fix($location): strip off empty hash segments when comparing

The url is the same whether or not there is an empty `#` marker at the end.
This prevents unwanted digest turns.

Closes #9635

Author: petebacondarwin

src/ng/location.js

@@ -68,6 +68,15 @@ function stripHash(url) {
   return index == -1 ? url : url.substr(0, index);
 }
 
+function getHash(url) {
+  var index = url.indexOf('#');
+  return index===-1 ? '' : url.substr(index+1);
+}
+
+function trimEmptyHash(url) {
+  return url.replace(/#$/,'');
+}
+
 
 function stripFile(url) {
   return url.substr(0, stripHash(url).lastIndexOf('/') + 1);
@@ -847,10 +856,11 @@ function $LocationProvider() {
 
     // update browser
     $rootScope.$watch(function $locationWatch() {
-      var oldUrl = $browser.url();
+      var oldUrl = trimEmptyHash($browser.url());
+      var newUrl = trimEmptyHash($location.absUrl());
       var oldState = $browser.state();
       var currentReplace = $location.$$replace;
-      var urlOrStateChanged = oldUrl !== $location.absUrl() ||
+      var urlOrStateChanged = oldUrl !== newUrl ||
         ($location.$$html5 && $sniffer.history && oldState !== $location.$$state);
 
       if (initializing || urlOrStateChanged) {