HADOOP-10140. Specification of HADOOP_CONF_DIR via the environment in hadoop_config.cmd. Contributed by Kiran Kumar M R.

(cherry picked from commit 67efab935e0366ff783cf2bbd2363da4ebb02772)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -185,6 +185,9 @@ Release 2.7.0 - UNRELEASED
 
     HADOOP-11579. Documentation for truncate. (shv)
 
+    HADOOP-10140. Specification of HADOOP_CONF_DIR via the environment in
+    hadoop_config.cmd. (Kiran Kumar M R via cnauroth)
+
   OPTIMIZATIONS
 
     HADOOP-11323. WritableComparator#compare keeps reference to byte array.

hadoop-common-project/hadoop-common/src/main/bin/hadoop-config.cmd

@@ -65,7 +65,9 @@ if not exist %HADOOP_HOME%\share\hadoop\common\hadoop-common-*.jar (
     exit /b 1
 )
 
-set HADOOP_CONF_DIR=%HADOOP_HOME%\etc\hadoop
+if not defined HADOOP_CONF_DIR (
+  set HADOOP_CONF_DIR=%HADOOP_HOME%\etc\hadoop
+)
 
 @rem
 @rem Allow alternate conf dir location.