fix($location): don't call indexOf() of undefined href attribute

Closes #7721

Author: caitp

src/ng/location.js

@@ -670,7 +670,7 @@ function $LocationProvider(){
         // http://msdn.microsoft.com/en-us/library/ie/dd347148(v=vs.85).aspx
         var href = elm.attr('href') || elm.attr('xlink:href');
 
-        if (href.indexOf('://') < 0) {         // Ignore absolute URLs
+        if (/*href &&*/ href.indexOf('://') < 0) {         // Ignore absolute URLs
           var prefix = '#' + hashPrefix;
           if (href[0] == '/') {
             // absolute path - replace old path

test/ng/directive/ngEventDirsSpec.js

@@ -39,4 +39,22 @@ describe('event directives', function() {
       expect($rootScope.formSubmitted).toEqual('foo');
     }));
   });
+
+
+  describe('ngClick', function() {
+    // Regression (gh-7721)
+    it('should be evaluated on anchor elements with no href in html5 mode', function() {
+      module(function($locationProvider) {
+        $locationProvider.html5Mode(true);
+      });
+      inject(function($rootScope, $compile) {
+        $rootScope.i = 0;
+        element = $compile('<a ng-click="i = i + 1">anchor</a>')($rootScope);
+
+        browserTrigger(element);
+
+        expect($rootScope.i).toBe(1);
+      });
+    });
+  });
 });