diff --git a/toolkit/components/places/tests/unit/test_frecency.js b/toolkit/components/places/tests/unit/test_frecency.js
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+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Bug 378079 unit test code.
+ *
+ * The Initial Developer of the Original Code is POTI Inc.
+ * Portions created by the Initial Developer are Copyright (C) 2007
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Matt Crocker <matt@songbirdnest.com>
+ *   Seth Spitzer <sspitzer@mozilla.org>
+ *   Edward Lee <edward.lee@engineering.uiuc.edu>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/**
+ * Test for bug 406358 to make sure frecency works for empty input/search, but
+ * this also tests for non-empty inputs as well. Because the interactions among
+ * *DIFFERENT* visit counts and visit dates is not well defined, this test
+ * holds one of the two values constant when modifying the other.
+ */
+var current_test = 0;
+
+function AutoCompleteInput(aSearches) {
+  this.searches = aSearches;
+}
+AutoCompleteInput.prototype = {
+  constructor: AutoCompleteInput,
+
+  searches: null,
+
+  minResultsForPopup: 0,
+  timeout: 10,
+  searchParam: "",
+  textValue: "",
+  disableAutoComplete: false,
+  completeDefaultIndex: false,
+
+  get searchCount() {
+    return this.searches.length;
+  },
+
+  getSearchAt: function(aIndex) {
+    return this.searches[aIndex];
+  },
+
+  onSearchComplete: function() {},
+
+  popupOpen: false,
+
+  popup: {
+    setSelectedIndex: function(aIndex) {},
+    invalidate: function() {},
+
+    // nsISupports implementation
+    QueryInterface: function(iid) {
+      if (iid.equals(Ci.nsISupports) ||
+          iid.equals(Ci.nsIAutoCompletePopup))
+        return this;
+
+      throw Components.results.NS_ERROR_NO_INTERFACE;
+    }
+  },
+
+  // nsISupports implementation
+  QueryInterface: function(iid) {
+    if (iid.equals(Ci.nsISupports) ||
+        iid.equals(Ci.nsIAutoCompleteInput))
+      return this;
+
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+  }
+}
+
+function ensure_results(uris, searchTerm)
+{
+  var controller = Components.classes["@mozilla.org/autocomplete/controller;1"].
+                   getService(Components.interfaces.nsIAutoCompleteController);
+
+  // Make an AutoCompleteInput that uses our searches
+  // and confirms results on search complete
+  var input = new AutoCompleteInput(["history"]);
+
+  controller.input = input;
+
+  // Search is asynchronous, so don't let the test finish immediately
+  do_test_pending();
+
+  input.onSearchComplete = function() {
+    do_check_eq(controller.searchStatus,
+                Ci.nsIAutoCompleteController.STATUS_COMPLETE_MATCH);
+    do_check_eq(controller.matchCount, uris.length);
+    for (var i=0; i<controller.matchCount; i++) {
+      do_check_eq(controller.getValueAt(i), uris[i].spec);
+    }
+
+    if (current_test < (tests.length - 1)) {
+      current_test++;
+      tests[current_test]();
+    }
+
+    do_test_finished();
+  };
+
+  controller.startSearch(searchTerm);
+}
+
+// Get history service
+try {
+  var histsvc = Cc["@mozilla.org/browser/nav-history-service;1"].getService(Ci.nsINavHistoryService);
+  var bhist = histsvc.QueryInterface(Ci.nsIBrowserHistory);
+} catch(ex) {
+  do_throw("Could not get history service\n");
+} 
+
+function setCountDate(aURI, aCount, aDate)
+{
+  // Set the visit count and date for a uri
+  histsvc.setPageDetails(aURI, aURI, aCount, false, true);
+  // We need visits so that frecency can be computed over multiple visits
+  for (let i = 0; i < aCount; i++)
+    histsvc.addVisit(aURI, aDate, null, histsvc.TRANSITION_TYPED, false, 0);
+}
+
+var uri1 = uri("http://site.tld/1");
+var uri2 = uri("http://site.tld/2");
+
+// d1 is younger (should show up higher) than d2 (PRTime is in usecs not msec)
+// Make sure the dates fall into different frecency buckets
+var d1 = new Date(Date.now() - 1000 * 60 * 60) * 1000;
+var d2 = new Date(Date.now() - 1000 * 60 * 60 * 24 * 10) * 1000;
+// c1 is larger (should show up higher) than c2
+var c1 = 10;
+var c2 = 1;
+
+function prepTest(desc) {
+  print("Test " + desc);
+  bhist.removeAllPages();
+}
+
+var tests = [
+// test things without a search term
+function() {
+  prepTest("0: same count, different date");
+  setCountDate(uri1, c1, d1);
+  setCountDate(uri2, c1, d2);
+  ensure_results([uri1, uri2], "");
+},
+function() {
+  prepTest("1: same count, different date");
+  setCountDate(uri1, c1, d2);
+  setCountDate(uri2, c1, d1);
+  ensure_results([uri2, uri1], "");
+},
+function() {
+  prepTest("2: different count, same date");
+  setCountDate(uri1, c1, d1);
+  setCountDate(uri2, c2, d1);
+  ensure_results([uri1, uri2], "");
+},
+function() {
+  prepTest("3: different count, same date");
+  setCountDate(uri1, c2, d1);
+  setCountDate(uri2, c1, d1);
+  ensure_results([uri2, uri1], "");
+},
+
+// test things with a search term
+function() {
+  prepTest("4: same count, different date");
+  setCountDate(uri1, c1, d1);
+  setCountDate(uri2, c1, d2);
+  ensure_results([uri1, uri2], "site");
+},
+function() {
+  prepTest("5: same count, different date");
+  setCountDate(uri1, c1, d2);
+  setCountDate(uri2, c1, d1);
+  ensure_results([uri2, uri1], "site");
+},
+function() {
+  prepTest("6: different count, same date");
+  setCountDate(uri1, c1, d1);
+  setCountDate(uri2, c2, d1);
+  ensure_results([uri1, uri2], "site");
+},
+function() {
+  prepTest("7: different count, same date");
+  setCountDate(uri1, c2, d1);
+  setCountDate(uri2, c1, d1);
+  ensure_results([uri2, uri1], "site");
+}
+];
+
+/**
+ * Test history autocomplete
+ */
+function run_test() {
+  tests[0]();
+}