From 07c004db06b56d38c9212079f3749d9a8cc95f7a Mon Sep 17 00:00:00 2001
From: Colin McCabe <cmccabe@apache.org>
Date: Mon, 27 Jan 2014 22:19:30 +0000
Subject: [PATCH] HDFS-5830. WebHdfsFileSystem.getFileBlockLocations throws
 IllegalArgumentException when accessing another cluster. (Yongjun Zhang via
 Colin Patrick McCabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561885 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt        |  4 ++++
 .../apache/hadoop/hdfs/protocol/LocatedBlock.java  |  5 ++---
 .../java/org/apache/hadoop/hdfs/TestDFSUtil.java   | 14 ++++++++++++++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index 0c4e2d80cf0..06f3c699ff2 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -1151,6 +1151,10 @@ Release 2.3.0 - UNRELEASED
     HDFS-5297. Fix dead links in HDFS site documents. (Akira Ajisaka via
     Arpit Agarwal)
 
+    HDFS-5830. WebHdfsFileSystem.getFileBlockLocations throws
+    IllegalArgumentException when accessing another cluster. (Yongjun Zhang via
+    Colin Patrick McCabe)
+
 Release 2.2.0 - 2013-10-13
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java
index 0e6dd125464..bb98db46f5a 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java
@@ -98,9 +98,8 @@ public LocatedBlock(ExtendedBlock b, DatanodeInfo[] locs, String[] storageIDs,
     }
     this.storageIDs = storageIDs;
     this.storageTypes = storageTypes;
-    Preconditions.checkArgument(cachedLocs != null,
-        "cachedLocs should not be null, use a different constructor");
-    if (cachedLocs.length == 0) {
+
+    if (cachedLocs == null || cachedLocs.length == 0) {
       this.cachedLocs = EMPTY_LOCS;
     } else {
       this.cachedLocs = cachedLocs;
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java
index cf72e7920e0..1d5728dbd2d 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSUtil.java
@@ -118,6 +118,20 @@ public void testLocatedBlocks2Locations() {
     assertEquals(0, bs.length);
   }
 
+  /**
+   * Test constructing LocatedBlock with null cachedLocs
+   */
+  @Test
+  public void testLocatedBlockConstructorWithNullCachedLocs() {
+    DatanodeInfo d = DFSTestUtil.getLocalDatanodeInfo();
+    DatanodeInfo[] ds = new DatanodeInfo[1];
+    ds[0] = d;
+    
+    ExtendedBlock b1 = new ExtendedBlock("bpid", 1, 1, 1);
+    LocatedBlock l1 = new LocatedBlock(b1, ds, null, null, 0, false, null);
+    final DatanodeInfo[] cachedLocs = l1.getCachedLocations();
+    assertTrue(cachedLocs.length == 0);
+  }
 
   private Configuration setupAddress(String key) {
     HdfsConfiguration conf = new HdfsConfiguration();