From a36fd8867107d78feefc8db3ee8bc7c3f63ee5c8 Mon Sep 17 00:00:00 2001
From: Colin Patrick Mccabe <cmccabe@cloudera.com>
Date: Thu, 23 Oct 2014 13:25:39 -0700
Subject: [PATCH] HDFS-7227. Fix findbugs warning about
 NP_DEREFERENCE_OF_READLINE_VALUE in SpanReceiverHost (cmccabe) (cherry picked
 from commit 7ab754545dca16518e8fe9353ef69b77f365426b)

---
 hadoop-common-project/hadoop-common/CHANGES.txt               | 3 +++
 .../main/java/org/apache/hadoop/tracing/SpanReceiverHost.java | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index e1730ca8a77..05d0e8cc0d5 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -22,6 +22,9 @@ Release 2.7.0 - UNRELEASED
 
     HADOOP-11166. Remove ulimit from test-patch.sh. (wang)
 
+    HDFS-7227. Fix findbugs warning about NP_DEREFERENCE_OF_READLINE_VALUE in
+    SpanReceiverHost (cmccabe)
+
 Release 2.6.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/tracing/SpanReceiverHost.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/tracing/SpanReceiverHost.java
index 13c92ac5b05..81993e9af2b 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/tracing/SpanReceiverHost.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/tracing/SpanReceiverHost.java
@@ -19,6 +19,7 @@ package org.apache.hadoop.tracing;
 
 import java.io.BufferedReader;
 import java.io.DataInputStream;
+import java.io.EOFException;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -101,6 +102,9 @@ public class SpanReceiverHost implements TraceAdminProtocol {
       reader = new BufferedReader(
           new InputStreamReader(new FileInputStream("/proc/self/stat")));
       String line = reader.readLine();
+      if (line == null) {
+        throw new EOFException();
+      }
       nonce = line.split(" ")[0];
     } catch (IOException e) {
     } finally {