HADOOP-8436. NPE In getLocalPathForWrite ( path, conf ) when the required context item is not configured. Contributed by Brahma Reddy Battula. (harsh)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1389799 13f79535-47bb-0310-9956-ffa450edef68
(cherry picked from commit a7e450c7cc0adef3ff832368a2a041bb51396945)

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

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

@@ -575,6 +575,10 @@ Release 2.8.0 - UNRELEASED
     HADOOP-12386. RetryPolicies.RETRY_FOREVER should be able to specify a 
     retry interval. (Sunil G via wangda)
 
+    HADOOP-8436. NPE In getLocalPathForWrite ( path, conf ) when the
+    required context item is not configured
+    (Brahma Reddy Battula via harsh)
+
   OPTIMIZATIONS
 
     HADOOP-12051. ProtobufRpcEngine.invoke() should use Exception.toString()

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/LocalDirAllocator.java

@@ -265,6 +265,9 @@ public class LocalDirAllocator {
     private synchronized void confChanged(Configuration conf) 
         throws IOException {
       String newLocalDirs = conf.get(contextCfgItemName);
+      if (null == newLocalDirs) {
+        throw new IOException(contextCfgItemName + " not configured");
+      }
       if (!newLocalDirs.equals(savedLocalDirs)) {
         localDirs = StringUtils.getTrimmedStrings(newLocalDirs);
         localFS = FileSystem.getLocal(conf);

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestLocalDirAllocator.java

@@ -299,6 +299,23 @@ public class TestLocalDirAllocator {
     }
   }
 
+  /*
+   * Test when mapred.local.dir not configured and called
+   * getLocalPathForWrite
+   */
+  @Test
+  public void testShouldNotthrowNPE() throws Exception {
+    Configuration conf1 = new Configuration();
+    try {
+      dirAllocator.getLocalPathForWrite("/test", conf1);
+      fail("Exception not thrown when " + CONTEXT + " is not set");
+    } catch (IOException e) {
+      assertEquals(CONTEXT + " not configured", e.getMessage());
+    } catch (NullPointerException e) {
+      fail("Lack of configuration should not have thrown an NPE.");
+    }
+  }
+
   /** Test no side effect files are left over. After creating a temp
    * temp file, remove both the temp file and its parent. Verify that
    * no files or directories are left over as can happen when File objects