From 2bbc95823ca1e8aca4004cb4ac3bd53400cf73d9 Mon Sep 17 00:00:00 2001
From: Michael Stack <stack@apache.org>
Date: Wed, 30 May 2012 17:55:58 +0000
Subject: [PATCH] HBASE-6049 Serializing 'List' containing null elements will
 cause NullPointerException in HbaseObjectWritable.writeObject()

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1344363 13f79535-47bb-0310-9956-ffa450edef68
---
 .../org/apache/hadoop/hbase/io/HbaseObjectWritable.java   | 5 +++--
 .../apache/hadoop/hbase/io/TestHbaseObjectWritable.java   | 8 ++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java
index 35b2c8b01cd..e19af32ba64 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/HbaseObjectWritable.java
@@ -477,8 +477,9 @@ public class HbaseObjectWritable implements Writable, WritableWithSize, Configur
       int length = list.size();
       out.writeInt(length);
       for (int i = 0; i < length; i++) {
-        writeObject(out, list.get(i),
-                  list.get(i).getClass(), conf);
+        Object elem = list.get(i);
+        writeObject(out, elem,
+                  elem == null ? Writable.class : elem.getClass(), conf);
       }
     } else if (declClass == String.class) {   // String
       Text.writeString(out, (String)instanceObj);
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/TestHbaseObjectWritable.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/TestHbaseObjectWritable.java
index d8e3ee1709b..2e666668d63 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/io/TestHbaseObjectWritable.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/io/TestHbaseObjectWritable.java
@@ -198,6 +198,14 @@ public class TestHbaseObjectWritable extends TestCase {
     obj = doType(conf, list, List.class);
     assertTrue(obj instanceof List);
     Assert.assertArrayEquals(list.toArray(), ((List)obj).toArray() );
+    //List.class with null values
+    List<String> listWithNulls = new ArrayList<String>();
+    listWithNulls.add("hello");
+    listWithNulls.add("world");
+    listWithNulls.add(null);
+    obj = doType(conf, listWithNulls, List.class);
+    assertTrue(obj instanceof List);
+    Assert.assertArrayEquals(listWithNulls.toArray(), ((List)obj).toArray() );
     //ArrayList.class
     ArrayList<String> arr = new ArrayList<String>();
     arr.add("hello");