From 634f63ef3c14adf3758dc1de0be83fb55350e7e1 Mon Sep 17 00:00:00 2001
From: Zhihong Yu <tedyu@apache.org>
Date: Tue, 21 May 2013 01:59:44 +0000
Subject: [PATCH] HBASE-8582 Possible NullPointerException in
 ZKInterProcessLockBase#visitLocks (Ted Yu)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1484643 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java
index 5a0fa641dda..d06800ccd79 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/lock/ZKInterProcessLockBase.java
@@ -423,7 +423,7 @@ public abstract class ZKInterProcessLockBase implements InterProcessLock {
       LOG.error("Unexpected ZooKeeper error when listing children", e);
       throw new IOException("Unexpected ZooKeeper exception", e);
     }
-    if (children.size() > 0) {
+    if (children != null && children.size() > 0) {
       for (String child : children) {
         if (isChildOfSameType(child)) {
           String znode = ZKUtil.joinZNode(parentLockNode, child);