From fc9faf85856ac4964f1a3073af184bd2388b57a9 Mon Sep 17 00:00:00 2001
From: larsh <larsh@unknown>
Date: Thu, 12 Apr 2012 21:53:54 +0000
Subject: [PATCH] HBASE-5775 ZKUtil doesn't handle deleteRecurisively cleanly
 (Jesse Yates)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1325540 13f79535-47bb-0310-9956-ffa450edef68
---
 .../java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java   | 9 +++++++--
 src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java | 5 +++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java b/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java
index 554bdae22f7..46a6fde43b3 100644
--- a/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java
+++ b/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java
@@ -1004,14 +1004,19 @@ public class ZKUtil {
 
   /**
    * Delete the specified node and all of it's children.
-   *
-   * Sets no watches.  Throws all exceptions besides dealing with deletion of
+   * <p>
+   * If the node does not exist, just returns.
+   * <p>
+   * Sets no watches. Throws all exceptions besides dealing with deletion of
    * children.
    */
   public static void deleteNodeRecursively(ZooKeeperWatcher zkw, String node)
   throws KeeperException {
     try {
       List<String> children = ZKUtil.listChildrenNoWatch(zkw, node);
+      // the node is already deleted, so we just finish
+      if (children == null) return;
+
       if(!children.isEmpty()) {
         for(String child : children) {
           deleteNodeRecursively(zkw, joinZNode(node, child));
diff --git a/src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java b/src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java
index d4f76e96058..6e655c5a2c5 100644
--- a/src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java
+++ b/src/test/java/org/apache/hadoop/hbase/TestZooKeeper.java
@@ -279,7 +279,12 @@ public class TestZooKeeper {
       assertNotNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2/l3/l4", null));
     }
     ZKUtil.deleteNodeRecursively(zkw, "/l1/l2");
+    // make sure it really is deleted
     assertNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2/l3/l4", null));
+
+    // do the same delete again and make sure it doesn't crash
+    ZKUtil.deleteNodeRecursively(zkw, "/l1/l2");
+
     ZKUtil.deleteNode(zkw, "/l1");
     assertNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2", null));
   }