From 806b5efcdfa907048e04512b3ab99d8c4e06dae9 Mon Sep 17 00:00:00 2001
From: Patrik Nordwall <patrik.nordwall@gmail.com>
Date: Thu, 6 Sep 2012 10:04:52 +0200
Subject: [PATCH] Fix NPE due to initialization order, see #2473

---
 akka-cluster/src/main/scala/akka/cluster/Cluster.scala | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/akka-cluster/src/main/scala/akka/cluster/Cluster.scala b/akka-cluster/src/main/scala/akka/cluster/Cluster.scala
index c76b637164..d648880396 100644
--- a/akka-cluster/src/main/scala/akka/cluster/Cluster.scala
+++ b/akka-cluster/src/main/scala/akka/cluster/Cluster.scala
@@ -149,7 +149,9 @@ class Cluster(val system: ExtendedActorSystem, val failureDetector: FailureDetec
   /**
    * INTERNAL API
    */
-  private[cluster] val clusterCore: ActorRef = {
+  private[cluster] lazy val clusterCore: ActorRef = {
+    // this val must be lazy for correct initialization order,
+    // ClusterDaemon children may use for example subscribe before we get the GetClusterCoreRef reply
     implicit val timeout = system.settings.CreationTimeout
     Await.result((clusterDaemons ? InternalClusterAction.GetClusterCoreRef).mapTo[ActorRef], timeout.duration)
   }