      mHTMLEditor->GetRightmostChild(&aBlock, true);
+
+    if (!rightmostNode) {
+      return nullptr;
+    }
+
+    testNode = rightmostNode->GetParentNode();
+    // Use offset + 1, so last node is included in our evaluation
+    testOffset = testNode->IndexOf(rightmostNode) + 1;
+  } else if (aOffset) {
+    testNode = &aBlock;
+    // We'll check everything to the left of the input position
+    testOffset = aOffset;
+  } else {
+    return nullptr;
+  }
+
+  WSRunObject wsTester(mHTMLEditor, testNode, testOffset);
+  if (WSType::br == wsTester.mStartReason) {
+    return wsTester.mStartReasonNode->AsElement();
+  }
+
+  return nullptr;
+}
+
+/**
+ * aLists and aTables allow the caller to specify what kind of content to
+ * "look inside".  If aTables is Tables::yes, look inside any table content,
+ * and insert the inner content into the supplied issupportsarray at offset
+ * aIndex.  Similarly with aLists and list content.  aIndex is updated to
+ * point past inserted elements.
+ */
+void
+HTMLEditRules::GetInnerContent(
+                 nsINode& aNode,
+                 nsTArray<OwningNonNull<nsINode>>& aOutArrayOfNodes,
+                 int32_t* aIndex,
+                 Lists aLists,
+                 Tables aTables)
+{
+  MOZ_ASSERT(aIndex);
+
+  for (nsCOMPtr<nsIContent> node = mHTMLEditor->GetFirstEditableChild(aNode);
+       node; node = node->GetNextSibling()) {
+    if ((aLists == Lists::yes && (HTMLEditUtils::IsList(node) ||
+                                  HTMLEditUtils::IsListItem(node))) ||
+        (aTables == Tables::yes && HTMLEditUtils::IsTableElement(node))) {
+      GetInnerContent(*node, aOutArrayOfNodes, aIndex, aLists, aTables);
+    } else {
+      aOutArrayOfNodes.InsertElementAt(*aIndex, *node);
+      (*aIndex)++;
+    }
+  }
+}
+
+/**
+ * Promotes selection to include blocks that have all their children selected.
+ */
+nsresult
+HTMLEditRules::ExpandSelectionForDeletion(Selection& aSelection)
+{
+  // Don't need to touch collapsed selections
+  if (aSelection.Collapsed()) {
+    return NS_OK;
+  }
+
+  // We don't need to mess with cell selections, and we assume multirange
+  // selections are those.
+  if (aSelection.RangeCount() != 1) {
+    return NS_OK;
+  }
+
+  // Find current sel start and end
+  NS_ENSURE_TRUE(aSelection.GetRangeAt(0), NS_ERROR_NULL_POINTER);
+  OwningNonNull<nsRange> range = *aSelection.GetRangeAt(0);
+
+  nsCOMPtr<nsINode> selStartNode = range->GetStartParent();
+  int32_t selStartOffset = range->StartOffset();
+  nsCOMPtr<nsINode> selEndNode = range->GetEndParent();
+  int32_t selEndOffset = range->EndOffset();
+
+  // Find current selection common block parent
+  nsCOMPtr<Element> selCommon =
+    HTMLEditor::GetBlock(*range->GetCommonAncestor());
+  NS_ENSURE_STATE(selCommon);
+
+  // Set up for loops and cache our root element
+  nsCOMPtr<nsINode> firstBRParent;
+  nsCOMPtr<nsINode> unused;
+  int32_t visOffset = 0, firstBROffset = 0;
+  WSType wsType;
+  nsCOMPtr<Element> root = mHTMLEditor->GetActiveEditingHost();
+  NS_ENSURE_TRUE(root, NS_ERROR_FAILURE);
+
+  // Find previous visible thingy before start of selection
+  if (selStartNode != selCommon && selStartNode != root) {
+    while (true) {
+      WSRunObject wsObj(mHTMLEditor, selStartNode, selStartOffset);
+      wsObj.PriorVisibleNode(selStartNode, selStartOffset, address_of(unused),
+                             &visOffset, &wsType);
+      if (wsType != WSType::thisBlock) {
+        break;
+      }
+      // We want to keep looking up.  But stop if we are crossing table
+      // element boundaries, or if we hit the root.
+      if (HTMLEditUtils::IsTableElement(wsObj.mStartReasonNode) ||
+          selCommon == wsObj.mStartReasonNode ||
+          root == wsObj.mStartReasonNode) {
+        break;
+      }
+      selStartNode = wsObj.mStartReasonNode->GetParentNode();
+      selStartOffset = selStartNode ?
+        selStartNode->IndexOf(wsObj.mStartReasonNode) : -1;
+    }
+  }
+
+  // Find next visible thingy after end of selection
+  if (selEndNode != selCommon && selEndNode != root) {
+    for (;;) {
+      WSRunObject wsObj(mHTMLEditor, selEndNode, selEndOffset);
+      wsObj.NextVisibleNode(selEndNode, selEndOffset, address_of(unused),
+                            &visOffset, &wsType);
+      if (wsType == WSType::br) {
+        if (mHTMLEditor->IsVisBreak(wsObj.mEndReasonNode)) {
+          break;
+        }
+        if (!firstBRParent) {
+          firstBRParent = selEndNode;
+          firstBROffset = selEndOffset;
+        }
+        selEndNode = wsObj.mEndReasonNode->GetParentNode();
+        selEndOffset = selEndNode
+          ? selEndNode->IndexOf(wsObj.mEndReasonNode) + 1 : 0;
+      } else if (wsType == WSType::thisBlock) {
+        // We want to keep looking up.  But stop if we are crossing table
+        // element boundaries, or if we hit the root.
+        if (HTMLEditUtils::IsTableElement(wsObj.mEndReasonNode) ||
+            selCommon == wsObj.mEndReasonNode ||
+            root == wsObj.mEndReasonNode) {
+          break;
+        }
+        selEndNode = wsObj.mEndReasonNode->GetParentNode();
+        selEndOffset = 1 + selEndNode->IndexOf(wsObj.mEndReasonNode);
+      } else {
+        break;
+      }
+    }
+  }
+  // Now set the selection to the new range
+  aSelection.Collapse(selStartNode, selStartOffset);
+
+  // Expand selection endpoint only if we didn't pass a br, or if we really
+  // needed to pass that br (i.e., its block is now totally selected)
+  bool doEndExpansion = true;
+  if (firstBRParent) {
+    // Find block node containing br
+    nsCOMPtr<Element> brBlock = HTMLEditor::GetBlock(*firstBRParent);
+    bool nodeBefore = false, nodeAfter = false;
+
+    // Create a range that represents expanded selection
+    RefPtr<nsRange> range = new nsRange(selStartNode);
+    nsresult rv = range->SetStart(selStartNode, selStartOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = range->SetEnd(selEndNode, selEndOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Check if block is entirely inside range
+    if (brBlock) {
+      nsRange::CompareNodeToRange(brBlock, range, &nodeBefore, &nodeAfter);
+    }
+
+    // If block isn't contained, forgo grabbing the br in expanded selection
+    if (nodeBefore || nodeAfter) {
+      doEndExpansion = false;
+    }
+  }
+  if (doEndExpansion) {
+    nsresult rv = aSelection.Extend(selEndNode, selEndOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    // Only expand to just before br
+    nsresult rv = aSelection.Extend(firstBRParent, firstBROffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+/**
+ * NormalizeSelection() tweaks non-collapsed selections to be more "natural".
+ * Idea here is to adjust selection endpoint so that they do not cross breaks
+ * or block boundaries unless something editable beyond that boundary is also
+ * selected.  This adjustment makes it much easier for the various block
+ * operations to determine what nodes to act on.
+ */
+nsresult
+HTMLEditRules::NormalizeSelection(Selection* inSelection)
+{
+  NS_ENSURE_TRUE(inSelection, NS_ERROR_NULL_POINTER);
+
+  // don't need to touch collapsed selections
+  if (inSelection->Collapsed()) {
+    return NS_OK;
+  }
+
+  int32_t rangeCount;
+  nsresult rv = inSelection->GetRangeCount(&rangeCount);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // we don't need to mess with cell selections, and we assume multirange selections are those.
+  if (rangeCount != 1) {
+    return NS_OK;
+  }
+
+  RefPtr<nsRange> range = inSelection->GetRangeAt(0);
+  NS_ENSURE_TRUE(range, NS_ERROR_NULL_POINTER);
+  nsCOMPtr<nsIDOMNode> startNode, endNode;
+  int32_t startOffset, endOffset;
+  nsCOMPtr<nsIDOMNode> newStartNode, newEndNode;
+  int32_t newStartOffset, newEndOffset;
+
+  rv = range->GetStartContainer(getter_AddRefs(startNode));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = range->GetStartOffset(&startOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = range->GetEndContainer(getter_AddRefs(endNode));
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = range->GetEndOffset(&endOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // adjusted values default to original values
+  newStartNode = startNode;
+  newStartOffset = startOffset;
+  newEndNode = endNode;
+  newEndOffset = endOffset;
+
+  // some locals we need for whitespace code
+  nsCOMPtr<nsINode> unused;
+  int32_t offset;
+  WSType wsType;
+
+  // let the whitespace code do the heavy lifting
+  WSRunObject wsEndObj(mHTMLEditor, endNode, endOffset);
+  // is there any intervening visible whitespace?  if so we can't push selection past that,
+  // it would visibly change maening of users selection
+  nsCOMPtr<nsINode> endNode_(do_QueryInterface(endNode));
+  wsEndObj.PriorVisibleNode(endNode_, endOffset, address_of(unused),
+                            &offset, &wsType);
+  if (wsType != WSType::text && wsType != WSType::normalWS) {
+    // eThisBlock and eOtherBlock conveniently distinquish cases
+    // of going "down" into a block and "up" out of a block.
+    if (wsEndObj.mStartReason == WSType::otherBlock) {
+      // endpoint is just after the close of a block.
+      nsCOMPtr<nsIDOMNode> child =
+        GetAsDOMNode(mHTMLEditor->GetRightmostChild(wsEndObj.mStartReasonNode,
+                                                    true));
+      if (child) {
+        newEndNode = EditorBase::GetNodeLocation(child, &newEndOffset);
+        ++newEndOffset; // offset *after* child
+      }
+      // else block is empty - we can leave selection alone here, i think.
+    } else if (wsEndObj.mStartReason == WSType::thisBlock) {
+      // endpoint is just after start of this block
+      nsCOMPtr<nsIDOMNode> child;
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->GetPriorHTMLNode(endNode, endOffset, address_of(child));
+      if (child) {
+        newEndNode = EditorBase::GetNodeLocation(child, &newEndOffset);
+        ++newEndOffset; // offset *after* child
+      }
+      // else block is empty - we can leave selection alone here, i think.
+    } else if (wsEndObj.mStartReason == WSType::br) {
+      // endpoint is just after break.  lets adjust it to before it.
+      newEndNode =
+        EditorBase::GetNodeLocation(GetAsDOMNode(wsEndObj.mStartReasonNode),
+                                    &newEndOffset);
+    }
+  }
+
+
+  // similar dealio for start of range
+  WSRunObject wsStartObj(mHTMLEditor, startNode, startOffset);
+  // is there any intervening visible whitespace?  if so we can't push selection past that,
+  // it would visibly change maening of users selection
+  nsCOMPtr<nsINode> startNode_(do_QueryInterface(startNode));
+  wsStartObj.NextVisibleNode(startNode_, startOffset, address_of(unused),
+                             &offset, &wsType);
+  if (wsType != WSType::text && wsType != WSType::normalWS) {
+    // eThisBlock and eOtherBlock conveniently distinquish cases
+    // of going "down" into a block and "up" out of a block.
+    if (wsStartObj.mEndReason == WSType::otherBlock) {
+      // startpoint is just before the start of a block.
+      nsCOMPtr<nsIDOMNode> child =
+        GetAsDOMNode(mHTMLEditor->GetLeftmostChild(wsStartObj.mEndReasonNode,
+                                                   true));
+      if (child) {
+        newStartNode = EditorBase::GetNodeLocation(child, &newStartOffset);
+      }
+      // else block is empty - we can leave selection alone here, i think.
+    } else if (wsStartObj.mEndReason == WSType::thisBlock) {
+      // startpoint is just before end of this block
+      nsCOMPtr<nsIDOMNode> child;
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->GetNextHTMLNode(startNode, startOffset, address_of(child));
+      if (child) {
+        newStartNode = EditorBase::GetNodeLocation(child, &newStartOffset);
+      }
+      // else block is empty - we can leave selection alone here, i think.
+    } else if (wsStartObj.mEndReason == WSType::br) {
+      // startpoint is just before a break.  lets adjust it to after it.
+      newStartNode =
+        EditorBase::GetNodeLocation(GetAsDOMNode(wsStartObj.mEndReasonNode),
+                                    &newStartOffset);
+      ++newStartOffset; // offset *after* break
+    }
+  }
+
+  // there is a demented possiblity we have to check for.  We might have a very strange selection
+  // that is not collapsed and yet does not contain any editable content, and satisfies some of the
+  // above conditions that cause tweaking.  In this case we don't want to tweak the selection into
+  // a block it was never in, etc.  There are a variety of strategies one might use to try to
+  // detect these cases, but I think the most straightforward is to see if the adjusted locations
+  // "cross" the old values: ie, new end before old start, or new start after old end.  If so
+  // then just leave things alone.
+
+  int16_t comp;
+  comp = nsContentUtils::ComparePoints(startNode, startOffset,
+                                       newEndNode, newEndOffset);
+  if (comp == 1) {
+    return NS_OK;  // New end before old start.
+  }
+  comp = nsContentUtils::ComparePoints(newStartNode, newStartOffset,
+                                       endNode, endOffset);
+  if (comp == 1) {
+    return NS_OK;  // New start after old end.
+  }
+
+  // otherwise set selection to new values.
+  inSelection->Collapse(newStartNode, newStartOffset);
+  inSelection->Extend(newEndNode, newEndOffset);
+  return NS_OK;
+}
+
+/**
+ * GetPromotedPoint() figures out where a start or end point for a block
+ * operation really is.
+ */
+void
+HTMLEditRules::GetPromotedPoint(RulesEndpoint aWhere,
+                                nsIDOMNode* aNode,
+                                int32_t aOffset,
+                                EditAction actionID,
+                                nsCOMPtr<nsIDOMNode>* outNode,
+                                int32_t* outOffset)
+{
+  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+  MOZ_ASSERT(node && outNode && outOffset);
+
+  // default values
+  *outNode = node->AsDOMNode();
+  *outOffset = aOffset;
+
+  // we do one thing for text actions, something else entirely for other
+  // actions
+  if (actionID == EditAction::insertText ||
+      actionID == EditAction::insertIMEText ||
+      actionID == EditAction::insertBreak ||
+      actionID == EditAction::deleteText) {
+    bool isSpace, isNBSP;
+    nsCOMPtr<nsIContent> content = do_QueryInterface(node), temp;
+    // for text actions, we want to look backwards (or forwards, as
+    // appropriate) for additional whitespace or nbsp's.  We may have to act on
+    // these later even though they are outside of the initial selection.  Even
+    // if they are in another node!
+    while (content) {
+      int32_t offset;
+      if (aWhere == kStart) {
+        NS_ENSURE_TRUE_VOID(mHTMLEditor);
+        mHTMLEditor->IsPrevCharInNodeWhitespace(content, *outOffset,
+                                                &isSpace, &isNBSP,
+                                                getter_AddRefs(temp), &offset);
+      } else {
+        NS_ENSURE_TRUE_VOID(mHTMLEditor);
+        mHTMLEditor->IsNextCharInNodeWhitespace(content, *outOffset,
+                                                &isSpace, &isNBSP,
+                                                getter_AddRefs(temp), &offset);
+      }
+      if (isSpace || isNBSP) {
+        content = temp;
+        *outOffset = offset;
+      } else {
+        break;
+      }
+    }
+
+    *outNode = content->AsDOMNode();
+    return;
+  }
+
+  int32_t offset = aOffset;
+
+  // else not a text section.  In this case we want to see if we should grab
+  // any adjacent inline nodes and/or parents and other ancestors
+  if (aWhere == kStart) {
+    // some special casing for text nodes
+    if (node->IsNodeOfType(nsINode::eTEXT)) {
+      if (!node->GetParentNode()) {
+        // Okay, can't promote any further
+        return;
+      }
+      offset = node->GetParentNode()->IndexOf(node);
+      node = node->GetParentNode();
+    }
+
+    // look back through any further inline nodes that aren't across a <br>
+    // from us, and that are enclosed in the same block.
+    NS_ENSURE_TRUE_VOID(mHTMLEditor);
+    nsCOMPtr<nsINode> priorNode =
+      mHTMLEditor->GetPriorHTMLNode(node, offset, true);
+
+    while (priorNode && priorNode->GetParentNode() &&
+           mHTMLEditor && !mHTMLEditor->IsVisBreak(priorNode) &&
+           !IsBlockNode(*priorNode)) {
+      offset = priorNode->GetParentNode()->IndexOf(priorNode);
+      node = priorNode->GetParentNode();
+      NS_ENSURE_TRUE_VOID(mHTMLEditor);
+      priorNode = mHTMLEditor->GetPriorHTMLNode(node, offset, true);
+    }
+
+    // finding the real start for this point.  look up the tree for as long as
+    // we are the first node in the container, and as long as we haven't hit
+    // the body node.
+    NS_ENSURE_TRUE_VOID(mHTMLEditor);
+    nsCOMPtr<nsIContent> nearNode =
+      mHTMLEditor->GetPriorHTMLNode(node, offset, true);
+    while (!nearNode && !node->IsHTMLElement(nsGkAtoms::body) &&
+           node->GetParentNode()) {
+      // some cutoffs are here: we don't need to also include them in the
+      // aWhere == kEnd case.  as long as they are in one or the other it will
+      // work.  special case for outdent: don't keep looking up if we have
+      // found a blockquote element to act on
+      if (actionID == EditAction::outdent &&
+          node->IsHTMLElement(nsGkAtoms::blockquote)) {
+        break;
+      }
+
+      int32_t parentOffset = node->GetParentNode()->IndexOf(node);
+      nsCOMPtr<nsINode> parent = node->GetParentNode();
+
+      // Don't walk past the editable section. Note that we need to check
+      // before walking up to a parent because we need to return the parent
+      // object, so the parent itself might not be in the editable area, but
+      // it's OK if we're not performing a block-level action.
+      bool blockLevelAction = actionID == EditAction::indent ||
+                              actionID == EditAction::outdent ||
+                              actionID == EditAction::align ||
+                              actionID == EditAction::makeBasicBlock;
+      NS_ENSURE_TRUE_VOID(mHTMLEditor);
+      if (!mHTMLEditor->IsDescendantOfEditorRoot(parent) &&
+          (blockLevelAction || !mHTMLEditor ||
+           !mHTMLEditor->IsDescendantOfEditorRoot(node))) {
+        NS_ENSURE_TRUE_VOID(mHTMLEditor);
+        break;
+      }
+
+      node = parent;
+      offset = parentOffset;
+      NS_ENSURE_TRUE_VOID(mHTMLEditor);
+      nearNode = mHTMLEditor->GetPriorHTMLNode(node, offset, true);
+    }
+    *outNode = node->AsDOMNode();
+    *outOffset = offset;
+    return;
+  }
+
+  // aWhere == kEnd
+  // some special casing for text nodes
+  if (node->IsNodeOfType(nsINode::eTEXT)) {
+    if (!node->GetParentNode()) {
+      // Okay, can't promote any further
+      return;
+    }
+    // want to be after the text node
+    offset = 1 + node->GetParentNode()->IndexOf(node);
+    node = node->GetParentNode();
+  }
+
+  // look ahead through any further inline nodes that aren't across a <br> from
+  // us, and that are enclosed in the same block.
+  NS_ENSURE_TRUE(mHTMLEditor, /* void */);
+  nsCOMPtr<nsIContent> nextNode =
+    mHTMLEditor->GetNextHTMLNode(node, offset, true);
+
+  while (nextNode && !IsBlockNode(*nextNode) && nextNode->GetParentNode()) {
+    offset = 1 + nextNode->GetParentNode()->IndexOf(nextNode);
+    node = nextNode->GetParentNode();
+    NS_ENSURE_TRUE_VOID(mHTMLEditor);
+    if (mHTMLEditor->IsVisBreak(nextNode)) {
+      break;
+    }
+
+    // Check for newlines in pre-formatted text nodes.
+    bool isPRE;
+    mHTMLEditor->IsPreformatted(nextNode->AsDOMNode(), &isPRE);
+    if (isPRE) {
+      nsCOMPtr<nsIDOMText> textNode = do_QueryInterface(nextNode);
+      if (textNode) {
+        nsAutoString tempString;
+        textNode->GetData(tempString);
+        int32_t newlinePos = tempString.FindChar(nsCRT::LF);
+        if (newlinePos >= 0) {
+          if (static_cast<uint32_t>(newlinePos) + 1 == tempString.Length()) {
+            // No need for special processing if the newline is at the end.
+            break;
+          }
+          *outNode = nextNode->AsDOMNode();
+          *outOffset = newlinePos + 1;
+          return;
+        }
+      }
+    }
+    NS_ENSURE_TRUE_VOID(mHTMLEditor);
+    nextNode = mHTMLEditor->GetNextHTMLNode(node, offset, true);
+  }
+
+  // finding the real end for this point.  look up the tree for as long as we
+  // are the last node in the container, and as long as we haven't hit the body
+  // node.
+  NS_ENSURE_TRUE_VOID(mHTMLEditor);
+  nsCOMPtr<nsIContent> nearNode =
+    mHTMLEditor->GetNextHTMLNode(node, offset, true);
+  while (!nearNode && !node->IsHTMLElement(nsGkAtoms::body) &&
+         node->GetParentNode()) {
+    int32_t parentOffset = node->GetParentNode()->IndexOf(node);
+    nsCOMPtr<nsINode> parent = node->GetParentNode();
+
+    // Don't walk past the editable section. Note that we need to check before
+    // walking up to a parent because we need to return the parent object, so
+    // the parent itself might not be in the editable area, but it's OK.
+    if ((!mHTMLEditor || !mHTMLEditor->IsDescendantOfEditorRoot(node)) &&
+        (!mHTMLEditor || !mHTMLEditor->IsDescendantOfEditorRoot(parent))) {
+      NS_ENSURE_TRUE_VOID(mHTMLEditor);
+      break;
+    }
+
+    node = parent;
+    // we want to be AFTER nearNode
+    offset = parentOffset + 1;
+    NS_ENSURE_TRUE_VOID(mHTMLEditor);
+    nearNode = mHTMLEditor->GetNextHTMLNode(node, offset, true);
+  }
+  *outNode = node->AsDOMNode();
+  *outOffset = offset;
+}
+
+/**
+ * GetPromotedRanges() runs all the selection range endpoint through
+ * GetPromotedPoint().
+ */
+void
+HTMLEditRules::GetPromotedRanges(Selection& aSelection,
+                                 nsTArray<RefPtr<nsRange>>& outArrayOfRanges,
+                                 EditAction inOperationType)
+{
+  uint32_t rangeCount = aSelection.RangeCount();
+
+  for (uint32_t i = 0; i < rangeCount; i++) {
+    RefPtr<nsRange> selectionRange = aSelection.GetRangeAt(i);
+    MOZ_ASSERT(selectionRange);
+
+    // Clone range so we don't muck with actual selection ranges
+    RefPtr<nsRange> opRange = selectionRange->CloneRange();
+
+    // Make a new adjusted range to represent the appropriate block content.
+    // The basic idea is to push out the range endpoints to truly enclose the
+    // blocks that we will affect.  This call alters opRange.
+    PromoteRange(*opRange, inOperationType);
+
+    // Stuff new opRange into array
+    outArrayOfRanges.AppendElement(opRange);
+  }
+}
+
+/**
+ * PromoteRange() expands a range to include any parents for which all editable
+ * children are already in range.
+ */
+void
+HTMLEditRules::PromoteRange(nsRange& aRange,
+                            EditAction aOperationType)
+{
+  NS_ENSURE_TRUE(mHTMLEditor, );
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  nsCOMPtr<nsINode> startNode = aRange.GetStartParent();
+  nsCOMPtr<nsINode> endNode = aRange.GetEndParent();
+  int32_t startOffset = aRange.StartOffset();
+  int32_t endOffset = aRange.EndOffset();
+
+  // MOOSE major hack:
+  // GetPromotedPoint doesn't really do the right thing for collapsed ranges
+  // inside block elements that contain nothing but a solo <br>.  It's easier
+  // to put a workaround here than to revamp GetPromotedPoint.  :-(
+  if (startNode == endNode && startOffset == endOffset) {
+    nsCOMPtr<Element> block = htmlEditor->GetBlock(*startNode);
+    if (block) {
+      bool bIsEmptyNode = false;
+      nsCOMPtr<nsIContent> root = htmlEditor->GetActiveEditingHost();
+      // Make sure we don't go higher than our root element in the content tree
+      NS_ENSURE_TRUE(root, );
+      if (!nsContentUtils::ContentIsDescendantOf(root, block)) {
+        htmlEditor->IsEmptyNode(block, &bIsEmptyNode, true, false);
+      }
+      if (bIsEmptyNode) {
+        startNode = block;
+        endNode = block;
+        startOffset = 0;
+        endOffset = block->Length();
+      }
+    }
+  }
+
+  // Make a new adjusted range to represent the appropriate block content.
+  // This is tricky.  The basic idea is to push out the range endpoints to
+  // truly enclose the blocks that we will affect.
+
+  nsCOMPtr<nsIDOMNode> opStartNode;
+  nsCOMPtr<nsIDOMNode> opEndNode;
+  int32_t opStartOffset, opEndOffset;
+
+  GetPromotedPoint(kStart, GetAsDOMNode(startNode), startOffset,
+                   aOperationType, address_of(opStartNode), &opStartOffset);
+  GetPromotedPoint(kEnd, GetAsDOMNode(endNode), endOffset, aOperationType,
+                   address_of(opEndNode), &opEndOffset);
+
+  // Make sure that the new range ends up to be in the editable section.
+  if (!htmlEditor->IsDescendantOfEditorRoot(
+        EditorBase::GetNodeAtRangeOffsetPoint(opStartNode, opStartOffset)) ||
+      !htmlEditor->IsDescendantOfEditorRoot(
+        EditorBase::GetNodeAtRangeOffsetPoint(opEndNode, opEndOffset - 1))) {
+    return;
+  }
+
+  DebugOnly<nsresult> rv = aRange.SetStart(opStartNode, opStartOffset);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+  rv = aRange.SetEnd(opEndNode, opEndOffset);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+}
+
+class UniqueFunctor final : public BoolDomIterFunctor
+{
+public:
+  explicit UniqueFunctor(nsTArray<OwningNonNull<nsINode>>& aArray)
+    : mArray(aArray)
+  {
+  }
+
+  // Used to build list of all nodes iterator covers.
+  virtual bool operator()(nsINode* aNode) const
+  {
+    return !mArray.Contains(aNode);
+  }
+
+private:
+  nsTArray<OwningNonNull<nsINode>>& mArray;
+};
+
+/**
+ * GetNodesForOperation() runs through the ranges in the array and construct a
+ * new array of nodes to be acted on.
+ */
+nsresult
+HTMLEditRules::GetNodesForOperation(
+                 nsTArray<RefPtr<nsRange>>& aArrayOfRanges,
+                 nsTArray<OwningNonNull<nsINode>>& aOutArrayOfNodes,
+                 EditAction aOperationType,
+                 TouchContent aTouchContent)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  int32_t rangeCount = aArrayOfRanges.Length();
+  if (aTouchContent == TouchContent::yes) {
+    // Split text nodes. This is necessary, since GetPromotedPoint() may return a
+    // range ending in a text node in case where part of a pre-formatted
+    // elements needs to be moved.
+    for (int32_t i = 0; i < rangeCount; i++) {
+      RefPtr<nsRange> r = aArrayOfRanges[i];
+      nsCOMPtr<nsIContent> endParent = do_QueryInterface(r->GetEndParent());
+      if (!htmlEditor->IsTextNode(endParent)) {
+        continue;
+      }
+      nsCOMPtr<nsIDOMText> textNode = do_QueryInterface(endParent);
+      if (textNode) {
+        int32_t offset = r->EndOffset();
+        nsAutoString tempString;
+        textNode->GetData(tempString);
+
+        if (0 < offset && offset < static_cast<int32_t>(tempString.Length())) {
+          // Split the text node.
+          nsCOMPtr<nsIDOMNode> tempNode;
+          nsresult rv = htmlEditor->SplitNode(endParent->AsDOMNode(), offset,
+                                              getter_AddRefs(tempNode));
+          NS_ENSURE_SUCCESS(rv, rv);
+
+          // Correct the range.
+          // The new end parent becomes the parent node of the text.
+          nsCOMPtr<nsIContent> newParent = endParent->GetParent();
+          r->SetEnd(newParent, newParent->IndexOf(endParent));
+        }
+      }
+    }
+  }
+
+  // Bust up any inlines that cross our range endpoints, but only if we are
+  // allowed to touch content.
+
+  if (aTouchContent == TouchContent::yes) {
+    nsTArray<OwningNonNull<RangeItem>> rangeItemArray;
+    rangeItemArray.AppendElements(rangeCount);
+
+    // First register ranges for special editor gravity
+    for (int32_t i = 0; i < rangeCount; i++) {
+      rangeItemArray[i] = new RangeItem();
+      rangeItemArray[i]->StoreRange(aArrayOfRanges[0]);
+      htmlEditor->mRangeUpdater.RegisterRangeItem(rangeItemArray[i]);
+      aArrayOfRanges.RemoveElementAt(0);
+    }
+    // Now bust up inlines.
+    nsresult rv = NS_OK;
+    for (auto& item : Reversed(rangeItemArray)) {
+      rv = BustUpInlinesAtRangeEndpoints(*item);
+      if (NS_FAILED(rv)) {
+        break;
+      }
+    }
+    // Then unregister the ranges
+    for (auto& item : rangeItemArray) {
+      htmlEditor->mRangeUpdater.DropRangeItem(item);
+      aArrayOfRanges.AppendElement(item->GetRange());
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  // Gather up a list of all the nodes
+  for (auto& range : aArrayOfRanges) {
+    DOMSubtreeIterator iter;
+    nsresult rv = iter.Init(*range);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (aOutArrayOfNodes.IsEmpty()) {
+      iter.AppendList(TrivialFunctor(), aOutArrayOfNodes);
+    } else {
+      // We don't want duplicates in aOutArrayOfNodes, so we use an
+      // iterator/functor that only return nodes that are not already in
+      // aOutArrayOfNodes.
+      nsTArray<OwningNonNull<nsINode>> nodes;
+      iter.AppendList(UniqueFunctor(aOutArrayOfNodes), nodes);
+      aOutArrayOfNodes.AppendElements(nodes);
+    }
+  }
+
+  // Certain operations should not act on li's and td's, but rather inside
+  // them.  Alter the list as needed.
+  if (aOperationType == EditAction::makeBasicBlock) {
+    for (int32_t i = aOutArrayOfNodes.Length() - 1; i >= 0; i--) {
+      OwningNonNull<nsINode> node = aOutArrayOfNodes[i];
+      if (HTMLEditUtils::IsListItem(node)) {
+        int32_t j = i;
+        aOutArrayOfNodes.RemoveElementAt(i);
+        GetInnerContent(*node, aOutArrayOfNodes, &j);
+      }
+    }
+  }
+  // Indent/outdent already do something special for list items, but we still
+  // need to make sure we don't act on table elements
+  else if (aOperationType == EditAction::outdent ||
+           aOperationType == EditAction::indent ||
+           aOperationType == EditAction::setAbsolutePosition) {
+    for (int32_t i = aOutArrayOfNodes.Length() - 1; i >= 0; i--) {
+      OwningNonNull<nsINode> node = aOutArrayOfNodes[i];
+      if (HTMLEditUtils::IsTableElementButNotTable(node)) {
+        int32_t j = i;
+        aOutArrayOfNodes.RemoveElementAt(i);
+        GetInnerContent(*node, aOutArrayOfNodes, &j);
+      }
+    }
+  }
+  // Outdent should look inside of divs.
+  if (aOperationType == EditAction::outdent &&
+      !htmlEditor->IsCSSEnabled()) {
+    for (int32_t i = aOutArrayOfNodes.Length() - 1; i >= 0; i--) {
+      OwningNonNull<nsINode> node = aOutArrayOfNodes[i];
+      if (node->IsHTMLElement(nsGkAtoms::div)) {
+        int32_t j = i;
+        aOutArrayOfNodes.RemoveElementAt(i);
+        GetInnerContent(*node, aOutArrayOfNodes, &j, Lists::no, Tables::no);
+      }
+    }
+  }
+
+
+  // Post-process the list to break up inline containers that contain br's, but
+  // only for operations that might care, like making lists or paragraphs
+  if (aOperationType == EditAction::makeBasicBlock ||
+      aOperationType == EditAction::makeList ||
+      aOperationType == EditAction::align ||
+      aOperationType == EditAction::setAbsolutePosition ||
+      aOperationType == EditAction::indent ||
+      aOperationType == EditAction::outdent) {
+    for (int32_t i = aOutArrayOfNodes.Length() - 1; i >= 0; i--) {
+      OwningNonNull<nsINode> node = aOutArrayOfNodes[i];
+      if (aTouchContent == TouchContent::yes && IsInlineNode(node) &&
+          htmlEditor->IsContainer(node) && !htmlEditor->IsTextNode(node)) {
+        nsTArray<OwningNonNull<nsINode>> arrayOfInlines;
+        nsresult rv = BustUpInlinesAtBRs(*node->AsContent(), arrayOfInlines);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // Put these nodes in aOutArrayOfNodes, replacing the current node
+        aOutArrayOfNodes.RemoveElementAt(i);
+        aOutArrayOfNodes.InsertElementsAt(i, arrayOfInlines);
+      }
+    }
+  }
+  return NS_OK;
+}
+
+void
+HTMLEditRules::GetChildNodesForOperation(
+                 nsINode& aNode,
+                 nsTArray<OwningNonNull<nsINode>>& outArrayOfNodes)
+{
+  for (nsCOMPtr<nsIContent> child = aNode.GetFirstChild();
+       child; child = child->GetNextSibling()) {
+    outArrayOfNodes.AppendElement(*child);
+  }
+}
+
+nsresult
+HTMLEditRules::GetListActionNodes(
+                 nsTArray<OwningNonNull<nsINode>>& aOutArrayOfNodes,
+                 EntireList aEntireList,
+                 TouchContent aTouchContent)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  RefPtr<Selection> selection = htmlEditor->GetSelection();
+  NS_ENSURE_TRUE(selection, NS_ERROR_FAILURE);
+
+  // Added this in so that ui code can ask to change an entire list, even if
+  // selection is only in part of it.  used by list item dialog.
+  if (aEntireList == EntireList::yes) {
+    uint32_t rangeCount = selection->RangeCount();
+    for (uint32_t rangeIdx = 0; rangeIdx < rangeCount; ++rangeIdx) {
+      RefPtr<nsRange> range = selection->GetRangeAt(rangeIdx);
+      for (nsCOMPtr<nsINode> parent = range->GetCommonAncestor();
+           parent; parent = parent->GetParentNode()) {
+        if (HTMLEditUtils::IsList(parent)) {
+          aOutArrayOfNodes.AppendElement(*parent);
+          break;
+        }
+      }
+    }
+    // If we didn't find any nodes this way, then try the normal way.  Perhaps
+    // the selection spans multiple lists but with no common list parent.
+    if (!aOutArrayOfNodes.IsEmpty()) {
+      return NS_OK;
+    }
+  }
+
+  {
+    // We don't like other people messing with our selection!
+    AutoTransactionsConserveSelection dontSpazMySelection(htmlEditor);
+
+    // contruct a list of nodes to act on.
+    nsresult rv = GetNodesFromSelection(*selection, EditAction::makeList,
+                                        aOutArrayOfNodes, aTouchContent);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // Pre-process our list of nodes
+  for (int32_t i = aOutArrayOfNodes.Length() - 1; i >= 0; i--) {
+    OwningNonNull<nsINode> testNode = aOutArrayOfNodes[i];
+
+    // Remove all non-editable nodes.  Leave them be.
+    if (!htmlEditor->IsEditable(testNode)) {
+      aOutArrayOfNodes.RemoveElementAt(i);
+      continue;
+    }
+
+    // Scan for table elements and divs.  If we find table elements other than
+    // table, replace it with a list of any editable non-table content.
+    if (HTMLEditUtils::IsTableElementButNotTable(testNode)) {
+      int32_t j = i;
+      aOutArrayOfNodes.RemoveElementAt(i);
+      GetInnerContent(*testNode, aOutArrayOfNodes, &j, Lists::no);
+    }
+  }
+
+  // If there is only one node in the array, and it is a list, div, or
+  // blockquote, then look inside of it until we find inner list or content.
+  LookInsideDivBQandList(aOutArrayOfNodes);
+
+  return NS_OK;
+}
+
+void
+HTMLEditRules::LookInsideDivBQandList(
+                 nsTArray<OwningNonNull<nsINode>>& aNodeArray)
+{
+  NS_ENSURE_TRUE(mHTMLEditor, );
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // If there is only one node in the array, and it is a list, div, or
+  // blockquote, then look inside of it until we find inner list or content.
+  if (aNodeArray.Length() != 1) {
+    return;
+  }
+
+  OwningNonNull<nsINode> curNode = aNodeArray[0];
+
+  while (curNode->IsHTMLElement(nsGkAtoms::div) ||
+         HTMLEditUtils::IsList(curNode) ||
+         curNode->IsHTMLElement(nsGkAtoms::blockquote)) {
+    // Dive as long as there's only one child, and it's a list, div, blockquote
+    uint32_t numChildren = htmlEditor->CountEditableChildren(curNode);
+    if (numChildren != 1) {
+      break;
+    }
+
+    // Keep diving!  XXX One would expect to dive into the one editable node.
+    nsCOMPtr<nsIContent> child = curNode->GetFirstChild();
+    if (!child->IsHTMLElement(nsGkAtoms::div) &&
+        !HTMLEditUtils::IsList(child) &&
+        !child->IsHTMLElement(nsGkAtoms::blockquote)) {
+      break;
+    }
+
+    // check editability XXX floppy moose
+    curNode = child;
+  }
+
+  // We've found innermost list/blockquote/div: replace the one node in the
+  // array with these nodes
+  aNodeArray.RemoveElementAt(0);
+  if (curNode->IsAnyOfHTMLElements(nsGkAtoms::div,
+                                   nsGkAtoms::blockquote)) {
+    int32_t j = 0;
+    GetInnerContent(*curNode, aNodeArray, &j, Lists::no, Tables::no);
+    return;
+  }
+
+  aNodeArray.AppendElement(*curNode);
+}
+
+void
+HTMLEditRules::GetDefinitionListItemTypes(dom::Element* aElement,
+                                          bool* aDT,
+                                          bool* aDD)
+{
+  MOZ_ASSERT(aElement);
+  MOZ_ASSERT(aElement->IsHTMLElement(nsGkAtoms::dl));
+  MOZ_ASSERT(aDT);
+  MOZ_ASSERT(aDD);
+
+  *aDT = *aDD = false;
+  for (nsIContent* child = aElement->GetFirstChild();
+       child;
+       child = child->GetNextSibling()) {
+    if (child->IsHTMLElement(nsGkAtoms::dt)) {
+      *aDT = true;
+    } else if (child->IsHTMLElement(nsGkAtoms::dd)) {
+      *aDD = true;
+    }
+  }
+}
+
+nsresult
+HTMLEditRules::GetParagraphFormatNodes(
+                 nsTArray<OwningNonNull<nsINode>>& outArrayOfNodes,
+                 TouchContent aTouchContent)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  RefPtr<Selection> selection = htmlEditor->GetSelection();
+  NS_ENSURE_STATE(selection);
+
+  // Contruct a list of nodes to act on.
+  nsresult rv = GetNodesFromSelection(*selection, EditAction::makeBasicBlock,
+                                      outArrayOfNodes, aTouchContent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Pre-process our list of nodes
+  for (int32_t i = outArrayOfNodes.Length() - 1; i >= 0; i--) {
+    OwningNonNull<nsINode> testNode = outArrayOfNodes[i];
+
+    // Remove all non-editable nodes.  Leave them be.
+    if (!htmlEditor->IsEditable(testNode)) {
+      outArrayOfNodes.RemoveElementAt(i);
+      continue;
+    }
+
+    // Scan for table elements.  If we find table elements other than table,
+    // replace it with a list of any editable non-table content.  Ditto for
+    // list elements.
+    if (HTMLEditUtils::IsTableElement(testNode) ||
+        HTMLEditUtils::IsList(testNode) ||
+        HTMLEditUtils::IsListItem(testNode)) {
+      int32_t j = i;
+      outArrayOfNodes.RemoveElementAt(i);
+      GetInnerContent(testNode, outArrayOfNodes, &j);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::BustUpInlinesAtRangeEndpoints(RangeItem& item)
+{
+  bool isCollapsed = ((item.startNode == item.endNode) && (item.startOffset == item.endOffset));
+
+  nsCOMPtr<nsIContent> endInline = GetHighestInlineParent(*item.endNode);
+
+  // if we have inline parents above range endpoints, split them
+  if (endInline && !isCollapsed) {
+    nsCOMPtr<nsINode> resultEndNode = endInline->GetParentNode();
+    NS_ENSURE_STATE(mHTMLEditor);
+    // item.endNode must be content if endInline isn't null
+    int32_t resultEndOffset =
+      mHTMLEditor->SplitNodeDeep(*endInline, *item.endNode->AsContent(),
+                                 item.endOffset,
+                                 EditorBase::EmptyContainers::no);
+    NS_ENSURE_TRUE(resultEndOffset != -1, NS_ERROR_FAILURE);
+    // reset range
+    item.endNode = resultEndNode;
+    item.endOffset = resultEndOffset;
+  }
+
+  nsCOMPtr<nsIContent> startInline = GetHighestInlineParent(*item.startNode);
+
+  if (startInline) {
+    nsCOMPtr<nsINode> resultStartNode = startInline->GetParentNode();
+    NS_ENSURE_STATE(mHTMLEditor);
+    int32_t resultStartOffset =
+      mHTMLEditor->SplitNodeDeep(*startInline, *item.startNode->AsContent(),
+                                 item.startOffset,
+                                 EditorBase::EmptyContainers::no);
+    NS_ENSURE_TRUE(resultStartOffset != -1, NS_ERROR_FAILURE);
+    // reset range
+    item.startNode = resultStartNode;
+    item.startOffset = resultStartOffset;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::BustUpInlinesAtBRs(
+                 nsIContent& aNode,
+                 nsTArray<OwningNonNull<nsINode>>& aOutArrayOfNodes)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // First build up a list of all the break nodes inside the inline container.
+  nsTArray<OwningNonNull<nsINode>> arrayOfBreaks;
+  BRNodeFunctor functor;
+  DOMIterator iter(aNode);
+  iter.AppendList(functor, arrayOfBreaks);
+
+  // If there aren't any breaks, just put inNode itself in the array
+  if (arrayOfBreaks.IsEmpty()) {
+    aOutArrayOfNodes.AppendElement(aNode);
+    return NS_OK;
+  }
+
+  // Else we need to bust up inNode along all the breaks
+  nsCOMPtr<nsINode> inlineParentNode = aNode.GetParentNode();
+  nsCOMPtr<nsIContent> splitDeepNode = &aNode;
+  nsCOMPtr<nsIContent> leftNode, rightNode;
+
+  for (uint32_t i = 0; i < arrayOfBreaks.Length(); i++) {
+    OwningNonNull<Element> breakNode = *arrayOfBreaks[i]->AsElement();
+    NS_ENSURE_TRUE(splitDeepNode, NS_ERROR_NULL_POINTER);
+    NS_ENSURE_TRUE(breakNode->GetParent(), NS_ERROR_NULL_POINTER);
+    OwningNonNull<nsIContent> splitParentNode = *breakNode->GetParent();
+    int32_t splitOffset = splitParentNode->IndexOf(breakNode);
+
+    int32_t resultOffset =
+      htmlEditor->SplitNodeDeep(*splitDeepNode, splitParentNode, splitOffset,
+                                HTMLEditor::EmptyContainers::yes,
+                                getter_AddRefs(leftNode),
+                                getter_AddRefs(rightNode));
+    NS_ENSURE_STATE(resultOffset != -1);
+
+    // Put left node in node list
+    if (leftNode) {
+      // Might not be a left node.  A break might have been at the very
+      // beginning of inline container, in which case SplitNodeDeep would not
+      // actually split anything
+      aOutArrayOfNodes.AppendElement(*leftNode);
+    }
+    // Move break outside of container and also put in node list
+    nsresult rv =
+      htmlEditor->MoveNode(breakNode, inlineParentNode, resultOffset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    aOutArrayOfNodes.AppendElement(*breakNode);
+
+    // Now rightNode becomes the new node to split
+    splitDeepNode = rightNode;
+  }
+  // Now tack on remaining rightNode, if any, to the list
+  if (rightNode) {
+    aOutArrayOfNodes.AppendElement(*rightNode);
+  }
+  return NS_OK;
+}
+
+nsIContent*
+HTMLEditRules::GetHighestInlineParent(nsINode& aNode)
+{
+  if (!aNode.IsContent() || IsBlockNode(aNode)) {
+    return nullptr;
+  }
+  OwningNonNull<nsIContent> node = *aNode.AsContent();
+
+  while (node->GetParent() && IsInlineNode(*node->GetParent())) {
+    node = *node->GetParent();
+  }
+  return node;
+}
+
+/**
+ * GetNodesFromPoint() constructs a list of nodes from a point that will be
+ * operated on.
+ */
+nsresult
+HTMLEditRules::GetNodesFromPoint(
+                 EditorDOMPoint aPoint,
+                 EditAction aOperation,
+                 nsTArray<OwningNonNull<nsINode>>& outArrayOfNodes,
+                 TouchContent aTouchContent)
+{
+  NS_ENSURE_STATE(aPoint.node);
+  RefPtr<nsRange> range = new nsRange(aPoint.node);
+  nsresult rv = range->SetStart(aPoint.node, aPoint.offset);
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+
+  // Expand the range to include adjacent inlines
+  PromoteRange(*range, aOperation);
+
+  // Make array of ranges
+  nsTArray<RefPtr<nsRange>> arrayOfRanges;
+
+  // Stuff new opRange into array
+  arrayOfRanges.AppendElement(range);
+
+  // Use these ranges to contruct a list of nodes to act on
+  rv = GetNodesForOperation(arrayOfRanges, outArrayOfNodes, aOperation,
+                            aTouchContent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+/**
+ * GetNodesFromSelection() constructs a list of nodes from the selection that
+ * will be operated on.
+ */
+nsresult
+HTMLEditRules::GetNodesFromSelection(
+                 Selection& aSelection,
+                 EditAction aOperation,
+                 nsTArray<OwningNonNull<nsINode>>& outArrayOfNodes,
+                 TouchContent aTouchContent)
+{
+  // Promote selection ranges
+  nsTArray<RefPtr<nsRange>> arrayOfRanges;
+  GetPromotedRanges(aSelection, arrayOfRanges, aOperation);
+
+  // Use these ranges to contruct a list of nodes to act on.
+  nsresult rv = GetNodesForOperation(arrayOfRanges, outArrayOfNodes,
+                                     aOperation, aTouchContent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+/**
+ * MakeTransitionList() detects all the transitions in the array, where a
+ * transition means that adjacent nodes in the array don't have the same parent.
+ */
+void
+HTMLEditRules::MakeTransitionList(nsTArray<OwningNonNull<nsINode>>& aNodeArray,
+                                  nsTArray<bool>& aTransitionArray)
+{
+  nsCOMPtr<nsINode> prevParent;
+
+  aTransitionArray.EnsureLengthAtLeast(aNodeArray.Length());
+  for (uint32_t i = 0; i < aNodeArray.Length(); i++) {
+    if (aNodeArray[i]->GetParentNode() != prevParent) {
+      // Different parents: transition point
+      aTransitionArray[i] = true;
+    } else {
+      // Same parents: these nodes grew up together
+      aTransitionArray[i] = false;
+    }
+    prevParent = aNodeArray[i]->GetParentNode();
+  }
+}
+
+/**
+ * If aNode is the descendant of a listitem, return that li.  But table element
+ * boundaries are stoppers on the search.  Also stops on the active editor host
+ * (contenteditable).  Also test if aNode is an li itself.
+ */
+Element*
+HTMLEditRules::IsInListItem(nsINode* aNode)
+{
+  NS_ENSURE_TRUE(aNode, nullptr);
+  if (HTMLEditUtils::IsListItem(aNode)) {
+    return aNode->AsElement();
+  }
+
+  Element* parent = aNode->GetParentElement();
+  while (parent &&
+         mHTMLEditor && mHTMLEditor->IsDescendantOfEditorRoot(parent) &&
+         !HTMLEditUtils::IsTableElement(parent)) {
+    if (HTMLEditUtils::IsListItem(parent)) {
+      return parent;
+    }
+    parent = parent->GetParentElement();
+  }
+  return nullptr;
+}
+
+/**
+ * ReturnInHeader: do the right thing for returns pressed in headers
+ */
+nsresult
+HTMLEditRules::ReturnInHeader(Selection& aSelection,
+                              Element& aHeader,
+                              nsINode& aNode,
+                              int32_t aOffset)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Remember where the header is
+  nsCOMPtr<nsINode> headerParent = aHeader.GetParentNode();
+  int32_t offset = headerParent ? headerParent->IndexOf(&aHeader) : -1;
+
+  // Get ws code to adjust any ws
+  nsCOMPtr<nsINode> node = &aNode;
+  nsresult rv = WSRunObject::PrepareToSplitAcrossBlocks(htmlEditor,
+                                                        address_of(node),
+                                                        &aOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Split the header
+  NS_ENSURE_STATE(node->IsContent());
+  htmlEditor->SplitNodeDeep(aHeader, *node->AsContent(), aOffset);
+
+  // If the left-hand heading is empty, put a mozbr in it
+  nsCOMPtr<nsIContent> prevItem = htmlEditor->GetPriorHTMLSibling(&aHeader);
+  if (prevItem && HTMLEditUtils::IsHeader(*prevItem)) {
+    bool isEmptyNode;
+    rv = htmlEditor->IsEmptyNode(prevItem, &isEmptyNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (isEmptyNode) {
+      rv = CreateMozBR(prevItem->AsDOMNode(), 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // If the new (righthand) header node is empty, delete it
+  bool isEmpty;
+  rv = IsEmptyBlock(aHeader, &isEmpty, MozBRCounts::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (isEmpty) {
+    rv = htmlEditor->DeleteNode(&aHeader);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Layout tells the caret to blink in a weird place if we don't place a
+    // break after the header.
+    nsCOMPtr<nsIContent> sibling =
+      htmlEditor->GetNextHTMLSibling(headerParent, offset + 1);
+    if (!sibling || !sibling->IsHTMLElement(nsGkAtoms::br)) {
+      ClearCachedStyles();
+      htmlEditor->mTypeInState->ClearAllProps();
+
+      // Create a paragraph
+      nsCOMPtr<Element> pNode =
+        htmlEditor->CreateNode(nsGkAtoms::p, headerParent, offset + 1);
+      NS_ENSURE_STATE(pNode);
+
+      // Append a <br> to it
+      nsCOMPtr<Element> brNode = htmlEditor->CreateBR(pNode, 0);
+      NS_ENSURE_STATE(brNode);
+
+      // Set selection to before the break
+      rv = aSelection.Collapse(pNode, 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      headerParent = sibling->GetParentNode();
+      offset = headerParent ? headerParent->IndexOf(sibling) : -1;
+      // Put selection after break
+      rv = aSelection.Collapse(headerParent, offset + 1);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  } else {
+    // Put selection at front of righthand heading
+    rv = aSelection.Collapse(&aHeader, 0);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+/**
+ * ReturnInParagraph() does the right thing for returns pressed in paragraphs.
+ */
+nsresult
+HTMLEditRules::ReturnInParagraph(Selection* aSelection,
+                                 nsIDOMNode* aPara,
+                                 nsIDOMNode* aNode,
+                                 int32_t aOffset,
+                                 bool* aCancel,
+                                 bool* aHandled)
+{
+  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+  if (!aSelection || !aPara || !node || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  *aCancel = false;
+  *aHandled = false;
+
+  int32_t offset;
+  nsCOMPtr<nsINode> parent = EditorBase::GetNodeLocation(node, &offset);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  bool doesCRCreateNewP = mHTMLEditor->GetReturnInParagraphCreatesNewParagraph();
+
+  bool newBRneeded = false;
+  bool newSelNode = false;
+  nsCOMPtr<nsIContent> sibling;
+  nsCOMPtr<nsIDOMNode> selNode = aNode;
+  int32_t selOffset = aOffset;
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (aNode == aPara && doesCRCreateNewP) {
+    // we are at the edges of the block, newBRneeded not needed!
+    sibling = node->AsContent();
+  } else if (mHTMLEditor->IsTextNode(aNode)) {
+    nsCOMPtr<nsIDOMText> textNode = do_QueryInterface(aNode);
+    uint32_t strLength;
+    nsresult rv = textNode->GetLength(&strLength);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // at beginning of text node?
+    if (!aOffset) {
+      // is there a BR prior to it?
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetPriorHTMLSibling(node);
+      if (!sibling || !mHTMLEditor || !mHTMLEditor->IsVisBreak(sibling) ||
+          TextEditUtils::HasMozAttr(GetAsDOMNode(sibling))) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        newBRneeded = true;
+      }
+    } else if (aOffset == (int32_t)strLength) {
+      // we're at the end of text node...
+      // is there a BR after to it?
+      NS_ENSURE_STATE(mHTMLEditor);
+      sibling = mHTMLEditor->GetNextHTMLSibling(node);
+      if (!sibling || !mHTMLEditor || !mHTMLEditor->IsVisBreak(sibling) ||
+          TextEditUtils::HasMozAttr(GetAsDOMNode(sibling))) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        newBRneeded = true;
+        offset++;
+      }
+    } else {
+      if (doesCRCreateNewP) {
+        nsCOMPtr<nsIDOMNode> tmp;
+        rv = mTextEditor->SplitNode(aNode, aOffset, getter_AddRefs(tmp));
+        NS_ENSURE_SUCCESS(rv, rv);
+        selNode = tmp;
+      }
+
+      newBRneeded = true;
+      offset++;
+    }
+  } else {
+    // not in a text node.
+    // is there a BR prior to it?
+    nsCOMPtr<nsIContent> nearNode;
+    NS_ENSURE_STATE(mHTMLEditor);
+    nearNode = mHTMLEditor->GetPriorHTMLNode(node, aOffset);
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!nearNode || !mHTMLEditor->IsVisBreak(nearNode) ||
+        TextEditUtils::HasMozAttr(GetAsDOMNode(nearNode))) {
+      // is there a BR after it?
+      NS_ENSURE_STATE(mHTMLEditor);
+      nearNode = mHTMLEditor->GetNextHTMLNode(node, aOffset);
+      NS_ENSURE_STATE(mHTMLEditor);
+      if (!nearNode || !mHTMLEditor->IsVisBreak(nearNode) ||
+          TextEditUtils::HasMozAttr(GetAsDOMNode(nearNode))) {
+        newBRneeded = true;
+        parent = node;
+        offset = aOffset;
+        newSelNode = true;
+      }
+    }
+    if (!newBRneeded) {
+      sibling = nearNode;
+    }
+  }
+  if (newBRneeded) {
+    // if CR does not create a new P, default to BR creation
+    NS_ENSURE_TRUE(doesCRCreateNewP, NS_OK);
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    sibling = mHTMLEditor->CreateBR(parent, offset);
+    if (newSelNode) {
+      // We split the parent after the br we've just inserted.
+      selNode = GetAsDOMNode(parent);
+      selOffset = offset + 1;
+    }
+  }
+  *aHandled = true;
+  return SplitParagraph(aPara, sibling, aSelection, address_of(selNode), &selOffset);
+}
+
+/**
+ * SplitParagraph() splits a paragraph at selection point, possibly deleting a
+ * br.
+ */
+nsresult
+HTMLEditRules::SplitParagraph(nsIDOMNode *aPara,
+                              nsIContent* aBRNode,
+                              Selection* aSelection,
+                              nsCOMPtr<nsIDOMNode>* aSelNode,
+                              int32_t* aOffset)
+{
+  nsCOMPtr<Element> para = do_QueryInterface(aPara);
+  NS_ENSURE_TRUE(para && aBRNode && aSelNode && *aSelNode && aOffset &&
+                 aSelection, NS_ERROR_NULL_POINTER);
+
+  // split para
+  // get ws code to adjust any ws
+  nsCOMPtr<nsIContent> leftPara, rightPara;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsINode> selNode(do_QueryInterface(*aSelNode));
+  nsresult rv =
+    WSRunObject::PrepareToSplitAcrossBlocks(mHTMLEditor,
+                                            address_of(selNode), aOffset);
+  // XXX When it fails, why do we need to return selection node?  (Why can the
+  //     caller trust the result even when it returns error?)
+  *aSelNode = GetAsDOMNode(selNode);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // split the paragraph
+  NS_ENSURE_STATE(mHTMLEditor);
+  NS_ENSURE_STATE(selNode->IsContent());
+  mHTMLEditor->SplitNodeDeep(*para, *selNode->AsContent(), *aOffset,
+                             HTMLEditor::EmptyContainers::yes,
+                             getter_AddRefs(leftPara),
+                             getter_AddRefs(rightPara));
+  // get rid of the break, if it is visible (otherwise it may be needed to prevent an empty p)
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (mHTMLEditor->IsVisBreak(aBRNode)) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->DeleteNode(aBRNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  // remove ID attribute on the paragraph we just created
+  nsCOMPtr<nsIDOMElement> rightElt = do_QueryInterface(rightPara);
+  NS_ENSURE_STATE(mHTMLEditor);
+  rv = mHTMLEditor->RemoveAttribute(rightElt, NS_LITERAL_STRING("id"));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // check both halves of para to see if we need mozBR
+  rv = InsertMozBRIfNeeded(*leftPara);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = InsertMozBRIfNeeded(*rightPara);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // selection to beginning of right hand para;
+  // look inside any containers that are up front.
+  nsCOMPtr<nsINode> rightParaNode = do_QueryInterface(rightPara);
+  NS_ENSURE_STATE(mHTMLEditor && rightParaNode);
+  nsCOMPtr<nsIDOMNode> child =
+    GetAsDOMNode(mHTMLEditor->GetLeftmostChild(rightParaNode, true));
+  if (mHTMLEditor->IsTextNode(child) ||
+      mHTMLEditor->IsContainer(child)) {
+    aSelection->Collapse(child,0);
+  } else {
+    int32_t offset;
+    nsCOMPtr<nsIDOMNode> parent = EditorBase::GetNodeLocation(child, &offset);
+    aSelection->Collapse(parent,offset);
+  }
+  return NS_OK;
+}
+
+/**
+ * ReturnInListItem: do the right thing for returns pressed in list items
+ */
+nsresult
+HTMLEditRules::ReturnInListItem(Selection& aSelection,
+                                Element& aListItem,
+                                nsINode& aNode,
+                                int32_t aOffset)
+{
+  MOZ_ASSERT(HTMLEditUtils::IsListItem(&aListItem));
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Get the item parent and the active editing host.
+  nsCOMPtr<Element> root = htmlEditor->GetActiveEditingHost();
+
+  nsCOMPtr<Element> list = aListItem.GetParentElement();
+  int32_t itemOffset = list ? list->IndexOf(&aListItem) : -1;
+
+  // If we are in an empty item, then we want to pop up out of the list, but
+  // only if prefs say it's okay and if the parent isn't the active editing
+  // host.
+  bool isEmpty;
+  nsresult rv = IsEmptyBlock(aListItem, &isEmpty, MozBRCounts::no);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (isEmpty && root != list && mReturnInEmptyLIKillsList) {
+    // Get the list offset now -- before we might eventually split the list
+    nsCOMPtr<nsINode> listParent = list->GetParentNode();
+    int32_t offset = listParent ? listParent->IndexOf(list) : -1;
+
+    // Are we the last list item in the list?
+    bool isLast;
+    rv = htmlEditor->IsLastEditableChild(aListItem.AsDOMNode(), &isLast);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!isLast) {
+      // We need to split the list!
+      ErrorResult rv;
+      htmlEditor->SplitNode(*list, itemOffset, rv);
+      NS_ENSURE_TRUE(!rv.Failed(), rv.StealNSResult());
+    }
+
+    // Are we in a sublist?
+    if (HTMLEditUtils::IsList(listParent)) {
+      // If so, move item out of this list and into the grandparent list
+      rv = htmlEditor->MoveNode(&aListItem, listParent, offset + 1);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = aSelection.Collapse(&aListItem, 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      // Otherwise kill this item
+      rv = htmlEditor->DeleteNode(&aListItem);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // Time to insert a paragraph
+      nsCOMPtr<Element> pNode =
+        htmlEditor->CreateNode(nsGkAtoms::p, listParent, offset + 1);
+      NS_ENSURE_STATE(pNode);
+
+      // Append a <br> to it
+      nsCOMPtr<Element> brNode = htmlEditor->CreateBR(pNode, 0);
+      NS_ENSURE_STATE(brNode);
+
+      // Set selection to before the break
+      rv = aSelection.Collapse(pNode, 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+    return NS_OK;
+  }
+
+  // Else we want a new list item at the same list level.  Get ws code to
+  // adjust any ws.
+  nsCOMPtr<nsINode> selNode = &aNode;
+  rv = WSRunObject::PrepareToSplitAcrossBlocks(htmlEditor,
+                                               address_of(selNode), &aOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  // Now split list item
+  NS_ENSURE_STATE(selNode->IsContent());
+  htmlEditor->SplitNodeDeep(aListItem, *selNode->AsContent(), aOffset);
+
+  // Hack: until I can change the damaged doc range code back to being
+  // extra-inclusive, I have to manually detect certain list items that may be
+  // left empty.
+  nsCOMPtr<nsIContent> prevItem = htmlEditor->GetPriorHTMLSibling(&aListItem);
+  if (prevItem && HTMLEditUtils::IsListItem(prevItem)) {
+    bool isEmptyNode;
+    rv = htmlEditor->IsEmptyNode(prevItem, &isEmptyNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (isEmptyNode) {
+      rv = CreateMozBR(prevItem->AsDOMNode(), 0);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      rv = htmlEditor->IsEmptyNode(&aListItem, &isEmptyNode, true);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (isEmptyNode) {
+        nsCOMPtr<nsIAtom> nodeAtom = aListItem.NodeInfo()->NameAtom();
+        if (nodeAtom == nsGkAtoms::dd || nodeAtom == nsGkAtoms::dt) {
+          nsCOMPtr<nsINode> list = aListItem.GetParentNode();
+          int32_t itemOffset = list ? list->IndexOf(&aListItem) : -1;
+
+          nsIAtom* listAtom = nodeAtom == nsGkAtoms::dt ? nsGkAtoms::dd
+                                                        : nsGkAtoms::dt;
+          nsCOMPtr<Element> newListItem =
+            htmlEditor->CreateNode(listAtom, list, itemOffset + 1);
+          NS_ENSURE_STATE(newListItem);
+          rv = mTextEditor->DeleteNode(&aListItem);
+          NS_ENSURE_SUCCESS(rv, rv);
+          rv = aSelection.Collapse(newListItem, 0);
+          NS_ENSURE_SUCCESS(rv, rv);
+
+          return NS_OK;
+        }
+
+        nsCOMPtr<Element> brNode;
+        rv = htmlEditor->CopyLastEditableChildStyles(GetAsDOMNode(prevItem),
+                                                     GetAsDOMNode(&aListItem),
+                                                     getter_AddRefs(brNode));
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (brNode) {
+          nsCOMPtr<nsINode> brParent = brNode->GetParentNode();
+          int32_t offset = brParent ? brParent->IndexOf(brNode) : -1;
+          rv = aSelection.Collapse(brParent, offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          return NS_OK;
+        }
+      } else {
+        WSRunObject wsObj(htmlEditor, &aListItem, 0);
+        nsCOMPtr<nsINode> visNode;
+        int32_t visOffset = 0;
+        WSType wsType;
+        wsObj.NextVisibleNode(&aListItem, 0, address_of(visNode),
+                              &visOffset, &wsType);
+        if (wsType == WSType::special || wsType == WSType::br ||
+            visNode->IsHTMLElement(nsGkAtoms::hr)) {
+          nsCOMPtr<nsINode> parent = visNode->GetParentNode();
+          int32_t offset = parent ? parent->IndexOf(visNode) : -1;
+          rv = aSelection.Collapse(parent, offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          return NS_OK;
+        } else {
+          rv = aSelection.Collapse(visNode, visOffset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          return NS_OK;
+        }
+      }
+    }
+  }
+  rv = aSelection.Collapse(&aListItem, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+/**
+ * MakeBlockquote() puts the list of nodes into one or more blockquotes.
+ */
+nsresult
+HTMLEditRules::MakeBlockquote(nsTArray<OwningNonNull<nsINode>>& aNodeArray)
+{
+  // The idea here is to put the nodes into a minimal number of blockquotes.
+  // When the user blockquotes something, they expect one blockquote.  That may
+  // not be possible (for instance, if they have two table cells selected, you
+  // need two blockquotes inside the cells).
+  nsCOMPtr<Element> curBlock;
+  nsCOMPtr<nsINode> prevParent;
+
+  for (auto& curNode : aNodeArray) {
+    // Get the node to act on, and its location
+    NS_ENSURE_STATE(curNode->IsContent());
+
+    // If the node is a table element or list item, dive inside
+    if (HTMLEditUtils::IsTableElementButNotTable(curNode) ||
+        HTMLEditUtils::IsListItem(curNode)) {
+      // Forget any previous block
+      curBlock = nullptr;
+      // Recursion time
+      nsTArray<OwningNonNull<nsINode>> childArray;
+      GetChildNodesForOperation(*curNode, childArray);
+      nsresult rv = MakeBlockquote(childArray);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // If the node has different parent than previous node, further nodes in a
+    // new parent
+    if (prevParent) {
+      if (prevParent != curNode->GetParentNode()) {
+        // Forget any previous blockquote node we were using
+        curBlock = nullptr;
+        prevParent = curNode->GetParentNode();
+      }
+    } else {
+      prevParent = curNode->GetParentNode();
+    }
+
+    // If no curBlock, make one
+    if (!curBlock) {
+      nsCOMPtr<nsINode> curParent = curNode->GetParentNode();
+      int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+      nsresult rv = SplitAsNeeded(*nsGkAtoms::blockquote, curParent, offset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      NS_ENSURE_STATE(mHTMLEditor);
+      curBlock = mHTMLEditor->CreateNode(nsGkAtoms::blockquote, curParent,
+                                         offset);
+      NS_ENSURE_STATE(curBlock);
+      // remember our new block for postprocessing
+      mNewBlock = curBlock;
+      // note: doesn't matter if we set mNewBlock multiple times.
+    }
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv = mHTMLEditor->MoveNode(curNode->AsContent(), curBlock, -1);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+/**
+ * RemoveBlockStyle() makes the nodes have no special block type.
+ */
+nsresult
+HTMLEditRules::RemoveBlockStyle(nsTArray<OwningNonNull<nsINode>>& aNodeArray)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Intent of this routine is to be used for converting to/from headers,
+  // paragraphs, pre, and address.  Those blocks that pretty much just contain
+  // inline things...
+  nsCOMPtr<Element> curBlock;
+  nsCOMPtr<nsIContent> firstNode, lastNode;
+  for (auto& curNode : aNodeArray) {
+    // If curNode is a address, p, header, address, or pre, remove it
+    if (HTMLEditUtils::IsFormatNode(curNode)) {
+      // Process any partial progress saved
+      if (curBlock) {
+        nsresult rv = RemovePartOfBlock(*curBlock, *firstNode, *lastNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        firstNode = lastNode = curBlock = nullptr;
+      }
+      // Remove current block
+      nsresult rv = htmlEditor->RemoveBlockContainer(*curNode->AsContent());
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else if (curNode->IsAnyOfHTMLElements(nsGkAtoms::table,
+                                            nsGkAtoms::tr,
+                                            nsGkAtoms::tbody,
+                                            nsGkAtoms::td,
+                                            nsGkAtoms::li,
+                                            nsGkAtoms::blockquote,
+                                            nsGkAtoms::div) ||
+                HTMLEditUtils::IsList(curNode)) {
+      // Process any partial progress saved
+      if (curBlock) {
+        nsresult rv = RemovePartOfBlock(*curBlock, *firstNode, *lastNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        firstNode = lastNode = curBlock = nullptr;
+      }
+      // Recursion time
+      nsTArray<OwningNonNull<nsINode>> childArray;
+      GetChildNodesForOperation(*curNode, childArray);
+      nsresult rv = RemoveBlockStyle(childArray);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else if (IsInlineNode(curNode)) {
+      if (curBlock) {
+        // If so, is this node a descendant?
+        if (EditorUtils::IsDescendantOf(curNode, curBlock)) {
+          // Then we don't need to do anything different for this node
+          lastNode = curNode->AsContent();
+          continue;
+        }
+        // Otherwise, we have progressed beyond end of curBlock, so let's
+        // handle it now.  We need to remove the portion of curBlock that
+        // contains [firstNode - lastNode].
+        nsresult rv = RemovePartOfBlock(*curBlock, *firstNode, *lastNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+        firstNode = lastNode = curBlock = nullptr;
+        // Fall out and handle curNode
+      }
+      curBlock = htmlEditor->GetBlockNodeParent(curNode);
+      if (curBlock && HTMLEditUtils::IsFormatNode(curBlock)) {
+        firstNode = lastNode = curNode->AsContent();
+      } else {
+        // Not a block kind that we care about.
+        curBlock = nullptr;
+      }
+    } else if (curBlock) {
+      // Some node that is already sans block style.  Skip over it and process
+      // any partial progress saved.
+      nsresult rv = RemovePartOfBlock(*curBlock, *firstNode, *lastNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      firstNode = lastNode = curBlock = nullptr;
+    }
+  }
+  // Process any partial progress saved
+  if (curBlock) {
+    nsresult rv = RemovePartOfBlock(*curBlock, *firstNode, *lastNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+    firstNode = lastNode = curBlock = nullptr;
+  }
+  return NS_OK;
+}
+
+/**
+ * ApplyBlockStyle() does whatever it takes to make the list of nodes into one
+ * or more blocks of type aBlockTag.
+ */
+nsresult
+HTMLEditRules::ApplyBlockStyle(nsTArray<OwningNonNull<nsINode>>& aNodeArray,
+                               nsIAtom& aBlockTag)
+{
+  // Intent of this routine is to be used for converting to/from headers,
+  // paragraphs, pre, and address.  Those blocks that pretty much just contain
+  // inline things...
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Remove all non-editable nodes.  Leave them be.
+  for (int32_t i = aNodeArray.Length() - 1; i >= 0; i--) {
+    if (!htmlEditor->IsEditable(aNodeArray[i])) {
+      aNodeArray.RemoveElementAt(i);
+    }
+  }
+
+  nsCOMPtr<Element> newBlock;
+
+  nsCOMPtr<Element> curBlock;
+  for (auto& curNode : aNodeArray) {
+    nsCOMPtr<nsINode> curParent = curNode->GetParentNode();
+    int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+    // Is it already the right kind of block?
+    if (curNode->IsHTMLElement(&aBlockTag)) {
+      // Forget any previous block used for previous inline nodes
+      curBlock = nullptr;
+      // Do nothing to this block
+      continue;
+    }
+
+    // If curNode is a address, p, header, address, or pre, replace it with a
+    // new block of correct type.
+    // XXX: pre can't hold everything the others can
+    if (HTMLEditUtils::IsMozDiv(curNode) ||
+        HTMLEditUtils::IsFormatNode(curNode)) {
+      // Forget any previous block used for previous inline nodes
+      curBlock = nullptr;
+      newBlock = htmlEditor->ReplaceContainer(curNode->AsElement(),
+                                              &aBlockTag, nullptr, nullptr,
+                                              EditorBase::eCloneAttributes);
+      NS_ENSURE_STATE(newBlock);
+    } else if (HTMLEditUtils::IsTable(curNode) ||
+               HTMLEditUtils::IsList(curNode) ||
+               curNode->IsAnyOfHTMLElements(nsGkAtoms::tbody,
+                                            nsGkAtoms::tr,
+                                            nsGkAtoms::td,
+                                            nsGkAtoms::li,
+                                            nsGkAtoms::blockquote,
+                                            nsGkAtoms::div)) {
+      // Forget any previous block used for previous inline nodes
+      curBlock = nullptr;
+      // Recursion time
+      nsTArray<OwningNonNull<nsINode>> childArray;
+      GetChildNodesForOperation(*curNode, childArray);
+      if (!childArray.IsEmpty()) {
+        nsresult rv = ApplyBlockStyle(childArray, aBlockTag);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } else {
+        // Make sure we can put a block here
+        nsresult rv = SplitAsNeeded(aBlockTag, curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        nsCOMPtr<Element> theBlock =
+          htmlEditor->CreateNode(&aBlockTag, curParent, offset);
+        NS_ENSURE_STATE(theBlock);
+        // Remember our new block for postprocessing
+        mNewBlock = theBlock;
+      }
+    } else if (curNode->IsHTMLElement(nsGkAtoms::br)) {
+      // If the node is a break, we honor it by putting further nodes in a new
+      // parent
+      if (curBlock) {
+        // Forget any previous block used for previous inline nodes
+        curBlock = nullptr;
+        nsresult rv = htmlEditor->DeleteNode(curNode);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } else {
+        // The break is the first (or even only) node we encountered.  Create a
+        // block for it.
+        nsresult rv = SplitAsNeeded(aBlockTag, curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        curBlock = htmlEditor->CreateNode(&aBlockTag, curParent, offset);
+        NS_ENSURE_STATE(curBlock);
+        // Remember our new block for postprocessing
+        mNewBlock = curBlock;
+        // Note: doesn't matter if we set mNewBlock multiple times.
+        rv = htmlEditor->MoveNode(curNode->AsContent(), curBlock, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    } else if (IsInlineNode(curNode)) {
+      // If curNode is inline, pull it into curBlock.  Note: it's assumed that
+      // consecutive inline nodes in aNodeArray are actually members of the
+      // same block parent.  This happens to be true now as a side effect of
+      // how aNodeArray is contructed, but some additional logic should be
+      // added here if that should change
+      //
+      // If curNode is a non editable, drop it if we are going to <pre>.
+      if (&aBlockTag == nsGkAtoms::pre && !htmlEditor->IsEditable(curNode)) {
+        // Do nothing to this block
+        continue;
+      }
+
+      // If no curBlock, make one
+      if (!curBlock) {
+        nsresult rv = SplitAsNeeded(aBlockTag, curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        curBlock = htmlEditor->CreateNode(&aBlockTag, curParent, offset);
+        NS_ENSURE_STATE(curBlock);
+        // Remember our new block for postprocessing
+        mNewBlock = curBlock;
+        // Note: doesn't matter if we set mNewBlock multiple times.
+      }
+
+      // XXX If curNode is a br, replace it with a return if going to <pre>
+
+      // This is a continuation of some inline nodes that belong together in
+      // the same block item.  Use curBlock.
+      nsresult rv = htmlEditor->MoveNode(curNode->AsContent(), curBlock, -1);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+/**
+ * Given a tag name, split inOutParent up to the point where we can insert the
+ * tag.  Adjust inOutParent and inOutOffset to point to new location for tag.
+ */
+nsresult
+HTMLEditRules::SplitAsNeeded(nsIAtom& aTag,
+                             OwningNonNull<nsINode>& aInOutParent,
+                             int32_t& aInOutOffset)
+{
+  // XXX Is there a better way to do this?
+  nsCOMPtr<nsINode> parent = aInOutParent.forget();
+  nsresult rv = SplitAsNeeded(aTag, parent, aInOutOffset);
+  aInOutParent = parent.forget();
+  return rv;
+}
+
+nsresult
+HTMLEditRules::SplitAsNeeded(nsIAtom& aTag,
+                             nsCOMPtr<nsINode>& inOutParent,
+                             int32_t& inOutOffset)
+{
+  NS_ENSURE_TRUE(inOutParent, NS_ERROR_NULL_POINTER);
+
+  // Check that we have a place that can legally contain the tag
+  nsCOMPtr<nsINode> tagParent, splitNode;
+  for (nsCOMPtr<nsINode> parent = inOutParent; parent;
+       parent = parent->GetParentNode()) {
+    // Sniffing up the parent tree until we find a legal place for the block
+
+    // Don't leave the active editing host
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (!mHTMLEditor->IsDescendantOfEditorRoot(parent)) {
+      // XXX Why do we need to check mHTMLEditor again here?
+      NS_ENSURE_STATE(mHTMLEditor);
+      if (parent != mHTMLEditor->GetActiveEditingHost()) {
+        return NS_ERROR_FAILURE;
+      }
+    }
+
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (mHTMLEditor->CanContainTag(*parent, aTag)) {
+      // Success
+      tagParent = parent;
+      break;
+    }
+
+    splitNode = parent;
+  }
+  if (!tagParent) {
+    // Could not find a place to build tag!
+    return NS_ERROR_FAILURE;
+  }
+  if (splitNode && splitNode->IsContent() && inOutParent->IsContent()) {
+    // We found a place for block, but above inOutParent. We need to split.
+    NS_ENSURE_STATE(mHTMLEditor);
+    int32_t offset = mHTMLEditor->SplitNodeDeep(*splitNode->AsContent(),
+                                                *inOutParent->AsContent(),
+                                                inOutOffset);
+    NS_ENSURE_STATE(offset != -1);
+    inOutParent = tagParent;
+    inOutOffset = offset;
+  }
+  return NS_OK;
+}
+
+/**
+ * JoinNodesSmart: Join two nodes, doing whatever makes sense for their
+ * children (which often means joining them, too).  aNodeLeft & aNodeRight must
+ * be same type of node.
+ *
+ * Returns the point where they're merged, or (nullptr, -1) on failure.
+ */
+EditorDOMPoint
+HTMLEditRules::JoinNodesSmart(nsIContent& aNodeLeft,
+                              nsIContent& aNodeRight)
+{
+  // Caller responsible for left and right node being the same type
+  nsCOMPtr<nsINode> parent = aNodeLeft.GetParentNode();
+  NS_ENSURE_TRUE(parent, EditorDOMPoint());
+  int32_t parOffset = parent->IndexOf(&aNodeLeft);
+  nsCOMPtr<nsINode> rightParent = aNodeRight.GetParentNode();
+
+  // If they don't have the same parent, first move the right node to after the
+  // left one
+  if (parent != rightParent) {
+    NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+    nsresult rv = mHTMLEditor->MoveNode(&aNodeRight, parent, parOffset);
+    NS_ENSURE_SUCCESS(rv, EditorDOMPoint());
+  }
+
+  EditorDOMPoint ret(&aNodeRight, aNodeLeft.Length());
+
+  // Separate join rules for differing blocks
+  if (HTMLEditUtils::IsList(&aNodeLeft) || aNodeLeft.GetAsText()) {
+    // For lists, merge shallow (wouldn't want to combine list items)
+    nsresult rv = mHTMLEditor->JoinNodes(aNodeLeft, aNodeRight);
+    NS_ENSURE_SUCCESS(rv, EditorDOMPoint());
+    return ret;
+  }
+
+  // Remember the last left child, and first right child
+  NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+  nsCOMPtr<nsIContent> lastLeft = mHTMLEditor->GetLastEditableChild(aNodeLeft);
+  NS_ENSURE_TRUE(lastLeft, EditorDOMPoint());
+
+  NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+  nsCOMPtr<nsIContent> firstRight = mHTMLEditor->GetFirstEditableChild(aNodeRight);
+  NS_ENSURE_TRUE(firstRight, EditorDOMPoint());
+
+  // For list items, divs, etc., merge smart
+  NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+  nsresult rv = mHTMLEditor->JoinNodes(aNodeLeft, aNodeRight);
+  NS_ENSURE_SUCCESS(rv, EditorDOMPoint());
+
+  if (lastLeft && firstRight && mHTMLEditor &&
+      mHTMLEditor->AreNodesSameType(lastLeft, firstRight) &&
+      (lastLeft->GetAsText() || !mHTMLEditor ||
+       (lastLeft->IsElement() && firstRight->IsElement() &&
+        mHTMLEditor->mCSSEditUtils->ElementsSameStyle(lastLeft->AsElement(),
+                                                  firstRight->AsElement())))) {
+    NS_ENSURE_TRUE(mHTMLEditor, EditorDOMPoint());
+    return JoinNodesSmart(*lastLeft, *firstRight);
+  }
+  return ret;
+}
+
+Element*
+HTMLEditRules::GetTopEnclosingMailCite(nsINode& aNode)
+{
+  nsCOMPtr<Element> ret;
+
+  for (nsCOMPtr<nsINode> node = &aNode; node; node = node->GetParentNode()) {
+    if ((IsPlaintextEditor() && node->IsHTMLElement(nsGkAtoms::pre)) ||
+        HTMLEditUtils::IsMailCite(node)) {
+      ret = node->AsElement();
+    }
+    if (node->IsHTMLElement(nsGkAtoms::body)) {
+      break;
+    }
+  }
+
+  return ret;
+}
+
+nsresult
+HTMLEditRules::CacheInlineStyles(nsIDOMNode* aNode)
+{
+  NS_ENSURE_TRUE(aNode, NS_ERROR_NULL_POINTER);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  bool useCSS = mHTMLEditor->IsCSSEnabled();
+
+  for (int32_t j = 0; j < SIZE_STYLE_TABLE; ++j) {
+    // If type-in state is set, don't intervene
+    bool typeInSet, unused;
+    if (NS_WARN_IF(!mHTMLEditor)) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    mHTMLEditor->mTypeInState->GetTypingState(typeInSet, unused,
+      mCachedStyles[j].tag, mCachedStyles[j].attr, nullptr);
+    if (typeInSet) {
+      continue;
+    }
+
+    bool isSet = false;
+    nsAutoString outValue;
+    // Don't use CSS for <font size>, we don't support it usefully (bug 780035)
+    if (!useCSS || (mCachedStyles[j].tag == nsGkAtoms::font &&
+                    mCachedStyles[j].attr.EqualsLiteral("size"))) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->IsTextPropertySetByContent(aNode, mCachedStyles[j].tag,
+                                              &(mCachedStyles[j].attr), nullptr,
+                                              isSet, &outValue);
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      mHTMLEditor->mCSSEditUtils->IsCSSEquivalentToHTMLInlineStyleSet(aNode,
+        mCachedStyles[j].tag, &(mCachedStyles[j].attr), isSet, outValue,
+        CSSEditUtils::eComputed);
+    }
+    if (isSet) {
+      mCachedStyles[j].mPresent = true;
+      mCachedStyles[j].value.Assign(outValue);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::ReapplyCachedStyles()
+{
+  // The idea here is to examine our cached list of styles and see if any have
+  // been removed.  If so, add typeinstate for them, so that they will be
+  // reinserted when new content is added.
+
+  // remember if we are in css mode
+  NS_ENSURE_STATE(mHTMLEditor);
+  bool useCSS = mHTMLEditor->IsCSSEnabled();
+
+  // get selection point; if it doesn't exist, we have nothing to do
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+  if (!selection) {
+    // If the document is removed from its parent document during executing an
+    // editor operation with DOMMutationEvent or something, there may be no
+    // selection.
+    return NS_OK;
+  }
+  if (!selection->RangeCount()) {
+    // Nothing to do
+    return NS_OK;
+  }
+  nsCOMPtr<nsIContent> selNode =
+    do_QueryInterface(selection->GetRangeAt(0)->GetStartParent());
+  if (!selNode) {
+    // Nothing to do
+    return NS_OK;
+  }
+
+  for (int32_t i = 0; i < SIZE_STYLE_TABLE; ++i) {
+    if (mCachedStyles[i].mPresent) {
+      bool bFirst, bAny, bAll;
+      bFirst = bAny = bAll = false;
+
+      nsAutoString curValue;
+      if (useCSS) {
+        // check computed style first in css case
+        NS_ENSURE_STATE(mHTMLEditor);
+        bAny = mHTMLEditor->mCSSEditUtils->IsCSSEquivalentToHTMLInlineStyleSet(
+          selNode, mCachedStyles[i].tag, &(mCachedStyles[i].attr), curValue,
+          CSSEditUtils::eComputed);
+      }
+      if (!bAny) {
+        // then check typeinstate and html style
+        NS_ENSURE_STATE(mHTMLEditor);
+        nsresult rv =
+          mHTMLEditor->GetInlinePropertyBase(*mCachedStyles[i].tag,
+                                             &(mCachedStyles[i].attr),
+                                             &(mCachedStyles[i].value),
+                                             &bFirst, &bAny, &bAll,
+                                             &curValue, false);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      // this style has disappeared through deletion.  Add to our typeinstate:
+      if (!bAny || IsStyleCachePreservingAction(mTheAction)) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        mHTMLEditor->mTypeInState->SetProp(mCachedStyles[i].tag,
+                                           mCachedStyles[i].attr,
+                                           mCachedStyles[i].value);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+void
+HTMLEditRules::ClearCachedStyles()
+{
+  // clear the mPresent bits in mCachedStyles array
+  for (uint32_t j = 0; j < SIZE_STYLE_TABLE; j++) {
+    mCachedStyles[j].mPresent = false;
+    mCachedStyles[j].value.Truncate();
+  }
+}
+
+void
+HTMLEditRules::AdjustSpecialBreaks()
+{
+  NS_ENSURE_TRUE_VOID(mHTMLEditor);
+
+  // Gather list of empty nodes
+  nsTArray<OwningNonNull<nsINode>> nodeArray;
+  EmptyEditableFunctor functor(mHTMLEditor);
+  DOMIterator iter;
+  if (NS_WARN_IF(NS_FAILED(iter.Init(*mDocChangeRange)))) {
+    return;
+  }
+  iter.AppendList(functor, nodeArray);
+
+  // Put moz-br's into these empty li's and td's
+  for (auto& node : nodeArray) {
+    // Need to put br at END of node.  It may have empty containers in it and
+    // still pass the "IsEmptyNode" test, and we want the br's to be after
+    // them.  Also, we want the br to be after the selection if the selection
+    // is in this node.
+    nsresult rv = CreateMozBR(node->AsDOMNode(), (int32_t)node->Length());
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return;
+    }
+  }
+}
+
+nsresult
+HTMLEditRules::AdjustWhitespace(Selection* aSelection)
+{
+  // get selection point
+  nsCOMPtr<nsIDOMNode> selNode;
+  int32_t selOffset;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(aSelection,
+                                       getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // ask whitespace object to tweak nbsp's
+  NS_ENSURE_STATE(mHTMLEditor);
+  return WSRunObject(mHTMLEditor, selNode, selOffset).AdjustWhitespace();
+}
+
+nsresult
+HTMLEditRules::PinSelectionToNewBlock(Selection* aSelection)
+{
+  NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
+  if (!aSelection->Collapsed()) {
+    return NS_OK;
+  }
+
+  // get the (collapsed) selection location
+  nsCOMPtr<nsIDOMNode> selNode, temp;
+  int32_t selOffset;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(aSelection,
+                                       getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  temp = selNode;
+
+  // use ranges and sRangeHelper to compare sel point to new block
+  nsCOMPtr<nsINode> node = do_QueryInterface(selNode);
+  NS_ENSURE_STATE(node);
+  RefPtr<nsRange> range = new nsRange(node);
+  rv = range->SetStart(selNode, selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = range->SetEnd(selNode, selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  nsCOMPtr<nsIContent> block = mNewBlock.get();
+  NS_ENSURE_TRUE(block, NS_ERROR_NO_INTERFACE);
+  bool nodeBefore, nodeAfter;
+  rv = nsRange::CompareNodeToRange(block, range, &nodeBefore, &nodeAfter);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (nodeBefore && nodeAfter) {
+    return NS_OK;  // selection is inside block
+  } else if (nodeBefore) {
+    // selection is after block.  put at end of block.
+    nsCOMPtr<nsIDOMNode> tmp = GetAsDOMNode(mNewBlock);
+    NS_ENSURE_STATE(mHTMLEditor);
+    tmp = GetAsDOMNode(mHTMLEditor->GetLastEditableChild(*block));
+    uint32_t endPoint;
+    if (mHTMLEditor->IsTextNode(tmp) ||
+        mHTMLEditor->IsContainer(tmp)) {
+      rv = EditorBase::GetLengthOfDOMNode(tmp, endPoint);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      tmp = EditorBase::GetNodeLocation(tmp, (int32_t*)&endPoint);
+      endPoint++;  // want to be after this node
+    }
+    return aSelection->Collapse(tmp, (int32_t)endPoint);
+  } else {
+    // selection is before block.  put at start of block.
+    nsCOMPtr<nsIDOMNode> tmp = GetAsDOMNode(mNewBlock);
+    NS_ENSURE_STATE(mHTMLEditor);
+    tmp = GetAsDOMNode(mHTMLEditor->GetFirstEditableChild(*block));
+    int32_t offset;
+    if (mHTMLEditor->IsTextNode(tmp) ||
+        mHTMLEditor->IsContainer(tmp)) {
+      tmp = EditorBase::GetNodeLocation(tmp, &offset);
+    }
+    return aSelection->Collapse(tmp, 0);
+  }
+}
+
+void
+HTMLEditRules::CheckInterlinePosition(Selection& aSelection)
+{
+  // If the selection isn't collapsed, do nothing.
+  if (!aSelection.Collapsed()) {
+    return;
+  }
+
+  NS_ENSURE_TRUE_VOID(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Get the (collapsed) selection location
+  NS_ENSURE_TRUE_VOID(aSelection.GetRangeAt(0) &&
+                      aSelection.GetRangeAt(0)->GetStartParent());
+  OwningNonNull<nsINode> selNode = *aSelection.GetRangeAt(0)->GetStartParent();
+  int32_t selOffset = aSelection.GetRangeAt(0)->StartOffset();
+
+  // First, let's check to see if we are after a <br>.  We take care of this
+  // special-case first so that we don't accidentally fall through into one of
+  // the other conditionals.
+  nsCOMPtr<nsIContent> node =
+    htmlEditor->GetPriorHTMLNode(selNode, selOffset, true);
+  if (node && node->IsHTMLElement(nsGkAtoms::br)) {
+    aSelection.SetInterlinePosition(true);
+    return;
+  }
+
+  // Are we after a block?  If so try set caret to following content
+  node = htmlEditor->GetPriorHTMLSibling(selNode, selOffset);
+  if (node && IsBlockNode(*node)) {
+    aSelection.SetInterlinePosition(true);
+    return;
+  }
+
+  // Are we before a block?  If so try set caret to prior content
+  node = htmlEditor->GetNextHTMLSibling(selNode, selOffset);
+  if (node && IsBlockNode(*node)) {
+    aSelection.SetInterlinePosition(false);
+  }
+}
+
+nsresult
+HTMLEditRules::AdjustSelection(Selection* aSelection,
+                               nsIEditor::EDirection aAction)
+{
+  NS_ENSURE_TRUE(aSelection, NS_ERROR_NULL_POINTER);
+
+  // if the selection isn't collapsed, do nothing.
+  // moose: one thing to do instead is check for the case of
+  // only a single break selected, and collapse it.  Good thing?  Beats me.
+  if (!aSelection->Collapsed()) {
+    return NS_OK;
+  }
+
+  // get the (collapsed) selection location
+  nsCOMPtr<nsINode> selNode, temp;
+  int32_t selOffset;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(aSelection,
+                                       getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  temp = selNode;
+
+  // are we in an editable node?
+  NS_ENSURE_STATE(mHTMLEditor);
+  while (!mHTMLEditor->IsEditable(selNode)) {
+    // scan up the tree until we find an editable place to be
+    selNode = EditorBase::GetNodeLocation(temp, &selOffset);
+    NS_ENSURE_TRUE(selNode, NS_ERROR_FAILURE);
+    temp = selNode;
+    NS_ENSURE_STATE(mHTMLEditor);
+  }
+
+  // make sure we aren't in an empty block - user will see no cursor.  If this
+  // is happening, put a <br> in the block if allowed.
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<Element> theblock = mHTMLEditor->GetBlock(*selNode);
+
+  if (theblock && mHTMLEditor->IsEditable(theblock)) {
+    bool bIsEmptyNode;
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->IsEmptyNode(theblock, &bIsEmptyNode, false, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // check if br can go into the destination node
+    NS_ENSURE_STATE(mHTMLEditor);
+    if (bIsEmptyNode && mHTMLEditor->CanContainTag(*selNode, *nsGkAtoms::br)) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<Element> rootNode = mHTMLEditor->GetRoot();
+      NS_ENSURE_TRUE(rootNode, NS_ERROR_FAILURE);
+      if (selNode == rootNode) {
+        // Our root node is completely empty. Don't add a <br> here.
+        // AfterEditInner() will add one for us when it calls
+        // CreateBogusNodeIfNeeded()!
+        return NS_OK;
+      }
+
+      // we know we can skip the rest of this routine given the cirumstance
+      return CreateMozBR(GetAsDOMNode(selNode), selOffset);
+    }
+  }
+
+  // are we in a text node?
+  nsCOMPtr<nsIDOMCharacterData> textNode = do_QueryInterface(selNode);
+  if (textNode)
+    return NS_OK; // we LIKE it when we are in a text node.  that RULZ
+
+  // do we need to insert a special mozBR?  We do if we are:
+  // 1) prior node is in same block where selection is AND
+  // 2) prior node is a br AND
+  // 3) that br is not visible
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIContent> nearNode =
+    mHTMLEditor->GetPriorHTMLNode(selNode, selOffset);
+  if (nearNode) {
+    // is nearNode also a descendant of same block?
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsCOMPtr<Element> block = mHTMLEditor->GetBlock(*selNode);
+    nsCOMPtr<Element> nearBlock = mHTMLEditor->GetBlockNodeParent(nearNode);
+    if (block && block == nearBlock) {
+      if (nearNode && TextEditUtils::IsBreak(nearNode)) {
+        NS_ENSURE_STATE(mHTMLEditor);
+        if (!mHTMLEditor->IsVisBreak(nearNode)) {
+          // need to insert special moz BR. Why?  Because if we don't
+          // the user will see no new line for the break.  Also, things
+          // like table cells won't grow in height.
+          nsCOMPtr<nsIDOMNode> brNode;
+          rv = CreateMozBR(GetAsDOMNode(selNode), selOffset,
+                           getter_AddRefs(brNode));
+          NS_ENSURE_SUCCESS(rv, rv);
+          nsCOMPtr<nsIDOMNode> brParent =
+            EditorBase::GetNodeLocation(brNode, &selOffset);
+          // selection stays *before* moz-br, sticking to it
+          aSelection->SetInterlinePosition(true);
+          rv = aSelection->Collapse(brParent, selOffset);
+          NS_ENSURE_SUCCESS(rv, rv);
+        } else {
+          NS_ENSURE_STATE(mHTMLEditor);
+          nsCOMPtr<nsIContent> nextNode =
+            mHTMLEditor->GetNextHTMLNode(nearNode, true);
+          if (nextNode && TextEditUtils::IsMozBR(nextNode)) {
+            // selection between br and mozbr.  make it stick to mozbr
+            // so that it will be on blank line.
+            aSelection->SetInterlinePosition(true);
+          }
+        }
+      }
+    }
+  }
+
+  // we aren't in a textnode: are we adjacent to text or a break or an image?
+  NS_ENSURE_STATE(mHTMLEditor);
+  nearNode = mHTMLEditor->GetPriorHTMLNode(selNode, selOffset, true);
+  if (nearNode && (TextEditUtils::IsBreak(nearNode) ||
+                   EditorBase::IsTextNode(nearNode) ||
+                   HTMLEditUtils::IsImage(nearNode) ||
+                   nearNode->IsHTMLElement(nsGkAtoms::hr))) {
+    // this is a good place for the caret to be
+    return NS_OK;
+  }
+  NS_ENSURE_STATE(mHTMLEditor);
+  nearNode = mHTMLEditor->GetNextHTMLNode(selNode, selOffset, true);
+  if (nearNode && (TextEditUtils::IsBreak(nearNode) ||
+                   EditorBase::IsTextNode(nearNode) ||
+                   nearNode->IsAnyOfHTMLElements(nsGkAtoms::img,
+                                                 nsGkAtoms::hr))) {
+    return NS_OK; // this is a good place for the caret to be
+  }
+
+  // look for a nearby text node.
+  // prefer the correct direction.
+  nsCOMPtr<nsIDOMNode> nearNodeDOM = GetAsDOMNode(nearNode);
+  rv = FindNearSelectableNode(GetAsDOMNode(selNode), selOffset, aAction,
+                              address_of(nearNodeDOM));
+  NS_ENSURE_SUCCESS(rv, rv);
+  nearNode = do_QueryInterface(nearNodeDOM);
+
+  if (!nearNode) {
+    return NS_OK;
+  }
+  EditorDOMPoint pt = GetGoodSelPointForNode(*nearNode, aAction);
+  rv = aSelection->Collapse(pt.node, pt.offset);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
+}
+
+
+nsresult
+HTMLEditRules::FindNearSelectableNode(nsIDOMNode* aSelNode,
+                                      int32_t aSelOffset,
+                                      nsIEditor::EDirection& aDirection,
+                                      nsCOMPtr<nsIDOMNode>* outSelectableNode)
+{
+  NS_ENSURE_TRUE(aSelNode && outSelectableNode, NS_ERROR_NULL_POINTER);
+  *outSelectableNode = nullptr;
+
+  nsCOMPtr<nsIDOMNode> nearNode, curNode;
+  if (aDirection == nsIEditor::ePrevious) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->GetPriorHTMLNode(aSelNode, aSelOffset, address_of(nearNode));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  } else {
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv =
+      mHTMLEditor->GetNextHTMLNode(aSelNode, aSelOffset, address_of(nearNode));
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  // Try the other direction then.
+  if (!nearNode) {
+    if (aDirection == nsIEditor::ePrevious) {
+      aDirection = nsIEditor::eNext;
+    } else {
+      aDirection = nsIEditor::ePrevious;
+    }
+
+    if (aDirection == nsIEditor::ePrevious) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->GetPriorHTMLNode(aSelNode, aSelOffset,
+                                                  address_of(nearNode));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->GetNextHTMLNode(aSelNode, aSelOffset,
+                                                 address_of(nearNode));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+  }
+
+  // scan in the right direction until we find an eligible text node,
+  // but don't cross any breaks, images, or table elements.
+  NS_ENSURE_STATE(mHTMLEditor);
+  while (nearNode && !(mHTMLEditor->IsTextNode(nearNode) ||
+                       TextEditUtils::IsBreak(nearNode) ||
+                       HTMLEditUtils::IsImage(nearNode))) {
+    curNode = nearNode;
+    if (aDirection == nsIEditor::ePrevious) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv =
+        mHTMLEditor->GetPriorHTMLNode(curNode, address_of(nearNode));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsresult rv = mHTMLEditor->GetNextHTMLNode(curNode, address_of(nearNode));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+    NS_ENSURE_STATE(mHTMLEditor);
+  }
+
+  if (nearNode) {
+    // don't cross any table elements
+    if (InDifferentTableElements(nearNode, aSelNode)) {
+      return NS_OK;
+    }
+
+    // otherwise, ok, we have found a good spot to put the selection
+    *outSelectableNode = do_QueryInterface(nearNode);
+  }
+  return NS_OK;
+}
+
+bool
+HTMLEditRules::InDifferentTableElements(nsIDOMNode* aNode1,
+                                        nsIDOMNode* aNode2)
+{
+  nsCOMPtr<nsINode> node1 = do_QueryInterface(aNode1);
+  nsCOMPtr<nsINode> node2 = do_QueryInterface(aNode2);
+  return InDifferentTableElements(node1, node2);
+}
+
+bool
+HTMLEditRules::InDifferentTableElements(nsINode* aNode1,
+                                        nsINode* aNode2)
+{
+  MOZ_ASSERT(aNode1 && aNode2);
+
+  while (aNode1 && !HTMLEditUtils::IsTableElement(aNode1)) {
+    aNode1 = aNode1->GetParentNode();
+  }
+
+  while (aNode2 && !HTMLEditUtils::IsTableElement(aNode2)) {
+    aNode2 = aNode2->GetParentNode();
+  }
+
+  return aNode1 != aNode2;
+}
+
+
+nsresult
+HTMLEditRules::RemoveEmptyNodes()
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  // Some general notes on the algorithm used here: the goal is to examine all
+  // the nodes in mDocChangeRange, and remove the empty ones.  We do this by
+  // using a content iterator to traverse all the nodes in the range, and
+  // placing the empty nodes into an array.  After finishing the iteration, we
+  // delete the empty nodes in the array.  (They cannot be deleted as we find
+  // them because that would invalidate the iterator.)
+  //
+  // Since checking to see if a node is empty can be costly for nodes with many
+  // descendants, there are some optimizations made.  I rely on the fact that
+  // the iterator is post-order: it will visit children of a node before
+  // visiting the parent node.  So if I find that a child node is not empty, I
+  // know that its parent is not empty without even checking.  So I put the
+  // parent on a "skipList" which is just a voidArray of nodes I can skip the
+  // empty check on.  If I encounter a node on the skiplist, i skip the
+  // processing for that node and replace its slot in the skiplist with that
+  // node's parent.
+  //
+  // An interesting idea is to go ahead and regard parent nodes that are NOT on
+  // the skiplist as being empty (without even doing the IsEmptyNode check) on
+  // the theory that if they weren't empty, we would have encountered a
+  // non-empty child earlier and thus put this parent node on the skiplist.
+  //
+  // Unfortunately I can't use that strategy here, because the range may
+  // include some children of a node while excluding others.  Thus I could find
+  // all the _examined_ children empty, but still not have an empty parent.
+
+  // need an iterator
+  nsCOMPtr<nsIContentIterator> iter = NS_NewContentIterator();
+
+  nsresult rv = iter->Init(mDocChangeRange);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsTArray<OwningNonNull<nsINode>> arrayOfEmptyNodes, arrayOfEmptyCites, skipList;
+
+  // Check for empty nodes
+  while (!iter->IsDone()) {
+    OwningNonNull<nsINode> node = *iter->GetCurrentNode();
+
+    nsCOMPtr<nsINode> parent = node->GetParentNode();
+
+    size_t idx = skipList.IndexOf(node);
+    if (idx != skipList.NoIndex) {
+      // This node is on our skip list.  Skip processing for this node, and
+      // replace its value in the skip list with the value of its parent
+      if (parent) {
+        skipList[idx] = parent;
+      }
+    } else {
+      bool bIsCandidate = false;
+      bool bIsEmptyNode = false;
+      bool bIsMailCite = false;
+
+      if (node->IsElement()) {
+        if (node->IsHTMLElement(nsGkAtoms::body)) {
+          // Don't delete the body
+        } else if ((bIsMailCite = HTMLEditUtils::IsMailCite(node)) ||
+                   node->IsHTMLElement(nsGkAtoms::a) ||
+                   HTMLEditUtils::IsInlineStyle(node) ||
+                   HTMLEditUtils::IsList(node) ||
+                   node->IsHTMLElement(nsGkAtoms::div)) {
+          // Only consider certain nodes to be empty for purposes of removal
+          bIsCandidate = true;
+        } else if (HTMLEditUtils::IsFormatNode(node) ||
+                   HTMLEditUtils::IsListItem(node) ||
+                   node->IsHTMLElement(nsGkAtoms::blockquote)) {
+          // These node types are candidates if selection is not in them.  If
+          // it is one of these, don't delete if selection inside.  This is so
+          // we can create empty headings, etc., for the user to type into.
+          bool bIsSelInNode;
+          rv = SelectionEndpointInNode(node, &bIsSelInNode);
+          NS_ENSURE_SUCCESS(rv, rv);
+          if (!bIsSelInNode) {
+            bIsCandidate = true;
+          }
+        }
+      }
+
+      if (bIsCandidate) {
+        // We delete mailcites even if they have a solo br in them.  Other
+        // nodes we require to be empty.
+        rv = htmlEditor->IsEmptyNode(node->AsDOMNode(), &bIsEmptyNode,
+                                     bIsMailCite, true);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (bIsEmptyNode) {
+          if (bIsMailCite) {
+            // mailcites go on a separate list from other empty nodes
+            arrayOfEmptyCites.AppendElement(*node);
+          } else {
+            arrayOfEmptyNodes.AppendElement(*node);
+          }
+        }
+      }
+
+      if (!bIsEmptyNode && parent) {
+        // put parent on skip list
+        skipList.AppendElement(*parent);
+      }
+    }
+
+    iter->Next();
+  }
+
+  // now delete the empty nodes
+  for (auto& delNode : arrayOfEmptyNodes) {
+    if (htmlEditor->IsModifiableNode(delNode)) {
+      rv = htmlEditor->DeleteNode(delNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // Now delete the empty mailcites.  This is a separate step because we want
+  // to pull out any br's and preserve them.
+  for (auto& delNode : arrayOfEmptyCites) {
+    bool bIsEmptyNode;
+    rv = htmlEditor->IsEmptyNode(delNode, &bIsEmptyNode, false, true);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!bIsEmptyNode) {
+      // We are deleting a cite that has just a br.  We want to delete cite,
+      // but preserve br.
+      nsCOMPtr<nsINode> parent = delNode->GetParentNode();
+      int32_t offset = parent ? parent->IndexOf(delNode) : -1;
+      nsCOMPtr<Element> br = htmlEditor->CreateBR(parent, offset);
+      NS_ENSURE_STATE(br);
+    }
+    rv = htmlEditor->DeleteNode(delNode);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::SelectionEndpointInNode(nsINode* aNode,
+                                       bool* aResult)
+{
+  NS_ENSURE_TRUE(aNode && aResult, NS_ERROR_NULL_POINTER);
+
+  nsIDOMNode* node = aNode->AsDOMNode();
+
+  *aResult = false;
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+  NS_ENSURE_STATE(selection);
+
+  uint32_t rangeCount = selection->RangeCount();
+  for (uint32_t rangeIdx = 0; rangeIdx < rangeCount; ++rangeIdx) {
+    RefPtr<nsRange> range = selection->GetRangeAt(rangeIdx);
+    nsCOMPtr<nsIDOMNode> startParent, endParent;
+    range->GetStartContainer(getter_AddRefs(startParent));
+    if (startParent) {
+      if (node == startParent) {
+        *aResult = true;
+        return NS_OK;
+      }
+      if (EditorUtils::IsDescendantOf(startParent, node)) {
+        *aResult = true;
+        return NS_OK;
+      }
+    }
+    range->GetEndContainer(getter_AddRefs(endParent));
+    if (startParent == endParent) {
+      continue;
+    }
+    if (endParent) {
+      if (node == endParent) {
+        *aResult = true;
+        return NS_OK;
+      }
+      if (EditorUtils::IsDescendantOf(endParent, node)) {
+        *aResult = true;
+        return NS_OK;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+/**
+ * IsEmptyInline: Return true if aNode is an empty inline container
+ */
+bool
+HTMLEditRules::IsEmptyInline(nsINode& aNode)
+{
+  NS_ENSURE_TRUE(mHTMLEditor, false);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  if (IsInlineNode(aNode) && htmlEditor->IsContainer(&aNode)) {
+    bool isEmpty = true;
+    htmlEditor->IsEmptyNode(&aNode, &isEmpty);
+    return isEmpty;
+  }
+  return false;
+}
+
+
+bool
+HTMLEditRules::ListIsEmptyLine(nsTArray<OwningNonNull<nsINode>>& aArrayOfNodes)
+{
+  // We have a list of nodes which we are candidates for being moved into a new
+  // block.  Determine if it's anything more than a blank line.  Look for
+  // editable content above and beyond one single BR.
+  NS_ENSURE_TRUE(aArrayOfNodes.Length(), true);
+
+  NS_ENSURE_TRUE(mHTMLEditor, false);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  int32_t brCount = 0;
+
+  for (auto& node : aArrayOfNodes) {
+    if (!htmlEditor->IsEditable(node)) {
+      continue;
+    }
+    if (TextEditUtils::IsBreak(node)) {
+      // First break doesn't count
+      if (brCount) {
+        return false;
+      }
+      brCount++;
+    } else if (IsEmptyInline(node)) {
+      // Empty inline, keep looking
+    } else {
+      return false;
+    }
+  }
+  return true;
+}
+
+
+nsresult
+HTMLEditRules::PopListItem(nsIDOMNode* aListItem,
+                           bool* aOutOfList)
+{
+  nsCOMPtr<Element> listItem = do_QueryInterface(aListItem);
+  // check parms
+  NS_ENSURE_TRUE(listItem && aOutOfList, NS_ERROR_NULL_POINTER);
+
+  // init out params
+  *aOutOfList = false;
+
+  nsCOMPtr<nsINode> curParent = listItem->GetParentNode();
+  int32_t offset = curParent ? curParent->IndexOf(listItem) : -1;
+
+  if (!HTMLEditUtils::IsListItem(listItem)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // if it's first or last list item, don't need to split the list
+  // otherwise we do.
+  nsCOMPtr<nsINode> curParPar = curParent->GetParentNode();
+  int32_t parOffset = curParPar ? curParPar->IndexOf(curParent) : -1;
+
+  bool bIsFirstListItem;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->IsFirstEditableChild(aListItem, &bIsFirstListItem);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool bIsLastListItem;
+  NS_ENSURE_STATE(mHTMLEditor);
+  rv = mHTMLEditor->IsLastEditableChild(aListItem, &bIsLastListItem);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!bIsFirstListItem && !bIsLastListItem) {
+    // split the list
+    nsCOMPtr<nsIDOMNode> newBlock;
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->SplitNode(GetAsDOMNode(curParent), offset,
+                                getter_AddRefs(newBlock));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  if (!bIsFirstListItem) {
+    parOffset++;
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  rv = mHTMLEditor->MoveNode(listItem, curParPar, parOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // unwrap list item contents if they are no longer in a list
+  if (!HTMLEditUtils::IsList(curParPar) &&
+      HTMLEditUtils::IsListItem(listItem)) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->RemoveBlockContainer(*listItem);
+    NS_ENSURE_SUCCESS(rv, rv);
+    *aOutOfList = true;
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::RemoveListStructure(Element& aList)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+  while (aList.GetFirstChild()) {
+    OwningNonNull<nsIContent> child = *aList.GetFirstChild();
+
+    if (HTMLEditUtils::IsListItem(child)) {
+      bool isOutOfList;
+      // Keep popping it out until it's not in a list anymore
+      do {
+        nsresult rv = PopListItem(child->AsDOMNode(), &isOutOfList);
+        NS_ENSURE_SUCCESS(rv, rv);
+      } while (!isOutOfList);
+    } else if (HTMLEditUtils::IsList(child)) {
+      nsresult rv = RemoveListStructure(*child->AsElement());
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      // Delete any non-list items for now
+      nsresult rv = htmlEditor->DeleteNode(child);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // Delete the now-empty list
+  nsresult rv = htmlEditor->RemoveBlockContainer(aList);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::ConfirmSelectionInBody()
+{
+  // get the body
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIDOMElement> rootElement = do_QueryInterface(mHTMLEditor->GetRoot());
+  NS_ENSURE_TRUE(rootElement, NS_ERROR_UNEXPECTED);
+
+  // get the selection
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<Selection> selection = mHTMLEditor->GetSelection();
+  NS_ENSURE_STATE(selection);
+
+  // get the selection start location
+  nsCOMPtr<nsIDOMNode> selNode, temp, parent;
+  int32_t selOffset;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(selection,
+                                       getter_AddRefs(selNode), &selOffset);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  temp = selNode;
+
+  // check that selNode is inside body
+  while (temp && !TextEditUtils::IsBody(temp)) {
+    temp->GetParentNode(getter_AddRefs(parent));
+    temp = parent;
+  }
+
+  // if we aren't in the body, force the issue
+  if (!temp) {
+//    uncomment this to see when we get bad selections
+//    NS_NOTREACHED("selection not in body");
+    selection->Collapse(rootElement, 0);
+  }
+
+  // get the selection end location
+  NS_ENSURE_STATE(mHTMLEditor);
+  rv = mHTMLEditor->GetEndNodeAndOffset(selection,
+                                        getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  temp = selNode;
+
+  // check that selNode is inside body
+  while (temp && !TextEditUtils::IsBody(temp)) {
+    rv = temp->GetParentNode(getter_AddRefs(parent));
+    temp = parent;
+  }
+
+  // if we aren't in the body, force the issue
+  if (!temp) {
+//    uncomment this to see when we get bad selections
+//    NS_NOTREACHED("selection not in body");
+    selection->Collapse(rootElement, 0);
+  }
+
+  // XXX This is the result of the last call of GetParentNode(), it doesn't
+  //     make sense...
+  return rv;
+}
+
+nsresult
+HTMLEditRules::UpdateDocChangeRange(nsRange* aRange)
+{
+  // first make sure aRange is in the document.  It might not be if
+  // portions of our editting action involved manipulating nodes
+  // prior to placing them in the document (e.g., populating a list item
+  // before placing it in its list)
+  nsCOMPtr<nsIDOMNode> startNode;
+  nsresult rv = aRange->GetStartContainer(getter_AddRefs(startNode));
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (!mHTMLEditor->IsDescendantOfRoot(startNode)) {
+    // just return - we don't need to adjust mDocChangeRange in this case
+    return NS_OK;
+  }
+
+  if (!mDocChangeRange) {
+    // clone aRange.
+    mDocChangeRange = aRange->CloneRange();
+  } else {
+    int16_t result;
+
+    // compare starts of ranges
+    rv = mDocChangeRange->CompareBoundaryPoints(nsIDOMRange::START_TO_START,
+                                                aRange, &result);
+    if (rv == NS_ERROR_NOT_INITIALIZED) {
+      // This will happen is mDocChangeRange is non-null, but the range is
+      // uninitialized. In this case we'll set the start to aRange start.
+      // The same test won't be needed further down since after we've set
+      // the start the range will be collapsed to that point.
+      result = 1;
+      rv = NS_OK;
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Positive result means mDocChangeRange start is after aRange start.
+    if (result > 0) {
+      int32_t startOffset;
+      rv = aRange->GetStartOffset(&startOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = mDocChangeRange->SetStart(startNode, startOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // compare ends of ranges
+    rv = mDocChangeRange->CompareBoundaryPoints(nsIDOMRange::END_TO_END,
+                                                aRange, &result);
+    NS_ENSURE_SUCCESS(rv, rv);
+    // Negative result means mDocChangeRange end is before aRange end.
+    if (result < 0) {
+      nsCOMPtr<nsIDOMNode> endNode;
+      int32_t endOffset;
+      rv = aRange->GetEndContainer(getter_AddRefs(endNode));
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = aRange->GetEndOffset(&endOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+      rv = mDocChangeRange->SetEnd(endNode, endOffset);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::InsertMozBRIfNeeded(nsINode& aNode)
+{
+  if (!IsBlockNode(aNode)) {
+    return NS_OK;
+  }
+
+  bool isEmpty;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv = mHTMLEditor->IsEmptyNode(&aNode, &isEmpty);
+  NS_ENSURE_SUCCESS(rv, rv);
+  if (!isEmpty) {
+    return NS_OK;
+  }
+
+  return CreateMozBR(aNode.AsDOMNode(), 0);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillCreateNode(const nsAString& aTag,
+                              nsIDOMNode* aParent,
+                              int32_t aPosition)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidCreateNode(const nsAString& aTag,
+                             nsIDOMNode* aNode,
+                             nsIDOMNode* aParent,
+                             int32_t aPosition,
+                             nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  // assumption that Join keeps the righthand node
+  nsresult rv = mUtilRange->SelectNode(aNode);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillInsertNode(nsIDOMNode* aNode,
+                              nsIDOMNode* aParent,
+                              int32_t aPosition)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidInsertNode(nsIDOMNode* aNode,
+                             nsIDOMNode* aParent,
+                             int32_t aPosition,
+                             nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  nsresult rv = mUtilRange->SelectNode(aNode);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillDeleteNode(nsIDOMNode* aChild)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  nsresult rv = mUtilRange->SelectNode(aChild);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidDeleteNode(nsIDOMNode* aChild,
+                             nsresult aResult)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillSplitNode(nsIDOMNode* aExistingRightNode,
+                             int32_t aOffset)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidSplitNode(nsIDOMNode* aExistingRightNode,
+                            int32_t aOffset,
+                            nsIDOMNode* aNewLeftNode,
+                            nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  nsresult rv = mUtilRange->SetStart(aNewLeftNode, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetEnd(aExistingRightNode, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillJoinNodes(nsIDOMNode* aLeftNode,
+                             nsIDOMNode* aRightNode,
+                             nsIDOMNode* aParent)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  // remember split point
+  return EditorBase::GetLengthOfDOMNode(aLeftNode, mJoinOffset);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidJoinNodes(nsIDOMNode* aLeftNode,
+                            nsIDOMNode* aRightNode,
+                            nsIDOMNode* aParent,
+                            nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  // assumption that Join keeps the righthand node
+  nsresult rv = mUtilRange->SetStart(aRightNode, mJoinOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetEnd(aRightNode, mJoinOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillInsertText(nsIDOMCharacterData* aTextNode,
+                              int32_t aOffset,
+                              const nsAString& aString)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidInsertText(nsIDOMCharacterData* aTextNode,
+                             int32_t aOffset,
+                             const nsAString& aString,
+                             nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  int32_t length = aString.Length();
+  nsCOMPtr<nsIDOMNode> theNode = do_QueryInterface(aTextNode);
+  nsresult rv = mUtilRange->SetStart(theNode, aOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetEnd(theNode, aOffset+length);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillDeleteText(nsIDOMCharacterData* aTextNode,
+                              int32_t aOffset,
+                              int32_t aLength)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidDeleteText(nsIDOMCharacterData* aTextNode,
+                             int32_t aOffset,
+                             int32_t aLength,
+                             nsresult aResult)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  nsCOMPtr<nsIDOMNode> theNode = do_QueryInterface(aTextNode);
+  nsresult rv = mUtilRange->SetStart(theNode, aOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetEnd(theNode, aOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::WillDeleteSelection(nsISelection* aSelection)
+{
+  if (!mListenerEnabled) {
+    return NS_OK;
+  }
+  if (NS_WARN_IF(!aSelection)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+  RefPtr<Selection> selection = aSelection->AsSelection();
+  // get the (collapsed) selection location
+  nsCOMPtr<nsIDOMNode> selNode;
+  int32_t selOffset;
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetStartNodeAndOffset(selection,
+                                       getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetStart(selNode, selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_STATE(mHTMLEditor);
+  rv = mHTMLEditor->GetEndNodeAndOffset(selection,
+                                        getter_AddRefs(selNode), &selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = mUtilRange->SetEnd(selNode, selOffset);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return UpdateDocChangeRange(mUtilRange);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DidDeleteSelection(nsISelection *aSelection)
+{
+  return NS_OK;
+}
+
+// Let's remove all alignment hints in the children of aNode; it can
+// be an ALIGN attribute (in case we just remove it) or a CENTER
+// element (here we have to remove the container and keep its
+// children). We break on tables and don't look at their children.
+nsresult
+HTMLEditRules::RemoveAlignment(nsIDOMNode* aNode,
+                               const nsAString& aAlignType,
+                               bool aChildrenOnly)
+{
+  NS_ENSURE_TRUE(aNode, NS_ERROR_NULL_POINTER);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  if (mHTMLEditor->IsTextNode(aNode) || HTMLEditUtils::IsTable(aNode)) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIDOMNode> child = aNode,tmp;
+  if (aChildrenOnly) {
+    aNode->GetFirstChild(getter_AddRefs(child));
+  }
+  NS_ENSURE_STATE(mHTMLEditor);
+  bool useCSS = mHTMLEditor->IsCSSEnabled();
+
+  while (child) {
+    if (aChildrenOnly) {
+      // get the next sibling right now because we could have to remove child
+      child->GetNextSibling(getter_AddRefs(tmp));
+    } else {
+      tmp = nullptr;
+    }
+    bool isBlock;
+    NS_ENSURE_STATE(mHTMLEditor);
+    nsresult rv = mHTMLEditor->NodeIsBlockStatic(child, &isBlock);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (EditorBase::NodeIsType(child, nsGkAtoms::center)) {
+      // the current node is a CENTER element
+      // first remove children's alignment
+      rv = RemoveAlignment(child, aAlignType, true);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // we may have to insert BRs in first and last position of element's children
+      // if the nodes before/after are not blocks and not BRs
+      rv = MakeSureElemStartsOrEndsOnCR(child);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      // now remove the CENTER container
+      NS_ENSURE_STATE(mHTMLEditor);
+      nsCOMPtr<Element> childAsElement = do_QueryInterface(child);
+      NS_ENSURE_STATE(childAsElement);
+      rv = mHTMLEditor->RemoveContainer(childAsElement);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else if (isBlock || HTMLEditUtils::IsHR(child)) {
+      // the current node is a block element
+      nsCOMPtr<nsIDOMElement> curElem = do_QueryInterface(child);
+      if (HTMLEditUtils::SupportsAlignAttr(child)) {
+        // remove the ALIGN attribute if this element can have it
+        NS_ENSURE_STATE(mHTMLEditor);
+        rv = mHTMLEditor->RemoveAttribute(curElem, NS_LITERAL_STRING("align"));
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+      if (useCSS) {
+        if (HTMLEditUtils::IsTable(child) || HTMLEditUtils::IsHR(child)) {
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->SetAttributeOrEquivalent(curElem,
+                                                     NS_LITERAL_STRING("align"),
+                                                     aAlignType, false);
+          if (NS_WARN_IF(NS_FAILED(rv))) {
+            return rv;
+          }
+        } else {
+          nsAutoString dummyCssValue;
+          NS_ENSURE_STATE(mHTMLEditor);
+          rv = mHTMLEditor->mCSSEditUtils->RemoveCSSInlineStyle(
+                                             child,
+                                             nsGkAtoms::textAlign,
+                                             dummyCssValue);
+          if (NS_WARN_IF(NS_FAILED(rv))) {
+            return rv;
+          }
+        }
+      }
+      if (!HTMLEditUtils::IsTable(child)) {
+        // unless this is a table, look at children
+        rv = RemoveAlignment(child, aAlignType, true);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+    child = tmp;
+  }
+  return NS_OK;
+}
+
+// Let's insert a BR as first (resp. last) child of aNode if its
+// first (resp. last) child is not a block nor a BR, and if the
+// previous (resp. next) sibling is not a block nor a BR
+nsresult
+HTMLEditRules::MakeSureElemStartsOrEndsOnCR(nsIDOMNode* aNode,
+                                            bool aStarts)
+{
+  nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+  NS_ENSURE_TRUE(node, NS_ERROR_NULL_POINTER);
+
+  nsCOMPtr<nsIDOMNode> child;
+  if (aStarts) {
+    NS_ENSURE_STATE(mHTMLEditor);
+    child = GetAsDOMNode(mHTMLEditor->GetFirstEditableChild(*node));
+  } else {
+    NS_ENSURE_STATE(mHTMLEditor);
+    child = GetAsDOMNode(mHTMLEditor->GetLastEditableChild(*node));
+  }
+  NS_ENSURE_TRUE(child, NS_OK);
+  bool isChildBlock;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv = mHTMLEditor->NodeIsBlockStatic(child, &isChildBlock);
+  NS_ENSURE_SUCCESS(rv, rv);
+  bool foundCR = false;
+  if (isChildBlock || TextEditUtils::IsBreak(child)) {
+    foundCR = true;
+  } else {
+    nsCOMPtr<nsIDOMNode> sibling;
+    if (aStarts) {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->GetPriorHTMLSibling(aNode, address_of(sibling));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    } else {
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->GetNextHTMLSibling(aNode, address_of(sibling));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+    if (sibling) {
+      bool isBlock;
+      NS_ENSURE_STATE(mHTMLEditor);
+      rv = mHTMLEditor->NodeIsBlockStatic(sibling, &isBlock);
+      NS_ENSURE_SUCCESS(rv, rv);
+      if (isBlock || TextEditUtils::IsBreak(sibling)) {
+        foundCR = true;
+      }
+    } else {
+      foundCR = true;
+    }
+  }
+  if (!foundCR) {
+    int32_t offset = 0;
+    if (!aStarts) {
+      nsCOMPtr<nsINode> node = do_QueryInterface(aNode);
+      NS_ENSURE_STATE(node);
+      offset = node->GetChildCount();
+    }
+    nsCOMPtr<nsIDOMNode> brNode;
+    NS_ENSURE_STATE(mHTMLEditor);
+    rv = mHTMLEditor->CreateBR(aNode, offset, address_of(brNode));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::MakeSureElemStartsOrEndsOnCR(nsIDOMNode* aNode)
+{
+  nsresult rv = MakeSureElemStartsOrEndsOnCR(aNode, false);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return MakeSureElemStartsOrEndsOnCR(aNode, true);
+}
+
+nsresult
+HTMLEditRules::AlignBlock(Element& aElement,
+                          const nsAString& aAlignType,
+                          ContentsOnly aContentsOnly)
+{
+  if (!IsBlockNode(aElement) && !aElement.IsHTMLElement(nsGkAtoms::hr)) {
+    // We deal only with blocks; early way out
+    return NS_OK;
+  }
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  nsresult rv = RemoveAlignment(aElement.AsDOMNode(), aAlignType,
+                                aContentsOnly == ContentsOnly::yes);
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_NAMED_LITERAL_STRING(attr, "align");
+  if (htmlEditor->IsCSSEnabled()) {
+    // Let's use CSS alignment; we use margin-left and margin-right for tables
+    // and text-align for other block-level elements
+    rv = htmlEditor->SetAttributeOrEquivalent(
+                       static_cast<nsIDOMElement*>(aElement.AsDOMNode()),
+                       attr, aAlignType, false);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    // HTML case; this code is supposed to be called ONLY if the element
+    // supports the align attribute but we'll never know...
+    if (HTMLEditUtils::SupportsAlignAttr(aElement.AsDOMNode())) {
+      rv = htmlEditor->SetAttribute(
+                         static_cast<nsIDOMElement*>(aElement.AsDOMNode()),
+                         attr, aAlignType);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::ChangeIndentation(Element& aElement,
+                                 Change aChange)
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  nsIAtom& marginProperty =
+    MarginPropertyAtomForIndent(*htmlEditor->mCSSEditUtils, aElement);
+  nsAutoString value;
+  htmlEditor->mCSSEditUtils->GetSpecifiedProperty(aElement, marginProperty,
+                                                  value);
+  float f;
+  nsCOMPtr<nsIAtom> unit;
+  htmlEditor->mCSSEditUtils->ParseLength(value, &f, getter_AddRefs(unit));
+  if (!f) {
+    nsAutoString defaultLengthUnit;
+    htmlEditor->mCSSEditUtils->GetDefaultLengthUnit(defaultLengthUnit);
+    unit = NS_Atomize(defaultLengthUnit);
+  }
+  int8_t multiplier = aChange == Change::plus ? +1 : -1;
+  if (nsGkAtoms::in == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_IN * multiplier;
+  } else if (nsGkAtoms::cm == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_CM * multiplier;
+  } else if (nsGkAtoms::mm == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_MM * multiplier;
+  } else if (nsGkAtoms::pt == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_PT * multiplier;
+  } else if (nsGkAtoms::pc == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_PC * multiplier;
+  } else if (nsGkAtoms::em == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_EM * multiplier;
+  } else if (nsGkAtoms::ex == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_EX * multiplier;
+  } else if (nsGkAtoms::px == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_PX * multiplier;
+  } else if (nsGkAtoms::percentage == unit) {
+    f += NS_EDITOR_INDENT_INCREMENT_PERCENT * multiplier;
+  }
+
+  if (0 < f) {
+    nsAutoString newValue;
+    newValue.AppendFloat(f);
+    newValue.Append(nsDependentAtomString(unit));
+    htmlEditor->mCSSEditUtils->SetCSSProperty(aElement, marginProperty,
+                                              newValue);
+    return NS_OK;
+  }
+
+  htmlEditor->mCSSEditUtils->RemoveCSSProperty(aElement, marginProperty,
+                                               value);
+
+  // Remove unnecessary divs
+  if (!aElement.IsHTMLElement(nsGkAtoms::div) ||
+      &aElement == htmlEditor->GetActiveEditingHost() ||
+      !htmlEditor->IsDescendantOfEditorRoot(&aElement) ||
+      HTMLEditor::HasAttributes(&aElement)) {
+    return NS_OK;
+  }
+
+  nsresult rv = htmlEditor->RemoveContainer(&aElement);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::WillAbsolutePosition(Selection& aSelection,
+                                    bool* aCancel,
+                                    bool* aHandled)
+{
+  MOZ_ASSERT(aCancel && aHandled);
+  NS_ENSURE_STATE(mHTMLEditor);
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+
+  WillInsert(aSelection, aCancel);
+
+  // We want to ignore result of WillInsert()
+  *aCancel = false;
+  *aHandled = true;
+
+  nsCOMPtr<Element> focusElement = htmlEditor->GetSelectionContainer();
+  if (focusElement && HTMLEditUtils::IsImage(focusElement)) {
+    mNewBlock = focusElement;
+    return NS_OK;
+  }
+
+  nsresult rv = NormalizeSelection(&aSelection);
+  NS_ENSURE_SUCCESS(rv, rv);
+  AutoSelectionRestorer selectionRestorer(&aSelection, htmlEditor);
+
+  // Convert the selection ranges into "promoted" selection ranges: this
+  // basically just expands the range to include the immediate block parent,
+  // and then further expands to include any ancestors whose children are all
+  // in the range.
+
+  nsTArray<RefPtr<nsRange>> arrayOfRanges;
+  GetPromotedRanges(aSelection, arrayOfRanges,
+                    EditAction::setAbsolutePosition);
+
+  // Use these ranges to contruct a list of nodes to act on.
+  nsTArray<OwningNonNull<nsINode>> arrayOfNodes;
+  rv = GetNodesForOperation(arrayOfRanges, arrayOfNodes,
+                            EditAction::setAbsolutePosition);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // If nothing visible in list, make an empty block
+  if (ListIsEmptyLine(arrayOfNodes)) {
+    // Get selection location
+    NS_ENSURE_STATE(aSelection.GetRangeAt(0) &&
+                    aSelection.GetRangeAt(0)->GetStartParent());
+    OwningNonNull<nsINode> parent =
+      *aSelection.GetRangeAt(0)->GetStartParent();
+    int32_t offset = aSelection.GetRangeAt(0)->StartOffset();
+
+    // Make sure we can put a block here
+    rv = SplitAsNeeded(*nsGkAtoms::div, parent, offset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<Element> positionedDiv =
+      htmlEditor->CreateNode(nsGkAtoms::div, parent, offset);
+    NS_ENSURE_STATE(positionedDiv);
+    // Remember our new block for postprocessing
+    mNewBlock = positionedDiv;
+    // Delete anything that was in the list of nodes
+    while (!arrayOfNodes.IsEmpty()) {
+      OwningNonNull<nsINode> curNode = arrayOfNodes[0];
+      rv = htmlEditor->DeleteNode(curNode);
+      NS_ENSURE_SUCCESS(rv, rv);
+      arrayOfNodes.RemoveElementAt(0);
+    }
+    // Put selection in new block
+    *aHandled = true;
+    rv = aSelection.Collapse(positionedDiv, 0);
+    // Don't restore the selection
+    selectionRestorer.Abort();
+    NS_ENSURE_SUCCESS(rv, rv);
+    return NS_OK;
+  }
+
+  // Okay, now go through all the nodes and put them in a blockquote, or
+  // whatever is appropriate.  Woohoo!
+  nsCOMPtr<Element> curList, curPositionedDiv, indentedLI;
+  for (uint32_t i = 0; i < arrayOfNodes.Length(); i++) {
+    // Here's where we actually figure out what to do
+    NS_ENSURE_STATE(arrayOfNodes[i]->IsContent());
+    OwningNonNull<nsIContent> curNode = *arrayOfNodes[i]->AsContent();
+
+    // Ignore all non-editable nodes.  Leave them be.
+    if (!htmlEditor->IsEditable(curNode)) {
+      continue;
+    }
+
+    nsCOMPtr<nsIContent> sibling;
+
+    nsCOMPtr<nsINode> curParent = curNode->GetParentNode();
+    int32_t offset = curParent ? curParent->IndexOf(curNode) : -1;
+
+    // Some logic for putting list items into nested lists...
+    if (HTMLEditUtils::IsList(curParent)) {
+      // Check to see if curList is still appropriate.  Which it is if curNode
+      // is still right after it in the same list.
+      if (curList) {
+        sibling = htmlEditor->GetPriorHTMLSibling(curNode);
+      }
+
+      if (!curList || (sibling && sibling != curList)) {
+        // Create a new nested list of correct type
+        rv =
+          SplitAsNeeded(*curParent->NodeInfo()->NameAtom(), curParent, offset);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (!curPositionedDiv) {
+          nsCOMPtr<nsINode> curParentParent = curParent->GetParentNode();
+          int32_t parentOffset = curParentParent
+            ? curParentParent->IndexOf(curParent) : -1;
+          curPositionedDiv = htmlEditor->CreateNode(nsGkAtoms::div, curParentParent,
+                                                    parentOffset);
+          mNewBlock = curPositionedDiv;
+        }
+        curList = htmlEditor->CreateNode(curParent->NodeInfo()->NameAtom(),
+                                         curPositionedDiv, -1);
+        NS_ENSURE_STATE(curList);
+        // curList is now the correct thing to put curNode in.  Remember our
+        // new block for postprocessing.
+      }
+      // Tuck the node into the end of the active list
+      rv = htmlEditor->MoveNode(curNode, curList, -1);
+      NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+      // Not a list item, use blockquote?  If we are inside a list item, we
+      // don't want to blockquote, we want to sublist the list item.  We may
+      // have several nodes listed in the array of nodes to act on, that are in
+      // the same list item.  Since we only want to indent that li once, we
+      // must keep track of the most recent indented list item, and not indent
+      // it if we find another node to act on that is still inside the same li.
+      nsCOMPtr<Element> listItem = IsInListItem(curNode);
+      if (listItem) {
+        if (indentedLI == listItem) {
+          // Already indented this list item
+          continue;
+        }
+        curParent = listItem->GetParentNode();
+        offset = curParent ? curParent->IndexOf(listItem) : -1;
+        // Check to see if curList is still appropriate.  Which it is if
+        // curNode is still right after it in the same list.
+        if (curList) {
+          sibling = htmlEditor->GetPriorHTMLSibling(curNode);
+        }
+
+        if (!curList || (sibling && sibling != curList)) {
+          // Create a new nested list of correct type
+          rv = SplitAsNeeded(*curParent->NodeInfo()->NameAtom(), curParent,
+                             offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          if (!curPositionedDiv) {
+            nsCOMPtr<nsINode> curParentParent = curParent->GetParentNode();
+            int32_t parentOffset = curParentParent ?
+              curParentParent->IndexOf(curParent) : -1;
+            curPositionedDiv = htmlEditor->CreateNode(nsGkAtoms::div,
+                                                      curParentParent,
+                                                      parentOffset);
+            mNewBlock = curPositionedDiv;
+          }
+          curList = htmlEditor->CreateNode(curParent->NodeInfo()->NameAtom(),
+                                           curPositionedDiv, -1);
+          NS_ENSURE_STATE(curList);
+        }
+        rv = htmlEditor->MoveNode(listItem, curList, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // Remember we indented this li
+        indentedLI = listItem;
+      } else {
+        // Need to make a div to put things in if we haven't already
+
+        if (!curPositionedDiv) {
+          if (curNode->IsHTMLElement(nsGkAtoms::div)) {
+            curPositionedDiv = curNode->AsElement();
+            mNewBlock = curPositionedDiv;
+            curList = nullptr;
+            continue;
+          }
+          rv = SplitAsNeeded(*nsGkAtoms::div, curParent, offset);
+          NS_ENSURE_SUCCESS(rv, rv);
+          curPositionedDiv = htmlEditor->CreateNode(nsGkAtoms::div, curParent,
+                                                    offset);
+          NS_ENSURE_STATE(curPositionedDiv);
+          // Remember our new block for postprocessing
+          mNewBlock = curPositionedDiv;
+          // curPositionedDiv is now the correct thing to put curNode in
+        }
+
+        // Tuck the node into the end of the active blockquote
+        rv = htmlEditor->MoveNode(curNode, curPositionedDiv, -1);
+        NS_ENSURE_SUCCESS(rv, rv);
+        // Forget curList, if any
+        curList = nullptr;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+HTMLEditRules::DidAbsolutePosition()
+{
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIHTMLAbsPosEditor> absPosHTMLEditor = mHTMLEditor;
+  nsCOMPtr<nsIDOMElement> elt =
+    static_cast<nsIDOMElement*>(GetAsDOMNode(mNewBlock));
+  return absPosHTMLEditor->AbsolutelyPositionElement(elt, true);
+}
+
+nsresult
+HTMLEditRules::WillRemoveAbsolutePosition(Selection* aSelection,
+                                          bool* aCancel,
+                                          bool* aHandled) {
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  WillInsert(*aSelection, aCancel);
+
+  // initialize out param
+  // we want to ignore aCancel from WillInsert()
+  *aCancel = false;
+  *aHandled = true;
+
+  nsCOMPtr<nsIDOMElement>  elt;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetAbsolutelyPositionedSelectionContainer(getter_AddRefs(elt));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIHTMLAbsPosEditor> absPosHTMLEditor = mHTMLEditor;
+  return absPosHTMLEditor->AbsolutelyPositionElement(elt, false);
+}
+
+nsresult
+HTMLEditRules::WillRelativeChangeZIndex(Selection* aSelection,
+                                        int32_t aChange,
+                                        bool* aCancel,
+                                        bool* aHandled)
+{
+  if (!aSelection || !aCancel || !aHandled) {
+    return NS_ERROR_NULL_POINTER;
+  }
+  WillInsert(*aSelection, aCancel);
+
+  // initialize out param
+  // we want to ignore aCancel from WillInsert()
+  *aCancel = false;
+  *aHandled = true;
+
+  nsCOMPtr<nsIDOMElement>  elt;
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsresult rv =
+    mHTMLEditor->GetAbsolutelyPositionedSelectionContainer(getter_AddRefs(elt));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  AutoSelectionRestorer selectionRestorer(aSelection, mHTMLEditor);
+
+  NS_ENSURE_STATE(mHTMLEditor);
+  nsCOMPtr<nsIHTMLAbsPosEditor> absPosHTMLEditor = mHTMLEditor;
+  int32_t zIndex;
+  return absPosHTMLEditor->RelativeChangeElementZIndex(elt, aChange, &zIndex);
+}
+
+NS_IMETHODIMP
+HTMLEditRules::DocumentModified()
+{
+  nsContentUtils::AddScriptRunner(
+    NewRunnableMethod(this, &HTMLEditRules::DocumentModifiedWorker));
+  return NS_OK;
+}
+
+void
+HTMLEditRules::DocumentModifiedWorker()
+{
+  if (!mHTMLEditor) {
+    return;
+  }
+
+  // DeleteNode below may cause a flush, which could destroy the editor
+  nsAutoScriptBlockerSuppressNodeRemoved scriptBlocker;
+
+  RefPtr<HTMLEditor> htmlEditor(mHTMLEditor);
+  RefPtr<Selection> selection = htmlEditor->GetSelection();
+  if (!selection) {
+    return;
+  }
+
+  // Delete our bogus node, if we have one, since the document might not be
+  // empty any more.
+  if (mBogusNode) {
+    mTextEditor->DeleteNode(mBogusNode);
+    mBogusNode = nullptr;
+  }
+
+  // Try to recreate the bogus node if needed.
+  CreateBogusNodeIfNeeded(selection);
+}
+
+} // namespace mozilla