Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1174 insertions, 0 deletions

diff --git a/extensions/spellcheck/src/mozInlineSpellWordUtil.cpp b/extensions/spellcheck/src/mozInlineSpellWordUtil.cpp
new file mode 100644
index 0000000000..731059f04b
--- /dev/null
+++ b/extensions/spellcheck/src/mozInlineSpellWordUtil.cpp
@@ -0,0 +1,1174 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "mozInlineSpellWordUtil.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "mozilla/BinarySearch.h"
+#include "mozilla/EditorBase.h"
+#include "mozilla/HTMLEditor.h"
+#include "mozilla/Logging.h"
+#include "mozilla/dom/Element.h"
+
+#include "nsDebug.h"
+#include "nsAtom.h"
+#include "nsComponentManagerUtils.h"
+#include "nsUnicodeProperties.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIContent.h"
+#include "nsTextFragment.h"
+#include "nsRange.h"
+#include "nsContentUtils.h"
+#include "nsIFrame.h"
+
+using namespace mozilla;
+
+static LazyLogModule sInlineSpellWordUtilLog{"InlineSpellWordUtil"};
+
+// IsIgnorableCharacter
+//
+//    These characters are ones that we should ignore in input.
+
+inline bool IsIgnorableCharacter(char ch) {
+  return (ch == static_cast<char>(0xAD));  // SOFT HYPHEN
+}
+
+inline bool IsIgnorableCharacter(char16_t ch) {
+  return (ch == 0xAD ||   // SOFT HYPHEN
+          ch == 0x1806);  // MONGOLIAN TODO SOFT HYPHEN
+}
+
+// IsConditionalPunctuation
+//
+//    Some characters (like apostrophes) require characters on each side to be
+//    part of a word, and are otherwise punctuation.
+
+inline bool IsConditionalPunctuation(char ch) {
+  return (ch == '\'' ||                    // RIGHT SINGLE QUOTATION MARK
+          ch == static_cast<char>(0xB7));  // MIDDLE DOT
+}
+
+inline bool IsConditionalPunctuation(char16_t ch) {
+  return (ch == '\'' || ch == 0x2019 ||  // RIGHT SINGLE QUOTATION MARK
+          ch == 0x00B7);                 // MIDDLE DOT
+}
+
+static bool IsAmbiguousDOMWordSeprator(char16_t ch) {
+  // This class may be CHAR_CLASS_SEPARATOR, but it depends on context.
+  return (ch == '@' || ch == ':' || ch == '.' || ch == '/' || ch == '-' ||
+          IsConditionalPunctuation(ch));
+}
+
+static bool IsAmbiguousDOMWordSeprator(char ch) {
+  // This class may be CHAR_CLASS_SEPARATOR, but it depends on context.
+  return IsAmbiguousDOMWordSeprator(static_cast<char16_t>(ch));
+}
+
+// IsDOMWordSeparator
+//
+//    Determines if the given character should be considered as a DOM Word
+//    separator. Basically, this is whitespace, although it could also have
+//    certain punctuation that we know ALWAYS breaks words. This is important.
+//    For example, we can't have any punctuation that could appear in a URL
+//    or email address in this, because those need to always fit into a single
+//    DOM word.
+
+static bool IsDOMWordSeparator(char ch) {
+  // simple spaces or no-break space
+  return (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' ||
+          ch == static_cast<char>(0xA0));
+}
+
+static bool IsDOMWordSeparator(char16_t ch) {
+  // simple spaces
+  if (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r') return true;
+
+  // complex spaces - check only if char isn't ASCII (uncommon)
+  if (ch >= 0xA0 && (ch == 0x00A0 ||  // NO-BREAK SPACE
+                     ch == 0x2002 ||  // EN SPACE
+                     ch == 0x2003 ||  // EM SPACE
+                     ch == 0x2009 ||  // THIN SPACE
+                     ch == 0x3000))   // IDEOGRAPHIC SPACE
+    return true;
+
+  // otherwise not a space
+  return false;
+}
+
+bool NodeOffset::operator==(
+    const mozilla::RangeBoundary& aRangeBoundary) const {
+  if (aRangeBoundary.Container() != mNode) {
+    return false;
+  }
+
+  const Maybe<uint32_t> rangeBoundaryOffset =
+      aRangeBoundary.Offset(RangeBoundary::OffsetFilter::kValidOffsets);
+
+  MOZ_ASSERT(mOffset >= 0);
+  return rangeBoundaryOffset &&
+         (*rangeBoundaryOffset == static_cast<uint32_t>(mOffset));
+}
+
+bool NodeOffsetRange::operator==(const nsRange& aRange) const {
+  return mBegin == aRange.StartRef() && mEnd == aRange.EndRef();
+}
+
+// static
+Maybe<mozInlineSpellWordUtil> mozInlineSpellWordUtil::Create(
+    const EditorBase& aEditorBase) {
+  dom::Document* document = aEditorBase.GetDocument();
+  if (NS_WARN_IF(!document)) {
+    return Nothing();
+  }
+
+  const bool isContentEditableOrDesignMode = aEditorBase.IsHTMLEditor();
+
+  // Find the root node for the editor. For contenteditable the mRootNode could
+  // change to shadow root if the begin and end are inside the shadowDOM.
+  nsINode* rootNode = aEditorBase.GetRoot();
+  if (NS_WARN_IF(!rootNode)) {
+    return Nothing();
+  }
+
+  mozInlineSpellWordUtil util{*document, isContentEditableOrDesignMode,
+                              *rootNode};
+  return Some(std::move(util));
+}
+
+static inline bool IsSpellCheckingTextNode(nsINode* aNode) {
+  nsIContent* parent = aNode->GetParent();
+  if (parent &&
+      parent->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style))
+    return false;
+  return aNode->IsText();
+}
+
+typedef void (*OnLeaveNodeFunPtr)(nsINode* aNode, void* aClosure);
+
+// Find the next node in the DOM tree in preorder.
+// Calls OnLeaveNodeFunPtr when the traversal leaves a node, which is
+// why we can't just use GetNextNode here, sadly.
+static nsINode* FindNextNode(nsINode* aNode, const nsINode* aRoot,
+                             OnLeaveNodeFunPtr aOnLeaveNode, void* aClosure) {
+  MOZ_ASSERT(aNode, "Null starting node?");
+
+  nsINode* next = aNode->GetFirstChild();
+  if (next) return next;
+
+  // Don't look at siblings or otherwise outside of aRoot
+  if (aNode == aRoot) return nullptr;
+
+  next = aNode->GetNextSibling();
+  if (next) return next;
+
+  // Go up
+  for (;;) {
+    if (aOnLeaveNode) {
+      aOnLeaveNode(aNode, aClosure);
+    }
+
+    next = aNode->GetParent();
+    if (next == aRoot || !next) return nullptr;
+    aNode = next;
+
+    next = aNode->GetNextSibling();
+    if (next) return next;
+  }
+}
+
+// aNode is not a text node. Find the first text node starting at aNode/aOffset
+// in a preorder DOM traversal.
+static nsINode* FindNextTextNode(nsINode* aNode, int32_t aOffset,
+                                 const nsINode* aRoot) {
+  MOZ_ASSERT(aNode, "Null starting node?");
+  MOZ_ASSERT(!IsSpellCheckingTextNode(aNode),
+             "FindNextTextNode should start with a non-text node");
+
+  nsINode* checkNode;
+  // Need to start at the aOffset'th child
+  nsIContent* child = aNode->GetChildAt_Deprecated(aOffset);
+
+  if (child) {
+    checkNode = child;
+  } else {
+    // aOffset was beyond the end of the child list.
+    // goto next node after the last descendant of aNode in
+    // a preorder DOM traversal.
+    checkNode = aNode->GetNextNonChildNode(aRoot);
+  }
+
+  while (checkNode && !IsSpellCheckingTextNode(checkNode)) {
+    checkNode = checkNode->GetNextNode(aRoot);
+  }
+  return checkNode;
+}
+
+// mozInlineSpellWordUtil::SetPositionAndEnd
+//
+//    We have two ranges "hard" and "soft". The hard boundary is simply
+//    the scope of the root node. The soft boundary is that which is set
+//    by the caller of this class by calling this function. If this function is
+//    not called, the soft boundary is the same as the hard boundary.
+//
+//    When we reach the soft boundary (mSoftText.GetEnd()), we keep
+//    going until we reach the end of a word. This allows the caller to set the
+//    end of the range to anything, and we will always check whole multiples of
+//    words. When we reach the hard boundary we stop no matter what.
+//
+//    There is no beginning soft boundary. This is because we only go to the
+//    previous node once, when finding the previous word boundary in
+//    SetPosition(). You might think of the soft boundary as being this initial
+//    position.
+
+nsresult mozInlineSpellWordUtil::SetPositionAndEnd(nsINode* aPositionNode,
+                                                   int32_t aPositionOffset,
+                                                   nsINode* aEndNode,
+                                                   int32_t aEndOffset) {
+  MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
+          ("%s: pos=(%p, %i), end=(%p, %i)", __FUNCTION__, aPositionNode,
+           aPositionOffset, aEndNode, aEndOffset));
+
+  MOZ_ASSERT(aPositionNode, "Null begin node?");
+  MOZ_ASSERT(aEndNode, "Null end node?");
+
+  MOZ_ASSERT(mRootNode, "Not initialized");
+
+  // Find a appropriate root if we are dealing with contenteditable nodes which
+  // are in the shadow DOM.
+  if (mIsContentEditableOrDesignMode) {
+    nsINode* rootNode = aPositionNode->SubtreeRoot();
+    if (rootNode != aEndNode->SubtreeRoot()) {
+      return NS_ERROR_FAILURE;
+    }
+
+    if (mozilla::dom::ShadowRoot::FromNode(rootNode)) {
+      mRootNode = rootNode;
+    }
+  }
+
+  mSoftText.Invalidate();
+
+  if (!IsSpellCheckingTextNode(aPositionNode)) {
+    // Start at the start of the first text node after aNode/aOffset.
+    aPositionNode = FindNextTextNode(aPositionNode, aPositionOffset, mRootNode);
+    aPositionOffset = 0;
+  }
+  NodeOffset softBegin = NodeOffset(aPositionNode, aPositionOffset);
+
+  if (!IsSpellCheckingTextNode(aEndNode)) {
+    // End at the start of the first text node after aEndNode/aEndOffset.
+    aEndNode = FindNextTextNode(aEndNode, aEndOffset, mRootNode);
+    aEndOffset = 0;
+  }
+  NodeOffset softEnd = NodeOffset(aEndNode, aEndOffset);
+
+  nsresult rv = EnsureWords(std::move(softBegin), std::move(softEnd));
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  int32_t textOffset = MapDOMPositionToSoftTextOffset(mSoftText.GetBegin());
+  if (textOffset < 0) {
+    return NS_OK;
+  }
+
+  mNextWordIndex = FindRealWordContaining(textOffset, HINT_END, true);
+  return NS_OK;
+}
+
+nsresult mozInlineSpellWordUtil::EnsureWords(NodeOffset aSoftBegin,
+                                             NodeOffset aSoftEnd) {
+  if (mSoftText.mIsValid) return NS_OK;
+  mSoftText.AdjustBeginAndBuildText(std::move(aSoftBegin), std::move(aSoftEnd),
+                                    mRootNode);
+
+  mRealWords.Clear();
+  Result<RealWords, nsresult> realWords = BuildRealWords();
+  if (realWords.isErr()) {
+    return realWords.unwrapErr();
+  }
+
+  mRealWords = realWords.unwrap();
+  mSoftText.mIsValid = true;
+  return NS_OK;
+}
+
+nsresult mozInlineSpellWordUtil::MakeRangeForWord(const RealWord& aWord,
+                                                  nsRange** aRange) const {
+  NodeOffset begin =
+      MapSoftTextOffsetToDOMPosition(aWord.mSoftTextOffset, HINT_BEGIN);
+  NodeOffset end = MapSoftTextOffsetToDOMPosition(aWord.EndOffset(), HINT_END);
+  return MakeRange(begin, end, aRange);
+}
+void mozInlineSpellWordUtil::MakeNodeOffsetRangeForWord(
+    const RealWord& aWord, NodeOffsetRange* aNodeOffsetRange) {
+  NodeOffset begin =
+      MapSoftTextOffsetToDOMPosition(aWord.mSoftTextOffset, HINT_BEGIN);
+  NodeOffset end = MapSoftTextOffsetToDOMPosition(aWord.EndOffset(), HINT_END);
+  *aNodeOffsetRange = NodeOffsetRange(begin, end);
+}
+
+// mozInlineSpellWordUtil::GetRangeForWord
+
+nsresult mozInlineSpellWordUtil::GetRangeForWord(nsINode* aWordNode,
+                                                 int32_t aWordOffset,
+                                                 nsRange** aRange) {
+  // Set our soft end and start
+  NodeOffset pt(aWordNode, aWordOffset);
+
+  if (!mSoftText.mIsValid || pt != mSoftText.GetBegin() ||
+      pt != mSoftText.GetEnd()) {
+    mSoftText.Invalidate();
+    NodeOffset softBegin = pt;
+    NodeOffset softEnd = pt;
+    nsresult rv = EnsureWords(std::move(softBegin), std::move(softEnd));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+  }
+
+  int32_t offset = MapDOMPositionToSoftTextOffset(pt);
+  if (offset < 0) return MakeRange(pt, pt, aRange);
+  int32_t wordIndex = FindRealWordContaining(offset, HINT_BEGIN, false);
+  if (wordIndex < 0) return MakeRange(pt, pt, aRange);
+  return MakeRangeForWord(mRealWords[wordIndex], aRange);
+}
+
+// This is to fix characters that the spellchecker may not like
+static void NormalizeWord(const nsAString& aInput, int32_t aPos, int32_t aLen,
+                          nsAString& aOutput) {
+  aOutput.Truncate();
+  for (int32_t i = 0; i < aLen; i++) {
+    char16_t ch = aInput.CharAt(i + aPos);
+
+    // remove ignorable characters from the word
+    if (IsIgnorableCharacter(ch)) continue;
+
+    // the spellchecker doesn't handle curly apostrophes in all languages
+    if (ch == 0x2019) {  // RIGHT SINGLE QUOTATION MARK
+      ch = '\'';
+    }
+
+    aOutput.Append(ch);
+  }
+}
+
+// mozInlineSpellWordUtil::GetNextWord
+//
+//    FIXME-optimization: we shouldn't have to generate a range every single
+//    time. It would be better if the inline spellchecker didn't require a
+//    range unless the word was misspelled. This may or may not be possible.
+
+bool mozInlineSpellWordUtil::GetNextWord(Word& aWord) {
+  MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
+          ("%s: mNextWordIndex=%d", __FUNCTION__, mNextWordIndex));
+
+  if (mNextWordIndex < 0 || mNextWordIndex >= int32_t(mRealWords.Length())) {
+    mNextWordIndex = -1;
+    aWord.mSkipChecking = true;
+    return false;
+  }
+
+  const RealWord& realWord = mRealWords[mNextWordIndex];
+  MakeNodeOffsetRangeForWord(realWord, &aWord.mNodeOffsetRange);
+  ++mNextWordIndex;
+  aWord.mSkipChecking = !realWord.mCheckableWord;
+  ::NormalizeWord(mSoftText.GetValue(), realWord.mSoftTextOffset,
+                  realWord.mLength, aWord.mText);
+
+  MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
+          ("%s: returning: %s (skip=%d)", __FUNCTION__,
+           NS_ConvertUTF16toUTF8(aWord.mText).get(), aWord.mSkipChecking));
+
+  return true;
+}
+
+// mozInlineSpellWordUtil::MakeRange
+//
+//    Convenience function for creating a range over the current document.
+
+nsresult mozInlineSpellWordUtil::MakeRange(NodeOffset aBegin, NodeOffset aEnd,
+                                           nsRange** aRange) const {
+  NS_ENSURE_ARG_POINTER(aBegin.mNode);
+  if (!mDocument) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  ErrorResult error;
+  RefPtr<nsRange> range = nsRange::Create(aBegin.mNode, aBegin.mOffset,
+                                          aEnd.mNode, aEnd.mOffset, error);
+  if (NS_WARN_IF(error.Failed())) {
+    return error.StealNSResult();
+  }
+  MOZ_ASSERT(range);
+  range.forget(aRange);
+  return NS_OK;
+}
+
+// static
+already_AddRefed<nsRange> mozInlineSpellWordUtil::MakeRange(
+    const NodeOffsetRange& aRange) {
+  IgnoredErrorResult ignoredError;
+  RefPtr<nsRange> range =
+      nsRange::Create(aRange.Begin().Node(), aRange.Begin().Offset(),
+                      aRange.End().Node(), aRange.End().Offset(), ignoredError);
+  NS_WARNING_ASSERTION(!ignoredError.Failed(), "Creating a range failed");
+  return range.forget();
+}
+
+/*********** Word Splitting ************/
+
+// classifies a given character in the DOM word
+enum CharClass {
+  CHAR_CLASS_WORD,
+  CHAR_CLASS_SEPARATOR,
+  CHAR_CLASS_END_OF_INPUT
+};
+
+// Encapsulates DOM-word to real-word splitting
+template <class T>
+struct MOZ_STACK_CLASS WordSplitState {
+  const T& mDOMWordText;
+  int32_t mDOMWordOffset;
+  CharClass mCurCharClass;
+
+  explicit WordSplitState(const T& aString)
+      : mDOMWordText(aString),
+        mDOMWordOffset(0),
+        mCurCharClass(CHAR_CLASS_END_OF_INPUT) {}
+
+  CharClass ClassifyCharacter(int32_t aIndex, bool aRecurse) const;
+  void Advance();
+  void AdvanceThroughSeparators();
+  void AdvanceThroughWord();
+
+  // Finds special words like email addresses and URLs that may start at the
+  // current position, and returns their length, or 0 if not found. This allows
+  // arbitrary word breaking rules to be used for these special entities, as
+  // long as they can not contain whitespace.
+  bool IsSpecialWord() const;
+
+  // Similar to IsSpecialWord except that this takes a split word as
+  // input. This checks for things that do not require special word-breaking
+  // rules.
+  bool ShouldSkipWord(int32_t aStart, int32_t aLength) const;
+
+  // Finds the last sequence of DOM word separators before aBeforeOffset and
+  // returns the offset to its first element.
+  Maybe<int32_t> FindOffsetOfLastDOMWordSeparatorSequence(
+      int32_t aBeforeOffset) const;
+
+  char16_t GetUnicharAt(int32_t aIndex) const;
+};
+
+// WordSplitState::ClassifyCharacter
+template <class T>
+CharClass WordSplitState<T>::ClassifyCharacter(int32_t aIndex,
+                                               bool aRecurse) const {
+  MOZ_ASSERT(aIndex >= 0 && aIndex <= int32_t(mDOMWordText.Length()),
+             "Index out of range");
+  if (aIndex == int32_t(mDOMWordText.Length())) return CHAR_CLASS_SEPARATOR;
+
+  // this will classify the character, we want to treat "ignorable" characters
+  // such as soft hyphens, and also ZWJ and ZWNJ as word characters.
+  nsUGenCategory charCategory =
+      mozilla::unicode::GetGenCategory(GetUnicharAt(aIndex));
+  if (charCategory == nsUGenCategory::kLetter ||
+      IsIgnorableCharacter(mDOMWordText[aIndex]) ||
+      mDOMWordText[aIndex] == 0x200C /* ZWNJ */ ||
+      mDOMWordText[aIndex] == 0x200D /* ZWJ */)
+    return CHAR_CLASS_WORD;
+
+  // If conditional punctuation is surrounded immediately on both sides by word
+  // characters it also counts as a word character.
+  if (IsConditionalPunctuation(mDOMWordText[aIndex])) {
+    if (!aRecurse) {
+      // not allowed to look around, this punctuation counts like a separator
+      return CHAR_CLASS_SEPARATOR;
+    }
+
+    // check the left-hand character
+    if (aIndex == 0) return CHAR_CLASS_SEPARATOR;
+    if (ClassifyCharacter(aIndex - 1, false) != CHAR_CLASS_WORD)
+      return CHAR_CLASS_SEPARATOR;
+    // If the previous charatcer is a word-char, make sure that it's not a
+    // special dot character.
+    if (mDOMWordText[aIndex - 1] == '.') return CHAR_CLASS_SEPARATOR;
+
+    // now we know left char is a word-char, check the right-hand character
+    if (aIndex == int32_t(mDOMWordText.Length() - 1)) {
+      return CHAR_CLASS_SEPARATOR;
+    }
+
+    if (ClassifyCharacter(aIndex + 1, false) != CHAR_CLASS_WORD)
+      return CHAR_CLASS_SEPARATOR;
+    // If the next charatcer is a word-char, make sure that it's not a
+    // special dot character.
+    if (mDOMWordText[aIndex + 1] == '.') return CHAR_CLASS_SEPARATOR;
+
+    // char on either side is a word, this counts as a word
+    return CHAR_CLASS_WORD;
+  }
+
+  // The dot character, if appearing at the end of a word, should
+  // be considered part of that word.  Example: "etc.", or
+  // abbreviations
+  if (aIndex > 0 && mDOMWordText[aIndex] == '.' &&
+      mDOMWordText[aIndex - 1] != '.' &&
+      ClassifyCharacter(aIndex - 1, false) != CHAR_CLASS_WORD) {
+    return CHAR_CLASS_WORD;
+  }
+
+  // all other punctuation
+  if (charCategory == nsUGenCategory::kSeparator ||
+      charCategory == nsUGenCategory::kOther ||
+      charCategory == nsUGenCategory::kPunctuation ||
+      charCategory == nsUGenCategory::kSymbol) {
+    // Don't break on hyphens, as hunspell handles them on its own.
+    if (aIndex > 0 && mDOMWordText[aIndex] == '-' &&
+        mDOMWordText[aIndex - 1] != '-' &&
+        ClassifyCharacter(aIndex - 1, false) == CHAR_CLASS_WORD) {
+      // A hyphen is only meaningful as a separator inside a word
+      // if the previous and next characters are a word character.
+      if (aIndex == int32_t(mDOMWordText.Length()) - 1)
+        return CHAR_CLASS_SEPARATOR;
+      if (mDOMWordText[aIndex + 1] != '.' &&
+          ClassifyCharacter(aIndex + 1, false) == CHAR_CLASS_WORD)
+        return CHAR_CLASS_WORD;
+    }
+    return CHAR_CLASS_SEPARATOR;
+  }
+
+  // any other character counts as a word
+  return CHAR_CLASS_WORD;
+}
+
+// WordSplitState::Advance
+template <class T>
+void WordSplitState<T>::Advance() {
+  MOZ_ASSERT(mDOMWordOffset >= 0, "Negative word index");
+  MOZ_ASSERT(mDOMWordOffset < (int32_t)mDOMWordText.Length(),
+             "Length beyond end");
+
+  mDOMWordOffset++;
+  if (mDOMWordOffset >= (int32_t)mDOMWordText.Length())
+    mCurCharClass = CHAR_CLASS_END_OF_INPUT;
+  else
+    mCurCharClass = ClassifyCharacter(mDOMWordOffset, true);
+}
+
+// WordSplitState::AdvanceThroughSeparators
+template <class T>
+void WordSplitState<T>::AdvanceThroughSeparators() {
+  while (mCurCharClass == CHAR_CLASS_SEPARATOR) Advance();
+}
+
+// WordSplitState::AdvanceThroughWord
+template <class T>
+void WordSplitState<T>::AdvanceThroughWord() {
+  while (mCurCharClass == CHAR_CLASS_WORD) Advance();
+}
+
+// WordSplitState::IsSpecialWord
+template <class T>
+bool WordSplitState<T>::IsSpecialWord() const {
+  // Search for email addresses. We simply define these as any sequence of
+  // characters with an '@' character in the middle. The DOM word is already
+  // split on whitepace, so we know that everything to the end is the address
+  int32_t firstColon = -1;
+  for (int32_t i = mDOMWordOffset; i < int32_t(mDOMWordText.Length()); i++) {
+    if (mDOMWordText[i] == '@') {
+      // only accept this if there are unambiguous word characters (don't bother
+      // recursing to disambiguate apostrophes) on each side. This prevents
+      // classifying, e.g. "@home" as an email address
+
+      // Use this condition to only accept words with '@' in the middle of
+      // them. It works, but the inlinespellcker doesn't like this. The problem
+      // is that you type "fhsgfh@" that's a misspelled word followed by a
+      // symbol, but when you type another letter "fhsgfh@g" that first word
+      // need to be unmarked misspelled. It doesn't do this. it only checks the
+      // current position for potentially removing a spelling range.
+      if (i > 0 && ClassifyCharacter(i - 1, false) == CHAR_CLASS_WORD &&
+          i < (int32_t)mDOMWordText.Length() - 1 &&
+          ClassifyCharacter(i + 1, false) == CHAR_CLASS_WORD) {
+        return true;
+      }
+    } else if (mDOMWordText[i] == ':' && firstColon < 0) {
+      firstColon = i;
+
+      // If the first colon is followed by a slash, consider it a URL
+      // This will catch things like asdf://foo.com
+      if (firstColon < (int32_t)mDOMWordText.Length() - 1 &&
+          mDOMWordText[firstColon + 1] == '/') {
+        return true;
+      }
+    }
+  }
+
+  // Check the text before the first colon against some known protocols. It
+  // is impossible to check against all protocols, especially since you can
+  // plug in new protocols. We also don't want to waste time here checking
+  // against a lot of obscure protocols.
+  if (firstColon > mDOMWordOffset) {
+    nsString protocol(
+        Substring(mDOMWordText, mDOMWordOffset, firstColon - mDOMWordOffset));
+    if (protocol.EqualsIgnoreCase("http") ||
+        protocol.EqualsIgnoreCase("https") ||
+        protocol.EqualsIgnoreCase("news") ||
+        protocol.EqualsIgnoreCase("file") ||
+        protocol.EqualsIgnoreCase("javascript") ||
+        protocol.EqualsIgnoreCase("data") || protocol.EqualsIgnoreCase("ftp")) {
+      return true;
+    }
+  }
+
+  // not anything special
+  return false;
+}
+
+// WordSplitState::ShouldSkipWord
+template <class T>
+bool WordSplitState<T>::ShouldSkipWord(int32_t aStart, int32_t aLength) const {
+  int32_t last = aStart + aLength;
+
+  // check to see if the word contains a digit
+  for (int32_t i = aStart; i < last; i++) {
+    if (mozilla::unicode::GetGenCategory(GetUnicharAt(i)) ==
+        nsUGenCategory::kNumber) {
+      return true;
+    }
+  }
+
+  // not special
+  return false;
+}
+
+template <class T>
+Maybe<int32_t> WordSplitState<T>::FindOffsetOfLastDOMWordSeparatorSequence(
+    const int32_t aBeforeOffset) const {
+  for (int32_t i = aBeforeOffset - 1; i >= 0; --i) {
+    if (IsDOMWordSeparator(mDOMWordText[i]) ||
+        (!IsAmbiguousDOMWordSeprator(mDOMWordText[i]) &&
+         ClassifyCharacter(i, true) == CHAR_CLASS_SEPARATOR)) {
+      // Be greedy, find as many separators as we can
+      for (int32_t j = i - 1; j >= 0; --j) {
+        if (IsDOMWordSeparator(mDOMWordText[j]) ||
+            (!IsAmbiguousDOMWordSeprator(mDOMWordText[j]) &&
+             ClassifyCharacter(j, true) == CHAR_CLASS_SEPARATOR)) {
+          i = j;
+        } else {
+          break;
+        }
+      }
+      return Some(i);
+    }
+  }
+  return Nothing();
+}
+
+template <>
+char16_t WordSplitState<nsDependentSubstring>::GetUnicharAt(
+    int32_t aIndex) const {
+  return mDOMWordText[aIndex];
+}
+
+template <>
+char16_t WordSplitState<nsDependentCSubstring>::GetUnicharAt(
+    int32_t aIndex) const {
+  return static_cast<char16_t>(static_cast<uint8_t>(mDOMWordText[aIndex]));
+}
+
+static inline bool IsBRElement(nsINode* aNode) {
+  return aNode->IsHTMLElement(nsGkAtoms::br);
+}
+
+/**
+ * Given a TextNode, finds the last sequence of DOM word separators before
+ * aBeforeOffset and returns the offset to its first element.
+ *
+ * @param aContent the TextNode to check.
+ * @param aBeforeOffset the offset in the TextNode before which we will search
+ *        for the DOM separator. You can pass INT32_MAX to search the entire
+ *        length of the string.
+ */
+static Maybe<int32_t> FindOffsetOfLastDOMWordSeparatorSequence(
+    nsIContent* aContent, int32_t aBeforeOffset) {
+  const nsTextFragment* textFragment = aContent->GetText();
+  MOZ_ASSERT(textFragment, "Where is our text?");
+  int32_t end = std::min(aBeforeOffset, int32_t(textFragment->GetLength()));
+
+  if (textFragment->Is2b()) {
+    nsDependentSubstring targetText(textFragment->Get2b(), end);
+    WordSplitState<nsDependentSubstring> state(targetText);
+    return state.FindOffsetOfLastDOMWordSeparatorSequence(end);
+  }
+
+  nsDependentCSubstring targetText(textFragment->Get1b(), end);
+  WordSplitState<nsDependentCSubstring> state(targetText);
+  return state.FindOffsetOfLastDOMWordSeparatorSequence(end);
+}
+
+/**
+ * Check if there's a DOM word separator before aBeforeOffset in this node.
+ * Always returns true if it's a BR element.
+ * aSeparatorOffset is set to the index of the first character in the last
+ * separator if any is found (0 for BR elements).
+ *
+ * This function does not modify aSeparatorOffset when it returns false.
+ */
+static bool ContainsDOMWordSeparator(nsINode* aNode, int32_t aBeforeOffset,
+                                     int32_t* aSeparatorOffset) {
+  if (IsBRElement(aNode)) {
+    *aSeparatorOffset = 0;
+    return true;
+  }
+
+  if (!IsSpellCheckingTextNode(aNode)) return false;
+
+  const Maybe<int32_t> separatorOffset =
+      FindOffsetOfLastDOMWordSeparatorSequence(aNode->AsContent(),
+                                               aBeforeOffset);
+  if (separatorOffset) {
+    *aSeparatorOffset = *separatorOffset;
+    return true;
+  }
+
+  return false;
+}
+
+static bool IsBreakElement(nsINode* aNode) {
+  if (!aNode->IsElement()) {
+    return false;
+  }
+
+  dom::Element* element = aNode->AsElement();
+  if (element->IsHTMLElement(nsGkAtoms::br)) {
+    return true;
+  }
+
+  // If we don't have a frame, we don't consider ourselves a break
+  // element.  In particular, words can span us.
+  nsIFrame* frame = element->GetPrimaryFrame();
+  if (!frame) {
+    return false;
+  }
+
+  auto* disp = frame->StyleDisplay();
+  // Anything that's not an inline element is a break element.
+  // XXXbz should replaced inlines be break elements, though?
+  // Also should inline-block and such be break elements?
+  //
+  // FIXME(emilio): We should teach the spell checker to deal with generated
+  // content (it doesn't at all), then remove the IsListItem() check, as there
+  // could be no marker, etc...
+  return !disp->IsInlineFlow() || disp->IsListItem();
+}
+
+struct CheckLeavingBreakElementClosure {
+  bool mLeftBreakElement;
+};
+
+static void CheckLeavingBreakElement(nsINode* aNode, void* aClosure) {
+  CheckLeavingBreakElementClosure* cl =
+      static_cast<CheckLeavingBreakElementClosure*>(aClosure);
+  if (!cl->mLeftBreakElement && IsBreakElement(aNode)) {
+    cl->mLeftBreakElement = true;
+  }
+}
+
+void mozInlineSpellWordUtil::NormalizeWord(nsAString& aWord) {
+  nsAutoString result;
+  ::NormalizeWord(aWord, 0, aWord.Length(), result);
+  aWord = result;
+}
+
+void mozInlineSpellWordUtil::SoftText::AdjustBeginAndBuildText(
+    NodeOffset aBegin, NodeOffset aEnd, const nsINode* aRootNode) {
+  MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug, ("%s", __FUNCTION__));
+
+  mBegin = std::move(aBegin);
+  mEnd = std::move(aEnd);
+
+  // First we have to work backwards from mBegin to find a text node
+  // containing a DOM word separator, a non-inline-element
+  // boundary, or the hard start node. That's where we'll start building the
+  // soft string from.
+  nsINode* node = mBegin.mNode;
+  int32_t firstOffsetInNode = 0;
+  int32_t checkBeforeOffset = mBegin.mOffset;
+  while (node) {
+    if (ContainsDOMWordSeparator(node, checkBeforeOffset, &firstOffsetInNode)) {
+      if (node == mBegin.mNode) {
+        // If we find a word separator on the first node, look at the preceding
+        // word on the text node as well.
+        if (firstOffsetInNode > 0) {
+          // Try to find the previous word boundary in the current node. If
+          // we can't find one, start checking previous sibling nodes (if any
+          // adjacent ones exist) to see if we can find any text nodes with
+          // DOM word separators. We bail out as soon as we see a node that is
+          // not a text node, or we run out of previous sibling nodes. In the
+          // event that we simply cannot find any preceding word separator, the
+          // offset is set to 0, and the soft text beginning node is set to the
+          // "most previous" text node before the original starting node, or
+          // kept at the original starting node if no previous text nodes exist.
+          int32_t newOffset = 0;
+          if (!ContainsDOMWordSeparator(node, firstOffsetInNode - 1,
+                                        &newOffset)) {
+            nsIContent* prevNode = node->GetPreviousSibling();
+            while (prevNode && IsSpellCheckingTextNode(prevNode)) {
+              mBegin.mNode = prevNode;
+              const Maybe<int32_t> separatorOffset =
+                  FindOffsetOfLastDOMWordSeparatorSequence(prevNode, INT32_MAX);
+              if (separatorOffset) {
+                newOffset = *separatorOffset;
+                break;
+              }
+              prevNode = prevNode->GetPreviousSibling();
+            }
+          }
+          firstOffsetInNode = newOffset;
+        } else {
+          firstOffsetInNode = 0;
+        }
+
+        MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
+                ("%s: adjusting mBegin.mOffset from %i to %i.", __FUNCTION__,
+                 mBegin.mOffset, firstOffsetInNode));
+        mBegin.mOffset = firstOffsetInNode;
+      }
+      break;
+    }
+    checkBeforeOffset = INT32_MAX;
+    if (IsBreakElement(node)) {
+      // Since GetPreviousContent follows tree *preorder*, we're about to
+      // traverse up out of 'node'. Since node induces breaks (e.g., it's a
+      // block), don't bother trying to look outside it, just stop now.
+      break;
+    }
+    // GetPreviousContent below expects aRootNode to be an ancestor of node.
+    if (!node->IsInclusiveDescendantOf(aRootNode)) {
+      break;
+    }
+    node = node->GetPreviousContent(aRootNode);
+  }
+
+  // Now build up the string moving forward through the DOM until we reach
+  // the soft end and *then* see a DOM word separator, a non-inline-element
+  // boundary, or the hard end node.
+  mValue.Truncate();
+  mDOMMapping.Clear();
+  bool seenSoftEnd = false;
+  // Leave this outside the loop so large heap string allocations can be reused
+  // across iterations
+  while (node) {
+    if (node == mEnd.mNode) {
+      seenSoftEnd = true;
+    }
+
+    bool exit = false;
+    if (IsSpellCheckingTextNode(node)) {
+      nsIContent* content = static_cast<nsIContent*>(node);
+      MOZ_ASSERT(content, "Where is our content?");
+      const nsTextFragment* textFragment = content->GetText();
+      MOZ_ASSERT(textFragment, "Where is our text?");
+      uint32_t lastOffsetInNode = textFragment->GetLength();
+
+      if (seenSoftEnd) {
+        // check whether we can stop after this
+        for (uint32_t i =
+                 node == mEnd.mNode ? AssertedCast<uint32_t>(mEnd.mOffset) : 0;
+             i < textFragment->GetLength(); ++i) {
+          if (IsDOMWordSeparator(textFragment->CharAt(i))) {
+            exit = true;
+            // stop at the first separator after the soft end point
+            lastOffsetInNode = i;
+            break;
+          }
+        }
+      }
+
+      if (firstOffsetInNode >= 0 &&
+          static_cast<uint32_t>(firstOffsetInNode) < lastOffsetInNode) {
+        const uint32_t len = lastOffsetInNode - firstOffsetInNode;
+        mDOMMapping.AppendElement(DOMTextMapping(
+            NodeOffset(node, firstOffsetInNode), mValue.Length(), len));
+
+        const bool ok = textFragment->AppendTo(
+            mValue, static_cast<uint32_t>(firstOffsetInNode), len,
+            mozilla::fallible);
+        if (!ok) {
+          // probably out of memory, remove from mDOMMapping
+          mDOMMapping.RemoveLastElement();
+          exit = true;
+        }
+      }
+
+      firstOffsetInNode = 0;
+    }
+
+    if (exit) break;
+
+    CheckLeavingBreakElementClosure closure = {false};
+    node = FindNextNode(node, aRootNode, CheckLeavingBreakElement, &closure);
+    if (closure.mLeftBreakElement || (node && IsBreakElement(node))) {
+      // We left, or are entering, a break element (e.g., block). Maybe we can
+      // stop now.
+      if (seenSoftEnd) break;
+      // Record the break
+      mValue.Append(' ');
+    }
+  }
+
+  MOZ_LOG(sInlineSpellWordUtilLog, LogLevel::Debug,
+          ("%s: got DOM string: %s", __FUNCTION__,
+           NS_ConvertUTF16toUTF8(mValue).get()));
+}
+
+auto mozInlineSpellWordUtil::BuildRealWords() const
+    -> Result<RealWords, nsresult> {
+  // This is pretty simple. We just have to walk mSoftText.GetValue(),
+  // tokenizing it into "real words". We do an outer traversal of words
+  // delimited by IsDOMWordSeparator, calling SplitDOMWordAndAppendTo on each of
+  // those DOM words
+  int32_t wordStart = -1;
+  RealWords realWords;
+  for (int32_t i = 0; i < int32_t(mSoftText.GetValue().Length()); ++i) {
+    if (IsDOMWordSeparator(mSoftText.GetValue().CharAt(i))) {
+      if (wordStart >= 0) {
+        nsresult rv = SplitDOMWordAndAppendTo(wordStart, i, realWords);
+        if (NS_FAILED(rv)) {
+          return Err(rv);
+        }
+        wordStart = -1;
+      }
+    } else {
+      if (wordStart < 0) {
+        wordStart = i;
+      }
+    }
+  }
+  if (wordStart >= 0) {
+    nsresult rv = SplitDOMWordAndAppendTo(
+        wordStart, mSoftText.GetValue().Length(), realWords);
+    if (NS_FAILED(rv)) {
+      return Err(rv);
+    }
+  }
+
+  return realWords;
+}
+
+/*********** DOM/realwords<->mSoftText.GetValue() mapping functions
+ * ************/
+
+int32_t mozInlineSpellWordUtil::MapDOMPositionToSoftTextOffset(
+    const NodeOffset& aNodeOffset) const {
+  if (!mSoftText.mIsValid) {
+    NS_ERROR("Soft text must be valid if we're to map into it");
+    return -1;
+  }
+
+  for (int32_t i = 0; i < int32_t(mSoftText.GetDOMMapping().Length()); ++i) {
+    const DOMTextMapping& map = mSoftText.GetDOMMapping()[i];
+    if (map.mNodeOffset.mNode == aNodeOffset.mNode) {
+      // Allow offsets at either end of the string, in particular, allow the
+      // offset that's at the end of the contributed string
+      int32_t offsetInContributedString =
+          aNodeOffset.mOffset - map.mNodeOffset.mOffset;
+      if (offsetInContributedString >= 0 &&
+          offsetInContributedString <= map.mLength)
+        return map.mSoftTextOffset + offsetInContributedString;
+      return -1;
+    }
+  }
+  return -1;
+}
+
+namespace {
+
+template <class T>
+class FirstLargerOffset {
+  int32_t mSoftTextOffset;
+
+ public:
+  explicit FirstLargerOffset(int32_t aSoftTextOffset)
+      : mSoftTextOffset(aSoftTextOffset) {}
+  int operator()(const T& t) const {
+    // We want the first larger offset, so never return 0 (which would
+    // short-circuit evaluation before finding the last such offset).
+    return mSoftTextOffset < t.mSoftTextOffset ? -1 : 1;
+  }
+};
+
+template <class T>
+bool FindLastNongreaterOffset(const nsTArray<T>& aContainer,
+                              int32_t aSoftTextOffset, size_t* aIndex) {
+  if (aContainer.Length() == 0) {
+    return false;
+  }
+
+  BinarySearchIf(aContainer, 0, aContainer.Length(),
+                 FirstLargerOffset<T>(aSoftTextOffset), aIndex);
+  if (*aIndex > 0) {
+    // There was at least one mapping with offset <= aSoftTextOffset. Step back
+    // to find the last element with |mSoftTextOffset <= aSoftTextOffset|.
+    *aIndex -= 1;
+  } else {
+    // Every mapping had offset greater than aSoftTextOffset.
+    MOZ_ASSERT(aContainer[*aIndex].mSoftTextOffset > aSoftTextOffset);
+  }
+  return true;
+}
+
+}  // namespace
+
+NodeOffset mozInlineSpellWordUtil::MapSoftTextOffsetToDOMPosition(
+    int32_t aSoftTextOffset, DOMMapHint aHint) const {
+  MOZ_ASSERT(mSoftText.mIsValid,
+             "Soft text must be valid if we're to map out of it");
+  if (!mSoftText.mIsValid) return NodeOffset(nullptr, -1);
+
+  // Find the last mapping, if any, such that mSoftTextOffset <= aSoftTextOffset
+  size_t index;
+  bool found = FindLastNongreaterOffset(mSoftText.GetDOMMapping(),
+                                        aSoftTextOffset, &index);
+  if (!found) {
+    return NodeOffset(nullptr, -1);
+  }
+
+  // 'index' is now the last mapping, if any, such that
+  // mSoftTextOffset <= aSoftTextOffset.
+  // If we're doing HINT_END, then we may want to return the end of the
+  // the previous mapping instead of the start of this mapping
+  if (aHint == HINT_END && index > 0) {
+    const DOMTextMapping& map = mSoftText.GetDOMMapping()[index - 1];
+    if (map.mSoftTextOffset + map.mLength == aSoftTextOffset)
+      return NodeOffset(map.mNodeOffset.mNode,
+                        map.mNodeOffset.mOffset + map.mLength);
+  }
+
+  // We allow ourselves to return the end of this mapping even if we're
+  // doing HINT_START. This will only happen if there is no mapping which this
+  // point is the start of. I'm not 100% sure this is OK...
+  const DOMTextMapping& map = mSoftText.GetDOMMapping()[index];
+  int32_t offset = aSoftTextOffset - map.mSoftTextOffset;
+  if (offset >= 0 && offset <= map.mLength)
+    return NodeOffset(map.mNodeOffset.mNode, map.mNodeOffset.mOffset + offset);
+
+  return NodeOffset(nullptr, -1);
+}
+
+// static
+void mozInlineSpellWordUtil::ToString(const DOMMapHint aHint,
+                                      nsACString& aResult) {
+  switch (aHint) {
+    case HINT_BEGIN:
+      aResult.AssignLiteral("begin");
+      break;
+    case HINT_END:
+      aResult.AssignLiteral("end");
+      break;
+  }
+}
+
+int32_t mozInlineSpellWordUtil::FindRealWordContaining(
+    int32_t aSoftTextOffset, DOMMapHint aHint, bool aSearchForward) const {
+  if (MOZ_LOG_TEST(sInlineSpellWordUtilLog, LogLevel::Debug)) {
+    nsAutoCString hint;
+    mozInlineSpellWordUtil::ToString(aHint, hint);
+
+    MOZ_LOG(
+        sInlineSpellWordUtilLog, LogLevel::Debug,
+        ("%s: offset=%i, hint=%s, searchForward=%i.", __FUNCTION__,
+         aSoftTextOffset, hint.get(), static_cast<int32_t>(aSearchForward)));
+  }
+
+  MOZ_ASSERT(mSoftText.mIsValid,
+             "Soft text must be valid if we're to map out of it");
+  if (!mSoftText.mIsValid) return -1;
+
+  // Find the last word, if any, such that mRealWords[index].mSoftTextOffset
+  // <= aSoftTextOffset
+  size_t index;
+  bool found = FindLastNongreaterOffset(mRealWords, aSoftTextOffset, &index);
+  if (!found) {
+    return -1;
+  }
+
+  // 'index' is now the last word, if any, such that
+  // mSoftTextOffset <= aSoftTextOffset.
+  // If we're doing HINT_END, then we may want to return the end of the
+  // the previous word instead of the start of this word
+  if (aHint == HINT_END && index > 0) {
+    const RealWord& word = mRealWords[index - 1];
+    if (word.EndOffset() == aSoftTextOffset) {
+      return index - 1;
+    }
+  }
+
+  // We allow ourselves to return the end of this word even if we're
+  // doing HINT_BEGIN. This will only happen if there is no word which this
+  // point is the start of. I'm not 100% sure this is OK...
+  const RealWord& word = mRealWords[index];
+  int32_t offset = aSoftTextOffset - word.mSoftTextOffset;
+  if (offset >= 0 && offset <= static_cast<int32_t>(word.mLength)) return index;
+
+  if (aSearchForward) {
+    if (mRealWords[0].mSoftTextOffset > aSoftTextOffset) {
+      // All words have mSoftTextOffset > aSoftTextOffset
+      return 0;
+    }
+    // 'index' is the last word such that mSoftTextOffset <= aSoftTextOffset.
+    // Word index+1, if it exists, will be the first with
+    // mSoftTextOffset > aSoftTextOffset.
+    if (index + 1 < mRealWords.Length()) return index + 1;
+  }
+
+  return -1;
+}
+
+// mozInlineSpellWordUtil::SplitDOMWordAndAppendTo
+
+nsresult mozInlineSpellWordUtil::SplitDOMWordAndAppendTo(
+    int32_t aStart, int32_t aEnd, nsTArray<RealWord>& aRealWords) const {
+  nsDependentSubstring targetText(mSoftText.GetValue(), aStart, aEnd - aStart);
+  WordSplitState<nsDependentSubstring> state(targetText);
+  state.mCurCharClass = state.ClassifyCharacter(0, true);
+
+  state.AdvanceThroughSeparators();
+  if (state.mCurCharClass != CHAR_CLASS_END_OF_INPUT && state.IsSpecialWord()) {
+    int32_t specialWordLength =
+        state.mDOMWordText.Length() - state.mDOMWordOffset;
+    if (!aRealWords.AppendElement(
+            RealWord(aStart + state.mDOMWordOffset, specialWordLength, false),
+            fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    return NS_OK;
+  }
+
+  while (state.mCurCharClass != CHAR_CLASS_END_OF_INPUT) {
+    state.AdvanceThroughSeparators();
+    if (state.mCurCharClass == CHAR_CLASS_END_OF_INPUT) break;
+
+    // save the beginning of the word
+    int32_t wordOffset = state.mDOMWordOffset;
+
+    // find the end of the word
+    state.AdvanceThroughWord();
+    int32_t wordLen = state.mDOMWordOffset - wordOffset;
+    if (!aRealWords.AppendElement(
+            RealWord(aStart + wordOffset, wordLen,
+                     !state.ShouldSkipWord(wordOffset, wordLen)),
+            fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+
+  return NS_OK;
+}