fix routing of remote messages bouncing nodes (there may be pathological cases ...)

- RemoteCommunicationSpec last test currently failing, lookup of
  deployment must be fixed to work zig-zag across nodes
- commit mainly to merge with Henrik’s router work and get the surface
  clean

akka-remote/src/main/scala/akka/remote/Remote.scala

@@ -254,6 +254,8 @@ class RemoteMessage(input: RemoteMessageProtocol, remote: RemoteSupport, classLo
 
   def provider = remote.system.asInstanceOf[ActorSystemImpl].provider
 
+  def originalReceiver = input.getRecipient.getPath
+
   lazy val sender: ActorRef =
     if (input.hasSender) provider.actorFor(provider.rootGuardian, input.getSender.getPath)
     else remote.system.deadLetters
@@ -332,6 +334,12 @@ trait RemoteMarshallingOps {
             throw new SecurityException("RemoteModule server is operating is untrusted mode, can not pass on a AutoReceivedMessage to the remote actor")
           case m ⇒ l.!(m)(remoteMessage.sender)
         }
+      case r: RemoteActorRef ⇒
+        remoteMessage.originalReceiver match {
+          case RemoteActorPath(address, _) if address == remote.remoteDaemon.path.address ⇒
+            r.!(remoteMessage.payload)(remoteMessage.sender)
+          case r ⇒ log.error("dropping message {} for non-local recipient {}", remoteMessage.payload, r)
+        }
       case r ⇒ log.error("dropping message {} for non-local recipient {}", remoteMessage.payload, r)
     }
   }