When root option omits traling slash, Backbone.History.navigate and Backbone.History.start set URL with a slash between the root and route fragment when using pushState

backbone.js

@@ -1023,6 +1023,9 @@
       var docMode           = document.documentMode;
       var oldIE             = (isExplorer.exec(navigator.userAgent.toLowerCase()) && (!docMode || docMode <= 7));
 
+      // Normalize root to always include trailing slash
+      if (!trailingSlash.test(this.options.root)) this.options.root = this.options.root + '/';
+
       if (oldIE && this._wantsHashChange) {
         this.iframe = Backbone.$('<iframe src="javascript:0" tabindex="-1" />').hide().appendTo('body')[0].contentWindow;
         this.navigate(fragment);
@@ -1042,7 +1045,8 @@
       // opened by a non-pushState browser.
       this.fragment = fragment;
       var loc = this.location;
-      var atRoot  = (loc.pathname === this.options.root) && !loc.search;
+      var atRoot =  (loc.pathname.replace(trailingSlash, '') === this.options.root.replace(trailingSlash, '')) &&
+                    !loc.search;
 
       // If we've started off with a route from a `pushState`-enabled browser,
       // but we're currently in a browser that doesn't support it...

test/router.js

@@ -318,4 +318,55 @@ $(document).ready(function() {
     strictEqual(Backbone.history.fragment, 'x');
   });
 
+  test("Router: insert slash before fragment when root fragment has no trailing slash", 3, function() {
+    Backbone.history.stop();
+    location.replace('http://example.com/root');
+    Backbone.history = new Backbone.History({
+      location: location,
+      history: {
+        pushState: function(state, title, url) {
+          strictEqual(url, '/root/fragment');
+        }
+      }
+    });
+    Backbone.history.start({
+      pushState: true,
+      root: '/root',
+      hashChange: false
+    });
+    Backbone.history.navigate('fragment');
+
+    Backbone.history.stop();
+    location.replace('http://example.com/root#fragment');
+    location.protocol = 'http:';
+    location.host = 'example.com';
+    Backbone.history = new Backbone.History({
+      location: location,
+      history: {
+        pushState: function(state, title, url) {},
+        replaceState: function(state, title, url) {
+          strictEqual(url, 'http://example.com/root/fragment');
+        }
+      }
+    });
+    Backbone.history.start({
+      pushState: true,
+      root: '/root'
+    });
+
+    Backbone.history.stop();
+    location.replace('http://example.com/root');
+    var backboneHistory = new Backbone.History({
+      location: location
+    });
+    backboneHistory.loadUrl = function() {
+      ok(true);
+    };
+    Backbone.history = backboneHistory;
+    Backbone.history.start({
+      pushState: true,
+      root: '/root'
+    });
+  });
+
 });