Fixing a ysod bug w/ content item admin bulk actions (http://orchard.codeplex.com/workitem/16498)

--HG--
branch : dev

src/Orchard.Web/Core/Contents/Controllers/AdminController.cs

@@ -140,6 +140,7 @@ namespace Orchard.Core.Contents.Controllers {
         [HttpPost, ActionName("List")]
         [FormValueRequired("submit.BulkEdit")]
         public ActionResult ListPOST(ContentOptions options, IEnumerable<int> itemIds, string returnUrl) {
+            if (itemIds != null) {
                 var accessChecked = false;
                 switch (options.BulkAction) {
                     case ContentsBulkAction.None:
@@ -180,6 +181,7 @@ namespace Orchard.Core.Contents.Controllers {
                     default:
                         throw new ArgumentOutOfRangeException();
                 }
+            }
 
             if (!String.IsNullOrEmpty(returnUrl))
                 return Redirect(returnUrl);