HDFS-5895. Merging change r1565440 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1565442 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -56,6 +56,9 @@ Release 2.4.0 - UNRELEASED
 
     HDFS-5881. Fix skip() of the short-circuit local reader(legacy). (kihwal)
 
+    HDFS-5895. HDFS cacheadmin -listPools has exit_code of 1 when the command
+    returns 0 result. (Tassapol Athiapinya via cnauroth)
+
 Release 2.3.0 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/CacheAdmin.java

@@ -962,9 +962,8 @@ public class CacheAdmin extends Configured implements Tool {
       if (numResults > 0) { 
         System.out.print(listing);
       }
-      // If there are no results, we return 1 (failure exit code);
-      // otherwise we return 0 (success exit code).
-      return (numResults == 0) ? 1 : 0;
+      // If list pools succeed, we return 0 (success exit code)
+      return 0;
     }
   }