Change for #271. Assumption about memory leak because of circular reference was incorrect (verified by testing). Moved functionality to set the ControllerContext property of the controller to the new ControllerContext instance within the MvcContextFactory.

Author: NightOwl888

src/MvcSiteMapProvider/MvcSiteMapProvider/Security/AuthorizeAttributeAclModule.cs

@@ -112,16 +112,10 @@ protected virtual bool VerifyController(ISiteMapNode node, RouteData routes, Typ
             var controllerContext = this.CreateControllerContext(node, routes, controllerType, controllerFactory, out factoryBuiltController);
             try
             {
-                // Fixes #271 - set controller's ControllerContext property for MVC
-                controllerContext.Controller.ControllerContext = controllerContext;
-
                 return this.VerifyControllerAttributes(node, controllerType, controllerContext);
             }
             finally
             {
-                // Release the circular reference between Controller-ControllerContext, so it can be GC'd
-                controllerContext.Controller.ControllerContext = null;
-
                 // Release controller
                 if (factoryBuiltController)
                     controllerFactory.ReleaseController(controllerContext.Controller);

src/MvcSiteMapProvider/MvcSiteMapProvider/Web/Mvc/MvcContextFactory.cs

@@ -52,7 +52,12 @@ public virtual ControllerContext CreateControllerContext(RequestContext requestC
             if (controller == null)
                 throw new ArgumentNullException("controller");
 
-            return new ControllerContext(requestContext, controller);
+            var result = new ControllerContext(requestContext, controller);
+
+            // Fixes #271 - set controller's ControllerContext property for MVC
+            result.Controller.ControllerContext = result;
+
+            return result;
         }
 
         public virtual IRequestCache GetRequestCache()