From 7f69e092900dde1dcb1def8f9402627dd082c1c2 Mon Sep 17 00:00:00 2001
From: FuzzingTeam <114765570+FuzzingTeam@users.noreply.github.com>
Date: Thu, 20 Oct 2022 22:42:17 +0530
Subject: [PATCH] HADOOP-18471. Fixed ArrayIndexOutOfBoundsException in
 DefaultStringifier (#4957)

Contributed by FuzzingTeam
---
 .../main/java/org/apache/hadoop/io/DefaultStringifier.java   | 3 +++
 .../java/org/apache/hadoop/io/TestDefaultStringifier.java    | 5 ++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DefaultStringifier.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DefaultStringifier.java
index 7453996eca..7be50b0c53 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DefaultStringifier.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/DefaultStringifier.java
@@ -158,6 +158,9 @@ public static <K> K load(Configuration conf, String keyName,
   public static <K> void storeArray(Configuration conf, K[] items,
       String keyName) throws IOException {
 
+    if (items.length == 0) {
+      throw new IndexOutOfBoundsException();
+    }
     DefaultStringifier<K> stringifier = new DefaultStringifier<K>(conf, 
         GenericsUtil.getClass(items[0]));
     try {
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestDefaultStringifier.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestDefaultStringifier.java
index b70e011f6a..c15ec8caa4 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestDefaultStringifier.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestDefaultStringifier.java
@@ -26,6 +26,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
 import static org.junit.Assert.assertEquals;
 
 public class TestDefaultStringifier {
@@ -98,7 +99,7 @@ public void testStoreLoad() throws IOException {
   }
 
   @Test
-  public void testStoreLoadArray() throws IOException {
+  public void testStoreLoadArray() throws Exception {
     LOG.info("Testing DefaultStringifier#storeArray() and #loadArray()");
     conf.set("io.serializations", "org.apache.hadoop.io.serializer.JavaSerialization");
 
@@ -107,6 +108,8 @@ public void testStoreLoadArray() throws IOException {
     Integer[] array = new Integer[] {1,2,3,4,5};
 
 
+    intercept(IndexOutOfBoundsException.class, () ->
+        DefaultStringifier.storeArray(conf, new Integer[] {}, keyName));
     DefaultStringifier.storeArray(conf, array, keyName);
 
     Integer[] claimedArray = DefaultStringifier.<Integer>loadArray(conf, keyName, Integer.class);