porting 7.6-rc1 into 8

src/Umbraco.Web/WebApi/SessionHttpControllerRouteHandler.cs

@@ -0,0 +1,31 @@
+using System.Web;
+using System.Web.Http.WebHost;
+using System.Web.Routing;
+using System.Web.SessionState;
+
+namespace Umbraco.Web.WebApi
+{
+    /// <summary>
+    /// A custom WebApi route handler that enables session on the HttpContext - use with caution! 
+    /// </summary>
+    /// <remarks>
+    /// WebApi controllers (and REST in general) shouldn't have session state enabled since it's stateless,
+    /// enabling session state puts additional locks on requests so only use this when absolutley needed 
+    /// </remarks>
+    internal class SessionHttpControllerRouteHandler : HttpControllerRouteHandler
+    {
+        protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
+        {
+            return new SessionHttpControllerHandler(requestContext.RouteData);
+        }
+
+        /// <summary>
+        /// A custom WebApi handler that enables session on the HttpContext
+        /// </summary>        
+        private class SessionHttpControllerHandler : HttpControllerHandler, IRequiresSessionState
+        {
+            public SessionHttpControllerHandler(RouteData routeData) : base(routeData)
+            { }
+        }
+    }
+}