Unset ActorCellKeepingSynchronizationContext in CallingThreadDispatcher

src/core/Akka.TestKit/ActorCellKeepingSynchronizationContext.cs

@@ -22,8 +22,6 @@ namespace Akka.TestKit
     class ActorCellKeepingSynchronizationContext : SynchronizationContext
     {
         private readonly ActorCell _cell;
-
-        internal static ActorCell AsyncCache { get; set; }
 
         /// <summary>
         /// TBD
@@ -46,7 +44,8 @@ public override void Post(SendOrPostCallback d, object state)
                 var oldCell = InternalCurrentActorCellKeeper.Current;
                 var oldContext = Current;
                 SetSynchronizationContext(this);
-                InternalCurrentActorCellKeeper.Current = AsyncCache ?? _cell;
+
+                InternalCurrentActorCellKeeper.Current = _cell;
 
                 try
                 {

src/core/Akka.TestKit/CallingThreadDispatcher.cs

@@ -6,6 +6,7 @@
 //-----------------------------------------------------------------------
 
 using System;
+using System.Threading;
 using Akka.Configuration;
 using Akka.Dispatch;
 
@@ -53,7 +54,22 @@ public CallingThreadDispatcher(MessageDispatcherConfigurator configurator) : bas
 
         protected override void ExecuteTask(IRunnable run)
         {
-            run.Run();
+            var currentSyncContext = SynchronizationContext.Current;
+
+            try
+            {
+                // Actors should not run with ActorCellKeepingSynchronizationContext
+                // (or any sync context that wraps ActorCellKeepingSynchronizationContext, e.g. Xunit's AsyncTestSyncContext)
+                // otherwise continuations in async message handlers will use ActorCellKeepingSynchronizationContext
+                // instead of ActorTaskScheduler which causes ActorContext to be incorrect.
+                SynchronizationContext.SetSynchronizationContext(null);
+
+                run.Run();
+            }
+            finally
+            {
+                SynchronizationContext.SetSynchronizationContext(currentSyncContext);
+            }
         }
 
         protected override void Shutdown()

src/core/Akka.TestKit/Internal/InternalTestActorRef.cs

@@ -323,18 +323,6 @@ internal TestActorTaskScheduler(ActorCell testActorCell, Action<object, Exceptio
                 _testActorCell = (TestActorCell) testActorCell;
             }
 
-            /// <inheritdoc />
-            protected override void OnBeforeTaskStarted()
-            {
-                ActorCellKeepingSynchronizationContext.AsyncCache = _testActorCell;
-            }
-
-            /// <inheritdoc />
-            protected override void OnAfterTaskCompleted()
-            {
-                ActorCellKeepingSynchronizationContext.AsyncCache = null;
-            }
-
             public void OnTaskCompleted(object message, Exception exception)
             {
                 _taskCallback(message, exception);