MAPREDUCE-6191. Improve clearing stale state of Java serialization

                testcase.  (Sam Liu via Eric Yang)
(cherry picked from commit c379e102ddab1b83fd69e4492a40c9901fb50675)

Conflicts:

	hadoop-mapreduce-project/CHANGES.txt
(cherry picked from commit 303c650d0dfcb10760cea589b8cef6ace8e36417)

hadoop-mapreduce-project/CHANGES.txt

@@ -445,6 +445,9 @@ Release 2.7.3 - UNRELEASED
     MAPREDUCE-6413. TestLocalJobSubmission is failing with unknown host
     (zhihai xu via jlowe)
 
+    MAPREDUCE-6191. Improve clearing stale state of Java serialization
+                    testcase.  (Sam Liu via Eric Yang)
+
 Release 2.7.2 - 2016-01-25
 
   INCOMPATIBLE CHANGES
@@ -732,6 +735,9 @@ Release 2.6.5 - UNRELEASED
     MAPREDUCE-6413. TestLocalJobSubmission is failing with unknown host
     (zhihai xu via jlowe)
 
+    MAPREDUCE-6191. Improve clearing stale state of Java serialization
+                    testcase.  (Sam Liu via Eric Yang)
+
 Release 2.6.4 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestJavaSerialization.java

@@ -81,7 +81,7 @@ public class TestJavaSerialization extends TestCase {
   }
 
   private void cleanAndCreateInput(FileSystem fs) throws IOException {
-    fs.delete(INPUT_FILE, true);
+    fs.delete(INPUT_DIR, true);
     fs.delete(OUTPUT_DIR, true);
 
     OutputStream os = fs.create(INPUT_FILE);