HDFS-6053. Fix TestDecommissioningStatus and TestDecommission in branch-2. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1574178 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -278,6 +278,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-6040. fix DFSClient issue without libhadoop.so and some other
     ShortCircuitShm cleanups (cmccabe)
 
+    HDFS-6053. Fix TestDecommissioningStatus and TestDecommission in branch-2.
+    (jing9)
+
   BREAKDOWN OF HDFS-5698 SUBTASKS AND RELATED JIRAS
 
     HDFS-5717. Save FSImage header in protobuf. (Haohui Mai via jing9)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -2936,7 +2936,7 @@ assert storedBlock.findDatanode(dn) < 0 : "Block " + block
                 
         if (isNeededReplication(block, curExpectedReplicas, curReplicas)) {
           if (curExpectedReplicas > curReplicas) {
-            if (bc instanceof MutableBlockCollection) {
+            if (bc.isUnderConstruction()) {
               if (block.equals(bc.getLastBlock()) && curReplicas > minReplication) {
                 continue;
               }