Cherry picked 9bf6ac5718.

src/Orchard.Web/Core/Settings/Commands/SiteSettingsCommands.cs

@@ -2,6 +2,7 @@
 using Orchard.ContentManagement;
 using Orchard.Core.Settings.Models;
 using Orchard.Mvc;
+using Orchard.Mvc.Extensions;
 using Orchard.Settings;
 using Orchard.Utility.Extensions;
 
@@ -38,7 +39,7 @@ namespace Orchard.Core.Settings.Commands {
 
             // Retrieve request URL if BaseUrl not provided as a switch value
             if (string.IsNullOrEmpty(BaseUrl)) {
-                if (_httpContextAccessor.Current() == null) {
+                if (_httpContextAccessor.Current().IsBackgroundContext()) {
                     Context.Output.WriteLine(T("No HTTP request available to determine the base url of the site"));
                     return;
                 }

src/Orchard/DisplayManagement/Implementation/DefaultDisplayManager.cs

@@ -11,6 +11,7 @@ using Orchard.DisplayManagement.Shapes;
 using Orchard.Localization;
 using Orchard.Logging;
 using Orchard.Mvc;
+using Orchard.Mvc.Extensions;
 
 namespace Orchard.DisplayManagement.Implementation {
     public class DefaultDisplayManager : IDisplayManager {
@@ -61,7 +62,7 @@ namespace Orchard.DisplayManagement.Implementation {
                 return CoerceHtmlString(context.Value);
 
             var workContext = _workContextAccessor.GetContext();
-            var shapeTable = _httpContextAccessor.Current() != null
+            var shapeTable = !_httpContextAccessor.Current().IsBackgroundContext()
                 ? _shapeTableLocator.Value.Lookup(workContext.CurrentTheme.Id)
                 : _shapeTableLocator.Value.Lookup(null);
 

src/Orchard/Environment/DefaultHostEnvironment.cs

@@ -3,6 +3,7 @@ using System.Web;
 using Orchard.Localization;
 using Orchard.Logging;
 using Orchard.Mvc;
+using Orchard.Mvc.Extensions;
 using Orchard.Services;
 using Orchard.Utility.Extensions;
 
@@ -41,7 +42,7 @@ namespace Orchard.Environment {
             // current request can be processed correctly.  So, we redirect to the same URL, so that the
             // new request will come to the newly started AppDomain.
             var httpContext = _httpContextAccessor.Current();
-            if (httpContext != null) {
+            if (!httpContext.IsBackgroundContext()) {
                 // Don't redirect posts...
                 if (httpContext.Request.RequestType == "GET") {
                     httpContext.Response.Redirect(HttpContext.Current.Request.ToUrlString(), true /*endResponse*/);

src/Orchard/Environment/OrchardStarter.cs

@@ -63,7 +63,7 @@ namespace Orchard.Environment {
             builder.RegisterType<AppDomainAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
             builder.RegisterType<GacAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
             builder.RegisterType<OrchardFrameworkAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
-            builder.RegisterType<HttpContextAccessor>().As<IHttpContextAccessor>().SingleInstance();
+            builder.RegisterType<HttpContextAccessor>().As<IHttpContextAccessor>().InstancePerDependency();
             builder.RegisterType<ViewsBackgroundCompilation>().As<IViewsBackgroundCompilation>().SingleInstance();
             builder.RegisterType<DefaultExceptionPolicy>().As<IExceptionPolicy>().SingleInstance();
             builder.RegisterType<DefaultCriticalErrorProvider>().As<ICriticalErrorProvider>().SingleInstance();

src/Orchard/Environment/WorkContextAccessor.cs

@@ -5,6 +5,7 @@ using System.Web;
 using Autofac;
 using Orchard.Logging;
 using Orchard.Mvc;
+using Orchard.Mvc.Extensions;
 
 namespace Orchard.Environment {
     public class WorkContextAccessor : IWorkContextAccessor {
@@ -31,7 +32,7 @@ namespace Orchard.Environment {
 
         public WorkContext GetContext() {
             var httpContext = _httpContextAccessor.Current();
-            if (httpContext != null)
+            if (!httpContext.IsBackgroundContext())
                 return GetContext(httpContext);
 
             WorkContext workContext;
@@ -55,7 +56,7 @@ namespace Orchard.Environment {
 
         public IWorkContextScope CreateWorkContextScope() {
             var httpContext = _httpContextAccessor.Current();
-            if (httpContext != null)
+            if (!httpContext.IsBackgroundContext())
                 return CreateWorkContextScope(httpContext);
 
             var workLifetime = _lifetimeScope.BeginLifetimeScope("work");

src/Orchard/Mvc/Extensions/HttpContextBaseExtensions.cs

@@ -0,0 +1,9 @@
+using System.Web;
+
+namespace Orchard.Mvc.Extensions {
+    public static class HttpContextBaseExtensions {
+        public static bool IsBackgroundContext(this HttpContextBase httpContextBase) {
+            return httpContextBase == null || httpContextBase is MvcModule.HttpContextPlaceholder;
+        }
+    }
+}

src/Orchard/Mvc/HttpContextAccessor.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Web;
 
 namespace Orchard.Mvc {

src/Orchard/Mvc/MvcModule.cs

@@ -85,7 +85,7 @@ namespace Orchard.Mvc {
         /// <summary>
         /// Standin context for background tasks.
         /// </summary>
-        class HttpContextPlaceholder : HttpContextBase {
+        public class HttpContextPlaceholder : HttpContextBase {
             private readonly Lazy<string> _baseUrl;
             private readonly IDictionary _items = new Dictionary<object, object>();
 
@@ -120,7 +120,7 @@ namespace Orchard.Mvc {
             }
         }
 
-        private class HttpResponsePlaceholder : HttpResponseBase {
+        public class HttpResponsePlaceholder : HttpResponseBase {
             public override string ApplyAppPathModifier(string virtualPath) {
                 return virtualPath;
             }
@@ -135,7 +135,7 @@ namespace Orchard.Mvc {
         /// <summary>
         /// standin context for background tasks. 
         /// </summary>
-        class HttpRequestPlaceholder : HttpRequestBase {
+        public class HttpRequestPlaceholder : HttpRequestBase {
             private readonly Uri _uri;
 
             public HttpRequestPlaceholder(Uri uri) {
@@ -217,7 +217,7 @@ namespace Orchard.Mvc {
             }
         }
 
-        class HttpBrowserCapabilitiesPlaceholder : HttpBrowserCapabilitiesBase {
+        public class HttpBrowserCapabilitiesPlaceholder : HttpBrowserCapabilitiesBase {
             public override string this[string key] {
                 get {
                     return "";

src/Orchard/Orchard.Framework.csproj

@@ -317,6 +317,7 @@
     <Compile Include="Mvc\DataAnnotations\LocalizedModelValidatorProvider.cs" />
     <Compile Include="Mvc\DataAnnotations\LocalizedRequiredAttribute.cs" />
     <Compile Include="Mvc\Extensions\RouteExtension.cs" />
+    <Compile Include="Mvc\Extensions\HttpContextBaseExtensions.cs" />
     <Compile Include="Mvc\FormValueRequiredAttribute.cs" />
     <Compile Include="Mvc\HttpContextAccessor.cs" />
     <Compile Include="Mvc\HttpContextWorkContext.cs" />

src/Orchard/Security/Providers/FormsAuthenticationService.cs

@@ -5,6 +5,7 @@ using Orchard.Environment.Configuration;
 using Orchard.Logging;
 using Orchard.ContentManagement;
 using Orchard.Mvc;
+using Orchard.Mvc.Extensions;
 using Orchard.Services;
 
 namespace Orchard.Security.Providers {
@@ -102,7 +103,7 @@ namespace Orchard.Security.Providers {
                 return _signedInUser;
 
             var httpContext = _httpContextAccessor.Current();
-            if (httpContext == null || !httpContext.Request.IsAuthenticated || !(httpContext.User.Identity is FormsIdentity)) {
+            if (httpContext.IsBackgroundContext() || !httpContext.Request.IsAuthenticated || !(httpContext.User.Identity is FormsIdentity)) {
                 return null;
             }