fix(form): do not prevent submit when action attribute equals to an empty string

src/ng/directive/form.js

@@ -307,7 +307,7 @@ var formDirectiveFactory = function(isNgForm) {
       compile: function() {
         return {
           pre: function(scope, formElement, attr, controller) {
-            if (!attr.action) {
+            if (!attr.action && attr.action !== '') {
               // we can't use jq events because if a form is destroyed during submission the default
               // action is not prevented. see #1238
               //

test/ng/directive/ngEventDirsSpec.js

@@ -12,7 +12,7 @@ describe('event directives', function() {
   describe('ngSubmit', function() {
 
     it('should get called on form submit', inject(function($rootScope, $compile) {
-      element = $compile('<form action="" ng-submit="submitted = true">' +
+      element = $compile('<form ng-submit="submitted = true">' +
         '<input type="submit"/>' +
         '</form>')($rootScope);
       $rootScope.$digest();
@@ -29,7 +29,7 @@ describe('event directives', function() {
         }
       };
 
-      element = $compile('<form action="" ng-submit="formSubmission($event)">' +
+      element = $compile('<form ng-submit="formSubmission($event)">' +
         '<input type="submit"/>' +
         '</form>')($rootScope);
       $rootScope.$digest();