Adding upstream version 110.0.1.upstream/110.0.1upstream

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

37 files changed, 5997 insertions, 0 deletions

diff --git a/toolkit/components/autocomplete/AutoCompleteSimpleSearch.jsm b/toolkit/components/autocomplete/AutoCompleteSimpleSearch.jsm
new file mode 100644
index 0000000000..2ef47d85c9
--- /dev/null
+++ b/toolkit/components/autocomplete/AutoCompleteSimpleSearch.jsm
@@ -0,0 +1,47 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+/**
+ * See nsIAutoCompleteSimpleSearch
+ */
+class AutoCompleteSimpleSearch {
+  constructor() {
+    this.classID = Components.ID("{dc185a77-ba88-4caa-8f16-465253f7599a}");
+    this.QueryInterface = ChromeUtils.generateQI([
+      "nsIAutoCompleteSimpleSearch",
+    ]);
+
+    let initialState = Cc[
+      "@mozilla.org/autocomplete/simple-result;1"
+    ].createInstance(Ci.nsIAutoCompleteSimpleResult);
+    initialState.setDefaultIndex(0);
+    initialState.setSearchResult(Ci.nsIAutoCompleteResult.RESULT_NOMATCH);
+    this.overrideNextResult(initialState);
+  }
+
+  _result = null;
+
+  /**
+   * See nsIAutoCompleteSimpleSearch
+   */
+  overrideNextResult(result) {
+    this._result = result;
+  }
+
+  /**
+   * See nsIAutoCompleteSearch
+   */
+  startSearch(searchString, searchParam, previousResult, listener) {
+    let result = this._result;
+    result.setSearchString(searchString);
+    listener.onSearchResult(this, result);
+  }
+
+  /**
+   * See nsIAutoCompleteSearch
+   */
+  stopSearch() {}
+}
+
+const EXPORTED_SYMBOLS = ["AutoCompleteSimpleSearch"];
diff --git a/toolkit/components/autocomplete/components.conf b/toolkit/components/autocomplete/components.conf
new file mode 100644
index 0000000000..432a6309ed
--- /dev/null
+++ b/toolkit/components/autocomplete/components.conf
@@ -0,0 +1,20 @@
+# -*- 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/.
+
+Classes = [
+    {
+        'cid': '{f6d5ebbd-34f4-487d-9d10-3d34123e3eb9}',
+        'contract_ids': ['@mozilla.org/autocomplete/controller;1'],
+        'type': 'nsAutoCompleteController',
+        'headers': ['/toolkit/components/autocomplete/nsAutoCompleteController.h'],
+    },
+    {
+        'cid': '{2ee3039b-2de4-43d9-93b0-649beacff39a}',
+        'contract_ids': ['@mozilla.org/autocomplete/simple-result;1'],
+        'type': 'nsAutoCompleteSimpleResult',
+        'headers': ['/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.h'],
+    },
+]
diff --git a/toolkit/components/autocomplete/moz.build b/toolkit/components/autocomplete/moz.build
new file mode 100644
index 0000000000..a751113054
--- /dev/null
+++ b/toolkit/components/autocomplete/moz.build
@@ -0,0 +1,39 @@
+# -*- 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/.
+
+XPCSHELL_TESTS_MANIFESTS += ["tests/unit/xpcshell.ini"]
+
+XPIDL_SOURCES += [
+    "nsIAutoCompleteController.idl",
+    "nsIAutoCompleteInput.idl",
+    "nsIAutoCompletePopup.idl",
+    "nsIAutoCompleteResult.idl",
+    "nsIAutoCompleteSearch.idl",
+    "nsIAutoCompleteSimpleResult.idl",
+    "nsIAutoCompleteSimpleSearch.idl",
+]
+
+XPIDL_MODULE = "autocomplete"
+
+EXTRA_JS_MODULES += [
+    "AutoCompleteSimpleSearch.jsm",
+]
+
+UNIFIED_SOURCES += [
+    "nsAutoCompleteController.cpp",
+    "nsAutoCompleteSimpleResult.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+FINAL_LIBRARY = "xul"
+
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Autocomplete")
+
+REQUIRES_UNIFIED_BUILD = True
diff --git a/toolkit/components/autocomplete/nsAutoCompleteController.cpp b/toolkit/components/autocomplete/nsAutoCompleteController.cpp
new file mode 100644
index 0000000000..dc9754997b
--- /dev/null
+++ b/toolkit/components/autocomplete/nsAutoCompleteController.cpp
@@ -0,0 +1,1767 @@
+/* -*- 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 "nsAutoCompleteController.h"
+#include "nsAutoCompleteSimpleResult.h"
+
+#include "nsNetCID.h"
+#include "nsIIOService.h"
+#include "nsReadableUtils.h"
+#include "nsUnicharUtils.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsIObserverService.h"
+#include "nsServiceManagerUtils.h"
+#include "mozilla/Services.h"
+#include "mozilla/Unused.h"
+#include "mozilla/dom/KeyboardEventBinding.h"
+#include "mozilla/dom/Event.h"
+
+static const char* kAutoCompleteSearchCID =
+    "@mozilla.org/autocomplete/search;1?name=";
+
+using namespace mozilla;
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(nsAutoCompleteController)
+
+MOZ_CAN_RUN_SCRIPT_BOUNDARY
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsAutoCompleteController)
+  MOZ_KnownLive(tmp)->SetInput(nullptr);
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsAutoCompleteController)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mInput)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSearches)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResults)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mResultCache)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsAutoCompleteController)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsAutoCompleteController)
+NS_INTERFACE_TABLE_HEAD(nsAutoCompleteController)
+  NS_INTERFACE_TABLE(nsAutoCompleteController, nsIAutoCompleteController,
+                     nsIAutoCompleteObserver, nsITimerCallback, nsINamed)
+  NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(nsAutoCompleteController)
+NS_INTERFACE_MAP_END
+
+nsAutoCompleteController::nsAutoCompleteController()
+    : mDefaultIndexCompleted(false),
+      mPopupClosedByCompositionStart(false),
+      mProhibitAutoFill(false),
+      mUserClearedAutoFill(false),
+      mClearingAutoFillSearchesAgain(false),
+      mCompositionState(eCompositionState_None),
+      mSearchStatus(nsAutoCompleteController::STATUS_NONE),
+      mMatchCount(0),
+      mSearchesOngoing(0),
+      mSearchesFailed(0),
+      mImmediateSearchesCount(0),
+      mCompletedSelectionIndex(-1) {}
+
+nsAutoCompleteController::~nsAutoCompleteController() { SetInput(nullptr); }
+
+void nsAutoCompleteController::SetValueOfInputTo(const nsString& aValue) {
+  mSetValue = aValue;
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  input->SetTextValue(aValue);
+}
+
+////////////////////////////////////////////////////////////////////////
+//// nsIAutoCompleteController
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetSearchStatus(uint16_t* aSearchStatus) {
+  *aSearchStatus = mSearchStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetMatchCount(uint32_t* aMatchCount) {
+  *aMatchCount = mMatchCount;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetInput(nsIAutoCompleteInput** aInput) {
+  *aInput = mInput;
+  NS_IF_ADDREF(*aInput);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::SetInitiallySelectedIndex(int32_t aSelectedIndex) {
+  // First forward to the popup.
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  NS_ENSURE_STATE(input);
+
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_STATE(popup);
+  popup->SetSelectedIndex(aSelectedIndex);
+
+  // Now take care of internal stuff.
+  bool completeSelection;
+  if (NS_SUCCEEDED(input->GetCompleteSelectedIndex(&completeSelection)) &&
+      completeSelection) {
+    mCompletedSelectionIndex = aSelectedIndex;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::SetInput(nsIAutoCompleteInput* aInput) {
+  // Don't do anything if the input isn't changing.
+  if (mInput == aInput) return NS_OK;
+
+  Unused << ResetInternalState();
+  if (mInput) {
+    mSearches.Clear();
+    ClosePopup();
+  }
+
+  mInput = aInput;
+
+  // Nothing more to do if the input was just being set to null.
+  if (!mInput) {
+    return NS_OK;
+  }
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  // Reset the current search string.
+  nsAutoString value;
+  input->GetTextValue(value);
+  SetSearchStringInternal(value);
+
+  // Since the controller can be used as a service it's important to reset this.
+  mClearingAutoFillSearchesAgain = false;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::ResetInternalState() {
+  // Clear out the current search context
+  if (mInput) {
+    nsAutoString value;
+    mInput->GetTextValue(value);
+    // Stop all searches in case they are async.
+    Unused << StopSearch();
+    Unused << ClearResults();
+    SetSearchStringInternal(value);
+  }
+
+  mPlaceholderCompletionString.Truncate();
+  mDefaultIndexCompleted = false;
+  mProhibitAutoFill = false;
+  mSearchStatus = nsIAutoCompleteController::STATUS_NONE;
+  mMatchCount = 0;
+  mCompletedSelectionIndex = -1;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::StartSearch(const nsAString& aSearchString) {
+  // If composition is ongoing don't start searching yet, until it is committed.
+  if (mCompositionState == eCompositionState_Composing) {
+    return NS_OK;
+  }
+
+  SetSearchStringInternal(aSearchString);
+  StartSearches();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleText(bool* _retval) {
+  *_retval = false;
+  // Note: the events occur in the following order when IME is used.
+  // 1. a compositionstart event(HandleStartComposition)
+  // 2. some input events (HandleText), eCompositionState_Composing
+  // 3. a compositionend event(HandleEndComposition)
+  // 4. an input event(HandleText), eCompositionState_Committing
+  // We should do nothing during composition.
+  if (mCompositionState == eCompositionState_Composing) {
+    return NS_OK;
+  }
+
+  bool handlingCompositionCommit =
+      (mCompositionState == eCompositionState_Committing);
+  bool popupClosedByCompositionStart = mPopupClosedByCompositionStart;
+  if (handlingCompositionCommit) {
+    mCompositionState = eCompositionState_None;
+    mPopupClosedByCompositionStart = false;
+  }
+
+  if (!mInput) {
+    // Stop all searches in case they are async.
+    StopSearch();
+    // Note: if now is after blur and IME end composition,
+    // check mInput before calling.
+    // See https://bugzilla.mozilla.org/show_bug.cgi?id=193544#c31
+    NS_ERROR(
+        "Called before attaching to the control or after detaching from the "
+        "control");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  nsAutoString newValue;
+  input->GetTextValue(newValue);
+
+  // Stop all searches in case they are async.
+  StopSearch();
+
+  if (!mInput) {
+    // StopSearch() can call PostSearchCleanup() which might result
+    // in a blur event, which could null out mInput, so we need to check it
+    // again.  See bug #395344 for more details
+    return NS_OK;
+  }
+
+  bool disabled;
+  input->GetDisableAutoComplete(&disabled);
+  NS_ENSURE_TRUE(!disabled, NS_OK);
+
+  // Usually we don't search again if the new string is the same as the last
+  // one. However, if this is called immediately after compositionend event, we
+  // need to search the same value again since the search was canceled at
+  // compositionstart event handler. The new string might also be the same as
+  // the last search if the autofilled portion was cleared. In this case, we may
+  // want to search again.
+
+  // Whether the user removed some text at the end.
+  bool userRemovedText =
+      newValue.Length() < mSearchString.Length() &&
+      Substring(mSearchString, 0, newValue.Length()).Equals(newValue);
+
+  // Whether the user is repeating the previous search.
+  bool repeatingPreviousSearch =
+      !userRemovedText && newValue.Equals(mSearchString);
+
+  mUserClearedAutoFill =
+      repeatingPreviousSearch &&
+      newValue.Length() < mPlaceholderCompletionString.Length() &&
+      Substring(mPlaceholderCompletionString, 0, newValue.Length())
+          .Equals(newValue);
+  bool searchAgainOnAutoFillClear =
+      mUserClearedAutoFill && mClearingAutoFillSearchesAgain;
+
+  if (!handlingCompositionCommit && !searchAgainOnAutoFillClear &&
+      newValue.Length() > 0 && repeatingPreviousSearch) {
+    return NS_OK;
+  }
+
+  if (userRemovedText || searchAgainOnAutoFillClear) {
+    if (userRemovedText) {
+      // We need to throw away previous results so we don't try to search
+      // through them again.
+      ClearResults();
+    }
+    mProhibitAutoFill = true;
+    mPlaceholderCompletionString.Truncate();
+  } else {
+    mProhibitAutoFill = false;
+  }
+
+  SetSearchStringInternal(newValue);
+
+  bool noRollupOnEmptySearch;
+  nsresult rv = input->GetNoRollupOnEmptySearch(&noRollupOnEmptySearch);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Don't search if the value is empty
+  if (newValue.Length() == 0 && !noRollupOnEmptySearch) {
+    // If autocomplete popup was closed by compositionstart event handler,
+    // we should reopen it forcibly even if the value is empty.
+    if (popupClosedByCompositionStart && handlingCompositionCommit) {
+      bool cancel;
+      HandleKeyNavigation(dom::KeyboardEvent_Binding::DOM_VK_DOWN, &cancel);
+      return NS_OK;
+    }
+    ClosePopup();
+    return NS_OK;
+  }
+
+  *_retval = true;
+  StartSearches();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleEnter(bool aIsPopupSelection,
+                                      dom::Event* aEvent, bool* _retval) {
+  *_retval = false;
+  if (!mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  // allow the event through unless there is something selected in the popup
+  input->GetPopupOpen(_retval);
+  if (*_retval) {
+    nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+    if (popup) {
+      int32_t selectedIndex;
+      popup->GetSelectedIndex(&selectedIndex);
+      *_retval = selectedIndex >= 0;
+    }
+  }
+
+  // Stop the search, and handle the enter.
+  StopSearch();
+  // StopSearch() can call PostSearchCleanup() which might result
+  // in a blur event, which could null out mInput, so we need to check it
+  // again.  See bug #408463 for more details
+  if (!mInput) {
+    return NS_OK;
+  }
+
+  EnterMatch(aIsPopupSelection, aEvent);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleEscape(bool* _retval) {
+  *_retval = false;
+  if (!mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  // allow the event through if the popup is closed
+  input->GetPopupOpen(_retval);
+
+  // Stop all searches in case they are async.
+  StopSearch();
+  ClearResults();
+  RevertTextValue();
+  ClosePopup();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleStartComposition() {
+  NS_ENSURE_TRUE(mCompositionState != eCompositionState_Composing, NS_OK);
+
+  mPopupClosedByCompositionStart = false;
+  mCompositionState = eCompositionState_Composing;
+
+  if (!mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  bool disabled;
+  input->GetDisableAutoComplete(&disabled);
+  if (disabled) return NS_OK;
+
+  // Stop all searches in case they are async.
+  StopSearch();
+
+  bool isOpen = false;
+  input->GetPopupOpen(&isOpen);
+  if (isOpen) {
+    ClosePopup();
+
+    bool stillOpen = false;
+    input->GetPopupOpen(&stillOpen);
+    mPopupClosedByCompositionStart = !stillOpen;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleEndComposition() {
+  NS_ENSURE_TRUE(mCompositionState == eCompositionState_Composing, NS_OK);
+
+  // We can't yet retrieve the committed value from the editor, since it isn't
+  // completely committed yet. Set mCompositionState to
+  // eCompositionState_Committing, so that when HandleText() is called (in
+  // response to the "input" event), we know that we should handle the
+  // committed text.
+  mCompositionState = eCompositionState_Committing;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleTab() {
+  bool cancel;
+  return HandleEnter(false, nullptr, &cancel);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleKeyNavigation(uint32_t aKey, bool* _retval) {
+  // By default, don't cancel the event
+  *_retval = false;
+
+  if (!mInput) {
+    // Stop all searches in case they are async.
+    StopSearch();
+    // Note: if now is after blur and IME end composition,
+    // check mInput before calling.
+    // See https://bugzilla.mozilla.org/show_bug.cgi?id=193544#c31
+    NS_ERROR(
+        "Called before attaching to the control or after detaching from the "
+        "control");
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_TRUE(popup != nullptr, NS_ERROR_FAILURE);
+
+  bool disabled;
+  input->GetDisableAutoComplete(&disabled);
+  NS_ENSURE_TRUE(!disabled, NS_OK);
+
+  if (aKey == dom::KeyboardEvent_Binding::DOM_VK_UP ||
+      aKey == dom::KeyboardEvent_Binding::DOM_VK_DOWN ||
+      aKey == dom::KeyboardEvent_Binding::DOM_VK_PAGE_UP ||
+      aKey == dom::KeyboardEvent_Binding::DOM_VK_PAGE_DOWN) {
+    bool isOpen = false;
+    input->GetPopupOpen(&isOpen);
+    if (isOpen) {
+      // Prevent the input from handling up/down events, as it may move
+      // the cursor to home/end on some systems
+      *_retval = true;
+      bool reverse = aKey == dom::KeyboardEvent_Binding::DOM_VK_UP ||
+                     aKey == dom::KeyboardEvent_Binding::DOM_VK_PAGE_UP;
+      bool page = aKey == dom::KeyboardEvent_Binding::DOM_VK_PAGE_UP ||
+                  aKey == dom::KeyboardEvent_Binding::DOM_VK_PAGE_DOWN;
+
+      // Fill in the value of the textbox with whatever is selected in the popup
+      // if the completeSelectedIndex attribute is set.  We check this before
+      // calling SelectBy of an earlier attempt to avoid crashing.
+      bool completeSelection;
+      input->GetCompleteSelectedIndex(&completeSelection);
+
+      // The user has keyed up or down to change the selection.  Stop the search
+      // (if there is one) now so that the results do not change while the user
+      // is making a selection.
+      Unused << StopSearch();
+
+      // Instruct the result view to scroll by the given amount and direction
+      popup->SelectBy(reverse, page);
+
+      if (completeSelection) {
+        int32_t selectedIndex;
+        popup->GetSelectedIndex(&selectedIndex);
+        if (selectedIndex >= 0) {
+          //  A result is selected, so fill in its value
+          nsAutoString value;
+          if (NS_SUCCEEDED(GetResultValueAt(selectedIndex, false, value))) {
+            // If the result is the previously autofilled string, then restore
+            // the search string and selection that existed when the result was
+            // autofilled.  Else, fill the result and move the caret to the end.
+            int32_t start;
+            if (value.Equals(mPlaceholderCompletionString,
+                             nsCaseInsensitiveStringComparator)) {
+              start = mSearchString.Length();
+              value = mPlaceholderCompletionString;
+              SetValueOfInputTo(value);
+            } else {
+              start = value.Length();
+              SetValueOfInputTo(value);
+            }
+
+            input->SelectTextRange(start, value.Length());
+          }
+          mCompletedSelectionIndex = selectedIndex;
+        } else {
+          // Nothing is selected, so fill in the last typed value
+          SetValueOfInputTo(mSearchString);
+          input->SelectTextRange(mSearchString.Length(),
+                                 mSearchString.Length());
+          mCompletedSelectionIndex = -1;
+        }
+      }
+    } else {
+      // Only show the popup if the caret is at the start or end of the input
+      // and there is no selection, so that the default defined key shortcuts
+      // for up and down move to the beginning and end of the field otherwise.
+      if (aKey == dom::KeyboardEvent_Binding::DOM_VK_UP ||
+          aKey == dom::KeyboardEvent_Binding::DOM_VK_DOWN) {
+        const bool isUp = aKey == dom::KeyboardEvent_Binding::DOM_VK_UP;
+
+        int32_t start, end;
+        input->GetSelectionStart(&start);
+        input->GetSelectionEnd(&end);
+
+        if (isUp) {
+          if (start > 0 || start != end) {
+            return NS_OK;
+          }
+        } else {
+          nsAutoString text;
+          input->GetTextValue(text);
+          if (start != end || end < (int32_t)text.Length()) {
+            return NS_OK;
+          }
+        }
+      }
+
+      nsAutoString oldSearchString;
+      uint16_t oldResult = 0;
+
+      // Open the popup if there has been a previous non-errored search, or
+      // else kick off a new search
+      if (!mResults.IsEmpty() &&
+          NS_SUCCEEDED(mResults[0]->GetSearchResult(&oldResult)) &&
+          oldResult != nsIAutoCompleteResult::RESULT_FAILURE &&
+          NS_SUCCEEDED(mResults[0]->GetSearchString(oldSearchString)) &&
+          oldSearchString.Equals(mSearchString,
+                                 nsCaseInsensitiveStringComparator)) {
+        if (mMatchCount) {
+          OpenPopup();
+        }
+      } else {
+        // Stop all searches in case they are async.
+        StopSearch();
+
+        if (!mInput) {
+          // StopSearch() can call PostSearchCleanup() which might result
+          // in a blur event, which could null out mInput, so we need to check
+          // it again.  See bug #395344 for more details
+          return NS_OK;
+        }
+
+        // Some script may have changed the value of the text field since our
+        // last keypress or after our focus handler and we don't want to
+        // search for a stale string.
+        nsAutoString value;
+        input->GetTextValue(value);
+        SetSearchStringInternal(value);
+
+        StartSearches();
+      }
+
+      bool isOpen = false;
+      input->GetPopupOpen(&isOpen);
+      if (isOpen) {
+        // Prevent the default action if we opened the popup in any of the code
+        // paths above.
+        *_retval = true;
+      }
+    }
+  } else if (aKey == dom::KeyboardEvent_Binding::DOM_VK_LEFT ||
+             aKey == dom::KeyboardEvent_Binding::DOM_VK_RIGHT
+#ifndef XP_MACOSX
+             || aKey == dom::KeyboardEvent_Binding::DOM_VK_HOME
+#endif
+  ) {
+    // The user hit a text-navigation key.
+    bool isOpen = false;
+    input->GetPopupOpen(&isOpen);
+
+    // If minresultsforpopup > 1 and there's less matches than the minimum
+    // required, the popup is not open, but the search suggestion is showing
+    // inline, so we should proceed as if we had the popup.
+    uint32_t minResultsForPopup;
+    input->GetMinResultsForPopup(&minResultsForPopup);
+    if (isOpen || (mMatchCount > 0 && mMatchCount < minResultsForPopup)) {
+      // For completeSelectedIndex autocomplete fields, if the popup shouldn't
+      // close when the caret is moved, don't adjust the text value or caret
+      // position.
+      bool completeSelection;
+      input->GetCompleteSelectedIndex(&completeSelection);
+      if (isOpen) {
+        bool noRollup;
+        input->GetNoRollupOnCaretMove(&noRollup);
+        if (noRollup) {
+          if (completeSelection) {
+            return NS_OK;
+          }
+        }
+      }
+
+      int32_t selectionEnd;
+      input->GetSelectionEnd(&selectionEnd);
+      int32_t selectionStart;
+      input->GetSelectionStart(&selectionStart);
+      bool shouldCompleteSelection =
+          (uint32_t)selectionEnd == mPlaceholderCompletionString.Length() &&
+          selectionStart < selectionEnd;
+      int32_t selectedIndex;
+      popup->GetSelectedIndex(&selectedIndex);
+      bool completeDefaultIndex;
+      input->GetCompleteDefaultIndex(&completeDefaultIndex);
+      if (completeDefaultIndex && shouldCompleteSelection) {
+        // We usually try to preserve the casing of what user has typed, but
+        // if he wants to autocomplete, we will replace the value with the
+        // actual autocomplete result. Note that the autocomplete input can also
+        // be showing e.g. "bar >> foo bar" if the search matched "bar", a
+        // word not at the start of the full value "foo bar".
+        // The user wants explicitely to use that result, so this ensures
+        // association of the result with the autocompleted text.
+        nsAutoString value;
+        nsAutoString inputValue;
+        input->GetTextValue(inputValue);
+        if (NS_SUCCEEDED(GetDefaultCompleteValue(-1, false, value))) {
+          nsAutoString suggestedValue;
+          int32_t pos = inputValue.Find(u" >> ");
+          if (pos > 0) {
+            inputValue.Right(suggestedValue, inputValue.Length() - pos - 4);
+          } else {
+            suggestedValue = inputValue;
+          }
+
+          if (value.Equals(suggestedValue, nsCaseInsensitiveStringComparator)) {
+            SetValueOfInputTo(value);
+            input->SelectTextRange(value.Length(), value.Length());
+          }
+        }
+      } else if (!completeDefaultIndex && !completeSelection &&
+                 selectedIndex >= 0) {
+        // The pop-up is open and has a selection, take its value
+        nsAutoString value;
+        if (NS_SUCCEEDED(GetResultValueAt(selectedIndex, false, value))) {
+          SetValueOfInputTo(value);
+          input->SelectTextRange(value.Length(), value.Length());
+        }
+      }
+
+      // Close the pop-up even if nothing was selected
+      ClearSearchTimer();
+      ClosePopup();
+    }
+    // Update last-searched string to the current input, since the input may
+    // have changed.  Without this, subsequent backspaces look like text
+    // additions, not text deletions.
+    nsAutoString value;
+    input->GetTextValue(value);
+    SetSearchStringInternal(value);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::HandleDelete(bool* _retval) {
+  *_retval = false;
+  if (!mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  bool isOpen = false;
+  input->GetPopupOpen(&isOpen);
+  if (!isOpen || mMatchCount == 0) {
+    // Nothing left to delete, proceed as normal
+    bool unused = false;
+    HandleText(&unused);
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_TRUE(popup, NS_ERROR_FAILURE);
+
+  int32_t index, searchIndex, matchIndex;
+  popup->GetSelectedIndex(&index);
+  if (index == -1) {
+    // No match is selected in the list
+    bool unused = false;
+    HandleText(&unused);
+    return NS_OK;
+  }
+
+  MatchIndexToSearch(index, &searchIndex, &matchIndex);
+  NS_ENSURE_TRUE(searchIndex >= 0 && matchIndex >= 0, NS_ERROR_FAILURE);
+
+  nsIAutoCompleteResult* result = mResults.SafeObjectAt(searchIndex);
+  NS_ENSURE_TRUE(result, NS_ERROR_FAILURE);
+
+  bool removable;
+  nsresult rv = result->IsRemovableAt(matchIndex, &removable);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!removable) {
+    return NS_OK;
+  }
+
+  nsAutoString search;
+  input->GetSearchParam(search);
+
+  // Clear the match in our result and in the DB.
+  result->RemoveValueAt(matchIndex);
+  --mMatchCount;
+
+  // We removed it, so make sure we cancel the event that triggered this call.
+  *_retval = true;
+
+  // Unselect the current item.
+  popup->SetSelectedIndex(-1);
+
+  // Adjust index, if needed.
+  MOZ_ASSERT(index >= 0);  // We verified this above, after MatchIndexToSearch.
+  if (static_cast<uint32_t>(index) >= mMatchCount) index = mMatchCount - 1;
+
+  if (mMatchCount > 0) {
+    // There are still matches in the popup, select the current index again.
+    popup->SetSelectedIndex(index);
+
+    // Complete to the new current value.
+    bool shouldComplete = false;
+    input->GetCompleteDefaultIndex(&shouldComplete);
+    if (shouldComplete) {
+      nsAutoString value;
+      if (NS_SUCCEEDED(GetResultValueAt(index, false, value))) {
+        CompleteValue(value);
+      }
+    }
+
+    // Invalidate the popup.
+    popup->Invalidate(nsIAutoCompletePopup::INVALIDATE_REASON_DELETE);
+  } else {
+    // Nothing left in the popup, clear any pending search timers and
+    // close the popup.
+    ClearSearchTimer();
+    uint32_t minResults;
+    input->GetMinResultsForPopup(&minResults);
+    if (minResults) {
+      ClosePopup();
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::GetResultAt(int32_t aIndex,
+                                               nsIAutoCompleteResult** aResult,
+                                               int32_t* aMatchIndex) {
+  int32_t searchIndex;
+  MatchIndexToSearch(aIndex, &searchIndex, aMatchIndex);
+  NS_ENSURE_TRUE(searchIndex >= 0 && *aMatchIndex >= 0, NS_ERROR_FAILURE);
+
+  *aResult = mResults.SafeObjectAt(searchIndex);
+  NS_ENSURE_TRUE(*aResult, NS_ERROR_FAILURE);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetValueAt(int32_t aIndex, nsAString& _retval) {
+  GetResultLabelAt(aIndex, _retval);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetLabelAt(int32_t aIndex, nsAString& _retval) {
+  GetResultLabelAt(aIndex, _retval);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetCommentAt(int32_t aIndex, nsAString& _retval) {
+  int32_t matchIndex;
+  nsIAutoCompleteResult* result;
+  nsresult rv = GetResultAt(aIndex, &result, &matchIndex);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return result->GetCommentAt(matchIndex, _retval);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetStyleAt(int32_t aIndex, nsAString& _retval) {
+  int32_t matchIndex;
+  nsIAutoCompleteResult* result;
+  nsresult rv = GetResultAt(aIndex, &result, &matchIndex);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return result->GetStyleAt(matchIndex, _retval);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetImageAt(int32_t aIndex, nsAString& _retval) {
+  int32_t matchIndex;
+  nsIAutoCompleteResult* result;
+  nsresult rv = GetResultAt(aIndex, &result, &matchIndex);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return result->GetImageAt(matchIndex, _retval);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetFinalCompleteValueAt(int32_t aIndex,
+                                                  nsAString& _retval) {
+  int32_t matchIndex;
+  nsIAutoCompleteResult* result;
+  nsresult rv = GetResultAt(aIndex, &result, &matchIndex);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return result->GetFinalCompleteValueAt(matchIndex, _retval);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::SetSearchString(const nsAString& aSearchString) {
+  SetSearchStringInternal(aSearchString);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetSearchString(nsAString& aSearchString) {
+  aSearchString = mSearchString;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////
+//// nsIAutoCompleteObserver
+
+NS_IMETHODIMP
+nsAutoCompleteController::OnSearchResult(nsIAutoCompleteSearch* aSearch,
+                                         nsIAutoCompleteResult* aResult) {
+  MOZ_ASSERT(mSearchesOngoing > 0 && mSearches.Contains(aSearch));
+
+  uint16_t result = 0;
+  if (aResult) {
+    aResult->GetSearchResult(&result);
+  }
+
+  // If our results are incremental, the search is still ongoing.
+  if (result != nsIAutoCompleteResult::RESULT_SUCCESS_ONGOING &&
+      result != nsIAutoCompleteResult::RESULT_NOMATCH_ONGOING) {
+    --mSearchesOngoing;
+  }
+
+  // Look up the index of the search which is returning.
+  for (uint32_t i = 0; i < mSearches.Length(); ++i) {
+    if (mSearches[i] == aSearch) {
+      ProcessResult(i, aResult);
+      break;
+    }
+  }
+
+  // If a match is found in ProcessResult, PostSearchCleanup will open the popup
+  PostSearchCleanup();
+
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////
+//// nsITimerCallback
+
+MOZ_CAN_RUN_SCRIPT_BOUNDARY
+NS_IMETHODIMP
+nsAutoCompleteController::Notify(nsITimer* timer) {
+  mTimer = nullptr;
+
+  if (mImmediateSearchesCount == 0) {
+    // If there were no immediate searches, BeforeSearches has not yet been
+    // called, so do it now.
+    nsresult rv = BeforeSearches();
+    if (NS_FAILED(rv)) return rv;
+  }
+  StartSearch(nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_DELAYED);
+  AfterSearches();
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////
+//// nsINamed
+
+NS_IMETHODIMP
+nsAutoCompleteController::GetName(nsACString& aName) {
+  aName.AssignLiteral("nsAutoCompleteController");
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////
+//// nsAutoCompleteController
+
+nsresult nsAutoCompleteController::OpenPopup() {
+  uint32_t minResults;
+  mInput->GetMinResultsForPopup(&minResults);
+
+  if (mMatchCount >= minResults) {
+    nsCOMPtr<nsIAutoCompleteInput> input = mInput;
+    return input->SetPopupOpen(true);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::ClosePopup() {
+  if (!mInput) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  bool isOpen = false;
+  input->GetPopupOpen(&isOpen);
+  if (!isOpen) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_TRUE(popup != nullptr, NS_ERROR_FAILURE);
+  MOZ_ALWAYS_SUCCEEDS(input->SetPopupOpen(false));
+  return popup->SetSelectedIndex(-1);
+}
+
+nsresult nsAutoCompleteController::BeforeSearches() {
+  NS_ENSURE_STATE(mInput);
+
+  mSearchStatus = nsIAutoCompleteController::STATUS_SEARCHING;
+  mDefaultIndexCompleted = false;
+
+  bool invalidatePreviousResult = false;
+  mInput->GetInvalidatePreviousResult(&invalidatePreviousResult);
+
+  if (!invalidatePreviousResult) {
+    // ClearResults will clear the mResults array, but we should pass the
+    // previous result to each search to allow reusing it.  So we temporarily
+    // cache the current results until AfterSearches().
+    if (!mResultCache.AppendObjects(mResults)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+  ClearResults(true);
+  mSearchesOngoing = mSearches.Length();
+  mSearchesFailed = 0;
+
+  // notify the input that the search is beginning
+  mInput->OnSearchBegin();
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::StartSearch(uint16_t aSearchType) {
+  NS_ENSURE_STATE(mInput);
+  nsCOMPtr<nsIAutoCompleteInput> input = mInput;
+
+  // Iterate a copy of |mSearches| so that we don't run into trouble if the
+  // array is mutated while we're still in the loop. An nsIAutoCompleteSearch
+  // implementation could synchronously start a new search when StartSearch()
+  // is called and that would lead to assertions down the way.
+  nsCOMArray<nsIAutoCompleteSearch> searchesCopy(mSearches);
+  for (uint32_t i = 0; i < searchesCopy.Length(); ++i) {
+    nsCOMPtr<nsIAutoCompleteSearch> search = searchesCopy[i];
+
+    // Filter on search type.  Not all the searches implement this interface,
+    // in such a case just consider them delayed.
+    uint16_t searchType = nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_DELAYED;
+    nsCOMPtr<nsIAutoCompleteSearchDescriptor> searchDesc =
+        do_QueryInterface(search);
+    if (searchDesc) searchDesc->GetSearchType(&searchType);
+    if (searchType != aSearchType) continue;
+
+    nsIAutoCompleteResult* result = mResultCache.SafeObjectAt(i);
+
+    if (result) {
+      uint16_t searchResult;
+      result->GetSearchResult(&searchResult);
+      if (searchResult != nsIAutoCompleteResult::RESULT_SUCCESS &&
+          searchResult != nsIAutoCompleteResult::RESULT_SUCCESS_ONGOING &&
+          searchResult != nsIAutoCompleteResult::RESULT_NOMATCH)
+        result = nullptr;
+    }
+
+    nsAutoString searchParam;
+    nsresult rv = input->GetSearchParam(searchParam);
+    if (NS_FAILED(rv)) return rv;
+
+    // FormFill expects the searchParam to only contain the input element id,
+    // other consumers may have other expectations, so this modifies it only
+    // for new consumers handling autoFill by themselves.
+    if (mProhibitAutoFill && mClearingAutoFillSearchesAgain) {
+      searchParam.AppendLiteral(" prohibit-autofill");
+    }
+
+    uint32_t userContextId;
+    rv = input->GetUserContextId(&userContextId);
+    if (NS_SUCCEEDED(rv) &&
+        userContextId != nsIScriptSecurityManager::DEFAULT_USER_CONTEXT_ID) {
+      searchParam.AppendLiteral(" user-context-id:");
+      searchParam.AppendInt(userContextId, 10);
+    }
+
+    rv = search->StartSearch(mSearchString, searchParam, result,
+                             static_cast<nsIAutoCompleteObserver*>(this),
+                             nullptr);
+    if (NS_FAILED(rv)) {
+      ++mSearchesFailed;
+      MOZ_ASSERT(mSearchesOngoing > 0);
+      --mSearchesOngoing;
+    }
+    // Because of the joy of nested event loops (which can easily happen when
+    // some code uses a generator for an asynchronous AutoComplete search),
+    // nsIAutoCompleteSearch::StartSearch might cause us to be detached from our
+    // input field.  The next time we iterate, we'd be touching something that
+    // we shouldn't be, and result in a crash.
+    if (!mInput) {
+      // The search operation has been finished.
+      return NS_OK;
+    }
+  }
+
+  return NS_OK;
+}
+
+void nsAutoCompleteController::AfterSearches() {
+  mResultCache.Clear();
+  // if the below evaluates to true, that means mSearchesOngoing must be 0
+  if (mSearchesFailed == mSearches.Length()) {
+    PostSearchCleanup();
+  }
+}
+
+NS_IMETHODIMP
+nsAutoCompleteController::StopSearch() {
+  // Stop the timer if there is one
+  ClearSearchTimer();
+
+  // Stop any ongoing asynchronous searches
+  if (mSearchStatus == nsIAutoCompleteController::STATUS_SEARCHING) {
+    for (uint32_t i = 0; i < mSearches.Length(); ++i) {
+      nsCOMPtr<nsIAutoCompleteSearch> search = mSearches[i];
+      search->StopSearch();
+    }
+    mSearchesOngoing = 0;
+    // since we were searching, but now we've stopped,
+    // we need to call PostSearchCleanup()
+    PostSearchCleanup();
+  }
+  return NS_OK;
+}
+
+void nsAutoCompleteController::MaybeCompletePlaceholder() {
+  MOZ_ASSERT(mInput);
+
+  if (!mInput) {  // or mInput depending on what you choose
+    MOZ_ASSERT_UNREACHABLE("Input should always be valid at this point");
+    return;
+  }
+
+  int32_t selectionStart;
+  mInput->GetSelectionStart(&selectionStart);
+  int32_t selectionEnd;
+  mInput->GetSelectionEnd(&selectionEnd);
+
+  // Check if the current input should be completed with the placeholder string
+  // from the last completion until the actual search results come back.
+  // The new input string needs to be compatible with the last completed string.
+  // E.g. if the new value is "fob", but the last completion was "foobar",
+  // then the last completion is incompatible.
+  // If the search string is the same as the last completion value, then don't
+  // complete the value again (this prevents completion to happen e.g. if the
+  // cursor is moved and StartSeaches() is invoked).
+  // In addition, the selection must be at the end of the current input to
+  // trigger the placeholder completion.
+  bool usePlaceholderCompletion =
+      !mUserClearedAutoFill && !mPlaceholderCompletionString.IsEmpty() &&
+      mPlaceholderCompletionString.Length() > mSearchString.Length() &&
+      selectionEnd == selectionStart &&
+      selectionEnd == (int32_t)mSearchString.Length() &&
+      StringBeginsWith(mPlaceholderCompletionString, mSearchString,
+                       nsCaseInsensitiveStringComparator);
+
+  if (usePlaceholderCompletion) {
+    CompleteValue(mPlaceholderCompletionString);
+  } else {
+    mPlaceholderCompletionString.Truncate();
+  }
+}
+
+nsresult nsAutoCompleteController::StartSearches() {
+  // Don't create a new search timer if we're already waiting for one to fire.
+  // If we don't check for this, we won't be able to cancel the original timer
+  // and may crash when it fires (bug 236659).
+  if (mTimer || !mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  if (!mSearches.Length()) {
+    // Initialize our list of search objects
+    uint32_t searchCount;
+    input->GetSearchCount(&searchCount);
+    mResults.SetCapacity(searchCount);
+    mSearches.SetCapacity(searchCount);
+    mImmediateSearchesCount = 0;
+
+    const char* searchCID = kAutoCompleteSearchCID;
+
+    for (uint32_t i = 0; i < searchCount; ++i) {
+      // Use the search name to create the contract id string for the search
+      // service
+      nsAutoCString searchName;
+      input->GetSearchAt(i, searchName);
+      nsAutoCString cid(searchCID);
+      cid.Append(searchName);
+
+      // Use the created cid to get a pointer to the search service and store it
+      // for later
+      nsCOMPtr<nsIAutoCompleteSearch> search = do_GetService(cid.get());
+      if (search) {
+        mSearches.AppendObject(search);
+
+        // Count immediate searches.
+        nsCOMPtr<nsIAutoCompleteSearchDescriptor> searchDesc =
+            do_QueryInterface(search);
+        if (searchDesc) {
+          uint16_t searchType =
+              nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_DELAYED;
+          if (NS_SUCCEEDED(searchDesc->GetSearchType(&searchType)) &&
+              searchType ==
+                  nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_IMMEDIATE) {
+            mImmediateSearchesCount++;
+          }
+
+          if (!mClearingAutoFillSearchesAgain) {
+            searchDesc->GetClearingAutoFillSearchesAgain(
+                &mClearingAutoFillSearchesAgain);
+          }
+        }
+      }
+    }
+  }
+
+  // Check if the current input should be completed with the placeholder string
+  // from the last completion until the actual search results come back.
+  MaybeCompletePlaceholder();
+
+  // Get the timeout for delayed searches.
+  uint32_t timeout;
+  input->GetTimeout(&timeout);
+
+  uint32_t immediateSearchesCount = mImmediateSearchesCount;
+  if (timeout == 0) {
+    // All the searches should be executed immediately.
+    immediateSearchesCount = mSearches.Length();
+  }
+
+  if (immediateSearchesCount > 0) {
+    nsresult rv = BeforeSearches();
+    if (NS_FAILED(rv)) return rv;
+    StartSearch(nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_IMMEDIATE);
+
+    if (mSearches.Length() == immediateSearchesCount) {
+      // Either all searches are immediate, or the timeout is 0.  In the
+      // latter case we still have to execute the delayed searches, otherwise
+      // this will be a no-op.
+      StartSearch(nsIAutoCompleteSearchDescriptor::SEARCH_TYPE_DELAYED);
+
+      // All the searches have been started, just finish.
+      AfterSearches();
+      return NS_OK;
+    }
+  }
+
+  MOZ_ASSERT(timeout > 0, "Trying to delay searches with a 0 timeout!");
+
+  // Now start the delayed searches.
+  return NS_NewTimerWithCallback(getter_AddRefs(mTimer), this, timeout,
+                                 nsITimer::TYPE_ONE_SHOT);
+}
+
+nsresult nsAutoCompleteController::ClearSearchTimer() {
+  if (mTimer) {
+    mTimer->Cancel();
+    mTimer = nullptr;
+  }
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::EnterMatch(bool aIsPopupSelection,
+                                              dom::Event* aEvent) {
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_TRUE(popup != nullptr, NS_ERROR_FAILURE);
+
+  bool forceComplete;
+  input->GetForceComplete(&forceComplete);
+
+  int32_t selectedIndex;
+  popup->GetSelectedIndex(&selectedIndex);
+
+  // Ask the popup if it wants to enter a special value into the textbox
+  nsAutoString value;
+  nsAutoString comment;
+
+  popup->GetOverrideValue(value);
+  if (value.IsEmpty()) {
+    bool shouldComplete;
+    input->GetCompleteDefaultIndex(&shouldComplete);
+    bool completeSelection;
+    input->GetCompleteSelectedIndex(&completeSelection);
+
+    if (selectedIndex >= 0) {
+      nsAutoString inputValue;
+      input->GetTextValue(inputValue);
+      GetCommentAt(selectedIndex, comment);
+      if (aIsPopupSelection || !completeSelection) {
+        // We need to fill-in the value if:
+        //  * completeselectedindex is false
+        //  * A match in the popup was confirmed
+        GetResultValueAt(selectedIndex, true, value);
+      } else if (mDefaultIndexCompleted &&
+                 inputValue.Equals(mPlaceholderCompletionString,
+                                   nsCaseInsensitiveStringComparator)) {
+        // We also need to fill-in the value if the default index completion was
+        // confirmed, though we cannot use the selectedIndex cause the selection
+        // may have been changed by the mouse in the meanwhile.
+        GetFinalDefaultCompleteValue(value);
+      } else if (mCompletedSelectionIndex != -1) {
+        // If completeselectedindex is true, and EnterMatch was not invoked by
+        // mouse-clicking a match (for example the user pressed Enter),
+        // don't fill in the value as it will have already been filled in as
+        // needed, unless the selected match has a final complete value that
+        // differs from the user-facing value.
+        nsAutoString finalValue;
+        GetResultValueAt(mCompletedSelectionIndex, true, finalValue);
+        if (!inputValue.Equals(finalValue)) {
+          value = finalValue;
+        }
+      }
+    } else if (shouldComplete) {
+      // We usually try to preserve the casing of what user has typed, but
+      // if he wants to autocomplete, we will replace the value with the
+      // actual autocomplete result.
+      // The user wants explicitely to use that result, so this ensures
+      // association of the result with the autocompleted text.
+      nsAutoString defaultIndexValue;
+      if (NS_SUCCEEDED(GetFinalDefaultCompleteValue(defaultIndexValue)))
+        value = defaultIndexValue;
+    }
+
+    if (forceComplete && value.IsEmpty() && shouldComplete) {
+      // See if inputValue is one of the autocomplete results. It can be an
+      // identical value, or if it matched the middle of a result it can be
+      // something like "bar >> foobar" (user entered bar and foobar is
+      // the result value).
+      // If the current search matches one of the autocomplete results, we
+      // should use that result, and not overwrite it with the default value.
+      // It's indeed possible EnterMatch gets called a second time (for example
+      // by the blur handler) and it should not overwrite the current match.
+      nsAutoString inputValue;
+      input->GetTextValue(inputValue);
+      nsAutoString suggestedValue;
+      int32_t pos = inputValue.Find(u" >> ");
+      if (pos > 0) {
+        inputValue.Right(suggestedValue, inputValue.Length() - pos - 4);
+      } else {
+        suggestedValue = inputValue;
+      }
+
+      for (uint32_t i = 0; i < mResults.Length(); ++i) {
+        nsIAutoCompleteResult* result = mResults[i];
+        if (result) {
+          uint32_t matchCount = 0;
+          result->GetMatchCount(&matchCount);
+          for (uint32_t j = 0; j < matchCount; ++j) {
+            nsAutoString matchValue;
+            result->GetValueAt(j, matchValue);
+            if (suggestedValue.Equals(matchValue,
+                                      nsCaseInsensitiveStringComparator)) {
+              nsAutoString finalMatchValue;
+              result->GetFinalCompleteValueAt(j, finalMatchValue);
+              value = finalMatchValue;
+              break;
+            }
+          }
+        }
+      }
+      // The value should have been set at this point. If not, then it's not
+      // a value that should be autocompleted.
+    } else if (forceComplete && value.IsEmpty() && completeSelection) {
+      // Since nothing was selected, and forceComplete is specified, that means
+      // we have to find the first default match and enter it instead.
+      for (uint32_t i = 0; i < mResults.Length(); ++i) {
+        nsIAutoCompleteResult* result = mResults[i];
+        if (result) {
+          int32_t defaultIndex;
+          result->GetDefaultIndex(&defaultIndex);
+          if (defaultIndex >= 0) {
+            result->GetFinalCompleteValueAt(defaultIndex, value);
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  if (comment.IsEmpty()) {
+    comment.Assign(u"{}");
+  }
+
+  nsCOMPtr<nsIObserverService> obsSvc = services::GetObserverService();
+  NS_ENSURE_STATE(obsSvc);
+  obsSvc->NotifyObservers(input, "autocomplete-will-enter-text", comment.get());
+
+  if (!value.IsEmpty()) {
+    SetValueOfInputTo(value);
+    input->SelectTextRange(value.Length(), value.Length());
+    SetSearchStringInternal(value);
+  }
+
+  obsSvc->NotifyObservers(input, "autocomplete-did-enter-text", nullptr);
+
+  bool cancel;
+  bool itemWasSelected = selectedIndex >= 0 && !value.IsEmpty();
+  input->OnTextEntered(aEvent, itemWasSelected, &cancel);
+
+  ClosePopup();
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::RevertTextValue() {
+  // StopSearch() can call PostSearchCleanup() which might result
+  // in a blur event, which could null out mInput, so we need to check it
+  // again.  See bug #408463 for more details
+  if (!mInput) return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  // If current input value is different from what we have set, it means
+  // somebody modified the value like JS of the web content.  In such case,
+  // we shouldn't overwrite it with the old value.
+  nsAutoString currentValue;
+  input->GetTextValue(currentValue);
+  if (currentValue != mSetValue) {
+    SetSearchStringInternal(currentValue);
+    return NS_OK;
+  }
+
+  bool cancel = false;
+  input->OnTextReverted(&cancel);
+
+  if (!cancel) {
+    nsCOMPtr<nsIObserverService> obsSvc = services::GetObserverService();
+    NS_ENSURE_STATE(obsSvc);
+    obsSvc->NotifyObservers(input, "autocomplete-will-revert-text", nullptr);
+
+    // Don't change the value if it is the same to prevent sending useless
+    // events. NOTE: how can |RevertTextValue| be called with inputValue !=
+    // oldValue?
+    if (mSearchString != currentValue) {
+      SetValueOfInputTo(mSearchString);
+    }
+
+    obsSvc->NotifyObservers(input, "autocomplete-did-revert-text", nullptr);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::ProcessResult(
+    int32_t aSearchIndex, nsIAutoCompleteResult* aResult) {
+  NS_ENSURE_STATE(mInput);
+  MOZ_ASSERT(aResult, "ProcessResult should always receive a result");
+  NS_ENSURE_ARG(aResult);
+
+  uint16_t searchResult = 0;
+  aResult->GetSearchResult(&searchResult);
+
+  // The following code supports incremental updating results in 2 ways:
+  //  * The search may reuse the same result, just by adding entries to it.
+  //  * The search may send a new result every time.  In this case we merge
+  //    the results and proceed on the same code path as before.
+  // This way both mSearches and mResults can be indexed by the search index,
+  // cause we'll always have only one result per search.
+  if (mResults.IndexOf(aResult) == -1) {
+    nsIAutoCompleteResult* oldResult = mResults.SafeObjectAt(aSearchIndex);
+    if (oldResult) {
+      MOZ_ASSERT(false,
+                 "Passing new matches to OnSearchResult with a new "
+                 "nsIAutoCompleteResult every time is deprecated, please "
+                 "update the same result until the search is done");
+      // Build a new nsIAutocompleteSimpleResult and merge results into it.
+      RefPtr<nsAutoCompleteSimpleResult> mergedResult =
+          new nsAutoCompleteSimpleResult();
+      mergedResult->AppendResult(oldResult);
+      mergedResult->AppendResult(aResult);
+      mResults.ReplaceObjectAt(mergedResult, aSearchIndex);
+    } else {
+      // This inserts and grows the array if needed.
+      mResults.ReplaceObjectAt(aResult, aSearchIndex);
+    }
+  }
+  // When found the result should have the same index as the search.
+  MOZ_ASSERT_IF(mResults.IndexOf(aResult) != -1,
+                mResults.IndexOf(aResult) == aSearchIndex);
+  MOZ_ASSERT(mResults.Count() >= aSearchIndex + 1,
+             "aSearchIndex should always be valid for mResults");
+
+  uint32_t oldMatchCount = mMatchCount;
+  // If the search failed, increase the match count to include the error
+  // description.
+  if (searchResult == nsIAutoCompleteResult::RESULT_FAILURE) {
+    nsAutoString error;
+    aResult->GetErrorDescription(error);
+    if (!error.IsEmpty()) {
+      ++mMatchCount;
+    }
+  } else if (searchResult == nsIAutoCompleteResult::RESULT_SUCCESS ||
+             searchResult == nsIAutoCompleteResult::RESULT_SUCCESS_ONGOING) {
+    // Increase the match count for all matches in this result.
+    uint32_t totalMatchCount = 0;
+    for (uint32_t i = 0; i < mResults.Length(); i++) {
+      nsIAutoCompleteResult* result = mResults.SafeObjectAt(i);
+      if (result) {
+        uint32_t matchCount = 0;
+        result->GetMatchCount(&matchCount);
+        totalMatchCount += matchCount;
+      }
+    }
+    uint32_t delta = totalMatchCount - oldMatchCount;
+    mMatchCount += delta;
+  }
+
+  // Try to autocomplete the default index for this search.
+  // Do this before invalidating so the binding knows about it.
+  CompleteDefaultIndex(aSearchIndex);
+
+  // Refresh the popup view to display the new search results
+  nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+  NS_ENSURE_TRUE(popup != nullptr, NS_ERROR_FAILURE);
+  popup->Invalidate(nsIAutoCompletePopup::INVALIDATE_REASON_NEW_RESULT);
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::PostSearchCleanup() {
+  NS_ENSURE_STATE(mInput);
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  uint32_t minResults;
+  input->GetMinResultsForPopup(&minResults);
+
+  if (mMatchCount || minResults == 0) {
+    OpenPopup();
+  } else if (mSearchesOngoing == 0) {
+    ClosePopup();
+  }
+
+  if (mSearchesOngoing == 0) {
+    mSearchStatus = mMatchCount
+                        ? nsIAutoCompleteController::STATUS_COMPLETE_MATCH
+                        : nsIAutoCompleteController::STATUS_COMPLETE_NO_MATCH;
+    // notify the input that the search is complete
+    input->OnSearchComplete();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::ClearResults(bool aIsSearching) {
+  int32_t oldMatchCount = mMatchCount;
+  mMatchCount = 0;
+  mResults.Clear();
+  if (oldMatchCount != 0) {
+    if (mInput) {
+      nsCOMPtr<nsIAutoCompletePopup> popup(GetPopup());
+      NS_ENSURE_TRUE(popup != nullptr, NS_ERROR_FAILURE);
+      // Clear the selection.
+      popup->SetSelectedIndex(-1);
+    }
+  }
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::CompleteDefaultIndex(int32_t aResultIndex) {
+  if (mDefaultIndexCompleted || mProhibitAutoFill ||
+      mSearchString.Length() == 0 || !mInput)
+    return NS_OK;
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+
+  int32_t selectionStart;
+  input->GetSelectionStart(&selectionStart);
+  int32_t selectionEnd;
+  input->GetSelectionEnd(&selectionEnd);
+
+  bool isPlaceholderSelected =
+      selectionEnd == (int32_t)mPlaceholderCompletionString.Length() &&
+      selectionStart == (int32_t)mSearchString.Length() &&
+      StringBeginsWith(mPlaceholderCompletionString, mSearchString,
+                       nsCaseInsensitiveStringComparator);
+
+  // Don't try to automatically complete to the first result if there's already
+  // a selection or the cursor isn't at the end of the input. In case the
+  // selection is from the current placeholder completion value, then still
+  // automatically complete.
+  if (!isPlaceholderSelected &&
+      (selectionEnd != selectionStart ||
+       selectionEnd != (int32_t)mSearchString.Length()))
+    return NS_OK;
+
+  bool shouldComplete;
+  input->GetCompleteDefaultIndex(&shouldComplete);
+  if (!shouldComplete) return NS_OK;
+
+  nsAutoString resultValue;
+  if (NS_SUCCEEDED(GetDefaultCompleteValue(aResultIndex, true, resultValue))) {
+    CompleteValue(resultValue);
+    mDefaultIndexCompleted = true;
+  } else {
+    // Reset the search string again, in case it was completed with
+    // mPlaceholderCompletionString, but the actually received result doesn't
+    // have a default index result. Only reset the input when necessary, to
+    // avoid triggering unnecessary new searches.
+    nsAutoString inputValue;
+    input->GetTextValue(inputValue);
+    if (!inputValue.Equals(mSearchString)) {
+      SetValueOfInputTo(mSearchString);
+      input->SelectTextRange(mSearchString.Length(), mSearchString.Length());
+    }
+    mPlaceholderCompletionString.Truncate();
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::GetDefaultCompleteResult(
+    int32_t aResultIndex, nsIAutoCompleteResult** _result,
+    int32_t* _defaultIndex) {
+  *_defaultIndex = -1;
+  int32_t resultIndex = aResultIndex;
+
+  // If a result index was not provided, find the first defaultIndex result.
+  for (int32_t i = 0; resultIndex < 0 && i < mResults.Count(); ++i) {
+    nsIAutoCompleteResult* result = mResults.SafeObjectAt(i);
+    if (result && NS_SUCCEEDED(result->GetDefaultIndex(_defaultIndex)) &&
+        *_defaultIndex >= 0) {
+      resultIndex = i;
+    }
+  }
+  if (resultIndex < 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *_result = mResults.SafeObjectAt(resultIndex);
+  NS_ENSURE_TRUE(*_result, NS_ERROR_FAILURE);
+
+  if (*_defaultIndex < 0) {
+    // The search must explicitly provide a default index in order
+    // for us to be able to complete.
+    (*_result)->GetDefaultIndex(_defaultIndex);
+  }
+
+  if (*_defaultIndex < 0) {
+    // We were given a result index, but that result doesn't want to
+    // be autocompleted.
+    return NS_ERROR_FAILURE;
+  }
+
+  // If the result wrongly notifies a RESULT_SUCCESS with no matches, or
+  // provides a defaultIndex greater than its matchCount, avoid trying to
+  // complete to an empty value.
+  uint32_t matchCount = 0;
+  (*_result)->GetMatchCount(&matchCount);
+  // Here defaultIndex is surely non-negative, so can be cast to unsigned.
+  if ((uint32_t)(*_defaultIndex) >= matchCount) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::GetDefaultCompleteValue(int32_t aResultIndex,
+                                                           bool aPreserveCasing,
+                                                           nsAString& _retval) {
+  nsIAutoCompleteResult* result;
+  int32_t defaultIndex = -1;
+  nsresult rv = GetDefaultCompleteResult(aResultIndex, &result, &defaultIndex);
+  if (NS_FAILED(rv)) return rv;
+
+  nsAutoString resultValue;
+  result->GetValueAt(defaultIndex, resultValue);
+  if (aPreserveCasing && StringBeginsWith(resultValue, mSearchString,
+                                          nsCaseInsensitiveStringComparator)) {
+    // We try to preserve user casing, otherwise we would end up changing
+    // the case of what he typed, if we have a result with a different casing.
+    // For example if we have result "Test", and user starts writing "tuna",
+    // after digiting t, we would convert it to T trying to autocomplete "Test".
+    // We will still complete to cased "Test" if the user explicitely choose
+    // that result, by either selecting it in the results popup, or with
+    // keyboard navigation or if autocompleting in the middle.
+    nsAutoString casedResultValue;
+    casedResultValue.Assign(mSearchString);
+    // Use what the user has typed so far.
+    casedResultValue.Append(
+        Substring(resultValue, mSearchString.Length(), resultValue.Length()));
+    _retval = casedResultValue;
+  } else
+    _retval = resultValue;
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::GetFinalDefaultCompleteValue(
+    nsAString& _retval) {
+  MOZ_ASSERT(mInput, "Must have a valid input");
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  nsIAutoCompleteResult* result;
+  int32_t defaultIndex = -1;
+  nsresult rv = GetDefaultCompleteResult(-1, &result, &defaultIndex);
+  if (NS_FAILED(rv)) return rv;
+
+  result->GetValueAt(defaultIndex, _retval);
+  nsAutoString inputValue;
+  input->GetTextValue(inputValue);
+  if (!_retval.Equals(inputValue, nsCaseInsensitiveStringComparator)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsAutoString finalCompleteValue;
+  rv = result->GetFinalCompleteValueAt(defaultIndex, finalCompleteValue);
+  if (NS_SUCCEEDED(rv)) {
+    _retval = finalCompleteValue;
+  }
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::CompleteValue(nsString& aValue)
+/* mInput contains mSearchString, which we want to autocomplete to aValue.  If
+ * selectDifference is true, select the remaining portion of aValue not
+ * contained in mSearchString. */
+{
+  MOZ_ASSERT(mInput, "Must have a valid input");
+
+  nsCOMPtr<nsIAutoCompleteInput> input(mInput);
+  const int32_t mSearchStringLength = mSearchString.Length();
+  int32_t endSelect = aValue.Length();  // By default, select all of aValue.
+
+  if (aValue.IsEmpty() || StringBeginsWith(aValue, mSearchString,
+                                           nsCaseInsensitiveStringComparator)) {
+    // aValue is empty (we were asked to clear mInput), or mSearchString
+    // matches the beginning of aValue.  In either case we can simply
+    // autocomplete to aValue.
+    mPlaceholderCompletionString = aValue;
+    SetValueOfInputTo(aValue);
+  } else {
+    nsresult rv;
+    nsCOMPtr<nsIIOService> ios = do_GetService(NS_IOSERVICE_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsAutoCString scheme;
+    if (NS_SUCCEEDED(
+            ios->ExtractScheme(NS_ConvertUTF16toUTF8(aValue), scheme))) {
+      // Trying to autocomplete a URI from somewhere other than the beginning.
+      // Only succeed if the missing portion is "http://"; otherwise do not
+      // autocomplete.  This prevents us from "helpfully" autocompleting to a
+      // URI that isn't equivalent to what the user expected.
+      const int32_t findIndex = 7;  // length of "http://"
+
+      if ((endSelect < findIndex + mSearchStringLength) ||
+          !scheme.EqualsLiteral("http") ||
+          !Substring(aValue, findIndex, mSearchStringLength)
+               .Equals(mSearchString, nsCaseInsensitiveStringComparator)) {
+        return NS_OK;
+      }
+
+      mPlaceholderCompletionString =
+          mSearchString +
+          Substring(aValue, mSearchStringLength + findIndex, endSelect);
+      SetValueOfInputTo(mPlaceholderCompletionString);
+
+      endSelect -= findIndex;  // We're skipping this many characters of aValue.
+    } else {
+      // Autocompleting something other than a URI from the middle.
+      // Use the format "searchstring >> full string" to indicate to the user
+      // what we are going to replace their search string with.
+      SetValueOfInputTo(mSearchString + u" >> "_ns + aValue);
+
+      endSelect = mSearchString.Length() + 4 + aValue.Length();
+
+      // Reset the last search completion.
+      mPlaceholderCompletionString.Truncate();
+    }
+  }
+
+  input->SelectTextRange(mSearchStringLength, endSelect);
+
+  return NS_OK;
+}
+
+nsresult nsAutoCompleteController::GetResultLabelAt(int32_t aIndex,
+                                                    nsAString& _retval) {
+  return GetResultValueLabelAt(aIndex, false, false, _retval);
+}
+
+nsresult nsAutoCompleteController::GetResultValueAt(int32_t aIndex,
+                                                    bool aGetFinalValue,
+                                                    nsAString& _retval) {
+  return GetResultValueLabelAt(aIndex, aGetFinalValue, true, _retval);
+}
+
+nsresult nsAutoCompleteController::GetResultValueLabelAt(int32_t aIndex,
+                                                         bool aGetFinalValue,
+                                                         bool aGetValue,
+                                                         nsAString& _retval) {
+  NS_ENSURE_TRUE(aIndex >= 0 && static_cast<uint32_t>(aIndex) < mMatchCount,
+                 NS_ERROR_ILLEGAL_VALUE);
+
+  int32_t matchIndex;
+  nsIAutoCompleteResult* result;
+  nsresult rv = GetResultAt(aIndex, &result, &matchIndex);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  uint16_t searchResult;
+  result->GetSearchResult(&searchResult);
+
+  if (searchResult == nsIAutoCompleteResult::RESULT_FAILURE) {
+    if (aGetValue) return NS_ERROR_FAILURE;
+    result->GetErrorDescription(_retval);
+  } else if (searchResult == nsIAutoCompleteResult::RESULT_SUCCESS ||
+             searchResult == nsIAutoCompleteResult::RESULT_SUCCESS_ONGOING) {
+    if (aGetFinalValue) {
+      // Some implementations may miss finalCompleteValue, try to be backwards
+      // compatible.
+      if (NS_FAILED(result->GetFinalCompleteValueAt(matchIndex, _retval))) {
+        result->GetValueAt(matchIndex, _retval);
+      }
+    } else if (aGetValue) {
+      result->GetValueAt(matchIndex, _retval);
+    } else {
+      result->GetLabelAt(matchIndex, _retval);
+    }
+  }
+
+  return NS_OK;
+}
+
+/**
+ * Given the index of a match in the autocomplete popup, find the
+ * corresponding nsIAutoCompleteSearch index, and sub-index into
+ * the search's results list.
+ */
+nsresult nsAutoCompleteController::MatchIndexToSearch(int32_t aMatchIndex,
+                                                      int32_t* aSearchIndex,
+                                                      int32_t* aItemIndex) {
+  *aSearchIndex = -1;
+  *aItemIndex = -1;
+
+  uint32_t index = 0;
+
+  // Move index through the results of each registered nsIAutoCompleteSearch
+  // until we find the given match
+  for (uint32_t i = 0; i < mSearches.Length(); ++i) {
+    nsIAutoCompleteResult* result = mResults.SafeObjectAt(i);
+    if (!result) continue;
+
+    uint32_t matchCount = 0;
+
+    uint16_t searchResult;
+    result->GetSearchResult(&searchResult);
+
+    // Find out how many results were provided by the
+    // current nsIAutoCompleteSearch.
+    if (searchResult == nsIAutoCompleteResult::RESULT_SUCCESS ||
+        searchResult == nsIAutoCompleteResult::RESULT_SUCCESS_ONGOING) {
+      result->GetMatchCount(&matchCount);
+    }
+
+    // If the given match index is within the results range
+    // of the current nsIAutoCompleteSearch then return the
+    // search index and sub-index into the results array
+    if ((matchCount != 0) &&
+        (index + matchCount - 1 >= (uint32_t)aMatchIndex)) {
+      *aSearchIndex = i;
+      *aItemIndex = aMatchIndex - index;
+      return NS_OK;
+    }
+
+    // Advance the popup table index cursor past the
+    // results of the current search.
+    index += matchCount;
+  }
+
+  return NS_OK;
+}
diff --git a/toolkit/components/autocomplete/nsAutoCompleteController.h b/toolkit/components/autocomplete/nsAutoCompleteController.h
new file mode 100644
index 0000000000..7e6d8a3b06
--- /dev/null
+++ b/toolkit/components/autocomplete/nsAutoCompleteController.h
@@ -0,0 +1,217 @@
+/* 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 __nsAutoCompleteController__
+#define __nsAutoCompleteController__
+
+#include "nsIAutoCompleteController.h"
+
+#include "nsCOMPtr.h"
+#include "nsIAutoCompleteInput.h"
+#include "nsIAutoCompletePopup.h"
+#include "nsIAutoCompleteResult.h"
+#include "nsIAutoCompleteSearch.h"
+#include "nsINamed.h"
+#include "nsString.h"
+#include "nsITimer.h"
+#include "nsTArray.h"
+#include "nsCOMArray.h"
+#include "nsCycleCollectionParticipant.h"
+#include "mozilla/dom/Element.h"
+
+class nsAutoCompleteController final : public nsIAutoCompleteController,
+                                       public nsIAutoCompleteObserver,
+                                       public nsITimerCallback,
+                                       public nsINamed {
+ public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsAutoCompleteController,
+                                           nsIAutoCompleteController)
+  NS_DECL_NSIAUTOCOMPLETECONTROLLER
+  NS_DECL_NSIAUTOCOMPLETEOBSERVER
+  NS_DECL_NSITIMERCALLBACK
+  NS_DECL_NSINAMED
+
+  nsAutoCompleteController();
+
+ protected:
+  MOZ_CAN_RUN_SCRIPT virtual ~nsAutoCompleteController();
+
+  /**
+   * SetValueOfInputTo() sets value of mInput to aValue.
+   */
+  void SetValueOfInputTo(const nsString& aValue);
+
+  /**
+   * SetSearchStringInternal() sets both mSearchString and mSetValue to
+   * aSearchString.
+   */
+  void SetSearchStringInternal(const nsAString& aSearchString) {
+    mSearchString = mSetValue = aSearchString;
+  }
+
+  MOZ_CAN_RUN_SCRIPT nsresult OpenPopup();
+  MOZ_CAN_RUN_SCRIPT nsresult ClosePopup();
+
+  nsresult StartSearch(uint16_t aSearchType);
+
+  nsresult BeforeSearches();
+  MOZ_CAN_RUN_SCRIPT nsresult StartSearches();
+  MOZ_CAN_RUN_SCRIPT void AfterSearches();
+  nsresult ClearSearchTimer();
+  void MaybeCompletePlaceholder();
+
+  MOZ_CAN_RUN_SCRIPT nsresult ProcessResult(int32_t aSearchIndex,
+                                            nsIAutoCompleteResult* aResult);
+  MOZ_CAN_RUN_SCRIPT nsresult PostSearchCleanup();
+
+  MOZ_CAN_RUN_SCRIPT nsresult EnterMatch(bool aIsPopupSelection,
+                                         mozilla::dom::Event* aEvent);
+  nsresult RevertTextValue();
+
+  nsresult CompleteDefaultIndex(int32_t aResultIndex);
+  nsresult CompleteValue(nsString& aValue);
+
+  nsresult GetResultAt(int32_t aIndex, nsIAutoCompleteResult** aResult,
+                       int32_t* aMatchIndex);
+  nsresult GetResultValueAt(int32_t aIndex, bool aGetFinalValue,
+                            nsAString& _retval);
+  nsresult GetResultLabelAt(int32_t aIndex, nsAString& _retval);
+
+  /**
+   * Returns autocomplete popup for the autocomplete input. nsIAutoCompleteInput
+   * can be implemented two different ways to return a popup. The first one is
+   * to return a popup object implementing nsIAutoCompletePopup interface,
+   * the second one is a DOM element representing a popup and implementing
+   * that interface.
+   */
+  already_AddRefed<nsIAutoCompletePopup> GetPopup() {
+    nsCOMPtr<nsIAutoCompletePopup> popup;
+    mInput->GetPopup(getter_AddRefs(popup));
+    if (popup) {
+      return popup.forget();
+    }
+
+    nsCOMPtr<mozilla::dom::Element> popupEl;
+    mInput->GetPopupElement(getter_AddRefs(popupEl));
+    if (popupEl) {
+      return popupEl->AsAutoCompletePopup();
+    }
+    return nullptr;
+  }
+
+ private:
+  nsresult GetResultValueLabelAt(int32_t aIndex, bool aGetFinalValue,
+                                 bool aGetValue, nsAString& _retval);
+
+  /**
+   * Gets and validates the defaultComplete result and the relative
+   * defaultIndex value.
+   *
+   * @param aResultIndex
+   *        Index of the defaultComplete result to be used.  Pass -1 to search
+   *        for the first result providing a valid defaultIndex.
+   * @param _result
+   *        The found result.
+   * @param _defaultIndex
+   *        The defaultIndex relative to _result.
+   */
+  nsresult GetDefaultCompleteResult(int32_t aResultIndex,
+                                    nsIAutoCompleteResult** _result,
+                                    int32_t* _defaultIndex);
+
+  /**
+   * Gets the defaultComplete value to be suggested to the user.
+   *
+   * @param aResultIndex
+   *        Index of the defaultComplete result to be used.
+   * @param aPreserveCasing
+   *        Whether user casing should be preserved.
+   * @param _retval
+   *        The value to be completed.
+   */
+  nsresult GetDefaultCompleteValue(int32_t aResultIndex, bool aPreserveCasing,
+                                   nsAString& _retval);
+
+  /**
+   * Gets the defaultComplete value to be used when the user confirms the
+   * current match.
+   * The value is returned only if it case-insensitively matches the current
+   * input text, otherwise the method returns NS_ERROR_FAILURE.
+   * This happens because we don't want to replace text if the user backspaces
+   * just before Enter.
+   *
+   * @param _retval
+   *        The value to be completed.
+   */
+  nsresult GetFinalDefaultCompleteValue(nsAString& _retval);
+
+  nsresult ClearResults(bool aIsSearching = false);
+
+  nsresult MatchIndexToSearch(int32_t aMatchIndex, int32_t* aSearchIndex,
+                              int32_t* aItemIndex);
+
+  // members //////////////////////////////////////////
+
+  nsCOMPtr<nsIAutoCompleteInput> mInput;
+
+  nsCOMArray<nsIAutoCompleteSearch> mSearches;
+  // This is used as a sparse array, always use SafeObjectAt to access it.
+  nsCOMArray<nsIAutoCompleteResult> mResults;
+  // Temporarily keeps the results alive while invoking startSearch() for each
+  // search.  This is needed to allow the searches to reuse the previous result,
+  // since otherwise the first search clears mResults.
+  nsCOMArray<nsIAutoCompleteResult> mResultCache;
+
+  nsCOMPtr<nsITimer> mTimer;
+
+  // mSearchString stores value which is the original value of the input or
+  // typed by the user.  When user is choosing an item from the popup, this
+  // is NOT modified by the item because this is used for reverting the input
+  // value when user cancels choosing an item from the popup.
+  // This should be set through only SetSearchStringInternal().
+  nsString mSearchString;
+  nsString mPlaceholderCompletionString;
+  // mSetValue stores value which is expected in the input.  So, if input's
+  // value and mSetValue are different, it means somebody has changed the
+  // value like JS of the web content.
+  // This is set only by SetValueOfInputTo() or when modifying mSearchString
+  // through SetSearchStringInternal().
+  nsString mSetValue;
+  bool mDefaultIndexCompleted;
+  bool mPopupClosedByCompositionStart;
+
+  // Whether autofill is allowed for the next search. May be retrieved by the
+  // search through the "prohibit-autofill" searchParam.
+  bool mProhibitAutoFill;
+
+  // Indicates whether the user cleared the autofilled part, returning to the
+  // originally entered search string.
+  bool mUserClearedAutoFill;
+
+  // Indicates whether clearing the autofilled string should issue a new search.
+  bool mClearingAutoFillSearchesAgain;
+
+  enum CompositionState {
+    eCompositionState_None,
+    eCompositionState_Composing,
+    eCompositionState_Committing
+  };
+  CompositionState mCompositionState;
+  uint16_t mSearchStatus;
+  uint32_t mMatchCount;
+  uint32_t mSearchesOngoing;
+  uint32_t mSearchesFailed;
+  uint32_t mImmediateSearchesCount;
+  // The index of the match on the popup that was selected using the keyboard,
+  // if the completeselectedindex attribute is set.
+  // This is used to distinguish that selection (which would have been put in
+  // the input on being selected) from a moused-over selectedIndex value. This
+  // distinction is used to prevent mouse moves from inadvertently changing
+  // what happens once the user hits Enter on the keyboard.
+  // See bug 1043584 for more details.
+  int32_t mCompletedSelectionIndex;
+};
+
+#endif /* __nsAutoCompleteController__ */
diff --git a/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.cpp b/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.cpp
new file mode 100644
index 0000000000..94e970132d
--- /dev/null
+++ b/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.cpp
@@ -0,0 +1,256 @@
+/* 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 "nsAutoCompleteSimpleResult.h"
+
+#define CHECK_MATCH_INDEX(_index, _insert)                                   \
+  if (_index < 0 ||                                                          \
+      static_cast<MatchesArray::size_type>(_index) > mMatches.Length() ||    \
+      (!_insert &&                                                           \
+       static_cast<MatchesArray::size_type>(_index) == mMatches.Length())) { \
+    MOZ_ASSERT(false, "Trying to use an invalid index on mMatches");         \
+    return NS_ERROR_ILLEGAL_VALUE;                                           \
+  }
+
+NS_IMPL_ISUPPORTS(nsAutoCompleteSimpleResult, nsIAutoCompleteResult,
+                  nsIAutoCompleteSimpleResult)
+
+nsAutoCompleteSimpleResult::nsAutoCompleteSimpleResult()
+    : mDefaultIndex(-1), mSearchResult(RESULT_NOMATCH) {}
+
+nsresult nsAutoCompleteSimpleResult::AppendResult(
+    nsIAutoCompleteResult* aResult) {
+  nsAutoString searchString;
+  nsresult rv = aResult->GetSearchString(searchString);
+  NS_ENSURE_SUCCESS(rv, rv);
+  mSearchString = searchString;
+
+  uint16_t searchResult;
+  rv = aResult->GetSearchResult(&searchResult);
+  NS_ENSURE_SUCCESS(rv, rv);
+  mSearchResult = searchResult;
+
+  nsAutoString errorDescription;
+  if (NS_SUCCEEDED(aResult->GetErrorDescription(errorDescription)) &&
+      !errorDescription.IsEmpty()) {
+    mErrorDescription = errorDescription;
+  }
+
+  int32_t defaultIndex = -1;
+  if (NS_SUCCEEDED(aResult->GetDefaultIndex(&defaultIndex)) &&
+      defaultIndex >= 0) {
+    mDefaultIndex = defaultIndex;
+  }
+
+  nsCOMPtr<nsIAutoCompleteSimpleResult> simpleResult =
+      do_QueryInterface(aResult);
+  if (simpleResult) {
+    nsCOMPtr<nsIAutoCompleteSimpleResultListener> listener;
+    if (NS_SUCCEEDED(simpleResult->GetListener(getter_AddRefs(listener))) &&
+        listener) {
+      listener.swap(mListener);
+    }
+  }
+
+  // Copy matches.
+  uint32_t matchCount = 0;
+  rv = aResult->GetMatchCount(&matchCount);
+  NS_ENSURE_SUCCESS(rv, rv);
+  for (size_t i = 0; i < matchCount; ++i) {
+    nsAutoString value, comment, image, style, finalCompleteValue, label;
+
+    rv = aResult->GetValueAt(i, value);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aResult->GetCommentAt(i, comment);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aResult->GetImageAt(i, image);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aResult->GetStyleAt(i, style);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aResult->GetFinalCompleteValueAt(i, finalCompleteValue);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aResult->GetLabelAt(i, label);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = AppendMatch(value, comment, image, style, finalCompleteValue, label);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+// searchString
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetSearchString(nsAString& aSearchString) {
+  aSearchString = mSearchString;
+  return NS_OK;
+}
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::SetSearchString(const nsAString& aSearchString) {
+  mSearchString.Assign(aSearchString);
+  return NS_OK;
+}
+
+// searchResult
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetSearchResult(uint16_t* aSearchResult) {
+  *aSearchResult = mSearchResult;
+  return NS_OK;
+}
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::SetSearchResult(uint16_t aSearchResult) {
+  mSearchResult = aSearchResult;
+  return NS_OK;
+}
+
+// defaultIndex
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetDefaultIndex(int32_t* aDefaultIndex) {
+  *aDefaultIndex = mDefaultIndex;
+  return NS_OK;
+}
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::SetDefaultIndex(int32_t aDefaultIndex) {
+  mDefaultIndex = aDefaultIndex;
+  return NS_OK;
+}
+
+// errorDescription
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetErrorDescription(nsAString& aErrorDescription) {
+  aErrorDescription = mErrorDescription;
+  return NS_OK;
+}
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::SetErrorDescription(
+    const nsAString& aErrorDescription) {
+  mErrorDescription.Assign(aErrorDescription);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::InsertMatchAt(
+    int32_t aIndex, const nsAString& aValue, const nsAString& aComment,
+    const nsAString& aImage, const nsAString& aStyle,
+    const nsAString& aFinalCompleteValue, const nsAString& aLabel) {
+  CHECK_MATCH_INDEX(aIndex, true);
+
+  AutoCompleteSimpleResultMatch match(aValue, aComment, aImage, aStyle,
+                                      aFinalCompleteValue, aLabel);
+
+  // XXX(Bug 1631371) Check if this should use a fallible operation as it
+  // pretended earlier.
+  mMatches.InsertElementAt(aIndex, match);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::AppendMatch(const nsAString& aValue,
+                                        const nsAString& aComment,
+                                        const nsAString& aImage,
+                                        const nsAString& aStyle,
+                                        const nsAString& aFinalCompleteValue,
+                                        const nsAString& aLabel) {
+  return InsertMatchAt(mMatches.Length(), aValue, aComment, aImage, aStyle,
+                       aFinalCompleteValue, aLabel);
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::RemoveMatchAt(int32_t aIndex) {
+  CHECK_MATCH_INDEX(aIndex, false);
+
+  mMatches.RemoveElementAt(aIndex);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetMatchCount(uint32_t* aMatchCount) {
+  *aMatchCount = mMatches.Length();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetValueAt(int32_t aIndex, nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetLabelAt(int32_t aIndex, nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mLabel;
+  if (_retval.IsEmpty()) {
+    _retval = mMatches[aIndex].mValue;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetCommentAt(int32_t aIndex, nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mComment;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetImageAt(int32_t aIndex, nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mImage;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetStyleAt(int32_t aIndex, nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mStyle;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetFinalCompleteValueAt(int32_t aIndex,
+                                                    nsAString& _retval) {
+  CHECK_MATCH_INDEX(aIndex, false);
+  _retval = mMatches[aIndex].mFinalCompleteValue;
+  if (_retval.IsEmpty()) {
+    _retval = mMatches[aIndex].mValue;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::SetListener(
+    nsIAutoCompleteSimpleResultListener* aListener) {
+  mListener = aListener;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::GetListener(
+    nsIAutoCompleteSimpleResultListener** aListener) {
+  nsCOMPtr<nsIAutoCompleteSimpleResultListener> listener(mListener);
+  listener.forget(aListener);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::IsRemovableAt(int32_t aRowIndex, bool* _retval) {
+  *_retval = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsAutoCompleteSimpleResult::RemoveValueAt(int32_t aRowIndex) {
+  CHECK_MATCH_INDEX(aRowIndex, false);
+
+  nsString value = mMatches[aRowIndex].mValue;
+  mMatches.RemoveElementAt(aRowIndex);
+
+  if (mListener) {
+    mListener->OnValueRemoved(this, value);
+  }
+
+  return NS_OK;
+}
diff --git a/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.h b/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.h
new file mode 100644
index 0000000000..0b2b482e71
--- /dev/null
+++ b/toolkit/components/autocomplete/nsAutoCompleteSimpleResult.h
@@ -0,0 +1,63 @@
+/* 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 __nsAutoCompleteSimpleResult__
+#define __nsAutoCompleteSimpleResult__
+
+#include "nsIAutoCompleteResult.h"
+#include "nsIAutoCompleteSimpleResult.h"
+
+#include "nsString.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+#include "mozilla/Attributes.h"
+
+struct AutoCompleteSimpleResultMatch {
+  AutoCompleteSimpleResultMatch(const nsAString& aValue,
+                                const nsAString& aComment,
+                                const nsAString& aImage,
+                                const nsAString& aStyle,
+                                const nsAString& aFinalCompleteValue,
+                                const nsAString& aLabel)
+      : mValue(aValue),
+        mComment(aComment),
+        mImage(aImage),
+        mStyle(aStyle),
+        mFinalCompleteValue(aFinalCompleteValue),
+        mLabel(aLabel) {}
+
+  nsString mValue;
+  nsString mComment;
+  nsString mImage;
+  nsString mStyle;
+  nsString mFinalCompleteValue;
+  nsString mLabel;
+};
+
+class nsAutoCompleteSimpleResult final : public nsIAutoCompleteSimpleResult {
+ public:
+  nsAutoCompleteSimpleResult();
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIAUTOCOMPLETERESULT
+  NS_DECL_NSIAUTOCOMPLETESIMPLERESULT
+
+  nsresult AppendResult(nsIAutoCompleteResult* aResult);
+
+ private:
+  ~nsAutoCompleteSimpleResult() = default;
+
+ protected:
+  typedef nsTArray<AutoCompleteSimpleResultMatch> MatchesArray;
+  MatchesArray mMatches;
+
+  nsString mSearchString;
+  nsString mErrorDescription;
+  int32_t mDefaultIndex;
+  uint32_t mSearchResult;
+
+  nsCOMPtr<nsIAutoCompleteSimpleResultListener> mListener;
+};
+
+#endif  // __nsAutoCompleteSimpleResult__
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteController.idl b/toolkit/components/autocomplete/nsIAutoCompleteController.idl
new file mode 100644
index 0000000000..148e704b4c
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteController.idl
@@ -0,0 +1,182 @@
+/* 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"
+
+interface nsIAutoCompleteInput;
+
+webidl Event;
+
+[scriptable, uuid(ff9f8465-204a-47a6-b3c9-0628b3856684)]
+interface nsIAutoCompleteController : nsISupports
+{
+  /*
+   * Possible values for the searchStatus attribute
+   */
+  const unsigned short STATUS_NONE = 1;
+  const unsigned short STATUS_SEARCHING = 2;
+  const unsigned short STATUS_COMPLETE_NO_MATCH = 3;
+  const unsigned short STATUS_COMPLETE_MATCH = 4;
+
+  /*
+   * The input widget that is currently being controlled.
+   */
+  [setter_can_run_script]
+  attribute nsIAutoCompleteInput input;
+
+  /*
+   * State which indicates the status of possible ongoing searches
+   */
+  readonly attribute unsigned short searchStatus;
+
+  /*
+   * The number of matches
+   */
+  readonly attribute unsigned long matchCount;
+
+  /*
+   * Start a search on a string, assuming the input property is already set.
+   */
+  [can_run_script] void startSearch(in AString searchString);
+
+  /*
+   * Stop all asynchronous searches
+   */
+  [can_run_script] void stopSearch();
+
+  /*
+   * Notify the controller that the user has changed text in the textbox.
+   * This includes all means of changing the text value, including typing a
+   * character, backspacing, deleting, pasting, committing composition or
+   * canceling composition.
+   *
+   * NOTE: handleText() must be called after composition actually ends, even if
+   *       the composition is canceled and the textbox value isn't changed.
+   *       Then, implementation of handleText() can access the editor when
+   *       it's not in composing mode. DOM compositionend event is not good
+   *       timing for calling handleText(). DOM input event immediately after
+   *       DOM compositionend event is the best timing to call this.
+   *
+   * @return whether this handler started a new search.
+   */
+  [can_run_script] boolean handleText();
+
+  /*
+   * Notify the controller that the user wishes to enter the current text. If
+   * aIsPopupSelection is true, then a selection was made from the popup, so
+   * fill this value into the input field before continuing. If false, just
+   * use the current value of the input field.
+   *
+   * @param aIsPopupSelection
+   *        Pass true if the selection was made from the popup.
+   * @param aEvent
+   *        The event that triggered the enter, like a key event if the user
+   *        pressed the Return key or a click event if the user clicked a popup
+   *        item.
+   * @return Whether the controller wishes to prevent event propagation and
+   *         default event.
+   */
+  [can_run_script] boolean handleEnter(in boolean aIsPopupSelection,
+                                       [optional] in Event aEvent);
+
+  /*
+   * Notify the controller that the user wishes to revert autocomplete
+   *
+   * @return Whether the controller wishes to prevent event propagation and
+   *         default event.
+   */
+  [can_run_script] boolean handleEscape();
+
+  /*
+   * Notify the controller that the user wishes to start composition
+   *
+   * NOTE: nsIAutoCompleteController implementation expects that this is called
+   *       by DOM compositionstart handler.
+   */
+  [can_run_script] void handleStartComposition();
+
+  /*
+   * Notify the controller that the user wishes to end composition
+   *
+   * NOTE: nsIAutoCompleteController implementation expects that this is called
+   *       by DOM compositionend handler.
+   */
+  void handleEndComposition();
+
+  /*
+   * Handle tab. Just closes up.
+   */
+  [can_run_script] void handleTab();
+
+  /*
+   * Notify the controller of the following key navigation events:
+   *   up, down, left, right, page up, page down
+   *
+   * @return Whether the controller wishes to prevent event propagation and
+   *         default event
+   */
+  [can_run_script] boolean handleKeyNavigation(in unsigned long key);
+
+  /*
+   * Notify the controller that the user chose to delete the current
+   * auto-complete result.
+   *
+   * @return Whether the controller removed a result item.
+   */
+  [can_run_script] boolean handleDelete();
+
+  /*
+   * Get the value of the result at a given index in the last completed search
+   */
+  AString getValueAt(in long index);
+
+  /*
+   * Get the label of the result at a given index in the last completed search
+   */
+  AString getLabelAt(in long index);
+
+  /*
+   * Get the comment of the result at a given index in the last completed search
+   */
+  AString getCommentAt(in long index);
+
+  /*
+   * Get the style hint for the result at a given index in the last completed search
+   */
+  AString getStyleAt(in long index);
+
+  /*
+   * Get the url of the image of the result at a given index in the last completed search
+   */
+  AString getImageAt(in long index);
+
+  /*
+   * For the last completed search, get the final value that should be completed
+   * when the user confirms the match at the given index
+   */
+  AString getFinalCompleteValueAt(in long index);
+
+  /*
+   * Get / set the current search string.  Note, setting will not start searching
+   */
+  attribute AString searchString;
+
+  /*
+   * Set the index of the result item that should be initially selected.
+   * This should be used when a search wants to pre-select an element before
+   * the user starts using results.
+   *
+   * @note Setting this is not the same as just setting selectedIndex in
+   * nsIAutocompletePopup, since this will take care of updating any internal
+   * tracking variables of features like completeSelectedIndex.
+   */
+  void setInitiallySelectedIndex(in long index);
+
+  /*
+   * Reset controller internal caches for cases where the input doesn't change
+   * but its context resets, thus it is about to start a completely new search
+   * session.
+   */
+  [can_run_script] void resetInternalState();
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteInput.idl b/toolkit/components/autocomplete/nsIAutoCompleteInput.idl
new file mode 100644
index 0000000000..6fd4e6e9c5
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteInput.idl
@@ -0,0 +1,167 @@
+/* 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 "nsIAutoCompleteController.idl"
+
+interface nsIAutoCompletePopup;
+
+webidl Event;
+webidl Element;
+
+[scriptable, uuid(B068E70F-F82C-4C12-AD87-82E271C5C180)]
+interface nsIAutoCompleteInput : nsISupports
+{
+  /*
+   * The result view that will be used to display results
+   */
+  readonly attribute Element popupElement;
+  readonly attribute nsIAutoCompletePopup popup;
+
+  /*
+   * The controller.
+   */
+  readonly attribute nsIAutoCompleteController controller;
+
+  /*
+   * Indicates if the popup is currently open
+   */
+  [can_run_script] attribute boolean popupOpen;
+
+  /*
+   * Option to disable autocomplete functionality
+   */
+  attribute boolean disableAutoComplete;
+
+  /*
+   * If a search result has its defaultIndex set, this will optionally
+   * try to complete the text in the textbox to the entire text of the
+   * result at the default index as the user types
+   */
+  attribute boolean completeDefaultIndex;
+
+  /*
+   * complete text in the textbox as the user selects from the dropdown
+   * options if set to true
+   */
+  attribute boolean completeSelectedIndex;
+
+  /*
+   * Option for completing to the default result whenever the user hits
+   * enter or the textbox loses focus
+   */
+  attribute boolean forceComplete;
+
+  /*
+   * Option to open the popup only after a certain number of results are available
+   */
+  attribute unsigned long minResultsForPopup;
+
+  /*
+   * The maximum number of rows to show in the autocomplete popup.
+   */
+  attribute unsigned long maxRows;
+
+  /*
+   * Number of milliseconds after a keystroke before a search begins
+   */
+  attribute unsigned long timeout;
+
+  /*
+   * An extra parameter to configure searches with.
+   */
+  attribute AString searchParam;
+
+  /*
+   * The number of autocomplete session to search
+   */
+  readonly attribute unsigned long searchCount;
+
+  /*
+   * Get the name of one of the autocomplete search session objects
+   */
+  ACString getSearchAt(in unsigned long index);
+
+  /*
+   * The value of text in the autocomplete textbox.
+   */
+  attribute AString textValue;
+
+  /*
+   * Report the starting index of the cursor in the textbox
+   */
+  readonly attribute long selectionStart;
+
+  /*
+   * Report the ending index of the cursor in the textbox
+   */
+  readonly attribute long selectionEnd;
+
+  /*
+   * Select a range of text in the autocomplete textbox
+   */
+  void selectTextRange(in long startIndex, in long endIndex);
+
+  /*
+   * Notification that the search has started
+   */
+  void onSearchBegin();
+
+  /*
+   * Notification that the search concluded successfully
+   */
+  void onSearchComplete();
+
+  /*
+   * Notification that the user selected and entered a result item
+   *
+   * @param aEvent
+   *        The event that triggered the enter.
+   * @param itemWasSelected
+   *        A boolean value that indicates whether
+   *        an item was selected from the autocomplete popup.
+   * @return True if the user wishes to prevent the enter
+   */
+  boolean onTextEntered([optional] in Event aEvent, [optional] in boolean itemWasSelected);
+
+  /*
+   * Notification that the user cancelled the autocomplete session
+   *
+   * @return True if the user wishes to prevent the revert
+   */
+  boolean onTextReverted();
+
+  /*
+   * This popup should consume or dispatch the rollup event.
+   * TRUE: should consume; FALSE: should dispatch.
+   */
+  readonly attribute boolean consumeRollupEvent;
+
+  /*
+   * Indicates whether this input is in a "private browsing" context.
+   * nsIAutoCompleteSearches for these inputs should not persist any data to disk
+   * (such as a history database).
+   */
+  readonly attribute boolean inPrivateContext;
+
+  /*
+   * Don't rollup the popup when the caret is moved.
+   */
+  readonly attribute boolean noRollupOnCaretMove;
+
+  /*
+   * Don't rollup the popup when the search string becomes "".
+   */
+  readonly attribute boolean noRollupOnEmptySearch;
+
+  /**
+   * The userContextId of the current browser.
+   */
+  readonly attribute unsigned long userContextId;
+
+  /**
+   * Since search content is updated, we shouldn't use previous search result.
+   */
+  readonly attribute boolean invalidatePreviousResult;
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompletePopup.idl b/toolkit/components/autocomplete/nsIAutoCompletePopup.idl
new file mode 100644
index 0000000000..607863c9a7
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompletePopup.idl
@@ -0,0 +1,72 @@
+/* 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"
+
+interface nsIAutoCompleteInput;
+
+webidl Element;
+
+[scriptable, uuid(bd3c2662-a988-41ab-8c94-c15ed0e6ac7d)]
+interface nsIAutoCompletePopup : nsISupports
+{
+  /*
+   * The input object that the popup is currently bound to
+   */
+  readonly attribute nsIAutoCompleteInput input;
+
+  /*
+   * An alternative value to be used when text is entered, rather than the
+   * value of the selected item
+   */
+  readonly attribute AString overrideValue;
+
+  /*
+   * The index of the result item that is currently selected
+   */
+  attribute long selectedIndex;
+
+  /*
+   * Indicates if the popup is currently open
+   */
+  readonly attribute boolean popupOpen;
+
+  /*
+   * Bind the popup to an input object and display it with the given coordinates
+   *
+   * @param input - The input object that the popup will be bound to
+   * @param element - The element that the popup will be aligned with
+   */
+  void openAutocompletePopup(in nsIAutoCompleteInput input, in Element element);
+
+  /*
+   * Close the popup and detach from the bound input
+   */
+  void closePopup();
+
+  /*
+   * Instruct the result view to repaint itself to reflect the most current
+   * underlying data
+   *
+   * @param reason - The reason the popup needs to be invalidated, one of the
+   *        INVALIDATE_REASON consts.
+   */
+  void invalidate(in unsigned short reason);
+
+  /*
+   * Possible values of invalidate()'s 'reason' argument.
+   */
+  const unsigned short INVALIDATE_REASON_NEW_RESULT = 0;
+  const unsigned short INVALIDATE_REASON_DELETE = 1;
+
+  /*
+   * Change the selection relative to the current selection and make sure
+   * the newly selected row is visible
+   *
+   * @param reverse - Select a row above the current selection
+   * @param page - Select a row that is a full visible page from the current selection
+   * @return The currently selected result item index
+   */
+  void selectBy(in boolean reverse, in boolean page);
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteResult.idl b/toolkit/components/autocomplete/nsIAutoCompleteResult.idl
new file mode 100644
index 0000000000..8e8b05ea46
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteResult.idl
@@ -0,0 +1,92 @@
+/* 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(9203c031-c4e7-4537-a4ec-81443d623d5a)]
+interface nsIAutoCompleteResult : nsISupports
+{
+  /**
+   * Possible values for the searchResult attribute
+   */
+  const unsigned short RESULT_IGNORED = 1; /* indicates invalid searchString */
+  const unsigned short RESULT_FAILURE = 2; /* indicates failure */
+  const unsigned short RESULT_NOMATCH = 3; /* indicates success with no matches
+                                              and that the search is complete */
+  const unsigned short RESULT_SUCCESS = 4; /* indicates success with matches
+                                              and that the search is complete */
+  const unsigned short RESULT_NOMATCH_ONGOING = 5; /* indicates success
+                                                      with no matches
+                                                      and that the search
+                                                      is still ongoing */
+  const unsigned short RESULT_SUCCESS_ONGOING = 6; /* indicates success
+                                                      with matches
+                                                      and that the search
+                                                      is still ongoing */
+  /**
+   * The original search string
+   */
+  readonly attribute AString searchString;
+
+  /**
+   * The result of the search
+   */
+  readonly attribute unsigned short searchResult;
+
+  /**
+   * Index of the default item that should be entered if none is selected
+   */
+  readonly attribute long defaultIndex;
+
+  /**
+   * A string describing the cause of a search failure
+   */
+  readonly attribute AString errorDescription;
+
+  /**
+   * The number of matches
+   */
+  readonly attribute unsigned long matchCount;
+
+  /**
+   * Get the value of the result at the given index
+   */
+  AString getValueAt(in long index);
+
+  /**
+   * This returns the string that is displayed in the dropdown
+   */
+  AString getLabelAt(in long index);
+
+  /**
+   * Get the comment of the result at the given index
+   */
+  AString getCommentAt(in long index);
+
+  /**
+   * Get the style hint for the result at the given index
+   */
+  AString getStyleAt(in long index);
+
+  /**
+   * Get the image of the result at the given index
+   */
+  AString getImageAt(in long index);
+
+  /**
+   * Get the final value that should be completed when the user confirms
+   * the match at the given index.
+   */
+  AString getFinalCompleteValueAt(in long index);
+
+  /**
+   * True if the value at the given index is removable.
+   */
+  bool isRemovableAt(in long rowIndex);
+
+  /**
+   * Remove the value at the given index from the autocomplete results.
+   */
+  void removeValueAt(in long rowIndex);
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteSearch.idl b/toolkit/components/autocomplete/nsIAutoCompleteSearch.idl
new file mode 100644
index 0000000000..0c86d7ab55
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteSearch.idl
@@ -0,0 +1,71 @@
+/* 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"
+
+interface nsIAutoCompleteResult;
+interface nsIAutoCompleteObserver;
+interface nsIPropertyBag2;
+
+[scriptable, uuid(DE8DB85F-C1DE-4d87-94BA-7844890F91FE)]
+interface nsIAutoCompleteSearch : nsISupports
+{
+  /*
+   * Search for a given string and notify a listener (either synchronously
+   * or asynchronously) of the result
+   *
+   * @param searchString - The string to search for
+   * @param searchParam - An extra parameter
+   * @param previousResult - A previous result to use for faster searching
+   * @param listener - A listener to notify when the search is complete
+   * @param options An optional set of additional search parameters that may be
+   *        passed to the underlying implementation.
+   */
+  void startSearch(in AString searchString,
+                   in AString searchParam,
+                   in nsIAutoCompleteResult previousResult,
+                   in nsIAutoCompleteObserver listener,
+                   [optional] in nsIPropertyBag2 options);
+
+  /*
+   * Stop all searches that are in progress
+   */
+  void stopSearch();
+};
+
+[scriptable, uuid(8bd1dbbc-dcce-4007-9afa-b551eb687b61)]
+interface nsIAutoCompleteObserver : nsISupports
+{
+  /*
+   * Called when a search is complete and the results are ready
+   *
+   * @param search - The search object that processed this search
+   * @param result - The search result object
+   */
+  [can_run_script] void onSearchResult(in nsIAutoCompleteSearch search,
+                                       in nsIAutoCompleteResult result);
+};
+
+[scriptable, uuid(4c3e7462-fbfb-4310-8f4b-239238392b75)]
+interface nsIAutoCompleteSearchDescriptor : nsISupports
+{
+  // The search is started after the timeout specified by the corresponding
+  // nsIAutoCompleteInput implementation.
+  const unsigned short SEARCH_TYPE_DELAYED = 0;
+  // The search is started synchronously, before any delayed searches.
+  const unsigned short SEARCH_TYPE_IMMEDIATE = 1;
+
+  /**
+   * Identifies the search behavior.
+   * Should be one of the SEARCH_TYPE_* constants above.
+   * Defaults to SEARCH_TYPE_DELAYED.
+   */
+  readonly attribute unsigned short searchType;
+
+  /*
+   * Whether a new search should be triggered when the user deletes the
+   * autofilled part.
+   */
+  readonly attribute boolean clearingAutoFillSearchesAgain;
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteSimpleResult.idl b/toolkit/components/autocomplete/nsIAutoCompleteSimpleResult.idl
new file mode 100644
index 0000000000..2be873eb59
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteSimpleResult.idl
@@ -0,0 +1,120 @@
+/* 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 "nsIAutoCompleteResult.idl"
+
+interface nsIAutoCompleteSimpleResultListener;
+
+/**
+ * This class implements nsIAutoCompleteResult and provides simple methods
+ * for setting the value and result items. It can be used whenever some basic
+ * auto complete results are needed that can be pre-generated and filled into
+ * an array.
+ */
+
+[scriptable, uuid(23de9c96-becb-4d0d-a9bb-1d131ce361b5)]
+interface nsIAutoCompleteSimpleResult : nsIAutoCompleteResult
+{
+  /**
+   * A writer for the readonly attribute 'searchString' which should contain
+   * the string that the user typed.
+   */
+  void setSearchString(in AString aSearchString);
+
+  /**
+   * A writer for the readonly attribute 'errorDescription'.
+   */
+  void setErrorDescription(in AString aErrorDescription);
+
+  /**
+   * A writer for the readonly attribute 'defaultIndex' which should contain
+   * the index of the list that will be selected by default (normally 0).
+   */
+  void setDefaultIndex(in long aDefaultIndex);
+
+  /**
+   * A writer for the readonly attribute 'searchResult' which should contain
+   * one of the constants nsIAutoCompleteResult.RESULT_* indicating the success
+   * of the search.
+   */
+  void setSearchResult(in unsigned short aSearchResult);
+
+  /**
+   * Inserts a match consisting of the given value, comment, image, style and
+   * the value to use for defaultIndex completion at a given position.
+   * @param aIndex
+   *        The index to insert at
+   * @param aValue
+   *        The value to autocomplete to
+   * @param aComment
+   *        Comment shown in the autocomplete widget to describe this match
+   * @param aImage
+   *        Image shown in the autocomplete widget for this match.
+   * @param aStyle
+   *        Describes how to style the match in the autocomplete widget
+   * @param aFinalCompleteValue
+   *        Value used when the user confirms selecting this match. If not
+   *        provided, aValue will be used.
+   */
+  void insertMatchAt(in long aIndex,
+                     in AString aValue,
+                     in AString aComment,
+                     [optional] in AString aImage,
+                     [optional] in AString aStyle,
+                     [optional] in AString aFinalCompleteValue,
+                     [optional] in AString aLabel);
+
+  /**
+   * Appends a match consisting of the given value, comment, image, style and
+   * the value to use for defaultIndex completion.
+   * @param aValue
+   *        The value to autocomplete to
+   * @param aComment
+   *        Comment shown in the autocomplete widget to describe this match
+   * @param aImage
+   *        Image shown in the autocomplete widget for this match.
+   * @param aStyle
+   *        Describes how to style the match in the autocomplete widget
+   * @param aFinalCompleteValue
+   *        Value used when the user confirms selecting this match. If not
+   *        provided, aValue will be used.
+   */
+  void appendMatch(in AString aValue,
+                   in AString aComment,
+                   [optional] in AString aImage,
+                   [optional] in AString aStyle,
+                   [optional] in AString aFinalCompleteValue,
+                   [optional] in AString aLabel);
+
+  /**
+   * Removes an existing match.
+   * @note this is different from removeValueAt, since it's not a consequence of
+   * a user action, and as such it won't notify onValueRemoved.
+   */
+  void removeMatchAt(in long aIndex);
+
+  /**
+   * Gets the listener for changes in the result.
+   */
+  nsIAutoCompleteSimpleResultListener getListener();
+
+  /**
+   * Sets a listener for changes in the result.
+   */
+  void setListener(in nsIAutoCompleteSimpleResultListener aListener);
+};
+
+[scriptable, uuid(004efdc5-1989-4874-8a7a-345bf2fa33af)]
+interface nsIAutoCompleteSimpleResultListener : nsISupports
+{
+  /**
+   * Dispatched after a value is removed from the result.
+   * @param aResult
+   *        The result from which aValue has been removed.
+   * @param aValue
+   *        The removed value.
+   */
+  void onValueRemoved(in nsIAutoCompleteSimpleResult aResult, in AString aValue);
+};
diff --git a/toolkit/components/autocomplete/nsIAutoCompleteSimpleSearch.idl b/toolkit/components/autocomplete/nsIAutoCompleteSimpleSearch.idl
new file mode 100644
index 0000000000..695cf5c589
--- /dev/null
+++ b/toolkit/components/autocomplete/nsIAutoCompleteSimpleSearch.idl
@@ -0,0 +1,17 @@
+/* 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 "nsIAutoCompleteSearch.idl"
+
+/*
+ * Simple interface that allows the results of the next search to be overridden.
+ */
+[scriptable, uuid(dc185a77-ba88-4caa-8f16-465253f7599a)]
+interface nsIAutoCompleteSimpleSearch : nsIAutoCompleteSearch
+{
+  /**
+   * Sets the result that should be used next time `startSearch` is called.
+   */
+  void overrideNextResult(in nsIAutoCompleteResult values);
+};
diff --git a/toolkit/components/autocomplete/tests/unit/head_autocomplete.js b/toolkit/components/autocomplete/tests/unit/head_autocomplete.js
new file mode 100644
index 0000000000..6aa0382d82
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/head_autocomplete.js
@@ -0,0 +1,203 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+var { XPCOMUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/XPCOMUtils.sys.mjs"
+);
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInputBase(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInputBase.prototype = {
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  // Text selection range
+  _selStart: 0,
+  _selEnd: 0,
+  get selectionStart() {
+    return this._selStart;
+  },
+  get selectionEnd() {
+    return this._selEnd;
+  },
+  selectTextRange(aStart, aEnd) {
+    this._selStart = aStart;
+    this._selEnd = aEnd;
+  },
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  get popup() {
+    if (!this._popup) {
+      this._popup = new AutocompletePopupBase(this);
+    }
+    return this._popup;
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResultBase(aValues) {
+  this._values = aValues;
+}
+AutoCompleteResultBase.prototype = {
+  // Arrays
+  _values: null,
+  _comments: [],
+  _styles: [],
+  _finalCompleteValues: [],
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: -1,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this._finalCompleteValues[aIndex] || this._values[aIndex];
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearchBase(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearchBase.prototype = {
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    var result = this._result;
+
+    result.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+    aListener.onSearchResult(this, result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+function AutocompletePopupBase(input) {
+  this.input = input;
+}
+AutocompletePopupBase.prototype = {
+  selectedIndex: 0,
+  invalidate() {},
+  selectBy(reverse, page) {
+    let numRows = this.input.controller.matchCount;
+    if (numRows > 0) {
+      let delta = reverse ? -1 : 1;
+      this.selectedIndex = (this.selectedIndex + delta) % numRows;
+      if (this.selectedIndex < 0) {
+        this.selectedIndex = numRows - 1;
+      }
+    }
+  },
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+  var cid = Services.uuid.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_330578.js b/toolkit/components/autocomplete/tests/unit/test_330578.js
new file mode 100644
index 0000000000..5f549cb4c7
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_330578.js
@@ -0,0 +1,41 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+var gResultListener = {
+  _lastResult: null,
+  _lastValue: "",
+
+  onValueRemoved(aResult, aValue) {
+    this._lastResult = aResult;
+    this._lastValue = aValue;
+  },
+};
+
+// main
+function run_test() {
+  var result = Cc["@mozilla.org/autocomplete/simple-result;1"].createInstance(
+    Ci.nsIAutoCompleteSimpleResult
+  );
+  result.appendMatch("a", "");
+  result.appendMatch("b", "");
+  result.appendMatch("c", "");
+  result.setListener(gResultListener);
+  Assert.equal(result.matchCount, 3);
+  result.removeValueAt(0);
+  Assert.equal(result.matchCount, 2);
+  Assert.equal(gResultListener._lastResult, result);
+  Assert.equal(gResultListener._lastValue, "a");
+
+  result.removeValueAt(0);
+  Assert.equal(result.matchCount, 1);
+  Assert.equal(gResultListener._lastValue, "b");
+
+  // check that we don't get notified if the listener is unset
+  result.setListener(null);
+  result.removeValueAt(0); // "c"
+  Assert.equal(result.matchCount, 0);
+  Assert.equal(gResultListener._lastValue, "b");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_378079.js b/toolkit/components/autocomplete/tests/unit/test_378079.js
new file mode 100644
index 0000000000..6e0051e948
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_378079.js
@@ -0,0 +1,255 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+/**
+ * Unit test for Bug 378079 - AutoComplete returns invalid rows when
+ * more than one AutoCompleteSearch is used.
+ */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex(aIndex) {},
+    invalidate() {},
+
+    // nsISupports implementation
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResult(aValues, aComments, aStyles) {
+  this._values = aValues;
+  this._comments = aComments;
+  this._styles = aStyles;
+
+  if (this._values.length) {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+  } else {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH;
+  }
+}
+AutoCompleteResult.prototype = {
+  constructor: AutoCompleteResult,
+
+  // Arrays
+  _values: null,
+  _comments: null,
+  _styles: null,
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: 0,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  /**
+   * Return the same result set for every search
+   */
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    aListener.onSearchResult(this, this._result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+
+  var uuidGenerator = Services.uuid;
+  var cid = uuidGenerator.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+/**
+ * Test AutoComplete with multiple AutoCompleteSearch sources.
+ */
+function run_test() {
+  // Make an AutoCompleteSearch that always returns nothing
+  var emptySearch = new AutoCompleteSearch(
+    "test-empty-search",
+    new AutoCompleteResult([], [], [])
+  );
+
+  // Make an AutoCompleteSearch that returns two values
+  var expectedValues = ["test1", "test2"];
+  var regularSearch = new AutoCompleteSearch(
+    "test-regular-search",
+    new AutoCompleteResult(expectedValues, [], [])
+  );
+
+  // Register searches so AutoCompleteController can find them
+  registerAutoCompleteSearch(emptySearch);
+  registerAutoCompleteSearch(regularSearch);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches
+  // and confirms results on search complete
+  var input = new AutoCompleteInput([emptySearch.name, regularSearch.name]);
+  var numSearchesStarted = 0;
+
+  input.onSearchBegin = function() {
+    numSearchesStarted++;
+    Assert.equal(numSearchesStarted, 1);
+  };
+
+  input.onSearchComplete = function() {
+    Assert.equal(numSearchesStarted, 1);
+
+    Assert.equal(
+      controller.searchStatus,
+      Ci.nsIAutoCompleteController.STATUS_COMPLETE_MATCH
+    );
+    Assert.equal(controller.matchCount, 2);
+
+    // Confirm expected result values
+    for (var i = 0; i < expectedValues.length; i++) {
+      Assert.equal(expectedValues[i], controller.getValueAt(i));
+    }
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(emptySearch);
+    unregisterAutoCompleteSearch(regularSearch);
+
+    do_test_finished();
+  };
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  controller.startSearch("test");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_393191.js b/toolkit/components/autocomplete/tests/unit/test_393191.js
new file mode 100644
index 0000000000..96bf15af64
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_393191.js
@@ -0,0 +1,240 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+/**
+ * Unit test for Bug 393191 - AutoComplete crashes if result is null
+ */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex(aIndex) {},
+    invalidate() {},
+
+    // nsISupports implementation
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResult(aValues, aComments, aStyles) {
+  this._values = aValues;
+  this._comments = aComments;
+  this._styles = aStyles;
+
+  if (this._values.length) {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+  } else {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH;
+  }
+}
+AutoCompleteResult.prototype = {
+  constructor: AutoCompleteResult,
+
+  // Arrays
+  _values: null,
+  _comments: null,
+  _styles: null,
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: 0,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  /**
+   * Return the same result set for every search
+   */
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    aListener.onSearchResult(this, this._result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+
+  var uuidGenerator = Services.uuid;
+  var cid = uuidGenerator.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+/**
+ * Test AutoComplete with a search that returns a null result
+ */
+function run_test() {
+  // Make an AutoCompleteSearch that always returns nothing
+  var emptySearch = new AutoCompleteSearch(
+    "test-empty-search",
+    new AutoCompleteResult([], [], [])
+  );
+
+  // Register search so AutoCompleteController can find them
+  registerAutoCompleteSearch(emptySearch);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our search
+  // and confirms results on search complete
+  var input = new AutoCompleteInput([emptySearch.name]);
+  var numSearchesStarted = 0;
+
+  input.onSearchBegin = function() {
+    numSearchesStarted++;
+    Assert.equal(numSearchesStarted, 1);
+  };
+
+  input.onSearchComplete = function() {
+    Assert.equal(numSearchesStarted, 1);
+
+    Assert.equal(
+      controller.searchStatus,
+      Ci.nsIAutoCompleteController.STATUS_COMPLETE_NO_MATCH
+    );
+    Assert.equal(controller.matchCount, 0);
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(emptySearch);
+
+    do_test_finished();
+  };
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  controller.startSearch("test");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_440866.js b/toolkit/components/autocomplete/tests/unit/test_440866.js
new file mode 100644
index 0000000000..4f8d793719
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_440866.js
@@ -0,0 +1,256 @@
+/* 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/. */
+
+/**
+ * Unit test for Bug 440866 - First AutoCompleteSearch that returns
+ * RESULT_NOMATCH cancels all other searches when popup is open
+ */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex(aIndex) {},
+    invalidate() {},
+
+    // nsISupports implementation
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResult(aValues, aComments, aStyles) {
+  this._values = aValues;
+  this._comments = aComments;
+  this._styles = aStyles;
+
+  if (this._values.length) {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+  } else {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH;
+  }
+}
+AutoCompleteResult.prototype = {
+  constructor: AutoCompleteResult,
+
+  // Arrays
+  _values: null,
+  _comments: null,
+  _styles: null,
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: 0,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  /**
+   * Return the same result set for every search
+   */
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    aListener.onSearchResult(this, this._result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+
+  var uuidGenerator = Services.uuid;
+  var cid = uuidGenerator.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+/**
+ * Test AutoComplete with multiple AutoCompleteSearch sources.
+ */
+function run_test() {
+  // Make an AutoCompleteSearch that always returns nothing
+  var emptySearch = new AutoCompleteSearch(
+    "test-empty-search",
+    new AutoCompleteResult([], [], [])
+  );
+
+  // Make an AutoCompleteSearch that returns two values
+  var expectedValues = ["test1", "test2"];
+  var regularSearch = new AutoCompleteSearch(
+    "test-regular-search",
+    new AutoCompleteResult(expectedValues, [], [])
+  );
+
+  // Register searches so AutoCompleteController can find them
+  registerAutoCompleteSearch(emptySearch);
+  registerAutoCompleteSearch(regularSearch);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches
+  // and confirms results on search complete
+  var input = new AutoCompleteInput([emptySearch.name, regularSearch.name]);
+  var numSearchesStarted = 0;
+
+  input.onSearchBegin = function() {
+    numSearchesStarted++;
+    Assert.equal(numSearchesStarted, 1);
+    Assert.equal(input.searchCount, 2);
+  };
+
+  input.onSearchComplete = function() {
+    Assert.equal(numSearchesStarted, 1);
+
+    Assert.equal(
+      controller.searchStatus,
+      Ci.nsIAutoCompleteController.STATUS_COMPLETE_MATCH
+    );
+    Assert.equal(controller.matchCount, 2);
+
+    // Confirm expected result values
+    for (var i = 0; i < expectedValues.length; i++) {
+      Assert.equal(expectedValues[i], controller.getValueAt(i));
+    }
+
+    Assert.ok(input.popupOpen);
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(emptySearch);
+    unregisterAutoCompleteSearch(regularSearch);
+
+    do_test_finished();
+  };
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  controller.startSearch("test");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_463023.js b/toolkit/components/autocomplete/tests/unit/test_463023.js
new file mode 100644
index 0000000000..48d2284c1b
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_463023.js
@@ -0,0 +1,13 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+// main
+function run_test() {
+  var result = Cc["@mozilla.org/autocomplete/controller;1"].createInstance(
+    Ci.nsIAutoCompleteController
+  );
+  Assert.equal(result.searchStatus, Ci.nsIAutoCompleteController.STATUS_NONE);
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_660156.js b/toolkit/components/autocomplete/tests/unit/test_660156.js
new file mode 100644
index 0000000000..2c247eb1a4
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_660156.js
@@ -0,0 +1,113 @@
+/**
+ * Search object that returns results at different times.
+ * First, the search that returns results asynchronously.
+ */
+function AutoCompleteAsyncSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteAsyncSearch.prototype = Object.create(
+  AutoCompleteSearchBase.prototype
+);
+AutoCompleteAsyncSearch.prototype.startSearch = function(
+  aSearchString,
+  aSearchParam,
+  aPreviousResult,
+  aListener
+) {
+  this._result.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH_ONGOING;
+  aListener.onSearchResult(this, this._result);
+
+  do_timeout(500, () => {
+    this._returnResults(aListener);
+  });
+};
+
+AutoCompleteAsyncSearch.prototype._returnResults = function(aListener) {
+  var result = this._result;
+
+  result.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+  aListener.onSearchResult(this, result);
+};
+
+/**
+ * The synchronous version
+ */
+function AutoCompleteSyncSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSyncSearch.prototype = Object.create(
+  AutoCompleteAsyncSearch.prototype
+);
+AutoCompleteSyncSearch.prototype.startSearch = function(
+  aSearchString,
+  aSearchParam,
+  aPreviousResult,
+  aListener
+) {
+  this._returnResults(aListener);
+};
+
+/**
+ * Results object
+ */
+function AutoCompleteResult(aValues, aDefaultIndex) {
+  this._values = aValues;
+  this.defaultIndex = aDefaultIndex;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+/**
+ * Test AutoComplete with multiple AutoCompleteSearch sources, with one of them
+ * (index != 0) returning before the rest.
+ */
+function run_test() {
+  do_test_pending();
+
+  var results = ["mozillaTest"];
+  var inputStr = "moz";
+
+  // Async search
+  var asyncSearch = new AutoCompleteAsyncSearch(
+    "Async",
+    new AutoCompleteResult(results, -1)
+  );
+  // Sync search
+  var syncSearch = new AutoCompleteSyncSearch(
+    "Sync",
+    new AutoCompleteResult(results, 0)
+  );
+
+  // Register searches so AutoCompleteController can find them
+  registerAutoCompleteSearch(asyncSearch);
+  registerAutoCompleteSearch(syncSearch);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches
+  // and confirms results on search complete.
+  // Async search MUST be FIRST to trigger the bug this tests.
+  var input = new AutoCompleteInputBase([asyncSearch.name, syncSearch.name]);
+  input.completeDefaultIndex = true;
+  input.textValue = inputStr;
+
+  // Caret must be at the end. Autofill doesn't happen unless you're typing
+  // characters at the end.
+  var strLen = inputStr.length;
+  input.selectTextRange(strLen, strLen);
+
+  controller.input = input;
+  controller.startSearch(inputStr);
+
+  input.onSearchComplete = function() {
+    Assert.equal(input.textValue, results[0]);
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(asyncSearch);
+    unregisterAutoCompleteSearch(syncSearch);
+    do_test_finished();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_autocomplete_multiple.js b/toolkit/components/autocomplete/tests/unit/test_autocomplete_multiple.js
new file mode 100644
index 0000000000..31f14a8626
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_autocomplete_multiple.js
@@ -0,0 +1,250 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex(aIndex) {},
+    invalidate() {},
+
+    // nsISupports implementation
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResult(aValues, aComments, aStyles) {
+  this._values = aValues;
+  this._comments = aComments;
+  this._styles = aStyles;
+}
+AutoCompleteResult.prototype = {
+  constructor: AutoCompleteResult,
+
+  // Arrays
+  _values: null,
+  _comments: null,
+  _styles: null,
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: 0,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  /**
+   * Return the same result set for every search
+   */
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    var result = this._result;
+    if (result._values.length) {
+      result.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS_ONGOING;
+    } else {
+      result.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH_ONGOING;
+    }
+    aListener.onSearchResult(this, result);
+
+    if (result._values.length) {
+      result.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+    } else {
+      result.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH;
+    }
+    aListener.onSearchResult(this, result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+
+  var uuidGenerator = Services.uuid;
+  var cid = uuidGenerator.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+/**
+ * Test AutoComplete with multiple AutoCompleteSearch sources.
+ */
+function run_test() {
+  var expected1 = ["1", "2", "3"];
+  var expected2 = ["a", "b", "c"];
+  var search1 = new AutoCompleteSearch(
+    "search1",
+    new AutoCompleteResult(expected1, [], [])
+  );
+  var search2 = new AutoCompleteSearch(
+    "search2",
+    new AutoCompleteResult(expected2, [], [])
+  );
+
+  // Register searches so AutoCompleteController can find them
+  registerAutoCompleteSearch(search1);
+  registerAutoCompleteSearch(search2);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches
+  // and confirms results on search complete
+  var input = new AutoCompleteInput([search1.name, search2.name]);
+  var numSearchesStarted = 0;
+
+  input.onSearchBegin = function() {
+    numSearchesStarted++;
+    Assert.equal(numSearchesStarted, 1);
+  };
+
+  input.onSearchComplete = function() {
+    Assert.equal(numSearchesStarted, 1);
+
+    Assert.equal(
+      controller.searchStatus,
+      Ci.nsIAutoCompleteController.STATUS_COMPLETE_MATCH
+    );
+    Assert.equal(controller.matchCount, expected1.length + expected2.length);
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(search1);
+    unregisterAutoCompleteSearch(search2);
+
+    do_test_finished();
+  };
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  controller.startSearch("test");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_autocomplete_userContextId.js b/toolkit/components/autocomplete/tests/unit/test_autocomplete_userContextId.js
new file mode 100644
index 0000000000..57d2573a81
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_autocomplete_userContextId.js
@@ -0,0 +1,44 @@
+"use strict";
+
+function AutoCompleteInput(aSearches, aUserContextId) {
+  this.searches = aSearches;
+  this.userContextId = aUserContextId;
+  this.popup.selectedIndex = -1;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+function AutoCompleteSearch(aName) {
+  this.name = aName;
+}
+AutoCompleteSearch.prototype = Object.create(AutoCompleteSearchBase.prototype);
+
+add_task(async function test_userContextId() {
+  let searchParam = await doSearch("test", 1);
+  Assert.equal(searchParam, " user-context-id:1");
+});
+
+function doSearch(aString, aUserContextId) {
+  return new Promise(resolve => {
+    let search = new AutoCompleteSearch("test");
+
+    search.startSearch = function(
+      aSearchString,
+      aSearchParam,
+      aPreviousResult,
+      aListener
+    ) {
+      unregisterAutoCompleteSearch(search);
+      resolve(aSearchParam);
+    };
+
+    registerAutoCompleteSearch(search);
+
+    let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+      Ci.nsIAutoCompleteController
+    );
+
+    let input = new AutoCompleteInput([search.name], aUserContextId);
+    controller.input = input;
+    controller.startSearch(aString);
+  });
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_autofillSelectedPopupIndex.js b/toolkit/components/autocomplete/tests/unit/test_autofillSelectedPopupIndex.js
new file mode 100644
index 0000000000..9b38b95c9c
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_autofillSelectedPopupIndex.js
@@ -0,0 +1,109 @@
+"use strict";
+
+add_task(async function sameCaseAsMatch() {
+  await runTest("moz");
+});
+
+add_task(async function differentCaseFromMatch() {
+  await runTest("MOZ");
+});
+
+async function runTest(searchStr) {
+  let matches = ["mozilla.org", "example.com"];
+  let result = new AutoCompleteResultBase(matches);
+  result.defaultIndex = 0;
+
+  let search = new AutoCompleteSearchBase("search", result);
+  registerAutoCompleteSearch(search);
+
+  let input = new AutoCompleteInputBase([search.name]);
+  input.completeSelectedIndex = true;
+  input.completeDefaultIndex = true;
+
+  // Start off with the search string in the input.  The selection must be
+  // collapsed and the caret must be at the end to trigger autofill below.
+  input.textValue = searchStr;
+  input.selectTextRange(searchStr.length, searchStr.length);
+  Assert.equal(
+    input.selectionStart,
+    searchStr.length,
+    "Selection should start at the end of the input"
+  );
+  Assert.equal(
+    input.selectionEnd,
+    searchStr.length,
+    "Selection should end at the end of the input"
+  );
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].createInstance(
+    Ci.nsIAutoCompleteController
+  );
+  controller.input = input;
+  input.controller = controller;
+
+  // Start a search.
+  await new Promise(resolve => {
+    controller.startSearch(searchStr);
+    input.onSearchComplete = () => {
+      // The first match should have autofilled, but the case of the search
+      // string should be preserved.
+      let expectedValue = searchStr + matches[0].substr(searchStr.length);
+      Assert.equal(input.textValue, expectedValue, "Should have autofilled");
+      Assert.equal(
+        input.selectionStart,
+        searchStr.length,
+        "Selection should start after search string"
+      );
+      Assert.equal(
+        input.selectionEnd,
+        expectedValue.length,
+        "Selection should end at the end of the input"
+      );
+      resolve();
+    };
+  });
+
+  // Key down to select the second match in the popup.
+  // Hardcode KeyboardEvent.DOM_VK_DOWN, because we can't easily
+  // include KeyboardEvent here.
+  controller.handleKeyNavigation(0x28 /* KeyboardEvent.DOM_VK_DOWN */);
+  let expectedValue = matches[1];
+  Assert.equal(
+    input.textValue,
+    expectedValue,
+    "Should have filled second match"
+  );
+  Assert.equal(
+    input.selectionStart,
+    expectedValue.length,
+    "Selection should start at the end of the input"
+  );
+  Assert.equal(
+    input.selectionEnd,
+    expectedValue.length,
+    "Selection should end at the end of the input"
+  );
+
+  // Key up to select the first match again.  The input should be restored
+  // exactly as it was when the first match was autofilled above: the search
+  // string's case should be preserved, and the selection should be preserved.
+  // Hardcode KeyboardEvent.DOM_VK_UP, because we can't easily
+  // include KeyboardEvent here.
+  controller.handleKeyNavigation(0x26 /* KeyboardEvent.DOM_VK_UP */);
+  expectedValue = searchStr + matches[0].substr(searchStr.length);
+  Assert.equal(
+    input.textValue,
+    expectedValue,
+    "Should have filled first match again"
+  );
+  Assert.equal(
+    input.selectionStart,
+    searchStr.length,
+    "Selection should start after search string again"
+  );
+  Assert.equal(
+    input.selectionEnd,
+    expectedValue.length,
+    "Selection should end at the end of the input again"
+  );
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_badDefaultIndex.js b/toolkit/components/autocomplete/tests/unit/test_badDefaultIndex.js
new file mode 100644
index 0000000000..0dea9ec236
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_badDefaultIndex.js
@@ -0,0 +1,100 @@
+/* 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/. */
+
+/**
+ * A results that wants to defaultComplete to 0, but it has no matches,
+ * though it notifies SUCCESS to the controller.
+ */
+function AutoCompleteNoMatchResult() {
+  this.defaultIndex = 0;
+}
+AutoCompleteNoMatchResult.prototype = Object.create(
+  AutoCompleteResultBase.prototype
+);
+
+/**
+ * A results that wants to defaultComplete to an index greater than the number
+ * of matches.
+ */
+function AutoCompleteBadIndexResult(aValues, aDefaultIndex) {
+  Assert.ok(aValues.length <= aDefaultIndex);
+  this._values = aValues;
+  this.defaultIndex = aDefaultIndex;
+}
+AutoCompleteBadIndexResult.prototype = Object.create(
+  AutoCompleteResultBase.prototype
+);
+
+add_test(function autocomplete_noMatch_success() {
+  const INPUT_STR = "moz";
+
+  let searchNoMatch = new AutoCompleteSearchBase(
+    "searchNoMatch",
+    new AutoCompleteNoMatchResult()
+  );
+  registerAutoCompleteSearch(searchNoMatch);
+
+  // Make an AutoCompleteInput that uses our search and confirms results.
+  let input = new AutoCompleteInputBase([searchNoMatch.name]);
+  input.completeDefaultIndex = true;
+  input.textValue = INPUT_STR;
+
+  // Caret must be at the end for autoFill to happen.
+  let strLen = INPUT_STR.length;
+  input.selectTextRange(strLen, strLen);
+  Assert.equal(input.selectionStart, strLen);
+  Assert.equal(input.selectionEnd, strLen);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+  controller.input = input;
+  controller.startSearch(INPUT_STR);
+
+  input.onSearchComplete = function() {
+    // Should not try to autoFill to an empty value.
+    Assert.equal(input.textValue, "moz");
+
+    // Clean up.
+    unregisterAutoCompleteSearch(searchNoMatch);
+    run_next_test();
+  };
+});
+
+add_test(function autocomplete_defaultIndex_exceeds_matchCount() {
+  const INPUT_STR = "moz";
+
+  // Result returning matches, but a bad defaultIndex.
+  let searchBadIndex = new AutoCompleteSearchBase(
+    "searchBadIndex",
+    new AutoCompleteBadIndexResult(["mozillaTest"], 1)
+  );
+  registerAutoCompleteSearch(searchBadIndex);
+
+  // Make an AutoCompleteInput that uses our search and confirms results.
+  let input = new AutoCompleteInputBase([searchBadIndex.name]);
+  input.completeDefaultIndex = true;
+  input.textValue = INPUT_STR;
+
+  // Caret must be at the end for autoFill to happen.
+  let strLen = INPUT_STR.length;
+  input.selectTextRange(strLen, strLen);
+  Assert.equal(input.selectionStart, strLen);
+  Assert.equal(input.selectionEnd, strLen);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+  controller.input = input;
+  controller.startSearch(INPUT_STR);
+
+  input.onSearchComplete = function() {
+    // Should not try to autoFill to an empty value.
+    Assert.equal(input.textValue, "moz");
+
+    // Clean up.
+    unregisterAutoCompleteSearch(searchBadIndex);
+    run_next_test();
+  };
+});
diff --git a/toolkit/components/autocomplete/tests/unit/test_completeDefaultIndex_casing.js b/toolkit/components/autocomplete/tests/unit/test_completeDefaultIndex_casing.js
new file mode 100644
index 0000000000..8d3d06b54b
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_completeDefaultIndex_casing.js
@@ -0,0 +1,64 @@
+/* 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/. */
+
+function AutoCompleteResult(aValues) {
+  this._values = aValues;
+  this.defaultIndex = 0;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = -1;
+  this.completeDefaultIndex = true;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_keyNavigation() {
+  doSearch("MOZ", "mozilla", function(aController) {
+    Assert.equal(aController.input.textValue, "MOZilla");
+    // Hardcode KeyboardEvent.DOM_VK_RIGHT, because we can't easily
+    // include KeyboardEvent here.
+    aController.handleKeyNavigation(0x27 /* KeyboardEvent.DOM_VK_RIGHT */);
+    Assert.equal(aController.input.textValue, "mozilla");
+  });
+});
+
+add_test(function test_handleEnter() {
+  doSearch("MOZ", "mozilla", function(aController) {
+    Assert.equal(aController.input.textValue, "MOZilla");
+    aController.handleEnter(false);
+    Assert.equal(aController.input.textValue, "mozilla");
+  });
+});
+
+function doSearch(aSearchString, aResultValue, aOnCompleteCallback) {
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult(["mozilla", "toolkit"], 0)
+  );
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches and confirms results.
+  let input = new AutoCompleteInput([search.name]);
+  input.textValue = aSearchString;
+
+  // Caret must be at the end for autofill to happen.
+  let strLen = aSearchString.length;
+  input.selectTextRange(strLen, strLen);
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    // Clean up.
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue.js b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue.js
new file mode 100644
index 0000000000..53d325ed78
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue.js
@@ -0,0 +1,59 @@
+function AutoCompleteResult(aValues, aFinalCompleteValues) {
+  this._values = aValues;
+  this._finalCompleteValues = aFinalCompleteValues;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = 0;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_handleEnter_mouse() {
+  doSearch("moz", "mozilla.com", "http://www.mozilla.com", function(
+    aController
+  ) {
+    Assert.equal(aController.input.textValue, "moz");
+    Assert.equal(
+      aController.getFinalCompleteValueAt(0),
+      "http://www.mozilla.com"
+    );
+    // Keyboard interaction is tested by test_finalCompleteValueSelectedIndex.js
+    // so here just test popup selection.
+    aController.handleEnter(true);
+    Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+  });
+});
+
+function doSearch(
+  aSearchString,
+  aResultValue,
+  aFinalCompleteValue,
+  aOnCompleteCallback
+) {
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult([aResultValue], [aFinalCompleteValue])
+  );
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches and confirms results.
+  let input = new AutoCompleteInput([search.name]);
+  input.textValue = aSearchString;
+
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    // Clean up.
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_finalCompleteValueSelectedIndex.js b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValueSelectedIndex.js
new file mode 100644
index 0000000000..cc5f748687
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValueSelectedIndex.js
@@ -0,0 +1,139 @@
+function AutoCompleteResult(aResultValues) {
+  this._values = aResultValues.map(x => x[0]);
+  this._finalCompleteValues = aResultValues.map(x => x[1]);
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+var selectByWasCalled = false;
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = 0;
+  this.popup.selectBy = function(reverse, page) {
+    Assert.equal(selectByWasCalled, false);
+    selectByWasCalled = true;
+    Assert.equal(reverse, false);
+    Assert.equal(page, false);
+    this.selectedIndex += (reverse ? -1 : 1) * (page ? 100 : 1);
+  };
+  this.completeSelectedIndex = true;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_handleEnter_key() {
+  let results = [
+    ["mozilla.com", "http://www.mozilla.com"],
+    ["mozilla.org", "http://www.mozilla.org"],
+  ];
+  // First check the case where we do select a value with the keyboard:
+  doSearch("moz", results, function(aController) {
+    Assert.equal(aController.input.textValue, "moz");
+    Assert.equal(
+      aController.getFinalCompleteValueAt(0),
+      "http://www.mozilla.com"
+    );
+    Assert.equal(
+      aController.getFinalCompleteValueAt(1),
+      "http://www.mozilla.org"
+    );
+
+    Assert.equal(aController.input.popup.selectedIndex, 0);
+    // Hardcode KeyboardEvent.DOM_VK_DOWN, because we can't easily
+    // include KeyboardEvent here.
+    aController.handleKeyNavigation(0x28 /* KeyboardEvent.DOM_VK_DOWN */);
+    Assert.equal(aController.input.popup.selectedIndex, 1);
+    // Simulate mouse interaction changing selectedIndex
+    // ie NOT keyboard interaction:
+    aController.input.popup.selectedIndex = 0;
+
+    aController.handleEnter(false);
+    // Verify that the keyboard-selected thing got inserted,
+    // and not the mouse selection:
+    Assert.equal(aController.input.textValue, "http://www.mozilla.org");
+  });
+});
+
+add_test(function test_handleEnter_mouse() {
+  let results = [
+    ["mozilla.com", "http://www.mozilla.com"],
+    ["mozilla.org", "http://www.mozilla.org"],
+  ];
+  // Then the case where we do not:
+  doSearch("moz", results, function(aController) {
+    Assert.equal(aController.input.textValue, "moz");
+    Assert.equal(
+      aController.getFinalCompleteValueAt(0),
+      "http://www.mozilla.com"
+    );
+    Assert.equal(
+      aController.getFinalCompleteValueAt(1),
+      "http://www.mozilla.org"
+    );
+
+    Assert.equal(aController.input.popup.selectedIndex, 0);
+    aController.input.popupOpen = true;
+    // Simulate mouse interaction changing selectedIndex
+    // ie NOT keyboard interaction:
+    aController.input.popup.selectedIndex = 1;
+    Assert.equal(selectByWasCalled, false);
+    Assert.equal(aController.input.popup.selectedIndex, 1);
+
+    aController.handleEnter(false);
+    // Verify that the input stayed the same, because no selection was made
+    // with the keyboard:
+    Assert.equal(aController.input.textValue, "moz");
+  });
+});
+
+add_test(function test_handleEnter_preselected() {
+  let results = [
+    ["mozilla.com", "http://www.mozilla.com"],
+    ["mozilla.org", "http://www.mozilla.org"],
+  ];
+  // Then test a preselection.
+  doSearch("moz", results, function(aController) {
+    Assert.equal(aController.input.textValue, "moz");
+    Assert.equal(
+      aController.getFinalCompleteValueAt(0),
+      "http://www.mozilla.com"
+    );
+    Assert.equal(
+      aController.getFinalCompleteValueAt(1),
+      "http://www.mozilla.org"
+    );
+
+    aController.setInitiallySelectedIndex(0);
+
+    aController.handleEnter(false);
+    // Verify that the input stayed the same, because no selection was made
+    // with the keyboard:
+    Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+  });
+});
+
+function doSearch(aSearchString, aResults, aOnCompleteCallback) {
+  selectByWasCalled = false;
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult(aResults)
+  );
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches and confirms results.
+  let input = new AutoCompleteInput([search.name]);
+  input.textValue = aSearchString;
+
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    // Clean up.
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_defaultIndex.js b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_defaultIndex.js
new file mode 100644
index 0000000000..7b8a51f03a
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_defaultIndex.js
@@ -0,0 +1,112 @@
+function AutoCompleteResult(aResultValues) {
+  this.defaultIndex = 0;
+  this._values = aResultValues.map(x => x[0]);
+  this._finalCompleteValues = aResultValues.map(x => x[1]);
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = 0;
+  this.completeSelectedIndex = true;
+  this.completeDefaultIndex = true;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_handleEnter() {
+  let results = [
+    ["mozilla.com", "https://www.mozilla.com"],
+    ["gomozilla.org", "http://www.gomozilla.org"],
+  ];
+  doSearch("moz", results, { selectedIndex: 0 }, controller => {
+    let input = controller.input;
+    Assert.equal(input.textValue, "mozilla.com");
+    Assert.equal(controller.getFinalCompleteValueAt(0), results[0][1]);
+    Assert.equal(controller.getFinalCompleteValueAt(1), results[1][1]);
+    Assert.equal(input.popup.selectedIndex, 0);
+
+    controller.handleEnter(false);
+    // Verify that the keyboard-selected thing got inserted,
+    // and not the mouse selection:
+    Assert.equal(controller.input.textValue, "https://www.mozilla.com");
+  });
+});
+
+add_test(function test_handleEnter_otherSelected() {
+  // The popup selection may not coincide with what is filled into the input
+  // field, for example if the user changed it with the mouse and then pressed
+  // Enter. In such a case we should still use the inputField value and not the
+  // popup selected value.
+  let results = [
+    ["mozilla.com", "https://www.mozilla.com"],
+    ["gomozilla.org", "http://www.gomozilla.org"],
+  ];
+  doSearch("moz", results, { selectedIndex: 1 }, controller => {
+    let input = controller.input;
+    Assert.equal(input.textValue, "mozilla.com");
+    Assert.equal(controller.getFinalCompleteValueAt(0), results[0][1]);
+    Assert.equal(controller.getFinalCompleteValueAt(1), results[1][1]);
+    Assert.equal(input.popup.selectedIndex, 1);
+
+    controller.handleEnter(false);
+    // Verify that the keyboard-selected thing got inserted,
+    // and not the mouse selection:
+    Assert.equal(controller.input.textValue, "https://www.mozilla.com");
+  });
+});
+
+add_test(function test_handleEnter_otherSelected_nocompleteselectedindex() {
+  let results = [
+    ["mozilla.com", "https://www.mozilla.com"],
+    ["gomozilla.org", "http://www.gomozilla.org"],
+  ];
+  doSearch(
+    "moz",
+    results,
+    { selectedIndex: 1, completeSelectedIndex: false },
+    controller => {
+      let input = controller.input;
+      Assert.equal(input.textValue, "mozilla.com");
+      Assert.equal(controller.getFinalCompleteValueAt(0), results[0][1]);
+      Assert.equal(controller.getFinalCompleteValueAt(1), results[1][1]);
+      Assert.equal(input.popup.selectedIndex, 1);
+
+      controller.handleEnter(false);
+      // Verify that the keyboard-selected result is inserted, not the
+      // defaultComplete.
+      Assert.equal(controller.input.textValue, "http://www.gomozilla.org");
+    }
+  );
+});
+
+function doSearch(aSearchString, aResults, aOptions, aOnCompleteCallback) {
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult(aResults)
+  );
+  registerAutoCompleteSearch(search);
+
+  let input = new AutoCompleteInput([search.name]);
+  input.textValue = aSearchString;
+  if ("selectedIndex" in aOptions) {
+    input.popup.selectedIndex = aOptions.selectedIndex;
+  }
+  if ("completeSelectedIndex" in aOptions) {
+    input.completeSelectedIndex = aOptions.completeSelectedIndex;
+  }
+  // Needed for defaultIndex completion.
+  input.selectTextRange(aSearchString.length, aSearchString.length);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_forceComplete.js b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_forceComplete.js
new file mode 100644
index 0000000000..4195c97988
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_finalCompleteValue_forceComplete.js
@@ -0,0 +1,138 @@
+/* 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/. */
+
+function AutoCompleteResult(aValues, aFinalCompleteValues) {
+  this._values = aValues;
+  this._finalCompleteValues = aFinalCompleteValues;
+  this.defaultIndex = 0;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = -1;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_handleEnterWithDirectMatchCompleteSelectedIndex() {
+  doSearch(
+    "moz",
+    "mozilla.com",
+    "http://www.mozilla.com",
+    { forceComplete: true, completeSelectedIndex: true },
+    function(aController) {
+      Assert.equal(aController.input.textValue, "moz");
+      Assert.equal(
+        aController.getFinalCompleteValueAt(0),
+        "http://www.mozilla.com"
+      );
+      aController.handleEnter(false);
+      // After enter the final complete value should be shown in the input.
+      Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+    }
+  );
+});
+
+add_test(function test_handleEnterWithDirectMatch() {
+  doSearch(
+    "mozilla",
+    "mozilla.com",
+    "http://www.mozilla.com",
+    { forceComplete: true, completeDefaultIndex: true },
+    function(aController) {
+      // Should autocomplete the search string to a suggestion.
+      Assert.equal(aController.input.textValue, "mozilla.com");
+      Assert.equal(
+        aController.getFinalCompleteValueAt(0),
+        "http://www.mozilla.com"
+      );
+      aController.handleEnter(false);
+      // After enter the final complete value should be shown in the input.
+      Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+    }
+  );
+});
+
+add_test(function test_handleEnterWithNoMatch() {
+  doSearch(
+    "mozilla",
+    "mozilla.com",
+    "http://www.mozilla.com",
+    { forceComplete: true, completeDefaultIndex: true },
+    function(aController) {
+      // Should autocomplete the search string to a suggestion.
+      Assert.equal(aController.input.textValue, "mozilla.com");
+      Assert.equal(
+        aController.getFinalCompleteValueAt(0),
+        "http://www.mozilla.com"
+      );
+      // Now input something that does not match...
+      aController.input.textValue = "mozillax";
+      // ... and confirm. We don't want one of the values from the previous
+      // results to be taken, since what's now in the input field doesn't match.
+      aController.handleEnter(false);
+      Assert.equal(aController.input.textValue, "mozillax");
+    }
+  );
+});
+
+add_test(function test_handleEnterWithIndirectMatch() {
+  doSearch(
+    "com",
+    "mozilla.com",
+    "http://www.mozilla.com",
+    { forceComplete: true, completeDefaultIndex: true },
+    function(aController) {
+      // Should autocomplete the search string to a suggestion.
+      Assert.equal(aController.input.textValue, "com >> mozilla.com");
+      Assert.equal(
+        aController.getFinalCompleteValueAt(0),
+        "http://www.mozilla.com"
+      );
+      aController.handleEnter(false);
+      // After enter the final complete value from the suggestion should be shown
+      // in the input.
+      Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+    }
+  );
+});
+
+function doSearch(
+  aSearchString,
+  aResultValue,
+  aFinalCompleteValue,
+  aInputProps,
+  aOnCompleteCallback
+) {
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult([aResultValue], [aFinalCompleteValue])
+  );
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches and confirms results.
+  let input = new AutoCompleteInput([search.name]);
+  for (var p in aInputProps) {
+    input[p] = aInputProps[p];
+  }
+  input.textValue = aSearchString;
+  // Place the cursor at the end of the input so that completion to
+  // default index will kick in.
+  input.selectTextRange(aSearchString.length, aSearchString.length);
+
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    // Clean up.
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_finalDefaultCompleteValue.js b/toolkit/components/autocomplete/tests/unit/test_finalDefaultCompleteValue.js
new file mode 100644
index 0000000000..cb4079b49c
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_finalDefaultCompleteValue.js
@@ -0,0 +1,74 @@
+/* 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/. */
+
+function AutoCompleteResult(aValues, aFinalCompleteValues) {
+  this._values = aValues;
+  this._finalCompleteValues = aFinalCompleteValues;
+  this.defaultIndex = 0;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+  this.popup.selectedIndex = -1;
+  this.completeDefaultIndex = true;
+}
+AutoCompleteInput.prototype = Object.create(AutoCompleteInputBase.prototype);
+
+add_test(function test_keyNavigation() {
+  doSearch("moz", "mozilla.com", "http://www.mozilla.com", function(
+    aController
+  ) {
+    Assert.equal(aController.input.textValue, "mozilla.com");
+    // Hardcode KeyboardEvent.DOM_VK_RIGHT, because we can't easily
+    // include KeyboardEvent here.
+    aController.handleKeyNavigation(0x27 /* KeyboardEvent.DOM_VK_RIGHT */);
+    Assert.equal(aController.input.textValue, "mozilla.com");
+  });
+});
+
+add_test(function test_handleEnter() {
+  doSearch("moz", "mozilla.com", "http://www.mozilla.com", function(
+    aController
+  ) {
+    Assert.equal(aController.input.textValue, "mozilla.com");
+    aController.handleEnter(false);
+    Assert.equal(aController.input.textValue, "http://www.mozilla.com");
+  });
+});
+
+function doSearch(
+  aSearchString,
+  aResultValue,
+  aFinalCompleteValue,
+  aOnCompleteCallback
+) {
+  let search = new AutoCompleteSearchBase(
+    "search",
+    new AutoCompleteResult([aResultValue], [aFinalCompleteValue])
+  );
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our searches and confirms results.
+  let input = new AutoCompleteInput([search.name]);
+  input.textValue = aSearchString;
+
+  // Caret must be at the end for autofill to happen.
+  let strLen = aSearchString.length;
+  input.selectTextRange(strLen, strLen);
+  controller.input = input;
+  controller.startSearch(aSearchString);
+
+  input.onSearchComplete = function onSearchComplete() {
+    aOnCompleteCallback(controller);
+
+    // Clean up.
+    unregisterAutoCompleteSearch(search);
+    run_next_test();
+  };
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_immediate_search.js b/toolkit/components/autocomplete/tests/unit/test_immediate_search.js
new file mode 100644
index 0000000000..67493d13a3
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_immediate_search.js
@@ -0,0 +1,174 @@
+/* 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/. */
+
+function AutoCompleteImmediateSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteImmediateSearch.prototype = Object.create(
+  AutoCompleteSearchBase.prototype
+);
+AutoCompleteImmediateSearch.prototype.searchType =
+  Ci.nsIAutoCompleteSearchDescriptor.SEARCH_TYPE_IMMEDIATE;
+AutoCompleteImmediateSearch.prototype.QueryInterface = ChromeUtils.generateQI([
+  "nsIFactory",
+  "nsIAutoCompleteSearch",
+  "nsIAutoCompleteSearchDescriptor",
+]);
+
+function AutoCompleteDelayedSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteDelayedSearch.prototype = Object.create(
+  AutoCompleteSearchBase.prototype
+);
+
+function AutoCompleteResult(aValues, aDefaultIndex) {
+  this._values = aValues;
+  this.defaultIndex = aDefaultIndex;
+}
+AutoCompleteResult.prototype = Object.create(AutoCompleteResultBase.prototype);
+
+/**
+ * An immediate search should be executed synchronously.
+ */
+add_test(function test_immediate_search() {
+  let inputStr = "moz";
+
+  let immediateSearch = new AutoCompleteImmediateSearch(
+    "immediate",
+    new AutoCompleteResult(["moz-immediate"], 0)
+  );
+  registerAutoCompleteSearch(immediateSearch);
+  let delayedSearch = new AutoCompleteDelayedSearch(
+    "delayed",
+    new AutoCompleteResult(["moz-delayed"], 0)
+  );
+  registerAutoCompleteSearch(delayedSearch);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  let input = new AutoCompleteInputBase([
+    delayedSearch.name,
+    immediateSearch.name,
+  ]);
+  input.completeDefaultIndex = true;
+  input.textValue = inputStr;
+
+  // Caret must be at the end. Autofill doesn't happen unless you're typing
+  // characters at the end.
+  let strLen = inputStr.length;
+  input.selectTextRange(strLen, strLen);
+
+  controller.input = input;
+  controller.startSearch(inputStr);
+
+  // Immediately check the result, the immediate search should have finished.
+  Assert.equal(input.textValue, "moz-immediate");
+
+  // Wait for both queries to finish.
+  input.onSearchComplete = function() {
+    // Sanity check.
+    Assert.equal(input.textValue, "moz-immediate");
+
+    unregisterAutoCompleteSearch(immediateSearch);
+    unregisterAutoCompleteSearch(delayedSearch);
+    run_next_test();
+  };
+});
+
+/**
+ * An immediate search should be executed before any delayed search.
+ */
+add_test(function test_immediate_search_notimeout() {
+  let inputStr = "moz";
+
+  let immediateSearch = new AutoCompleteImmediateSearch(
+    "immediate",
+    new AutoCompleteResult(["moz-immediate"], 0)
+  );
+  registerAutoCompleteSearch(immediateSearch);
+
+  let delayedSearch = new AutoCompleteDelayedSearch(
+    "delayed",
+    new AutoCompleteResult(["moz-delayed"], 0)
+  );
+  registerAutoCompleteSearch(delayedSearch);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  let input = new AutoCompleteInputBase([
+    delayedSearch.name,
+    immediateSearch.name,
+  ]);
+  input.completeDefaultIndex = true;
+  input.textValue = inputStr;
+  input.timeout = 0;
+
+  // Caret must be at the end. Autofill doesn't happen unless you're typing
+  // characters at the end.
+  let strLen = inputStr.length;
+  input.selectTextRange(strLen, strLen);
+
+  controller.input = input;
+  let complete = false;
+  input.onSearchComplete = function() {
+    complete = true;
+  };
+  controller.startSearch(inputStr);
+  Assert.ok(complete);
+
+  // Immediately check the result, the immediate search should have finished.
+  Assert.equal(input.textValue, "moz-immediate");
+
+  unregisterAutoCompleteSearch(immediateSearch);
+  unregisterAutoCompleteSearch(delayedSearch);
+  run_next_test();
+});
+
+/**
+ * A delayed search should be executed synchronously with a zero timeout.
+ */
+add_test(function test_delayed_search_notimeout() {
+  let inputStr = "moz";
+
+  let delayedSearch = new AutoCompleteDelayedSearch(
+    "delayed",
+    new AutoCompleteResult(["moz-delayed"], 0)
+  );
+  registerAutoCompleteSearch(delayedSearch);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  let input = new AutoCompleteInputBase([delayedSearch.name]);
+  input.completeDefaultIndex = true;
+  input.textValue = inputStr;
+  input.timeout = 0;
+
+  // Caret must be at the end. Autofill doesn't happen unless you're typing
+  // characters at the end.
+  let strLen = inputStr.length;
+  input.selectTextRange(strLen, strLen);
+
+  controller.input = input;
+  let complete = false;
+  input.onSearchComplete = function() {
+    complete = true;
+  };
+  controller.startSearch(inputStr);
+  Assert.ok(complete);
+
+  // Immediately check the result, the delayed search should have finished.
+  Assert.equal(input.textValue, "moz-delayed");
+
+  unregisterAutoCompleteSearch(delayedSearch);
+  run_next_test();
+});
diff --git a/toolkit/components/autocomplete/tests/unit/test_insertMatchAt.js b/toolkit/components/autocomplete/tests/unit/test_insertMatchAt.js
new file mode 100644
index 0000000000..cef3fb9683
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_insertMatchAt.js
@@ -0,0 +1,15 @@
+function run_test() {
+  let result = Cc["@mozilla.org/autocomplete/simple-result;1"].createInstance(
+    Ci.nsIAutoCompleteSimpleResult
+  );
+  result.appendMatch("a", "");
+  result.appendMatch("c", "");
+  result.insertMatchAt(1, "b", "");
+  result.insertMatchAt(3, "d", "");
+
+  Assert.equal(result.matchCount, 4);
+  Assert.equal(result.getValueAt(0), "a");
+  Assert.equal(result.getValueAt(1), "b");
+  Assert.equal(result.getValueAt(2), "c");
+  Assert.equal(result.getValueAt(3), "d");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_previousResult.js b/toolkit/components/autocomplete/tests/unit/test_previousResult.js
new file mode 100644
index 0000000000..57f5b2f6bb
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_previousResult.js
@@ -0,0 +1,257 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* 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/. */
+
+/**
+ * Unit test for Bug 438861 - Previous search results not returned to multiple
+ * searches.
+ */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  // Array of AutoCompleteSearch names
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchBegin() {},
+  onSearchComplete() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex(aIndex) {},
+    invalidate() {},
+
+    // nsISupports implementation
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteResult implementation
+ */
+function AutoCompleteResult(aValues, aComments, aStyles) {
+  this._values = aValues;
+  this._comments = aComments;
+  this._styles = aStyles;
+  if (this._values.length) {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_SUCCESS;
+  } else {
+    this.searchResult = Ci.nsIAutoCompleteResult.RESULT_NOMATCH;
+  }
+}
+AutoCompleteResult.prototype = {
+  constructor: AutoCompleteResult,
+
+  // Arrays
+  _values: null,
+  _comments: null,
+  _styles: null,
+
+  searchString: "",
+  searchResult: null,
+
+  defaultIndex: 0,
+
+  get matchCount() {
+    return this._values.length;
+  },
+
+  getValueAt(aIndex) {
+    return this._values[aIndex];
+  },
+
+  getLabelAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  getCommentAt(aIndex) {
+    return this._comments[aIndex];
+  },
+
+  getStyleAt(aIndex) {
+    return this._styles[aIndex];
+  },
+
+  getImageAt(aIndex) {
+    return "";
+  },
+
+  getFinalCompleteValueAt(aIndex) {
+    return this.getValueAt(aIndex);
+  },
+
+  isRemovableAt(aRowIndex) {
+    return true;
+  },
+
+  removeValueAt(aRowIndex) {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteResult"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation that always returns
+ * the same result set.
+ */
+function AutoCompleteSearch(aName, aResult) {
+  this.name = aName;
+  this._result = aResult;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+
+  // Search name. Used by AutoCompleteController
+  name: null,
+
+  // AutoCompleteResult
+  _result: null,
+
+  _previousResult: null,
+
+  /**
+   * Return the same result set for every search
+   */
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    this._previousResult = aPreviousResult;
+    aListener.onSearchResult(this, this._result);
+  },
+
+  stopSearch() {},
+
+  // nsISupports implementation
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+
+  // nsIFactory implementation
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  var name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+
+  var uuidGenerator = Services.uuid;
+  var cid = uuidGenerator.generateUUID();
+
+  var desc = "Test AutoCompleteSearch";
+
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  var componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+/**
+ */
+function run_test() {
+  // Make an AutoCompleteSearch that always returns nothing
+  var search1 = new AutoCompleteSearch(
+    "test-previous-result1",
+    new AutoCompleteResult(["hello1"], [""], [""])
+  );
+
+  var search2 = new AutoCompleteSearch(
+    "test-previous-result2",
+    new AutoCompleteResult(["hello2"], [""], [""])
+  );
+
+  // Register search so AutoCompleteController can find them
+  registerAutoCompleteSearch(search1);
+  registerAutoCompleteSearch(search2);
+
+  var controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our search
+  // and confirms results on search complete
+  var input = new AutoCompleteInput([search1.name, search2.name]);
+  var numSearchesStarted = 0;
+
+  input.onSearchBegin = function() {
+    numSearchesStarted++;
+  };
+
+  input.onSearchComplete = function() {
+    Assert.equal(
+      controller.searchStatus,
+      Ci.nsIAutoCompleteController.STATUS_COMPLETE_MATCH
+    );
+    Assert.equal(controller.matchCount, 2);
+
+    if (numSearchesStarted == 1) {
+      Assert.equal(search1._previousResult, null);
+      Assert.equal(search2._previousResult, null);
+
+      // Now start it again
+      controller.startSearch("test");
+      return;
+    }
+    Assert.notEqual(search1._previousResult, null);
+    Assert.notEqual(search2._previousResult, null);
+
+    // Unregister searches
+    unregisterAutoCompleteSearch(search1);
+    unregisterAutoCompleteSearch(search2);
+
+    do_test_finished();
+  };
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  controller.startSearch("test");
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_removeMatchAt.js b/toolkit/components/autocomplete/tests/unit/test_removeMatchAt.js
new file mode 100644
index 0000000000..c8abf0b832
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_removeMatchAt.js
@@ -0,0 +1,16 @@
+function run_test() {
+  let result = Cc["@mozilla.org/autocomplete/simple-result;1"].createInstance(
+    Ci.nsIAutoCompleteSimpleResult
+  );
+  result.appendMatch("a", "");
+  result.appendMatch("b", "");
+  result.removeMatchAt(0);
+  Assert.equal(result.matchCount, 1);
+  Assert.equal(result.getValueAt(0), "b");
+  result.appendMatch("c", "");
+  result.removeMatchAt(1);
+  Assert.equal(result.matchCount, 1);
+  Assert.equal(result.getValueAt(0), "b");
+  result.removeMatchAt(0);
+  Assert.equal(result.matchCount, 0);
+}
diff --git a/toolkit/components/autocomplete/tests/unit/test_stopSearch.js b/toolkit/components/autocomplete/tests/unit/test_stopSearch.js
new file mode 100644
index 0000000000..889c75512b
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/test_stopSearch.js
@@ -0,0 +1,171 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/**
+ * Purpose of the test is to check that a stopSearch call comes always before a
+ * startSearch call.
+ */
+
+/**
+ * Dummy nsIAutoCompleteInput source that returns
+ * the given list of AutoCompleteSearch names.
+ *
+ * Implements only the methods needed for this test.
+ */
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "hello",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+  set popupOpen(val) {}, // ignore
+  get popupOpen() {
+    return false;
+  },
+  get searchCount() {
+    return this.searches.length;
+  },
+  getSearchAt(aIndex) {
+    return this.searches[aIndex];
+  },
+  onSearchBegin() {},
+  onSearchComplete() {},
+  onTextReverted() {},
+  onTextEntered() {},
+  popup: {
+    selectBy() {},
+    invalidate() {},
+    set selectedIndex(val) {}, // ignore
+    get selectedIndex() {
+      return -1;
+    },
+    QueryInterface: ChromeUtils.generateQI(["nsIAutoCompletePopup"]),
+  },
+  QueryInterface: ChromeUtils.generateQI(["nsIAutoCompleteInput"]),
+};
+
+/**
+ * nsIAutoCompleteSearch implementation.
+ */
+function AutoCompleteSearch(aName) {
+  this.name = aName;
+}
+AutoCompleteSearch.prototype = {
+  constructor: AutoCompleteSearch,
+  stopSearchInvoked: true,
+  startSearch(aSearchString, aSearchParam, aPreviousResult, aListener) {
+    info("Check stop search has been called");
+    Assert.ok(this.stopSearchInvoked);
+    this.stopSearchInvoked = false;
+  },
+  stopSearch() {
+    this.stopSearchInvoked = true;
+  },
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIFactory",
+    "nsIAutoCompleteSearch",
+  ]),
+  createInstance(iid) {
+    return this.QueryInterface(iid);
+  },
+};
+
+/**
+ * Helper to register an AutoCompleteSearch with the given name.
+ * Allows the AutoCompleteController to find the search.
+ */
+function registerAutoCompleteSearch(aSearch) {
+  let name = "@mozilla.org/autocomplete/search;1?name=" + aSearch.name;
+  let uuidGenerator = Services.uuid;
+  let cid = uuidGenerator.generateUUID();
+  let desc = "Test AutoCompleteSearch";
+  let componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.registerFactory(cid, desc, name, aSearch);
+  // Keep the id on the object so we can unregister later
+  aSearch.cid = cid;
+}
+
+/**
+ * Helper to unregister an AutoCompleteSearch.
+ */
+function unregisterAutoCompleteSearch(aSearch) {
+  let componentManager = Components.manager.QueryInterface(
+    Ci.nsIComponentRegistrar
+  );
+  componentManager.unregisterFactory(aSearch.cid, aSearch);
+}
+
+var gTests = [
+  function(controller) {
+    info("handleText");
+    controller.input.textValue = "hel";
+    controller.handleText();
+  },
+  function(controller) {
+    info("handleStartComposition");
+    controller.handleStartComposition();
+    info("handleEndComposition");
+    controller.handleEndComposition();
+    // an input event always follows compositionend event.
+    controller.handleText();
+  },
+  function(controller) {
+    info("handleEscape");
+    controller.handleEscape();
+  },
+  function(controller) {
+    info("handleEnter");
+    controller.handleEnter(false);
+  },
+  function(controller) {
+    info("handleTab");
+    controller.handleTab();
+  },
+
+  function(controller) {
+    info("handleKeyNavigation");
+    // Hardcode KeyboardEvent.DOM_VK_RIGHT, because we can't easily
+    // include KeyboardEvent here.
+    controller.handleKeyNavigation(0x26 /* KeyboardEvent.DOM_VK_UP */);
+  },
+];
+
+add_task(async function() {
+  // Make an AutoCompleteSearch that always returns nothing
+  let search = new AutoCompleteSearch("test");
+  registerAutoCompleteSearch(search);
+
+  let controller = Cc["@mozilla.org/autocomplete/controller;1"].getService(
+    Ci.nsIAutoCompleteController
+  );
+
+  // Make an AutoCompleteInput that uses our search.
+  let input = new AutoCompleteInput([search.name]);
+  controller.input = input;
+
+  for (let testFn of gTests) {
+    input.onSearchBegin = function() {
+      executeSoon(() => testFn(controller));
+    };
+    let promise = new Promise(resolve => {
+      input.onSearchComplete = function() {
+        resolve();
+      };
+    });
+    controller.startSearch("hello");
+    await promise;
+  }
+
+  unregisterAutoCompleteSearch(search);
+  controller.stopSearch();
+  controller.input = null;
+});
diff --git a/toolkit/components/autocomplete/tests/unit/xpcshell.ini b/toolkit/components/autocomplete/tests/unit/xpcshell.ini
new file mode 100644
index 0000000000..32cdefe08e
--- /dev/null
+++ b/toolkit/components/autocomplete/tests/unit/xpcshell.ini
@@ -0,0 +1,24 @@
+[DEFAULT]
+head = head_autocomplete.js
+
+[test_330578.js]
+[test_378079.js]
+[test_393191.js]
+[test_440866.js]
+[test_463023.js]
+[test_660156.js]
+[test_autocomplete_multiple.js]
+[test_autocomplete_userContextId.js]
+[test_autofillSelectedPopupIndex.js]
+[test_badDefaultIndex.js]
+[test_completeDefaultIndex_casing.js]
+[test_finalCompleteValue.js]
+[test_finalCompleteValue_defaultIndex.js]
+[test_finalCompleteValue_forceComplete.js]
+[test_finalCompleteValueSelectedIndex.js]
+[test_finalDefaultCompleteValue.js]
+[test_immediate_search.js]
+[test_insertMatchAt.js]
+[test_previousResult.js]
+[test_removeMatchAt.js]
+[test_stopSearch.js]