ARTEMIS-243 - fix possible null pointer

https://issues.apache.org/jira/browse/ARTEMIS-243

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/cluster/ha/ReplicaPolicy.java

@@ -33,6 +33,11 @@ public class ReplicaPolicy extends BackupPolicy {
 
    private boolean restartBackup = ActiveMQDefaultConfiguration.isDefaultRestartBackup();
 
+   //used if we create a replicated policy for when we become live.
+   private boolean allowFailback = ActiveMQDefaultConfiguration.isDefaultAllowAutoFailback();
+
+   private long failbackDelay = ActiveMQDefaultConfiguration.getDefaultFailbackDelay();
+
    private ReplicatedPolicy replicatedPolicy;
 
    public ReplicaPolicy() {
@@ -49,9 +54,9 @@ public class ReplicaPolicy extends BackupPolicy {
       this.maxSavedReplicatedJournalsSize = maxSavedReplicatedJournalsSize;
       this.groupName = groupName;
       this.restartBackup = restartBackup;
+      this.allowFailback = allowFailback;
+      this.failbackDelay = failbackDelay;
       this.scaleDownPolicy = scaleDownPolicy;
-      //todo check default settings
-      replicatedPolicy = new ReplicatedPolicy(false, allowFailback, failbackDelay, groupName, clusterName, this);
    }
 
    public ReplicaPolicy(String clusterName,
@@ -81,6 +86,9 @@ public class ReplicaPolicy extends BackupPolicy {
    }
 
    public ReplicatedPolicy getReplicatedPolicy() {
+      if (replicatedPolicy == null) {
+         replicatedPolicy = new ReplicatedPolicy(false, allowFailback, failbackDelay, groupName, clusterName, this);
+      }
       return replicatedPolicy;
    }
 
@@ -121,6 +129,22 @@ public class ReplicaPolicy extends BackupPolicy {
       return scaleDownPolicy != null;
    }
 
+   public boolean isAllowFailback() {
+      return allowFailback;
+   }
+
+   public void setAllowFailback(boolean allowFailback) {
+      this.allowFailback = allowFailback;
+   }
+
+   public long getFailbackDelay() {
+      return failbackDelay;
+   }
+
+   public void setFailbackDelay(long failbackDelay) {
+      this.failbackDelay = failbackDelay;
+   }
+
    @Override
    public Activation createActivation(ActiveMQServerImpl server,
                                       boolean wasLive,

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/cluster/ha/ReplicatedPolicy.java

@@ -40,11 +40,12 @@ public class ReplicatedPolicy implements HAPolicy<LiveActivation> {
    private long failbackDelay = ActiveMQDefaultConfiguration.getDefaultFailbackDelay();
 
    /*
-   * this is used as the policy when the server is started after a failover
+   * this are only used as the policy when the server is started as a live after a failover
    * */
    private ReplicaPolicy replicaPolicy;
 
    public ReplicatedPolicy() {
+      replicaPolicy = new ReplicaPolicy(clusterName, -1, groupName, this);
    }
 
    public ReplicatedPolicy(boolean checkForLiveServer, String groupName, String clusterName) {
@@ -54,7 +55,6 @@ public class ReplicatedPolicy implements HAPolicy<LiveActivation> {
       /*
       * we create this with sensible defaults in case we start after a failover
       * */
-      replicaPolicy = new ReplicaPolicy(clusterName, -1, groupName, this);
    }
 
    public ReplicatedPolicy(boolean checkForLiveServer,
@@ -100,6 +100,9 @@ public class ReplicatedPolicy implements HAPolicy<LiveActivation> {
    }
 
    public ReplicaPolicy getReplicaPolicy() {
+      if (replicaPolicy == null) {
+         replicaPolicy = new ReplicaPolicy(clusterName, -1, groupName, this);
+      }
       return replicaPolicy;
    }
 
@@ -147,6 +150,10 @@ public class ReplicatedPolicy implements HAPolicy<LiveActivation> {
       return null;
    }
 
+   public void setAllowAutoFailBack(boolean allowAutoFailBack) {
+      this.allowAutoFailBack = allowAutoFailBack;
+   }
+
    @Override
    public LiveActivation createActivation(ActiveMQServerImpl server,
                                           boolean wasLive,

artemis-server/src/main/java/org/apache/activemq/artemis/core/server/cluster/ha/SharedStoreSlavePolicy.java

@@ -47,7 +47,6 @@ public class SharedStoreSlavePolicy extends BackupPolicy {
       this.restartBackup = restartBackup;
       this.allowAutoFailBack = allowAutoFailBack;
       this.scaleDownPolicy = scaleDownPolicy;
-      sharedStoreMasterPolicy = new SharedStoreMasterPolicy(failbackDelay, failoverOnServerShutdown);
    }
 
    public long getFailbackDelay() {
@@ -67,6 +66,9 @@ public class SharedStoreSlavePolicy extends BackupPolicy {
    }
 
    public SharedStoreMasterPolicy getSharedStoreMasterPolicy() {
+      if (sharedStoreMasterPolicy == null) {
+         sharedStoreMasterPolicy = new SharedStoreMasterPolicy(failbackDelay, failoverOnServerShutdown);
+      }
       return sharedStoreMasterPolicy;
    }