From b76b843c8bd3906aaa5ad633d8a939aebc671907 Mon Sep 17 00:00:00 2001
From: Inigo Goiri <inigoiri@apache.org>
Date: Mon, 24 Jun 2019 17:52:33 -0700
Subject: [PATCH] HDFS-13371. NPE for FsServerDefaults.getKeyProviderUri() for
 clientProtocol communication between 2.7 and 3.X. Contributed by Sherwood
 Zheng.

---
 .../apache/hadoop/hdfs/protocolPB/PBHelperClient.java  | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java
index 829d3ef640a..b0eb99c8088 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelperClient.java
@@ -2265,7 +2265,7 @@ public class PBHelperClient {
 
   public static FsServerDefaultsProto convert(FsServerDefaults fs) {
     if (fs == null) return null;
-    return FsServerDefaultsProto.newBuilder().
+    FsServerDefaultsProto.Builder builder = FsServerDefaultsProto.newBuilder().
         setBlockSize(fs.getBlockSize()).
         setBytesPerChecksum(fs.getBytesPerChecksum()).
         setWritePacketSize(fs.getWritePacketSize())
@@ -2274,9 +2274,11 @@ public class PBHelperClient {
         .setEncryptDataTransfer(fs.getEncryptDataTransfer())
         .setTrashInterval(fs.getTrashInterval())
         .setChecksumType(convert(fs.getChecksumType()))
-        .setKeyProviderUri(fs.getKeyProviderUri())
-        .setPolicyId(fs.getDefaultStoragePolicyId())
-        .build();
+        .setPolicyId(fs.getDefaultStoragePolicyId());
+    if (fs.getKeyProviderUri() != null) {
+      builder.setKeyProviderUri(fs.getKeyProviderUri());
+    }
+    return builder.build();
   }
 
   public static EnumSetWritable<CreateFlag> convertCreateFlag(int flag) {