From 40e487b8f7ac636158a5e4be210bd173a80ce702 Mon Sep 17 00:00:00 2001
From: Nithin Asokan <Nithin.Asokan@Cerner.com>
Date: Fri, 11 Sep 2015 11:35:41 -0500
Subject: [PATCH] SPARK-10554: Fix NPE with ShutdownHook

SPARK-10554: Fix javadoc
---
 .../scala/org/apache/spark/storage/DiskBlockManager.scala     | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/src/main/scala/org/apache/spark/storage/DiskBlockManager.scala b/core/src/main/scala/org/apache/spark/storage/DiskBlockManager.scala
index 3f8d26e1d4cab..f7e84a2c2e14c 100644
--- a/core/src/main/scala/org/apache/spark/storage/DiskBlockManager.scala
+++ b/core/src/main/scala/org/apache/spark/storage/DiskBlockManager.scala
@@ -164,7 +164,9 @@ private[spark] class DiskBlockManager(blockManager: BlockManager, conf: SparkCon
 
   private def doStop(): Unit = {
     // Only perform cleanup if an external service is not serving our shuffle files.
-    if (!blockManager.externalShuffleServiceEnabled || blockManager.blockManagerId.isDriver) {
+    // Also blockManagerId could be null if block manager is not initialized properly.
+    if (!blockManager.externalShuffleServiceEnabled ||
+      (blockManager.blockManagerId != null && blockManager.blockManagerId.isDriver)) {
       localDirs.foreach { localDir =>
         if (localDir.isDirectory() && localDir.exists()) {
           try {