From 21a1c8acbafc8364a204f23369a3adbefdff1f3e Mon Sep 17 00:00:00 2001
From: Aaron Myers <atm@apache.org>
Date: Thu, 7 Mar 2013 23:50:40 +0000
Subject: [PATCH] HADOOP-9369. DNS#reverseDns() can return hostname with .
 appended at the end. Contributed by Karthik Kambatla.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1454172 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-common-project/hadoop-common/CHANGES.txt            | 3 +++
 .../src/main/java/org/apache/hadoop/net/DNS.java           | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 7e0e6a5617..bbba5c2bd8 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -547,6 +547,9 @@ Release 2.0.4-alpha - UNRELEASED
 
   BUG FIXES
 
+    HADOOP-9369. DNS#reverseDns() can return hostname with . appended at the
+    end. (Karthik Kambatla via atm)
+
 Release 2.0.3-alpha - 2013-02-06 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNS.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNS.java
index 73bbd4a631..f19e80235b 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNS.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/DNS.java
@@ -89,7 +89,12 @@ public class DNS {
       ictx.close();
     }
 
-    return attribute.get("PTR").get().toString();
+    String hostname = attribute.get("PTR").get().toString();
+    int hostnameLength = hostname.length();
+    if (hostname.charAt(hostnameLength - 1) == '.') {
+      hostname = hostname.substring(0, hostnameLength - 1);
+    }
+    return hostname;
   }
 
   /**