Adding upstream version 124.0.1.upstream/124.0.1

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

13 files changed, 2762 insertions, 0 deletions

diff --git a/toolkit/components/find/moz.build b/toolkit/components/find/moz.build
new file mode 100644
index 0000000000..af2ba59806
--- /dev/null
+++ b/toolkit/components/find/moz.build
@@ -0,0 +1,29 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Find Toolbar")
+
+XPIDL_SOURCES += [
+    "nsIFind.idl",
+    "nsIFindService.idl",
+    "nsIWebBrowserFind.idl",
+]
+
+XPIDL_MODULE = "mozfind"
+
+UNIFIED_SOURCES += [
+    "nsFind.cpp",
+    "nsWebBrowserFind.cpp",
+]
+
+SOURCES += [
+    "nsFindService.cpp",
+]
+
+MOCHITEST_MANIFESTS += ["test/mochitest/mochitest.toml"]
+
+FINAL_LIBRARY = "xul"
diff --git a/toolkit/components/find/nsFind.cpp b/toolkit/components/find/nsFind.cpp
new file mode 100644
index 0000000000..13745e7fbe
--- /dev/null
+++ b/toolkit/components/find/nsFind.cpp
@@ -0,0 +1,991 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+// #define DEBUG_FIND 1
+
+#include "nsFind.h"
+#include "mozilla/Likely.h"
+#include "nsContentCID.h"
+#include "nsIContent.h"
+#include "nsINode.h"
+#include "nsIFrame.h"
+#include "nsITextControlFrame.h"
+#include "nsIFormControl.h"
+#include "nsTextFragment.h"
+#include "nsString.h"
+#include "nsAtom.h"
+#include "nsServiceManagerUtils.h"
+#include "nsUnicharUtils.h"
+#include "nsUnicodeProperties.h"
+#include "nsCRT.h"
+#include "nsRange.h"
+#include "nsReadableUtils.h"
+#include "nsContentUtils.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/TextEditor.h"
+#include "mozilla/dom/ChildIterator.h"
+#include "mozilla/dom/TreeIterator.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLOptionElement.h"
+#include "mozilla/dom/HTMLSelectElement.h"
+#include "mozilla/dom/Text.h"
+#include "mozilla/intl/Segmenter.h"
+#include "mozilla/intl/UnicodeProperties.h"
+#include "mozilla/StaticPrefs_browser.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::unicode;
+
+// Yikes!  Casting a char to unichar can fill with ones!
+#define CHAR_TO_UNICHAR(c) ((char16_t)(unsigned char)c)
+
+#define CH_SHY ((char16_t)0xAD)
+
+// nsFind::Find casts CH_SHY to char before calling StripChars
+// This works correctly if and only if CH_SHY <= 255
+static_assert(CH_SHY <= 255, "CH_SHY is not an ascii character");
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsFind)
+  NS_INTERFACE_MAP_ENTRY(nsIFind)
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsFind)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsFind)
+
+NS_IMPL_CYCLE_COLLECTION(nsFind)
+
+#ifdef DEBUG_FIND
+#  define DEBUG_FIND_PRINTF(...) printf(__VA_ARGS__)
+#else
+#  define DEBUG_FIND_PRINTF(...) /* nothing */
+#endif
+
+static nsIContent& AnonymousSubtreeRootParentOrHost(const nsINode& aNode) {
+  MOZ_ASSERT(aNode.IsInNativeAnonymousSubtree());
+  return *aNode.GetClosestNativeAnonymousSubtreeRootParentOrHost();
+}
+
+static void DumpNode(const nsINode* aNode) {
+#ifdef DEBUG_FIND
+  if (!aNode) {
+    printf(">>>> Node: NULL\n");
+    return;
+  }
+  nsString nodeName = aNode->NodeName();
+  if (aNode->IsText()) {
+    nsAutoString newText;
+    aNode->AsText()->AppendTextTo(newText);
+    printf(">>>> Text node (node name %s): '%s'\n",
+           NS_LossyConvertUTF16toASCII(nodeName).get(),
+           NS_LossyConvertUTF16toASCII(newText).get());
+  } else {
+    printf(">>>> Node: %s\n", NS_LossyConvertUTF16toASCII(nodeName).get());
+  }
+#endif
+}
+
+static bool IsBlockNode(const nsIContent* aContent) {
+  if (aContent->IsElement() && aContent->AsElement()->IsDisplayContents()) {
+    return false;
+  }
+
+  // FIXME(emilio): This is dubious...
+  if (aContent->IsAnyOfHTMLElements(nsGkAtoms::img, nsGkAtoms::hr,
+                                    nsGkAtoms::th, nsGkAtoms::td)) {
+    return true;
+  }
+
+  nsIFrame* frame = aContent->GetPrimaryFrame();
+  if (!frame) {
+    return false;
+  }
+
+  const auto& disp = *frame->StyleDisplay();
+  // We also treat internal table frames as "blocks" for the purpose of
+  // locating boundaries for searches (see
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=1645990).
+  return disp.IsBlockOutsideStyle() || disp.IsInternalTableStyleExceptCell();
+}
+
+static bool IsDisplayedNode(const nsINode* aNode) {
+  if (!aNode->IsContent()) {
+    return false;
+  }
+
+  if (aNode->AsContent()->GetPrimaryFrame()) {
+    return true;
+  }
+
+  // If there's no frame, it's not displayed, unless it's display: contents.
+  return aNode->IsElement() && aNode->AsElement()->IsDisplayContents();
+}
+
+static bool IsRubyAnnotationNode(const nsINode* aNode) {
+  if (!aNode->IsContent()) {
+    return false;
+  }
+
+  nsIFrame* frame = aNode->AsContent()->GetPrimaryFrame();
+  if (!frame) {
+    return false;
+  }
+
+  StyleDisplay display = frame->StyleDisplay()->mDisplay;
+  return StyleDisplay::RubyText == display ||
+         StyleDisplay::RubyTextContainer == display;
+}
+
+static bool IsFindableNode(const nsINode* aNode) {
+  if (!IsDisplayedNode(aNode)) {
+    return false;
+  }
+
+  nsIFrame* frame = aNode->AsContent()->GetPrimaryFrame();
+  if (!frame) {
+    // display: contents
+    return true;
+  }
+
+  if (frame->StyleUI()->IsInert() ||
+      frame->HidesContent(nsIFrame::IncludeContentVisibility::Hidden) ||
+      frame->IsHiddenByContentVisibilityOnAnyAncestor(
+          nsIFrame::IncludeContentVisibility::Hidden)) {
+    return false;
+  }
+
+  return frame->StyleVisibility()->IsVisible();
+}
+
+static bool ShouldFindAnonymousContent(const nsIContent& aContent) {
+  MOZ_ASSERT(aContent.IsInNativeAnonymousSubtree());
+
+  nsIContent& host = AnonymousSubtreeRootParentOrHost(aContent);
+  if (nsCOMPtr<nsIFormControl> formControl = do_QueryInterface(&host)) {
+    if (formControl->IsTextControl(/* aExcludePassword = */ true)) {
+      // Only editable NAC in textfields should be findable. That is, we want to
+      // find "bar" in `<input value="bar">`, but not in `<input
+      // placeholder="bar">`.
+      //
+      // TODO(emilio): Ideally we could lift this restriction, but we hide the
+      // placeholder text at paint-time instead of with CSS visibility, which
+      // means that we won't skip it even if invisible. We should probably fix
+      // that.
+      return aContent.IsEditable();
+    }
+
+    // We want to avoid finding in password inputs anyway, as it is confusing.
+    if (formControl->ControlType() == FormControlType::InputPassword) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+static bool SkipNode(const nsIContent* aContent) {
+  const nsIContent* content = aContent;
+  while (content) {
+    if (!IsDisplayedNode(content) || content->IsComment() ||
+        content->IsAnyOfHTMLElements(nsGkAtoms::select)) {
+      DEBUG_FIND_PRINTF("Skipping node: ");
+      DumpNode(content);
+      return true;
+    }
+
+    // Skip option nodes if their select is a combo box, or if they
+    // have no select (somehow).
+    if (const auto* option = HTMLOptionElement::FromNode(content)) {
+      auto* select = HTMLSelectElement::FromNodeOrNull(option->GetParent());
+      if (!select || select->IsCombobox()) {
+        DEBUG_FIND_PRINTF("Skipping node: ");
+        DumpNode(content);
+        return true;
+      }
+    }
+
+    if (StaticPrefs::browser_find_ignore_ruby_annotations() &&
+        IsRubyAnnotationNode(content)) {
+      DEBUG_FIND_PRINTF("Skipping node: ");
+      DumpNode(content);
+      return true;
+    }
+
+    if (content->IsInNativeAnonymousSubtree() &&
+        !ShouldFindAnonymousContent(*content)) {
+      DEBUG_FIND_PRINTF("Skipping node: ");
+      DumpNode(content);
+      return true;
+    }
+
+    // Only climb to the nearest block node
+    if (IsBlockNode(content)) {
+      return false;
+    }
+
+    content = content->GetFlattenedTreeParent();
+  }
+
+  return false;
+}
+
+static const nsIContent* GetBlockParent(const Text& aNode) {
+  for (const nsIContent* current = aNode.GetFlattenedTreeParent(); current;
+       current = current->GetFlattenedTreeParent()) {
+    if (IsBlockNode(current)) {
+      return current;
+    }
+  }
+  return nullptr;
+}
+
+static bool NonTextNodeForcesBreak(const nsINode& aNode) {
+  nsIFrame* frame =
+      aNode.IsContent() ? aNode.AsContent()->GetPrimaryFrame() : nullptr;
+  // TODO(emilio): Maybe we should treat <br> more like a space instead of a
+  // forced break? Unclear...
+  return frame && frame->IsBrFrame();
+}
+
+static bool ForceBreakBetweenText(const Text& aPrevious, const Text& aNext) {
+  return GetBlockParent(aPrevious) != GetBlockParent(aNext);
+}
+
+struct nsFind::State final {
+  State(bool aFindBackward, nsIContent& aRoot, const nsRange& aStartPoint)
+      : mFindBackward(aFindBackward),
+        mInitialized(false),
+        mFoundBreak(false),
+        mIterOffset(-1),
+        mIterator(aRoot),
+        mStartPoint(aStartPoint) {}
+
+  void PositionAt(Text& aNode) { mIterator.Seek(aNode); }
+
+  bool ForcedBreak() const { return mFoundBreak; }
+
+  Text* GetCurrentNode() const {
+    if (MOZ_UNLIKELY(!mInitialized)) {
+      return nullptr;
+    }
+    nsINode* node = mIterator.GetCurrent();
+    MOZ_ASSERT(!node || node->IsText());
+    return node ? node->GetAsText() : nullptr;
+  }
+
+  Text* GetNextNode(bool aAlreadyMatching) {
+    if (MOZ_UNLIKELY(!mInitialized)) {
+      MOZ_ASSERT(!aAlreadyMatching);
+      Initialize();
+    } else {
+      Advance(Initializing::No, aAlreadyMatching);
+      mIterOffset = -1;  // mIterOffset only really applies to the first node.
+    }
+    return GetCurrentNode();
+  }
+
+ private:
+  enum class Initializing { No, Yes };
+
+  // Advance to the next visible text-node.
+  void Advance(Initializing, bool aAlreadyMatching);
+  // Sets up the first node position and offset.
+  void Initialize();
+
+  // Returns whether the node should be used (true) or skipped over (false)
+  static bool AnalyzeNode(const nsINode& aNode, const Text* aPrev,
+                          bool aAlreadyMatching, bool* aForcedBreak) {
+    if (!aNode.IsText()) {
+      *aForcedBreak = *aForcedBreak || NonTextNodeForcesBreak(aNode);
+      return false;
+    }
+    if (SkipNode(aNode.AsText())) {
+      return false;
+    }
+    *aForcedBreak = *aForcedBreak ||
+                    (aPrev && ForceBreakBetweenText(*aPrev, *aNode.AsText()));
+    if (*aForcedBreak) {
+      // If we've already found a break, we can stop searching and just use this
+      // node, regardless of the subtree we're on. There's no point to continue
+      // a match across different blocks, regardless of which subtree you're
+      // looking into.
+      return true;
+    }
+
+    // TODO(emilio): We can't represent ranges that span native anonymous /
+    // shadow tree boundaries, but if we did the following check could / should
+    // be removed.
+    if (aAlreadyMatching && aPrev &&
+        !nsContentUtils::IsInSameAnonymousTree(&aNode, aPrev)) {
+      // As an optimization, if we were finding inside an native-anonymous
+      // subtree (like a pseudo-element), we know those trees are "atomic" and
+      // can't have any other subtrees in between, so we can just break the
+      // match here.
+      if (aPrev->IsInNativeAnonymousSubtree()) {
+        *aForcedBreak = true;
+        return true;
+      }
+      // Otherwise we can skip the node and keep looking past this subtree.
+      return false;
+    }
+
+    return true;
+  }
+
+  const bool mFindBackward;
+
+  // Whether we've called GetNextNode() at least once.
+  bool mInitialized;
+
+ public:
+  // Whether we've found a forced break from the last node to the current one.
+  bool mFoundBreak;
+  // An offset into the text of the first node we're starting to search at.
+  int mIterOffset;
+  TreeIterator<StyleChildrenIterator> mIterator;
+
+  // These are only needed for the first GetNextNode() call.
+  const nsRange& mStartPoint;
+};
+
+void nsFind::State::Advance(Initializing aInitializing, bool aAlreadyMatching) {
+  MOZ_ASSERT(mInitialized);
+
+  // The Advance() call during Initialize() calls us in a partial state, where
+  // mIterator may not be pointing to a text node yet. aInitializing prevents
+  // tripping the invariants of GetCurrentNode().
+  const Text* prev =
+      aInitializing == Initializing::Yes ? nullptr : GetCurrentNode();
+  mFoundBreak = false;
+
+  while (true) {
+    nsIContent* current =
+        mFindBackward ? mIterator.GetPrev() : mIterator.GetNext();
+    if (!current) {
+      return;
+    }
+    if (AnalyzeNode(*current, prev, aAlreadyMatching, &mFoundBreak)) {
+      break;
+    }
+  }
+}
+
+void nsFind::State::Initialize() {
+  MOZ_ASSERT(!mInitialized);
+  mInitialized = true;
+  mIterOffset = mFindBackward ? -1 : 0;
+
+  nsINode* container = mFindBackward ? mStartPoint.GetStartContainer()
+                                     : mStartPoint.GetEndContainer();
+
+  // Set up ourselves at the first node we want to start searching at.
+  nsIContent* beginning = mFindBackward ? mStartPoint.GetChildAtStartOffset()
+                                        : mStartPoint.GetChildAtEndOffset();
+  if (beginning) {
+    mIterator.Seek(*beginning);
+    // If the start point is pointing to a node, when looking backwards we'd
+    // start looking at the children of that node, and we don't really want
+    // that. When looking forwards, we look at the next sibling afterwards.
+    if (mFindBackward) {
+      mIterator.GetPrevSkippingChildren();
+    }
+  } else if (container && container->IsContent()) {
+    // Text-only range, or pointing to past the end of the node, for example.
+    mIterator.Seek(*container->AsContent());
+  }
+
+  nsINode* current = mIterator.GetCurrent();
+  if (!current) {
+    return;
+  }
+
+  const bool kAlreadyMatching = false;
+  if (!AnalyzeNode(*current, nullptr, kAlreadyMatching, &mFoundBreak)) {
+    Advance(Initializing::Yes, kAlreadyMatching);
+    current = mIterator.GetCurrent();
+    if (!current) {
+      return;
+    }
+  }
+
+  if (current != container) {
+    return;
+  }
+
+  mIterOffset =
+      mFindBackward ? mStartPoint.StartOffset() : mStartPoint.EndOffset();
+}
+
+class MOZ_STACK_CLASS nsFind::StateRestorer final {
+ public:
+  explicit StateRestorer(State& aState)
+      : mState(aState),
+        mIterOffset(aState.mIterOffset),
+        mFoundBreak(aState.mFoundBreak),
+        mCurrNode(aState.GetCurrentNode()) {}
+
+  ~StateRestorer() {
+    mState.mFoundBreak = mFoundBreak;
+    mState.mIterOffset = mIterOffset;
+    if (mCurrNode) {
+      mState.PositionAt(*mCurrNode);
+    }
+  }
+
+ private:
+  State& mState;
+
+  int32_t mIterOffset;
+  bool mFoundBreak;
+  Text* mCurrNode;
+};
+
+NS_IMETHODIMP
+nsFind::GetFindBackwards(bool* aFindBackward) {
+  if (!aFindBackward) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  *aFindBackward = mFindBackward;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::SetFindBackwards(bool aFindBackward) {
+  mFindBackward = aFindBackward;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::GetCaseSensitive(bool* aCaseSensitive) {
+  if (!aCaseSensitive) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  *aCaseSensitive = mCaseSensitive;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::SetCaseSensitive(bool aCaseSensitive) {
+  mCaseSensitive = aCaseSensitive;
+  return NS_OK;
+}
+
+/* attribute boolean entireWord; */
+NS_IMETHODIMP
+nsFind::GetEntireWord(bool* aEntireWord) {
+  if (!aEntireWord) return NS_ERROR_NULL_POINTER;
+
+  *aEntireWord = mEntireWord;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::SetEntireWord(bool aEntireWord) {
+  mEntireWord = aEntireWord;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::GetMatchDiacritics(bool* aMatchDiacritics) {
+  if (!aMatchDiacritics) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  *aMatchDiacritics = mMatchDiacritics;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsFind::SetMatchDiacritics(bool aMatchDiacritics) {
+  mMatchDiacritics = aMatchDiacritics;
+  return NS_OK;
+}
+
+// Here begins the find code. A ten-thousand-foot view of how it works: Find
+// needs to be able to compare across inline (but not block) nodes, e.g. find
+// for "abc" should match a<b>b</b>c. So after we've searched a node, we're not
+// done with it; in the case of a partial match we may need to reset the
+// iterator to go back to a previously visited node, so we always save the
+// "match anchor" node and offset.
+//
+// Text nodes store their text in an nsTextFragment, which is effectively a
+// union of a one-byte string or a two-byte string. Single and double strings
+// are intermixed in the dom. We don't have string classes which can deal with
+// intermixed strings, so all the handling is done explicitly here.
+
+char32_t nsFind::DecodeChar(const char16_t* t2b, int32_t* index) const {
+  char32_t c = t2b[*index];
+  if (mFindBackward) {
+    if (*index >= 1 && NS_IS_SURROGATE_PAIR(t2b[*index - 1], t2b[*index])) {
+      c = SURROGATE_TO_UCS4(t2b[*index - 1], t2b[*index]);
+      (*index)--;
+    }
+  } else {
+    if (NS_IS_SURROGATE_PAIR(t2b[*index], t2b[*index + 1])) {
+      c = SURROGATE_TO_UCS4(t2b[*index], t2b[*index + 1]);
+      (*index)++;
+    }
+  }
+  return c;
+}
+
+bool nsFind::BreakInBetween(char32_t x, char32_t y) const {
+  nsAutoStringN<4> text;
+  AppendUCS4ToUTF16(x, text);
+  const uint32_t x16Len = text.Length();
+  AppendUCS4ToUTF16(y, text);
+
+  intl::WordBreakIteratorUtf16 iter(text);
+  return *iter.Seek(x16Len - 1) == x16Len;
+}
+
+char32_t nsFind::PeekNextChar(State& aState, bool aAlreadyMatching) const {
+  // We need to restore the necessary state before this function returns.
+  StateRestorer restorer(aState);
+
+  while (true) {
+    const Text* text = aState.GetNextNode(aAlreadyMatching);
+    if (!text || aState.ForcedBreak()) {
+      return L'\0';
+    }
+
+    const nsTextFragment& frag = text->TextFragment();
+    uint32_t len = frag.GetLength();
+    if (!len) {
+      continue;
+    }
+
+    const char16_t* t2b = nullptr;
+    const char* t1b = nullptr;
+
+    if (frag.Is2b()) {
+      t2b = frag.Get2b();
+    } else {
+      t1b = frag.Get1b();
+    }
+
+    int32_t index = mFindBackward ? len - 1 : 0;
+    return t1b ? CHAR_TO_UNICHAR(t1b[index]) : DecodeChar(t2b, &index);
+  }
+}
+
+#define NBSP_CHARCODE (CHAR_TO_UNICHAR(160))
+#define IsSpace(c) (nsCRT::IsAsciiSpace(c) || (c) == NBSP_CHARCODE)
+#define OVERFLOW_PINDEX (mFindBackward ? pindex < 0 : pindex > patLen)
+#define DONE_WITH_PINDEX (mFindBackward ? pindex <= 0 : pindex >= patLen)
+
+// Take nodes out of the tree with NextNode, until null (NextNode will return 0
+// at the end of our range).
+NS_IMETHODIMP
+nsFind::Find(const nsAString& aPatText, nsRange* aSearchRange,
+             nsRange* aStartPoint, nsRange* aEndPoint, nsRange** aRangeRet) {
+  DEBUG_FIND_PRINTF("============== nsFind::Find('%s'%s, %p, %p, %p)\n",
+                    NS_LossyConvertUTF16toASCII(aPatText).get(),
+                    mFindBackward ? " (backward)" : " (forward)",
+                    (void*)aSearchRange, (void*)aStartPoint, (void*)aEndPoint);
+
+  NS_ENSURE_ARG(aSearchRange);
+  NS_ENSURE_ARG(aStartPoint);
+  NS_ENSURE_ARG(aEndPoint);
+  NS_ENSURE_ARG_POINTER(aRangeRet);
+
+  Document* document =
+      aStartPoint->GetRoot() ? aStartPoint->GetRoot()->OwnerDoc() : nullptr;
+  NS_ENSURE_ARG(document);
+
+  Element* root = document->GetRootElement();
+  NS_ENSURE_ARG(root);
+
+  *aRangeRet = 0;
+
+  nsAutoString patAutoStr(aPatText);
+  if (!mCaseSensitive) {
+    ToFoldedCase(patAutoStr);
+  }
+  if (!mMatchDiacritics) {
+    ToNaked(patAutoStr);
+  }
+
+  // Ignore soft hyphens in the pattern
+  static const char16_t kShy[] = {CH_SHY, 0};
+  patAutoStr.StripChars(kShy);
+
+  const char16_t* patStr = patAutoStr.get();
+  int32_t patLen = patAutoStr.Length() - 1;
+
+  // If this function is called with an empty string, we should early exit.
+  if (patLen < 0) {
+    return NS_OK;
+  }
+
+  const int32_t patternStart = mFindBackward ? patLen : 0;
+
+  // current offset into the pattern -- reset to beginning/end:
+  int32_t pindex = patternStart;
+
+  // Current offset into the fragment
+  int32_t findex = 0;
+
+  // Direction to move pindex and ptr*
+  int incr = mFindBackward ? -1 : 1;
+
+  const nsTextFragment* frag = nullptr;
+  int32_t fragLen = 0;
+
+  // Pointers into the current fragment:
+  const char16_t* t2b = nullptr;
+  const char* t1b = nullptr;
+
+  // Keep track of when we're in whitespace:
+  // (only matters when we're matching)
+  bool inWhitespace = false;
+
+  // Place to save the range start point in case we find a match:
+  Text* matchAnchorNode = nullptr;
+  int32_t matchAnchorOffset = 0;
+  char32_t matchAnchorChar = 0;
+
+  // Get the end point, so we know when to end searches:
+  nsINode* endNode = aEndPoint->GetEndContainer();
+  uint32_t endOffset = aEndPoint->EndOffset();
+
+  char32_t c = 0;
+  char32_t patc = 0;
+  char32_t prevCharInMatch = 0;
+
+  State state(mFindBackward, *root, *aStartPoint);
+  Text* current = nullptr;
+
+  auto EndPartialMatch = [&]() -> bool {
+    // If we didn't match, go back to the beginning of patStr, and set findex
+    // back to the next char after we started the current match.
+    //
+    // There's no need to do this if we're still at the beginning of the pattern
+    // (this can happen e.g. with whitespace, and prevents exponential
+    // complexity when scanning a pattern that starts with whitespace).
+    const bool restart = !!matchAnchorNode && pindex != patternStart;
+    if (restart) {  // we're ending a partial match
+      findex = matchAnchorOffset;
+      state.mIterOffset = matchAnchorOffset;
+      c = matchAnchorChar;
+      // +incr will be added to findex when we continue
+
+      // Are we going back to a previous node?
+      if (matchAnchorNode != state.GetCurrentNode()) {
+        frag = nullptr;
+        state.PositionAt(*matchAnchorNode);
+        DEBUG_FIND_PRINTF("Repositioned anchor node\n");
+      }
+      DEBUG_FIND_PRINTF(
+          "Ending a partial match; findex -> %d, mIterOffset -> %d\n", findex,
+          state.mIterOffset);
+    }
+    matchAnchorNode = nullptr;
+    matchAnchorOffset = 0;
+    matchAnchorChar = 0;
+    inWhitespace = false;
+    prevCharInMatch = 0;
+    pindex = patternStart;
+    DEBUG_FIND_PRINTF("Setting findex back to %d, pindex to %d\n", findex,
+                      pindex);
+    return restart;
+  };
+
+  while (true) {
+    DEBUG_FIND_PRINTF("Loop (pindex = %d)...\n", pindex);
+
+    // If this is our first time on a new node, reset the pointers:
+    if (!frag) {
+      current = state.GetNextNode(!!matchAnchorNode);
+      if (!current) {
+        DEBUG_FIND_PRINTF("Reached the end, matching: %d\n", !!matchAnchorNode);
+        if (EndPartialMatch()) {
+          continue;
+        }
+        return NS_OK;
+      }
+
+      // We have a new text content. See if we need to force a break due to
+      // <br>, different blocks or what not.
+      if (state.ForcedBreak()) {
+        DEBUG_FIND_PRINTF("Forced break!\n");
+        if (EndPartialMatch()) {
+          continue;
+        }
+        // This ensures word breaking thinks it has a new word, which is
+        // effectively what we want.
+        c = 0;
+      }
+
+      frag = &current->TextFragment();
+      fragLen = frag->GetLength();
+
+      // Set our starting point in this node. If we're going back to the anchor
+      // node, which means that we just ended a partial match, use the saved
+      // offset:
+      //
+      // FIXME(emilio): How could current ever be the anchor node, if we had not
+      // seen current so far?
+      if (current == matchAnchorNode) {
+        findex = matchAnchorOffset + (mFindBackward ? 1 : 0);
+      } else if (state.mIterOffset >= 0) {
+        findex = state.mIterOffset - (mFindBackward ? 1 : 0);
+      } else {
+        findex = mFindBackward ? (fragLen - 1) : 0;
+      }
+
+      // Offset can only apply to the first node:
+      state.mIterOffset = -1;
+
+      DEBUG_FIND_PRINTF("Starting from offset %d of %d\n", findex, fragLen);
+
+      // If this is outside the bounds of the string, then skip this node:
+      if (findex < 0 || findex > fragLen - 1) {
+        DEBUG_FIND_PRINTF(
+            "At the end of a text node -- skipping to the next\n");
+        frag = nullptr;
+        continue;
+      }
+
+      if (frag->Is2b()) {
+        t2b = frag->Get2b();
+        t1b = nullptr;
+#ifdef DEBUG_FIND
+        nsAutoString str2(t2b, fragLen);
+        DEBUG_FIND_PRINTF("2 byte, '%s'\n",
+                          NS_LossyConvertUTF16toASCII(str2).get());
+#endif
+      } else {
+        t1b = frag->Get1b();
+        t2b = nullptr;
+#ifdef DEBUG_FIND
+        nsAutoCString str1(t1b, fragLen);
+        DEBUG_FIND_PRINTF("1 byte, '%s'\n", str1.get());
+#endif
+      }
+    } else {
+      // Still on the old node. Advance the pointers, then see if we need to
+      // pull a new node.
+      findex += incr;
+      DEBUG_FIND_PRINTF("Same node -- (%d, %d)\n", pindex, findex);
+      if (mFindBackward ? (findex < 0) : (findex >= fragLen)) {
+        DEBUG_FIND_PRINTF(
+            "Will need to pull a new node: mAO = %d, frag len=%d\n",
+            matchAnchorOffset, fragLen);
+        // Done with this node.  Pull a new one.
+        frag = nullptr;
+        continue;
+      }
+    }
+
+    // Have we gone past the endpoint yet? If we have, and we're not in the
+    // middle of a match, return.
+    if (state.GetCurrentNode() == endNode &&
+        ((mFindBackward && findex < static_cast<int32_t>(endOffset)) ||
+         (!mFindBackward && findex > static_cast<int32_t>(endOffset)))) {
+      DEBUG_FIND_PRINTF("Reached the end and not in the middle of a match\n");
+      return NS_OK;
+    }
+
+    // Save the previous character for word boundary detection
+    char32_t prevChar = c;
+    // The two characters we'll be comparing are c and patc. If not matching
+    // diacritics, don't leave c set to a combining diacritical mark. (patc is
+    // already guaranteed to not be a combining diacritical mark.)
+    c = (t2b ? DecodeChar(t2b, &findex) : CHAR_TO_UNICHAR(t1b[findex]));
+    if (!mMatchDiacritics && IsCombiningDiacritic(c) &&
+        !intl::UnicodeProperties::IsMathOrMusicSymbol(prevChar)) {
+      continue;
+    }
+    patc = DecodeChar(patStr, &pindex);
+
+    DEBUG_FIND_PRINTF(
+        "Comparing '%c'=%#x to '%c'=%#x (%d of %d), findex=%d%s\n", (char)c,
+        (int)c, (char)patc, (int)patc, pindex, patLen, findex,
+        inWhitespace ? " (inWhitespace)" : "");
+
+    // Do we need to go back to non-whitespace mode? If inWhitespace, then this
+    // space in the pat str has already matched at least one space in the
+    // document.
+    if (inWhitespace && !IsSpace(c)) {
+      inWhitespace = false;
+      pindex += incr;
+#ifdef DEBUG
+      // This shouldn't happen -- if we were still matching, and we were at the
+      // end of the pat string, then we should have caught it in the last
+      // iteration and returned success.
+      if (OVERFLOW_PINDEX) {
+        NS_ASSERTION(false, "Missed a whitespace match");
+      }
+#endif
+      patc = DecodeChar(patStr, &pindex);
+    }
+    if (!inWhitespace && IsSpace(patc)) {
+      inWhitespace = true;
+    } else if (!inWhitespace) {
+      if (!mCaseSensitive) {
+        c = ToFoldedCase(c);
+      }
+      if (!mMatchDiacritics) {
+        c = ToNaked(c);
+      }
+    }
+
+    if (c == CH_SHY) {
+      // ignore soft hyphens in the document
+      continue;
+    }
+
+    if (pindex != patternStart && c != patc && !inWhitespace) {
+      // A non-matching '\n' between CJ characters is ignored
+      if (c == '\n' && t2b && IS_CJ_CHAR(prevCharInMatch)) {
+        int32_t nindex = findex + incr;
+        if (mFindBackward ? (nindex >= 0) : (nindex < fragLen)) {
+          if (IS_CJ_CHAR(t2b[nindex])) {
+            continue;
+          }
+        }
+      }
+
+      // We also ignore ZWSP and other default-ignorable characters.
+      if (IsDefaultIgnorable(c)) {
+        continue;
+      }
+    }
+
+    // Figure whether the previous char is a word-breaking one,
+    // if we care about word boundaries.
+    bool wordBreakPrev = true;
+    if (mEntireWord && prevChar) {
+      if (prevChar == NBSP_CHARCODE) {
+        prevChar = CHAR_TO_UNICHAR(' ');
+      }
+      wordBreakPrev = BreakInBetween(prevChar, c);
+    }
+
+    // Compare. Match if we're in whitespace and c is whitespace, or if the
+    // characters match and at least one of the following is true:
+    // a) we're not matching the entire word
+    // b) a match has already been stored
+    // c) the previous character is a different "class" than the current
+    // character.
+    if ((c == patc && (!mEntireWord || matchAnchorNode || wordBreakPrev)) ||
+        (inWhitespace && IsSpace(c))) {
+      prevCharInMatch = c;
+      if (inWhitespace) {
+        DEBUG_FIND_PRINTF("YES (whitespace)(%d of %d)\n", pindex, patLen);
+      } else {
+        DEBUG_FIND_PRINTF("YES! '%c' == '%c' (%d of %d)\n", c, patc, pindex,
+                          patLen);
+      }
+
+      // Save the range anchors if we haven't already:
+      if (!matchAnchorNode) {
+        matchAnchorNode = state.GetCurrentNode();
+        matchAnchorOffset = findex;
+        if (!IS_IN_BMP(c)) {
+          matchAnchorOffset -= incr;
+        }
+        matchAnchorChar = c;
+      }
+
+      // Are we done?
+      if (DONE_WITH_PINDEX) {
+        // Matched the whole string!
+        DEBUG_FIND_PRINTF("Found a match!\n");
+
+        // Make the range:
+        // Check for word break (if necessary)
+        if (mEntireWord || inWhitespace) {
+          int32_t nextfindex = findex + incr;
+
+          char32_t nextChar;
+          // If still in array boundaries, get nextChar.
+          if (mFindBackward ? (nextfindex >= 0) : (nextfindex < fragLen)) {
+            if (t2b) {
+              nextChar = DecodeChar(t2b, &nextfindex);
+            } else {
+              nextChar = CHAR_TO_UNICHAR(t1b[nextfindex]);
+            }
+          } else {
+            // Get next character from the next node.
+            nextChar = PeekNextChar(state, !!matchAnchorNode);
+          }
+
+          if (nextChar == NBSP_CHARCODE) {
+            nextChar = CHAR_TO_UNICHAR(' ');
+          }
+
+          // If a word break isn't there when it needs to be, reset search.
+          if (mEntireWord && nextChar && !BreakInBetween(c, nextChar)) {
+            matchAnchorNode = nullptr;
+            continue;
+          }
+
+          if (inWhitespace && IsSpace(nextChar)) {
+            // If the next character is also an space, keep going, this space
+            // will collapse.
+            continue;
+          }
+        }
+
+        int32_t matchStartOffset;
+        int32_t matchEndOffset;
+        // convert char index to range point:
+        int32_t mao = matchAnchorOffset + (mFindBackward ? 1 : 0);
+        Text* startParent;
+        Text* endParent;
+        if (mFindBackward) {
+          startParent = current;
+          endParent = matchAnchorNode;
+          matchStartOffset = findex;
+          matchEndOffset = mao;
+        } else {
+          startParent = matchAnchorNode;
+          endParent = current;
+          matchStartOffset = mao;
+          matchEndOffset = findex + 1;
+        }
+
+        RefPtr<nsRange> range = nsRange::Create(current);
+        if (startParent && endParent && IsFindableNode(startParent) &&
+            IsFindableNode(endParent)) {
+          IgnoredErrorResult rv;
+          range->SetStart(*startParent, matchStartOffset, rv);
+          if (!rv.Failed()) {
+            range->SetEnd(*endParent, matchEndOffset, rv);
+          }
+          if (!rv.Failed()) {
+            range.forget(aRangeRet);
+            return NS_OK;
+          }
+        }
+
+        // This match is no good, continue on in document
+        matchAnchorNode = nullptr;
+      }
+
+      if (matchAnchorNode) {
+        // Not done, but still matching. Advance and loop around for the next
+        // characters. But don't advance from a space to a non-space:
+        if (!inWhitespace || DONE_WITH_PINDEX ||
+            IsSpace(patStr[pindex + incr])) {
+          pindex += incr;
+          inWhitespace = false;
+          DEBUG_FIND_PRINTF("Advancing pindex to %d\n", pindex);
+        }
+
+        continue;
+      }
+    }
+
+    DEBUG_FIND_PRINTF("NOT: %c == %c\n", c, patc);
+    EndPartialMatch();
+  }
+}
diff --git a/toolkit/components/find/nsFind.h b/toolkit/components/find/nsFind.h
new file mode 100644
index 0000000000..bf431a2d2f
--- /dev/null
+++ b/toolkit/components/find/nsFind.h
@@ -0,0 +1,62 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef nsFind_h__
+#define nsFind_h__
+
+#include "nsIFind.h"
+
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsINode.h"
+
+#define NS_FIND_CONTRACTID "@mozilla.org/embedcomp/rangefind;1"
+
+#define NS_FIND_CID                                  \
+  {                                                  \
+    0x471f4944, 0x1dd2, 0x11b2, {                    \
+      0x87, 0xac, 0x90, 0xbe, 0x0a, 0x51, 0xd6, 0x09 \
+    }                                                \
+  }
+
+class nsFind : public nsIFind {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_NSIFIND
+  NS_DECL_CYCLE_COLLECTION_CLASS(nsFind)
+
+ protected:
+  virtual ~nsFind() = default;
+
+  // Parameters set from the interface:
+  bool mFindBackward = false;
+  bool mCaseSensitive = false;
+  bool mMatchDiacritics = false;
+
+  // Use "find entire words" mode by setting mEntireWord to true; or false to
+  // disable "entire words" mode.
+  bool mEntireWord = false;
+
+  struct State;
+  class StateRestorer;
+
+  // Extract a character from a string, handling surrogate pairs and
+  // incrementing the index if a surrogate pair is encountered
+  char32_t DecodeChar(const char16_t* t2b, int32_t* index) const;
+
+  // Determine if a line break can occur between two characters
+  //
+  // This could be improved because some languages require more context than two
+  // characters to determine where line breaks can occur
+  bool BreakInBetween(char32_t x, char32_t y) const;
+
+  // Get the first character from the next node (last if mFindBackward).
+  //
+  // This will mutate the state, but then restore it afterwards.
+  char32_t PeekNextChar(State&, bool aAlreadyMatching) const;
+};
+
+#endif  // nsFind_h__
diff --git a/toolkit/components/find/nsFindService.cpp b/toolkit/components/find/nsFindService.cpp
new file mode 100644
index 0000000000..7499132c2c
--- /dev/null
+++ b/toolkit/components/find/nsFindService.cpp
@@ -0,0 +1,91 @@
+/* -*- 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/. */
+
+/*
+ * The sole purpose of the Find service is to store globally the
+ * last used Find settings
+ *
+ */
+
+#include "nsFindService.h"
+
+nsFindService::nsFindService()
+    : mFindBackwards(false),
+      mWrapFind(true),
+      mEntireWord(false),
+      mMatchCase(false) {}
+
+nsFindService::~nsFindService() = default;
+
+NS_IMPL_ISUPPORTS(nsFindService, nsIFindService)
+
+NS_IMETHODIMP nsFindService::GetSearchString(nsAString& aSearchString) {
+  aSearchString = mSearchString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::SetSearchString(const nsAString& aSearchString) {
+  mSearchString = aSearchString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetReplaceString(nsAString& aReplaceString) {
+  aReplaceString = mReplaceString;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetReplaceString(const nsAString& aReplaceString) {
+  mReplaceString = aReplaceString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetFindBackwards(bool* aFindBackwards) {
+  NS_ENSURE_ARG_POINTER(aFindBackwards);
+  *aFindBackwards = mFindBackwards;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetFindBackwards(bool aFindBackwards) {
+  mFindBackwards = aFindBackwards;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetWrapFind(bool* aWrapFind) {
+  NS_ENSURE_ARG_POINTER(aWrapFind);
+  *aWrapFind = mWrapFind;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetWrapFind(bool aWrapFind) {
+  mWrapFind = aWrapFind;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetEntireWord(bool* aEntireWord) {
+  NS_ENSURE_ARG_POINTER(aEntireWord);
+  *aEntireWord = mEntireWord;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetEntireWord(bool aEntireWord) {
+  mEntireWord = aEntireWord;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetMatchCase(bool* aMatchCase) {
+  NS_ENSURE_ARG_POINTER(aMatchCase);
+  *aMatchCase = mMatchCase;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetMatchCase(bool aMatchCase) {
+  mMatchCase = aMatchCase;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsFindService::GetMatchDiacritics(bool* aMatchDiacritics) {
+  NS_ENSURE_ARG_POINTER(aMatchDiacritics);
+  *aMatchDiacritics = mMatchDiacritics;
+  return NS_OK;
+}
+NS_IMETHODIMP nsFindService::SetMatchDiacritics(bool aMatchDiacritics) {
+  mMatchDiacritics = aMatchDiacritics;
+  return NS_OK;
+}
diff --git a/toolkit/components/find/nsFindService.h b/toolkit/components/find/nsFindService.h
new file mode 100644
index 0000000000..5204076f5d
--- /dev/null
+++ b/toolkit/components/find/nsFindService.h
@@ -0,0 +1,44 @@
+/* -*- 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/. */
+
+/*
+ * The sole purpose of the Find service is to store globally the
+ * last used Find settings
+ *
+ */
+
+#include "nsString.h"
+
+#include "nsIFindService.h"
+
+// {5060b803-340e-11d5-be5b-b3e063ec6a3c}
+#define NS_FIND_SERVICE_CID                          \
+  {                                                  \
+    0x5060b803, 0x340e, 0x11d5, {                    \
+      0xbe, 0x5b, 0xb3, 0xe0, 0x63, 0xec, 0x6a, 0x3c \
+    }                                                \
+  }
+
+#define NS_FIND_SERVICE_CONTRACTID "@mozilla.org/find/find_service;1"
+
+class nsFindService : public nsIFindService {
+ public:
+  nsFindService();
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIFINDSERVICE
+
+ protected:
+  virtual ~nsFindService();
+
+  nsString mSearchString;
+  nsString mReplaceString;
+
+  bool mFindBackwards;
+  bool mWrapFind;
+  bool mEntireWord;
+  bool mMatchCase;
+  bool mMatchDiacritics;
+};
diff --git a/toolkit/components/find/nsIFind.idl b/toolkit/components/find/nsIFind.idl
new file mode 100644
index 0000000000..1e8016514b
--- /dev/null
+++ b/toolkit/components/find/nsIFind.idl
@@ -0,0 +1,34 @@
+/* -*- 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 "nsISupports.idl"
+
+webidl Range;
+
+[scriptable, uuid(40aba110-2a56-4678-be90-e2c17a9ae7d7)]
+interface nsIFind : nsISupports
+{
+  attribute boolean findBackwards;
+  attribute boolean caseSensitive;
+  attribute boolean entireWord;
+  attribute boolean matchDiacritics;
+
+  /**
+   * Find some text in the current context. The implementation is
+   * responsible for performing the find and highlighting the text.
+   *
+   * @param aPatText     The text to search for.
+   * @param aSearchRange A Range specifying domain of search.
+   * @param aStartPoint  A Range specifying search start point.
+   *                     If not collapsed, we'll start from
+   *                     end (forward) or start (backward).
+   * @param aEndPoint    A Range specifying search end point.
+   *                     If not collapsed, we'll end at
+   *                     end (forward) or start (backward).
+   * @retval             A range spanning the match that was found (or null).
+   */
+  Range Find(in AString aPatText, in Range aSearchRange,
+             in Range aStartPoint, in Range aEndPoint);
+};
diff --git a/toolkit/components/find/nsIFindService.idl b/toolkit/components/find/nsIFindService.idl
new file mode 100644
index 0000000000..f5a5e18ce6
--- /dev/null
+++ b/toolkit/components/find/nsIFindService.idl
@@ -0,0 +1,27 @@
+/* -*- 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 "nsISupports.idl"
+
+[scriptable, uuid(5060b801-340e-11d5-be5b-b3e063ec6a3c)]
+interface nsIFindService : nsISupports
+{
+
+    /*
+     * The sole purpose of the Find service is to store globally the
+     * last used Find settings
+     *
+     */
+
+    attribute AString searchString;
+    attribute AString replaceString;
+
+    attribute boolean findBackwards;
+    attribute boolean wrapFind;
+    attribute boolean entireWord;
+    attribute boolean matchCase;
+    attribute boolean matchDiacritics;
+
+};
diff --git a/toolkit/components/find/nsIWebBrowserFind.idl b/toolkit/components/find/nsIWebBrowserFind.idl
new file mode 100644
index 0000000000..f06941329c
--- /dev/null
+++ b/toolkit/components/find/nsIWebBrowserFind.idl
@@ -0,0 +1,152 @@
+/* -*- Mode: IDL; tab-width: 4; 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 "nsISupports.idl"
+
+#include "domstubs.idl"
+
+interface mozIDOMWindowProxy;
+
+/* THIS IS A PUBLIC EMBEDDING API */
+
+
+/**
+ * nsIWebBrowserFind
+ *
+ * Searches for text in a web browser.
+ *
+ * Get one by doing a GetInterface on an nsIWebBrowser.
+ *
+ * By default, the implementation will search the focussed frame, or
+ * if there is no focussed frame, the web browser content area. It
+ * does not by default search subframes or iframes. To change this
+ * behaviour, and to explicitly set the frame to search,
+ * QueryInterface to nsIWebBrowserFindInFrames.
+ */
+
+[scriptable, uuid(e4920136-b3e0-49e0-b1cd-6c783d2591a8)]
+interface nsIWebBrowserFind : nsISupports
+{
+    /**
+     * findNext
+     *
+     * Finds, highlights, and scrolls into view the next occurrence of the
+     * search string, using the current search settings. Fails if the
+     * search string is empty.
+     *
+     * @return  Whether an occurrence was found
+     */
+    boolean findNext();
+
+    /**
+     * searchString
+     *
+     * The string to search for. This must be non-empty to search.
+     */
+    attribute AString searchString;
+
+    /**
+     * findBackwards
+     *
+     * Whether to find backwards (towards the beginning of the document).
+     * Default is false (search forward).
+     */
+    attribute boolean findBackwards;
+
+    /**
+     * wrapFind
+     *
+     * Whether the search wraps around to the start (or end) of the document
+     * if no match was found between the current position and the end (or
+     * beginning). Works correctly when searching backwards. Default is
+     * false.
+     */
+    attribute boolean wrapFind;
+
+    /**
+     * entireWord
+     *
+     * Whether to match entire words only. Default is false.
+     */
+    attribute boolean entireWord;
+
+    /**
+     * matchCase
+     *
+     * Whether to match case (case sensitive) when searching. Default is false.
+     */
+    attribute boolean matchCase;
+
+    /**
+     * matchDiacritics
+     *
+     * Whether to match diacritics when searching. Default is false.
+     */
+    attribute boolean matchDiacritics;
+
+    /**
+     * searchFrames
+     *
+     * Whether to search through all frames in the content area. Default is true.
+     *
+     * Note that you can control whether the search propagates into child or
+     * parent frames explicitly using nsIWebBrowserFindInFrames, but if one,
+     * but not both, of searchSubframes and searchParentFrames are set, this
+     * returns false.
+     */
+    attribute boolean searchFrames;
+};
+
+
+
+/**
+ * nsIWebBrowserFindInFrames
+ *
+ * Controls how find behaves when multiple frames or iframes are present.
+ *
+ * Get by doing a QueryInterface from nsIWebBrowserFind.
+ */
+
+[scriptable, uuid(e0f5d182-34bc-11d5-be5b-b760676c6ebc)]
+interface nsIWebBrowserFindInFrames : nsISupports
+{
+    /**
+     * currentSearchFrame
+     *
+     * Frame at which to start the search. Once the search is done, this will
+     * be set to be the last frame searched, whether or not a result was found.
+     * Has to be equal to or contained within the rootSearchFrame.
+     */
+    attribute mozIDOMWindowProxy  currentSearchFrame;
+
+    /**
+     * rootSearchFrame
+     *
+     * Frame within which to confine the search (normally the content area frame).
+     * Set this to only search a subtree of the frame hierarchy.
+     */
+    attribute mozIDOMWindowProxy  rootSearchFrame;
+
+    /**
+     * searchSubframes
+     *
+     * Whether to recurse down into subframes while searching. Default is true.
+     *
+     * Setting nsIWebBrowserfind.searchFrames to true sets this to true.
+     */
+    attribute boolean searchSubframes;
+
+    /**
+     * searchParentFrames
+     *
+     * Whether to allow the search to propagate out of the currentSearchFrame into its
+     * parent frame(s). Search is always confined within the rootSearchFrame. Default
+     * is true.
+     *
+     * Setting nsIWebBrowserfind.searchFrames to true sets this to true.
+     */
+    attribute boolean searchParentFrames;
+
+};
diff --git a/toolkit/components/find/nsWebBrowserFind.cpp b/toolkit/components/find/nsWebBrowserFind.cpp
new file mode 100644
index 0000000000..2e06f65fc8
--- /dev/null
+++ b/toolkit/components/find/nsWebBrowserFind.cpp
@@ -0,0 +1,764 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsWebBrowserFind.h"
+
+// Only need this for NS_FIND_CONTRACTID,
+// else we could use nsRange.h and nsIFind.h.
+#include "nsFind.h"
+
+#include "mozilla/dom/ScriptSettings.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsPIDOMWindow.h"
+#include "nsIDocShell.h"
+#include "nsPresContext.h"
+#include "mozilla/dom/Document.h"
+#include "nsISelectionController.h"
+#include "nsIFrame.h"
+#include "nsITextControlFrame.h"
+#include "nsReadableUtils.h"
+#include "nsIContent.h"
+#include "nsContentCID.h"
+#include "nsIObserverService.h"
+#include "nsISupportsPrimitives.h"
+#include "nsFind.h"
+#include "nsError.h"
+#include "nsFocusManager.h"
+#include "nsRange.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/Services.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/Selection.h"
+#include "nsISimpleEnumerator.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentUtils.h"
+#include "nsGenericHTMLElement.h"
+
+#if DEBUG
+#  include "nsIWebNavigation.h"
+#  include "nsString.h"
+#endif
+
+using namespace mozilla;
+using mozilla::dom::Document;
+using mozilla::dom::Element;
+using mozilla::dom::Selection;
+
+nsWebBrowserFind::nsWebBrowserFind()
+    : mFindBackwards(false),
+      mWrapFind(false),
+      mEntireWord(false),
+      mMatchCase(false),
+      mMatchDiacritics(false),
+      mSearchSubFrames(true),
+      mSearchParentFrames(true) {}
+
+nsWebBrowserFind::~nsWebBrowserFind() = default;
+
+NS_IMPL_ISUPPORTS(nsWebBrowserFind, nsIWebBrowserFind,
+                  nsIWebBrowserFindInFrames)
+
+NS_IMETHODIMP
+nsWebBrowserFind::FindNext(bool* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = false;
+
+  NS_ENSURE_TRUE(CanFindNext(), NS_ERROR_NOT_INITIALIZED);
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsPIDOMWindowOuter> searchFrame =
+      do_QueryReferent(mCurrentSearchFrame);
+  NS_ENSURE_TRUE(searchFrame, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsPIDOMWindowOuter> rootFrame = do_QueryReferent(mRootSearchFrame);
+  NS_ENSURE_TRUE(rootFrame, NS_ERROR_NOT_INITIALIZED);
+
+  // first, if there's a "cmd_findagain" observer around, check to see if it
+  // wants to perform the find again command . If it performs the find again
+  // it will return true, in which case we exit ::FindNext() early.
+  // Otherwise, nsWebBrowserFind needs to perform the find again command itself
+  // this is used by nsTypeAheadFind, which controls find again when it was
+  // the last executed find in the current window.
+  nsCOMPtr<nsIObserverService> observerSvc =
+      mozilla::services::GetObserverService();
+  if (observerSvc) {
+    nsCOMPtr<nsISupportsInterfacePointer> windowSupportsData =
+        do_CreateInstance(NS_SUPPORTS_INTERFACE_POINTER_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsCOMPtr<nsISupports> searchWindowSupports = do_QueryInterface(rootFrame);
+    windowSupportsData->SetData(searchWindowSupports);
+    observerSvc->NotifyObservers(windowSupportsData,
+                                 "nsWebBrowserFind_FindAgain",
+                                 mFindBackwards ? u"up" : u"down");
+    windowSupportsData->GetData(getter_AddRefs(searchWindowSupports));
+    // findnext performed if search window data cleared out
+    *aResult = searchWindowSupports == nullptr;
+    if (*aResult) {
+      return NS_OK;
+    }
+  }
+
+  // next, look in the current frame. If found, return.
+
+  // Beware! This may flush notifications via synchronous
+  // ScrollSelectionIntoView.
+  rv = SearchInFrame(searchFrame, false, aResult);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  if (*aResult) {
+    return OnFind(searchFrame);  // we are done
+  }
+
+  // if we are not searching other frames, return
+  if (!mSearchSubFrames && !mSearchParentFrames) {
+    return NS_OK;
+  }
+
+  nsIDocShell* rootDocShell = rootFrame->GetDocShell();
+  if (!rootDocShell) {
+    return NS_ERROR_FAILURE;
+  }
+
+  auto enumDirection = mFindBackwards ? nsIDocShell::ENUMERATE_BACKWARDS
+                                      : nsIDocShell::ENUMERATE_FORWARDS;
+
+  nsTArray<RefPtr<nsIDocShell>> docShells;
+  rv = rootDocShell->GetAllDocShellsInSubtree(nsIDocShellTreeItem::typeAll,
+                                              enumDirection, docShells);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // remember where we started
+  nsCOMPtr<nsIDocShellTreeItem> startingItem = searchFrame->GetDocShell();
+
+  // XXX We should avoid searching in frameset documents here.
+  // We also need to honour mSearchSubFrames and mSearchParentFrames.
+  bool doFind = false;
+  for (const auto& curItem : docShells) {
+    if (doFind) {
+      searchFrame = curItem->GetWindow();
+      if (!searchFrame) {
+        break;
+      }
+
+      OnStartSearchFrame(searchFrame);
+
+      // Beware! This may flush notifications via synchronous
+      // ScrollSelectionIntoView.
+      rv = SearchInFrame(searchFrame, false, aResult);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      if (*aResult) {
+        return OnFind(searchFrame);  // we are done
+      }
+
+      OnEndSearchFrame(searchFrame);
+    }
+
+    if (curItem.get() == startingItem.get()) {
+      doFind = true;  // start looking in frames after this one
+    }
+  }
+
+  if (!mWrapFind) {
+    // remember where we left off
+    SetCurrentSearchFrame(searchFrame);
+    return NS_OK;
+  }
+
+  // From here on, we're wrapping, first through the other frames, then finally
+  // from the beginning of the starting frame back to the starting point.
+
+  // because nsISimpleEnumerator is bad and isn't resettable, I have to
+  // make a new one
+  rv = rootDocShell->GetAllDocShellsInSubtree(nsIDocShellTreeItem::typeAll,
+                                              enumDirection, docShells);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  for (const auto& curItem : docShells) {
+    searchFrame = curItem->GetWindow();
+    if (!searchFrame) {
+      rv = NS_ERROR_FAILURE;
+      break;
+    }
+
+    if (curItem.get() == startingItem.get()) {
+      // Beware! This may flush notifications via synchronous
+      // ScrollSelectionIntoView.
+      rv = SearchInFrame(searchFrame, true, aResult);
+      if (NS_FAILED(rv)) {
+        return rv;
+      }
+      if (*aResult) {
+        return OnFind(searchFrame);  // we are done
+      }
+      break;
+    }
+
+    OnStartSearchFrame(searchFrame);
+
+    // Beware! This may flush notifications via synchronous
+    // ScrollSelectionIntoView.
+    rv = SearchInFrame(searchFrame, false, aResult);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+    if (*aResult) {
+      return OnFind(searchFrame);  // we are done
+    }
+
+    OnEndSearchFrame(searchFrame);
+  }
+
+  // remember where we left off
+  SetCurrentSearchFrame(searchFrame);
+
+  NS_ASSERTION(NS_SUCCEEDED(rv), "Something failed");
+  return rv;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetSearchString(nsAString& aSearchString) {
+  aSearchString = mSearchString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetSearchString(const nsAString& aSearchString) {
+  mSearchString = aSearchString;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetFindBackwards(bool* aFindBackwards) {
+  NS_ENSURE_ARG_POINTER(aFindBackwards);
+  *aFindBackwards = mFindBackwards;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetFindBackwards(bool aFindBackwards) {
+  mFindBackwards = aFindBackwards;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetWrapFind(bool* aWrapFind) {
+  NS_ENSURE_ARG_POINTER(aWrapFind);
+  *aWrapFind = mWrapFind;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetWrapFind(bool aWrapFind) {
+  mWrapFind = aWrapFind;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetEntireWord(bool* aEntireWord) {
+  NS_ENSURE_ARG_POINTER(aEntireWord);
+  *aEntireWord = mEntireWord;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetEntireWord(bool aEntireWord) {
+  mEntireWord = aEntireWord;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetMatchCase(bool* aMatchCase) {
+  NS_ENSURE_ARG_POINTER(aMatchCase);
+  *aMatchCase = mMatchCase;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetMatchCase(bool aMatchCase) {
+  mMatchCase = aMatchCase;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetMatchDiacritics(bool* aMatchDiacritics) {
+  NS_ENSURE_ARG_POINTER(aMatchDiacritics);
+  *aMatchDiacritics = mMatchDiacritics;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetMatchDiacritics(bool aMatchDiacritics) {
+  mMatchDiacritics = aMatchDiacritics;
+  return NS_OK;
+}
+
+void nsWebBrowserFind::SetSelectionAndScroll(nsPIDOMWindowOuter* aWindow,
+                                             nsRange* aRange) {
+  RefPtr<Document> doc = aWindow->GetDoc();
+  if (!doc) {
+    return;
+  }
+
+  PresShell* presShell = doc->GetPresShell();
+  if (!presShell) {
+    return;
+  }
+
+  nsCOMPtr<nsINode> node = aRange->GetStartContainer();
+  nsCOMPtr<nsIContent> content(do_QueryInterface(node));
+  nsIFrame* frame = content->GetPrimaryFrame();
+  if (!frame) {
+    return;
+  }
+  nsCOMPtr<nsISelectionController> selCon;
+  frame->GetSelectionController(presShell->GetPresContext(),
+                                getter_AddRefs(selCon));
+
+  // since the match could be an anonymous textnode inside a
+  // <textarea> or text <input>, we need to get the outer frame
+  nsITextControlFrame* tcFrame = nullptr;
+  for (; content; content = content->GetParent()) {
+    if (!content->IsInNativeAnonymousSubtree()) {
+      nsIFrame* f = content->GetPrimaryFrame();
+      if (!f) {
+        return;
+      }
+      tcFrame = do_QueryFrame(f);
+      break;
+    }
+  }
+
+  selCon->SetDisplaySelection(nsISelectionController::SELECTION_ON);
+  RefPtr<Selection> selection =
+      selCon->GetSelection(nsISelectionController::SELECTION_NORMAL);
+  if (selection) {
+    selection->RemoveAllRanges(IgnoreErrors());
+    selection->AddRangeAndSelectFramesAndNotifyListeners(*aRange,
+                                                         IgnoreErrors());
+
+    if (RefPtr<nsFocusManager> fm = nsFocusManager::GetFocusManager()) {
+      if (tcFrame) {
+        RefPtr<Element> newFocusedElement = Element::FromNode(content);
+        fm->SetFocus(newFocusedElement, nsIFocusManager::FLAG_NOSCROLL);
+      } else {
+        RefPtr<Element> result;
+        fm->MoveFocus(aWindow, nullptr, nsIFocusManager::MOVEFOCUS_CARET,
+                      nsIFocusManager::FLAG_NOSCROLL, getter_AddRefs(result));
+      }
+    }
+
+    // Scroll if necessary to make the selection visible:
+    // Must be the last thing to do - bug 242056
+
+    // After ScrollSelectionIntoView(), the pending notifications might be
+    // flushed and PresShell/PresContext/Frames may be dead. See bug 418470.
+    selCon->ScrollSelectionIntoView(
+        nsISelectionController::SELECTION_NORMAL,
+        nsISelectionController::SELECTION_WHOLE_SELECTION,
+        nsISelectionController::SCROLL_CENTER_VERTICALLY |
+            nsISelectionController::SCROLL_SYNCHRONOUS);
+  }
+}
+
+// Adapted from TextServicesDocument::GetDocumentContentRootNode
+nsresult nsWebBrowserFind::GetRootNode(Document* aDoc, Element** aNode) {
+  NS_ENSURE_ARG_POINTER(aDoc);
+  NS_ENSURE_ARG_POINTER(aNode);
+  *aNode = 0;
+
+  if (aDoc->IsHTMLOrXHTML()) {
+    Element* body = aDoc->GetBody();
+    NS_ENSURE_ARG_POINTER(body);
+    NS_ADDREF(*aNode = body);
+    return NS_OK;
+  }
+
+  // For non-HTML documents, the content root node will be the doc element.
+  Element* root = aDoc->GetDocumentElement();
+  NS_ENSURE_ARG_POINTER(root);
+  NS_ADDREF(*aNode = root);
+  return NS_OK;
+}
+
+nsresult nsWebBrowserFind::SetRangeAroundDocument(nsRange* aSearchRange,
+                                                  nsRange* aStartPt,
+                                                  nsRange* aEndPt,
+                                                  Document* aDoc) {
+  RefPtr<Element> bodyContent;
+  nsresult rv = GetRootNode(aDoc, getter_AddRefs(bodyContent));
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_ARG_POINTER(bodyContent);
+
+  uint32_t childCount = bodyContent->GetChildCount();
+
+  aSearchRange->SetStart(*bodyContent, 0, IgnoreErrors());
+  aSearchRange->SetEnd(*bodyContent, childCount, IgnoreErrors());
+
+  if (mFindBackwards) {
+    aStartPt->SetStart(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aEndPt->SetStart(*bodyContent, 0, IgnoreErrors());
+    aEndPt->SetEnd(*bodyContent, 0, IgnoreErrors());
+  } else {
+    aStartPt->SetStart(*bodyContent, 0, IgnoreErrors());
+    aStartPt->SetEnd(*bodyContent, 0, IgnoreErrors());
+    aEndPt->SetStart(*bodyContent, childCount, IgnoreErrors());
+    aEndPt->SetEnd(*bodyContent, childCount, IgnoreErrors());
+  }
+
+  return NS_OK;
+}
+
+// Set the range to go from the end of the current selection to the end of the
+// document (forward), or beginning to beginning (reverse). or around the whole
+// document if there's no selection.
+nsresult nsWebBrowserFind::GetSearchLimits(nsRange* aSearchRange,
+                                           nsRange* aStartPt, nsRange* aEndPt,
+                                           Document* aDoc, Selection* aSel,
+                                           bool aWrap) {
+  NS_ENSURE_ARG_POINTER(aSel);
+
+  // There is a selection.
+  const uint32_t rangeCount = aSel->RangeCount();
+  if (rangeCount < 1) {
+    return SetRangeAroundDocument(aSearchRange, aStartPt, aEndPt, aDoc);
+  }
+
+  // Need bodyContent, for the start/end of the document
+  RefPtr<Element> bodyContent;
+  nsresult rv = GetRootNode(aDoc, getter_AddRefs(bodyContent));
+  NS_ENSURE_SUCCESS(rv, rv);
+  NS_ENSURE_ARG_POINTER(bodyContent);
+
+  uint32_t childCount = bodyContent->GetChildCount();
+
+  // There are four possible range endpoints we might use:
+  // DocumentStart, SelectionStart, SelectionEnd, DocumentEnd.
+
+  RefPtr<const nsRange> range;
+  nsCOMPtr<nsINode> node;
+  uint32_t offset;
+
+  // Prevent the security checks in nsRange from getting into effect for the
+  // purposes of determining the search range. These ranges will never be
+  // exposed to content.
+  mozilla::dom::AutoNoJSAPI nojsapi;
+
+  // Forward, not wrapping: SelEnd to DocEnd
+  if (!mFindBackwards && !aWrap) {
+    // This isn't quite right, since the selection's ranges aren't
+    // necessarily in order; but they usually will be.
+    range = aSel->GetRangeAt(rangeCount - 1);
+    if (!range) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    node = range->GetEndContainer();
+    if (!node) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    offset = range->EndOffset();
+
+    aSearchRange->SetStart(*node, offset, IgnoreErrors());
+    aSearchRange->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetStart(*node, offset, IgnoreErrors());
+    aStartPt->SetEnd(*node, offset, IgnoreErrors());
+    aEndPt->SetStart(*bodyContent, childCount, IgnoreErrors());
+    aEndPt->SetEnd(*bodyContent, childCount, IgnoreErrors());
+  }
+  // Backward, not wrapping: DocStart to SelStart
+  else if (mFindBackwards && !aWrap) {
+    range = aSel->GetRangeAt(0);
+    if (!range) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    node = range->GetStartContainer();
+    if (!node) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    offset = range->StartOffset();
+
+    aSearchRange->SetStart(*bodyContent, 0, IgnoreErrors());
+    aSearchRange->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetStart(*node, offset, IgnoreErrors());
+    aStartPt->SetEnd(*node, offset, IgnoreErrors());
+    aEndPt->SetStart(*bodyContent, 0, IgnoreErrors());
+    aEndPt->SetEnd(*bodyContent, 0, IgnoreErrors());
+  }
+  // Forward, wrapping: DocStart to SelEnd
+  else if (!mFindBackwards && aWrap) {
+    range = aSel->GetRangeAt(rangeCount - 1);
+    if (!range) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    node = range->GetEndContainer();
+    if (!node) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    offset = range->EndOffset();
+
+    aSearchRange->SetStart(*bodyContent, 0, IgnoreErrors());
+    aSearchRange->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetStart(*bodyContent, 0, IgnoreErrors());
+    aStartPt->SetEnd(*bodyContent, 0, IgnoreErrors());
+    aEndPt->SetStart(*node, offset, IgnoreErrors());
+    aEndPt->SetEnd(*node, offset, IgnoreErrors());
+  }
+  // Backward, wrapping: SelStart to DocEnd
+  else if (mFindBackwards && aWrap) {
+    range = aSel->GetRangeAt(0);
+    if (!range) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    node = range->GetStartContainer();
+    if (!node) {
+      return NS_ERROR_UNEXPECTED;
+    }
+    offset = range->StartOffset();
+
+    aSearchRange->SetStart(*bodyContent, 0, IgnoreErrors());
+    aSearchRange->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetStart(*bodyContent, childCount, IgnoreErrors());
+    aStartPt->SetEnd(*bodyContent, childCount, IgnoreErrors());
+    aEndPt->SetStart(*node, offset, IgnoreErrors());
+    aEndPt->SetEnd(*node, offset, IgnoreErrors());
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetSearchFrames(bool* aSearchFrames) {
+  NS_ENSURE_ARG_POINTER(aSearchFrames);
+  // this only returns true if we are searching both sub and parent frames.
+  // There is ambiguity if the caller has previously set one, but not both of
+  // these.
+  *aSearchFrames = mSearchSubFrames && mSearchParentFrames;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetSearchFrames(bool aSearchFrames) {
+  mSearchSubFrames = aSearchFrames;
+  mSearchParentFrames = aSearchFrames;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetCurrentSearchFrame(
+    mozIDOMWindowProxy** aCurrentSearchFrame) {
+  NS_ENSURE_ARG_POINTER(aCurrentSearchFrame);
+  nsCOMPtr<mozIDOMWindowProxy> searchFrame =
+      do_QueryReferent(mCurrentSearchFrame);
+  searchFrame.forget(aCurrentSearchFrame);
+  return (*aCurrentSearchFrame) ? NS_OK : NS_ERROR_NOT_INITIALIZED;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetCurrentSearchFrame(
+    mozIDOMWindowProxy* aCurrentSearchFrame) {
+  // is it ever valid to set this to null?
+  NS_ENSURE_ARG(aCurrentSearchFrame);
+  mCurrentSearchFrame = do_GetWeakReference(aCurrentSearchFrame);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetRootSearchFrame(mozIDOMWindowProxy** aRootSearchFrame) {
+  NS_ENSURE_ARG_POINTER(aRootSearchFrame);
+  nsCOMPtr<mozIDOMWindowProxy> searchFrame = do_QueryReferent(mRootSearchFrame);
+  searchFrame.forget(aRootSearchFrame);
+  return (*aRootSearchFrame) ? NS_OK : NS_ERROR_NOT_INITIALIZED;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetRootSearchFrame(mozIDOMWindowProxy* aRootSearchFrame) {
+  // is it ever valid to set this to null?
+  NS_ENSURE_ARG(aRootSearchFrame);
+  mRootSearchFrame = do_GetWeakReference(aRootSearchFrame);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetSearchSubframes(bool* aSearchSubframes) {
+  NS_ENSURE_ARG_POINTER(aSearchSubframes);
+  *aSearchSubframes = mSearchSubFrames;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetSearchSubframes(bool aSearchSubframes) {
+  mSearchSubFrames = aSearchSubframes;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::GetSearchParentFrames(bool* aSearchParentFrames) {
+  NS_ENSURE_ARG_POINTER(aSearchParentFrames);
+  *aSearchParentFrames = mSearchParentFrames;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserFind::SetSearchParentFrames(bool aSearchParentFrames) {
+  mSearchParentFrames = aSearchParentFrames;
+  return NS_OK;
+}
+
+/*
+    This method handles finding in a single window (aka frame).
+
+*/
+nsresult nsWebBrowserFind::SearchInFrame(nsPIDOMWindowOuter* aWindow,
+                                         bool aWrapping, bool* aDidFind) {
+  NS_ENSURE_ARG(aWindow);
+  NS_ENSURE_ARG_POINTER(aDidFind);
+
+  *aDidFind = false;
+
+  // Do security check, to ensure that the frame we're searching is
+  // accessible from the frame where the Find is being run.
+
+  // get a uri for the window
+  RefPtr<Document> theDoc = aWindow->GetDoc();
+  if (!theDoc) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (!nsContentUtils::SubjectPrincipal()->Subsumes(theDoc->NodePrincipal())) {
+    return NS_ERROR_DOM_PROP_ACCESS_DENIED;
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIFind> find = do_CreateInstance(NS_FIND_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  (void)find->SetCaseSensitive(mMatchCase);
+  (void)find->SetMatchDiacritics(mMatchDiacritics);
+  (void)find->SetFindBackwards(mFindBackwards);
+
+  (void)find->SetEntireWord(mEntireWord);
+
+  // Now make sure the content (for actual finding) and frame (for
+  // selection) models are up to date.
+  theDoc->FlushPendingNotifications(FlushType::Frames);
+
+  RefPtr<Selection> sel = GetFrameSelection(aWindow);
+  NS_ENSURE_ARG_POINTER(sel);
+
+  RefPtr<nsRange> searchRange = nsRange::Create(theDoc);
+  RefPtr<nsRange> startPt = nsRange::Create(theDoc);
+  RefPtr<nsRange> endPt = nsRange::Create(theDoc);
+
+  RefPtr<nsRange> foundRange;
+
+  rv = GetSearchLimits(searchRange, startPt, endPt, theDoc, sel, aWrapping);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = find->Find(mSearchString, searchRange, startPt, endPt,
+                  getter_AddRefs(foundRange));
+
+  if (NS_SUCCEEDED(rv) && foundRange) {
+    *aDidFind = true;
+    sel->RemoveAllRanges(IgnoreErrors());
+    // Beware! This may flush notifications via synchronous
+    // ScrollSelectionIntoView.
+    SetSelectionAndScroll(aWindow, foundRange);
+  }
+
+  return rv;
+}
+
+// called when we start searching a frame that is not the initial focussed
+// frame. Prepare the frame to be searched. we clear the selection, so that the
+// search starts from the top of the frame.
+nsresult nsWebBrowserFind::OnStartSearchFrame(nsPIDOMWindowOuter* aWindow) {
+  return ClearFrameSelection(aWindow);
+}
+
+// called when we are done searching a frame and didn't find anything, and about
+// about to start searching the next frame.
+nsresult nsWebBrowserFind::OnEndSearchFrame(nsPIDOMWindowOuter* aWindow) {
+  return NS_OK;
+}
+
+already_AddRefed<Selection> nsWebBrowserFind::GetFrameSelection(
+    nsPIDOMWindowOuter* aWindow) {
+  RefPtr<Document> doc = aWindow->GetDoc();
+  if (!doc) {
+    return nullptr;
+  }
+
+  PresShell* presShell = doc->GetPresShell();
+  if (!presShell) {
+    return nullptr;
+  }
+
+  // text input controls have their independent selection controllers that we
+  // must use when they have focus.
+  nsPresContext* presContext = presShell->GetPresContext();
+
+  nsCOMPtr<nsPIDOMWindowOuter> focusedWindow;
+  nsCOMPtr<nsIContent> focusedContent = nsFocusManager::GetFocusedDescendant(
+      aWindow, nsFocusManager::eOnlyCurrentWindow,
+      getter_AddRefs(focusedWindow));
+
+  nsIFrame* frame =
+      focusedContent ? focusedContent->GetPrimaryFrame() : nullptr;
+
+  nsCOMPtr<nsISelectionController> selCon;
+  RefPtr<Selection> sel;
+  if (frame) {
+    frame->GetSelectionController(presContext, getter_AddRefs(selCon));
+    sel = selCon->GetSelection(nsISelectionController::SELECTION_NORMAL);
+    if (sel && sel->RangeCount() > 0) {
+      return sel.forget();
+    }
+  }
+
+  sel = presShell->GetSelection(nsISelectionController::SELECTION_NORMAL);
+  return sel.forget();
+}
+
+nsresult nsWebBrowserFind::ClearFrameSelection(nsPIDOMWindowOuter* aWindow) {
+  NS_ENSURE_ARG(aWindow);
+  RefPtr<Selection> selection = GetFrameSelection(aWindow);
+  if (selection) {
+    selection->RemoveAllRanges(IgnoreErrors());
+  }
+
+  return NS_OK;
+}
+
+nsresult nsWebBrowserFind::OnFind(nsPIDOMWindowOuter* aFoundWindow) {
+  SetCurrentSearchFrame(aFoundWindow);
+
+  // We don't want a selection to appear in two frames simultaneously
+  nsCOMPtr<nsPIDOMWindowOuter> lastFocusedWindow =
+      do_QueryReferent(mLastFocusedWindow);
+  if (lastFocusedWindow && lastFocusedWindow != aFoundWindow) {
+    ClearFrameSelection(lastFocusedWindow);
+  }
+
+  if (RefPtr<nsFocusManager> fm = nsFocusManager::GetFocusManager()) {
+    // get the containing frame and focus it. For top-level windows, the right
+    // window should already be focused.
+    if (RefPtr<Element> frameElement =
+            aFoundWindow->GetFrameElementInternal()) {
+      fm->SetFocus(frameElement, 0);
+    }
+
+    mLastFocusedWindow = do_GetWeakReference(aFoundWindow);
+  }
+
+  return NS_OK;
+}
diff --git a/toolkit/components/find/nsWebBrowserFind.h b/toolkit/components/find/nsWebBrowserFind.h
new file mode 100644
index 0000000000..0c846d2f17
--- /dev/null
+++ b/toolkit/components/find/nsWebBrowserFind.h
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef nsWebBrowserFindImpl_h__
+#define nsWebBrowserFindImpl_h__
+
+#include "nsIWebBrowserFind.h"
+
+#include "nsCOMPtr.h"
+#include "nsIWeakReferenceUtils.h"
+#include "nsPIDOMWindow.h"
+
+#include "nsString.h"
+
+class nsIDOMWindow;
+class nsIDocShell;
+class nsRange;
+
+namespace mozilla {
+namespace dom {
+class Document;
+class Element;
+class Selection;
+}  // namespace dom
+}  // namespace mozilla
+
+//*****************************************************************************
+// class nsWebBrowserFind
+//*****************************************************************************
+
+class nsWebBrowserFind : public nsIWebBrowserFind,
+                         public nsIWebBrowserFindInFrames {
+ public:
+  nsWebBrowserFind();
+
+  // nsISupports
+  NS_DECL_ISUPPORTS
+
+  // nsIWebBrowserFind
+  NS_DECL_NSIWEBBROWSERFIND
+
+  // nsIWebBrowserFindInFrames
+  NS_DECL_NSIWEBBROWSERFINDINFRAMES
+
+ protected:
+  virtual ~nsWebBrowserFind();
+
+  bool CanFindNext() { return mSearchString.Length() != 0; }
+
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult
+  SearchInFrame(nsPIDOMWindowOuter* aWindow, bool aWrapping, bool* aDidFind);
+
+  nsresult OnStartSearchFrame(nsPIDOMWindowOuter* aWindow);
+  nsresult OnEndSearchFrame(nsPIDOMWindowOuter* aWindow);
+
+  already_AddRefed<mozilla::dom::Selection> GetFrameSelection(
+      nsPIDOMWindowOuter* aWindow);
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult
+  ClearFrameSelection(nsPIDOMWindowOuter* aWindow);
+
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult OnFind(nsPIDOMWindowOuter* aFoundWindow);
+
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void SetSelectionAndScroll(
+      nsPIDOMWindowOuter* aWindow, nsRange* aRange);
+
+  nsresult GetRootNode(mozilla::dom::Document* aDomDoc,
+                       mozilla::dom::Element** aNode);
+  nsresult GetSearchLimits(nsRange* aRange, nsRange* aStartPt, nsRange* aEndPt,
+                           mozilla::dom::Document* aDoc,
+                           mozilla::dom::Selection* aSel, bool aWrap);
+  nsresult SetRangeAroundDocument(nsRange* aSearchRange, nsRange* aStartPoint,
+                                  nsRange* aEndPoint,
+                                  mozilla::dom::Document* aDoc);
+
+ protected:
+  nsString mSearchString;
+
+  bool mFindBackwards;
+  bool mWrapFind;
+  bool mEntireWord;
+  bool mMatchCase;
+  bool mMatchDiacritics;
+
+  bool mSearchSubFrames;
+  bool mSearchParentFrames;
+
+  // These are all weak because who knows if windows can go away during our
+  // lifetime.
+  nsWeakPtr mCurrentSearchFrame;
+  nsWeakPtr mRootSearchFrame;
+  nsWeakPtr mLastFocusedWindow;
+};
+
+#endif
diff --git a/toolkit/components/find/test/mochitest/mochitest.toml b/toolkit/components/find/test/mochitest/mochitest.toml
new file mode 100644
index 0000000000..db7adf4394
--- /dev/null
+++ b/toolkit/components/find/test/mochitest/mochitest.toml
@@ -0,0 +1,6 @@
+[DEFAULT]
+prefs = ["layout.css.content-visibility.enabled=true"]
+
+["test_bug499115.html"]
+
+["test_nsFind.html"]
diff --git a/toolkit/components/find/test/mochitest/test_bug499115.html b/toolkit/components/find/test/mochitest/test_bug499115.html
new file mode 100644
index 0000000000..18cea93690
--- /dev/null
+++ b/toolkit/components/find/test/mochitest/test_bug499115.html
@@ -0,0 +1,66 @@
+<!DOCTYPE HTML>
+<!-- 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/. -->
+
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=499115
+-->
+<head>
+  <title>Test for Bug 499115</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body onload="onLoad();">
+  <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=499115">Mozilla Bug 499115</a>
+  <p id="display"></p>
+  <div id="content" style="display: none">
+  </div>
+  <pre id="test">
+    <script type="application/javascript">
+
+      /** Test for Bug 499115 */
+      SimpleTest.waitForExplicitFinish();
+
+      const SEARCH_TEXT = "minefield";
+
+      function getMatches() {
+        var numMatches = 0;
+
+        var searchRange = document.createRange();
+        searchRange.selectNodeContents(document.body);
+
+        var startPoint = searchRange.cloneRange();
+        startPoint.collapse(true);
+
+        var endPoint = searchRange.cloneRange();
+        endPoint.collapse(false);
+
+        var retRange = null;
+        var finder = SpecialPowers.Cc["@mozilla.org/embedcomp/rangefind;1"]
+                                  .createInstance(SpecialPowers.Ci.nsIFind);
+
+        finder.caseSensitive = false;
+
+        while ((retRange = finder.Find(SEARCH_TEXT, searchRange,
+                                       startPoint, endPoint))) {
+          numMatches++;
+
+          // Start next search from end of current match
+          startPoint = retRange.cloneRange();
+          startPoint.collapse(false);
+        }
+
+        return numMatches;
+       }
+
+       function onLoad() {
+         var matches = getMatches();
+         is(matches, 2, "found second match in anonymous content");
+         SimpleTest.finish();
+       }
+   </script>
+  </pre>
+<input type="text" value="minefield minefield"></body>
+</html>
diff --git a/toolkit/components/find/test/mochitest/test_nsFind.html b/toolkit/components/find/test/mochitest/test_nsFind.html
new file mode 100644
index 0000000000..0d6bc3d562
--- /dev/null
+++ b/toolkit/components/find/test/mochitest/test_nsFind.html
@@ -0,0 +1,399 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=202251
+https://bugzilla.mozilla.org/show_bug.cgi?id=450048
+https://bugzilla.mozilla.org/show_bug.cgi?id=812837
+https://bugzilla.mozilla.org/show_bug.cgi?id=969980
+https://bugzilla.mozilla.org/show_bug.cgi?id=1589786
+https://bugzilla.mozilla.org/show_bug.cgi?id=1611568
+https://bugzilla.mozilla.org/show_bug.cgi?id=1649187
+https://bugzilla.mozilla.org/show_bug.cgi?id=1699599
+-->
+<head>
+  <meta charset="UTF-8">
+  <title>Test for nsFind::Find()</title>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+
+<script type="application/javascript">
+
+SimpleTest.waitForExplicitFinish();
+
+async function runTests() {
+  // Check nsFind class and its nsIFind interface.
+
+  // Inject some text that we'll search for later.
+  const NULL_CHARACTER = "\0";
+  const INJECTED_NULL_TEXT = "injected null\0";
+  const nullcharsinjected = document.getElementById("nullcharsinjected");
+  const nulltextnode = document.createTextNode(INJECTED_NULL_TEXT);
+  nullcharsinjected.appendChild(nulltextnode);
+
+  // Take steps to ensure that the frame is created for the newly added
+  // nulltextnode. Our find code is dependent upon finding visible frames.
+  // One way to ensure the frame exists is to ask for its bounds.
+  const injectionBounds = nullcharsinjected.getBoundingClientRect();
+  ok(injectionBounds, "Got a bounding rect for the injected text container.");
+
+  var rf = SpecialPowers.Cc["@mozilla.org/embedcomp/rangefind;1"]
+                        .getService(SpecialPowers.Ci.nsIFind);
+
+  var display = window.document.getElementById("display");
+  var searchRange = window.document.createRange();
+  searchRange.setStart(display, 0);
+  searchRange.setEnd(display, display.childNodes.length);
+  var startPt = searchRange;
+  var endPt = searchRange;
+
+  var searchValue, retRange;
+
+  rf.findBackwards = false;
+
+  rf.caseSensitive = false;
+  rf.matchDiacritics = false;
+  rf.entireWord = false;
+
+  searchValue = "TexT";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "λογος";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "유";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (not caseSensitive)");
+
+  searchValue = "కె";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (not caseSensitive)");
+
+  searchValue = "𑂥";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "istanbul";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "wroclaw";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "goteborg";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "degrees k";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "≠";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (not caseSensitive)");
+
+  searchValue = "guahe";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "g̃uah̰e";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "𐐸𐐯𐑊𐐬";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (not caseSensitive)");
+
+  searchValue = "東京駅"
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found");
+
+  rf.matchDiacritics = true;
+
+  searchValue = "λογος";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (matchDiacritics on)");
+
+  searchValue = "g̃uahe";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (matchDiacritics on)");
+
+  searchValue = "guahe";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (matchDiacritics on)");
+
+  rf.caseSensitive = true;
+
+  searchValue = "TexT";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (caseSensitive)");
+
+  searchValue = "text";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found");
+
+  // Matches |i<b>n&shy;t</b>o|.
+  searchValue = "into";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found");
+
+  // Matches inside |search|.
+  searchValue = "ear";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found");
+
+  // Set new start point (to end of last search).
+  startPt = retRange.endContainer.ownerDocument.createRange();
+  startPt.setStart(retRange.endContainer, retRange.endOffset);
+  startPt.setEnd(retRange.endContainer, retRange.endOffset);
+
+  searchValue = "t";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (forward)");
+
+  searchValue = "the";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(!retRange, "\"" + searchValue + "\" found (forward)");
+
+  rf.findBackwards = true;
+
+  // searchValue = "the";
+  retRange = rf.Find(searchValue, searchRange, startPt, endPt);
+  ok(retRange, "\"" + searchValue + "\" not found (backward)");
+
+  // Curly quotes and straight quotes should match.
+
+  rf.matchDiacritics = false;
+  rf.findBackwards = false;
+
+  function find(node, value) {
+    var range = document.createRange();
+    range.setStart(node, 0);
+    range.setEnd(node, node.childNodes.length);
+    return rf.Find(value, range, range, range);
+  }
+
+  function assertFound(node, value) {
+    ok(find(node, value), "\"" + value + "\" should be found");
+  }
+
+  function assertNotFound(node, value) {
+    ok(!find(node, value), "\"" + value + "\" should not be found");
+  }
+
+  var quotes = document.getElementById("quotes");
+
+  assertFound(quotes, "\"straight\"");
+  assertFound(quotes, "\u201Cstraight\u201D");
+
+  assertNotFound(quotes, "'straight'");
+  assertNotFound(quotes, "\u2018straight\u2019");
+  assertNotFound(quotes, "\u2019straight\u2018");
+  assertNotFound(quotes, ".straight.");
+
+  assertFound(quotes, "\"curly\"");
+  assertFound(quotes, "\u201Ccurly\u201D");
+
+  assertNotFound(quotes, "'curly'");
+  assertNotFound(quotes, "\u2018curly\u2019");
+  assertNotFound(quotes, ".curly.");
+
+  assertFound(quotes, "didn't");
+  assertFound(quotes, "didn\u2018t");
+  assertFound(quotes, "didn\u2019t");
+
+  assertNotFound(quotes, "didnt");
+  assertNotFound(quotes, "didn t");
+  assertNotFound(quotes, "didn.t");
+
+  assertFound(quotes, "'didn't'");
+  assertFound(quotes, "'didn\u2018t'");
+  assertFound(quotes, "'didn\u2019t'");
+  assertFound(quotes, "\u2018didn't\u2019");
+  assertFound(quotes, "\u2019didn't\u2018");
+  assertFound(quotes, "\u2018didn't\u2018");
+  assertFound(quotes, "\u2019didn't\u2019");
+  assertFound(quotes, "\u2018didn\u2019t\u2019");
+  assertFound(quotes, "\u2019didn\u2018t\u2019");
+  assertFound(quotes, "\u2018didn\u2019t\u2018");
+
+  assertNotFound(quotes, "\"didn't\"");
+  assertNotFound(quotes, "\u201Cdidn't\u201D");
+
+  assertFound(quotes, "doesn't");
+  assertFound(quotes, "doesn\u2018t");
+  assertFound(quotes, "doesn\u2019t");
+
+  assertNotFound(quotes, "doesnt");
+  assertNotFound(quotes, "doesn t");
+  assertNotFound(quotes, "doesn.t");
+
+  assertFound(quotes, "'doesn't'");
+  assertFound(quotes, "'doesn\u2018t'");
+  assertFound(quotes, "'doesn\u2019t'");
+  assertFound(quotes, "\u2018doesn't\u2019");
+  assertFound(quotes, "\u2019doesn't\u2018");
+  assertFound(quotes, "\u2018doesn't\u2018");
+  assertFound(quotes, "\u2019doesn't\u2019");
+  assertFound(quotes, "\u2018doesn\u2019t\u2019");
+  assertFound(quotes, "\u2019doesn\u2018t\u2019");
+  assertFound(quotes, "\u2018doesn\u2019t\u2018");
+
+  assertNotFound(quotes, "\"doesn't\"");
+  assertNotFound(quotes, "\u201Cdoesn't\u201D");
+
+  // Curly quotes and straight quotes should not match.
+  rf.matchDiacritics = true;
+
+  assertFound(quotes, "\"straight\"");
+  assertNotFound(quotes, "\u201Cstraight\u201D");
+
+  assertNotFound(quotes, "\"curly\"");
+  assertFound(quotes, "\u201Ccurly\u201D");
+
+  assertFound(quotes, "\u2018didn't\u2019");
+  assertNotFound(quotes, "'didn't'");
+
+  assertFound(quotes, "'doesn\u2019t'");
+  assertNotFound(quotes, "'doesn\u2018t'");
+  assertNotFound(quotes, "'doesn't'");
+
+  // Embedded strings containing null characters can't be found, because
+  // the HTML parser converts them to \ufffd, which is the replacement
+  // character.
+  const nullcharsnative = document.getElementById("nullcharsnative");
+  assertFound(nullcharsnative, "native null\ufffd");
+
+  // Injected strings containing null characters can be found.
+  assertFound(nullcharsinjected, NULL_CHARACTER);
+  assertFound(nullcharsinjected, INJECTED_NULL_TEXT);
+
+  // Content skipped via content-visibility can't be found.
+  assertNotFound(quotes, "Tardigrade");
+  assertNotFound(quotes, "Amoeba");
+
+  // Simple checks for behavior of the entireWord option.
+  var entireWord = document.getElementById("entireWord");
+  rf.entireWord = true;
+  assertFound(entireWord, "one");
+  assertNotFound(entireWord, "on");
+  assertFound(entireWord, "(one)");
+  assertFound(entireWord, "two");
+  assertFound(entireWord, "[two]");
+  assertFound(entireWord, "[three]");
+  assertFound(entireWord, "foo");
+  assertFound(entireWord, "-foo");
+  assertFound(entireWord, "bar");
+  assertFound(entireWord, "-bar");
+  assertNotFound(entireWord, "-fo");
+  assertNotFound(entireWord, "-ba");
+
+  rf.entireWord = false;
+  assertFound(entireWord, "on");
+  assertFound(entireWord, "-fo");
+  assertFound(entireWord, "-ba");
+
+  // Searching in elements with display: table-*, bug 1645990
+  var table = document.getElementById("tabular");
+  assertFound(table, "One");
+  assertFound(table, "TwoThree");  // across adjacent cells
+  assertNotFound(table, "wordsanother");  // not across rows
+  rf.entireWord = true;
+  assertNotFound(table, "One");  // because nothing separates it from next cell
+  assertFound(table, "several");
+  assertFound(table, "whole");
+  assertFound(table, "words");
+  rf.entireWord = false;
+
+  // Do these test at the end since they trigger failure screenshots in
+  // the test harness, and we want as much information as possible about
+  // any OTHER tests that may have already failed.
+
+  // Check |null| detection on |aSearchRange| parameter.
+  try {
+    rf.Find("", null, startPt, endPt);
+
+    ok(false, "Missing NS_ERROR_ILLEGAL_VALUE exception");
+  } catch (e) {
+    let wrappedError = SpecialPowers.wrap(e);
+    if (wrappedError.result == SpecialPowers.Cr.NS_ERROR_ILLEGAL_VALUE) {
+      ok(true, null);
+    } else {
+      throw wrappedError;
+    }
+  }
+
+  // Check |null| detection on |aStartPoint| parameter.
+  try {
+    rf.Find("", searchRange, null, endPt);
+
+    ok(false, "Missing NS_ERROR_ILLEGAL_VALUE exception");
+  } catch (e) {
+    let wrappedError = SpecialPowers.wrap(e);
+    if (wrappedError.result == SpecialPowers.Cr.NS_ERROR_ILLEGAL_VALUE) {
+      ok(true, null);
+    } else {
+      throw wrappedError;
+    }
+  }
+
+  // Check |null| detection on |aEndPoint| parameter.
+  try {
+    rf.Find("", searchRange, startPt, null);
+
+    ok(false, "Missing NS_ERROR_ILLEGAL_VALUE exception");
+  } catch (e) {
+    let wrappedError = SpecialPowers.wrap(e);
+    if (wrappedError.result == SpecialPowers.Cr.NS_ERROR_ILLEGAL_VALUE) {
+      ok(true, null);
+    } else {
+      throw wrappedError;
+    }
+  }
+
+  SimpleTest.finish();
+}
+</script>
+<style>
+#tabular { display: table; }
+#tabular div { display: table-row; }
+#tabular div div { display: table-cell; }
+</style>
+</head>
+<body onload="runTests()">
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=450048">Mozilla Bug 450048</a>
+<p id="display">This is the text to search i<b>n&shy;t</b>o</p>
+<p id="quotes">"straight" and &ldquo;curly&rdquo; and &lsquo;didn't&rsquo; and 'doesn&rsquo;t'</p>
+<p id="nullcharsnative">native null&#0;</p>
+<p id="nullcharsinjected"></p>
+<p id="greek">ΛΌΓΟΣ</p>
+<p id="korean">위</p>
+<p id="telugu">కై</p>
+<p id="kaithi">𑂫</p>
+<p id="turkish">İstanbul</p>
+<p id="polish">Wrocław</p>
+<p id="norwegian">Gøteborg</p>
+<p id="kelvin">degrees &#x212A;</p>
+<p id="math">=</p>
+<p id="guarani">G̃uahe</p>
+<p id="deseret">𐐐𐐯𐑊𐐬 𐐶𐐯𐑉𐑊𐐼!</p>
+<p id="ruby"><ruby>東<rt>とう</rt></ruby><ruby>京<rt>きょう</ruby>駅</p>
+<div id="content-visibility-hidden" style="content-visibility: hidden">
+    Tardigrade
+    <div>Amoeba</div>
+</div>
+<div id="entireWord"><p>(one)</p><p>[two] [three]</p><p>-foo -bar</p></div>
+<div id="content" style="display: none">
+
+</div>
+<div id="tabular">
+  <div><div>One</div><div>Two</div><div>Three</div></div>
+  <div><div></div><div></div><div>several whole words</div></div>
+  <div><div>one</div><div>more</div><div>row</div></div>
+</div>
+<pre id="test">
+</pre>
+</body>
+</html>