From 68d098fbef58f41f6bea48f87d7f38fea9acf87a Mon Sep 17 00:00:00 2001
From: Mark Robert Miller <markrmiller@apache.org>
Date: Mon, 26 Sep 2011 04:13:38 +0000
Subject: [PATCH] it's possible to get an NPE here on shutdown in tests

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1175656 13f79535-47bb-0310-9956-ffa450edef68
---
 solr/core/src/test/org/apache/solr/cloud/ZkTestServer.java | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/solr/core/src/test/org/apache/solr/cloud/ZkTestServer.java b/solr/core/src/test/org/apache/solr/cloud/ZkTestServer.java
index e5dcfed39fe..06afd547162 100644
--- a/solr/core/src/test/org/apache/solr/cloud/ZkTestServer.java
+++ b/solr/core/src/test/org/apache/solr/cloud/ZkTestServer.java
@@ -35,6 +35,7 @@ import org.apache.solr.SolrTestCaseJ4;
 import org.apache.zookeeper.jmx.ManagedUtil;
 import org.apache.zookeeper.server.NIOServerCnxn;
 import org.apache.zookeeper.server.ServerConfig;
+import org.apache.zookeeper.server.ZKDatabase;
 import org.apache.zookeeper.server.ZooKeeperServer;
 import org.apache.zookeeper.server.SessionTracker.Session;
 import org.apache.zookeeper.server.persistence.FileTxnSnapLog;
@@ -108,7 +109,10 @@ public class ZkTestServer {
      */
     protected void shutdown() throws IOException {
       zooKeeperServer.shutdown();
-      zooKeeperServer.getZKDatabase().close();
+      ZKDatabase zkDb = zooKeeperServer.getZKDatabase();
+      if (zkDb != null) {
+        zkDb.close();
+      }
       waitForServerDown(getZkHost() + ":" + getPort(), 5000);
       cnxnFactory.shutdown();
     }