fix(browser): fix location $digest() loop, ng-angular#3951

This is a refactor of the proposed solution, which guards
against changing the url() from inside the location watcher.

Author: xrg

src/ng/browser.js

@@ -125,7 +125,8 @@ function Browser(window, document, $log, $sniffer) {
 
   var lastBrowserUrl = location.href,
       baseElement = document.find('base'),
-      replacedUrl = null;
+      replacedUrl = null,
+      ignoreHashChange = false;
 
   /**
    * @name ng.$browser#url
@@ -151,9 +152,13 @@ function Browser(window, document, $log, $sniffer) {
     // setter
     if (url) {
       if (lastBrowserUrl == url) return;
+      ignoreHashChange = true;
+      try{
+      // Flag to ignore hashchange events occasionally generated in Android 2.2, 2.3
       lastBrowserUrl = url;
       if ($sniffer.history) {
-        if (replace) history.replaceState(null, '', url);
+        if (replace)
+            history.replaceState(null, '', url);
         else {
           history.pushState(null, '', url);
           // Crazy Opera Bug: http://my.opera.com/community/forums/topic.dml?id=1185462
@@ -168,6 +173,9 @@ function Browser(window, document, $log, $sniffer) {
           replacedUrl = null;
         }
       }
+      } finally {
+        ignoreHashChange = false;
+      }
       return self;
     // getter
     } else {
@@ -182,7 +190,7 @@ function Browser(window, document, $log, $sniffer) {
       urlChangeInit = false;
 
   function fireUrlChange() {
-    if (lastBrowserUrl == self.url()) return;
+    if (lastBrowserUrl == self.url() || ignoreHashChange) return;
 
     lastBrowserUrl = self.url();
     forEach(urlChangeListeners, function(listener) {