fix review comments

akka-actor/src/main/scala/akka/actor/ActorPath.scala

@@ -59,7 +59,7 @@ sealed trait ActorPath extends Comparable[ActorPath] with Serializable {
   /**
    * Recursively create a descendant’s path by appending all child names.
    */
-  def /(child: Iterable[String]): ActorPath = (this /: child)(_ / _)
+  def /(child: Iterable[String]): ActorPath = (this /: child)((path, elem) ⇒ if (elem.isEmpty) path else path / elem)
 
   /**
    * ''Java API'': Recursively create a descendant’s path by appending all child names.

akka-actor/src/main/scala/akka/actor/ActorRefProvider.scala

@@ -478,7 +478,7 @@ class LocalActorRefProvider(
     } else ref.getChild(path.iterator) match {
       case Nobody ⇒
         log.debug("look-up of path sequence '{}' failed", path)
-        new EmptyLocalActorRef(eventStream, dispatcher, ref.path / path.filterNot(_.isEmpty))
+        new EmptyLocalActorRef(eventStream, dispatcher, ref.path / path)
       case x ⇒ x
     }
 

akka-actor/src/main/scala/akka/routing/Routing.scala

@@ -179,6 +179,14 @@ case object FromConfig extends RouterConfig {
     throw new ConfigurationException("router " + ref + " needs external configuration from file (e.g. application.conf)")
 }
 
+/**
+ * Java API: Router configuration which has no default, i.e. external configuration is required.
+ */
+case class FromConfig() extends RouterConfig {
+  def createRoute(props: Props, actorContext: ActorContext, ref: RoutedActorRef): Route =
+    throw new ConfigurationException("router " + ref + " needs external configuration from file (e.g. application.conf)")
+}
+
 object RoundRobinRouter {
   def apply(routees: Iterable[ActorRef]) = new RoundRobinRouter(routees = routees map (_.path.toString))
 }

akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala

@@ -71,7 +71,7 @@ abstract class RemoteClient private[akka] (
   /**
    * Sends the message across the wire
    */
-  def send(request: RemoteMessageProtocol): Unit = {
+  private def send(request: RemoteMessageProtocol): Unit = {
     try {
       val payload = remoteSupport.createMessageSendEnvelope(request)
       currentChannel.write(payload).addListener(