HDFS-4168. Fix a NullPointerException in FSNamesystem.removeBlocks(..). Jing Zhao

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1@1407270 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -310,6 +310,9 @@ Release 1.2.0 - unreleased
     MAPREDUCE-4765. Restarting the JobTracker programmatically can cause
     DelegationTokenRenewal to throw an exception. (rkanter via tucu)
 
+    HDFS-4168. Fix a NullPointerException in FSNamesystem.removeBlocks(..).
+    (Jing Zhao via szetszwo)
+
 Release 1.1.1 - Unreleased
 
   INCOMPATIBLE CHANGES

src/hdfs/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -2209,7 +2209,9 @@ public class FSNamesystem implements FSConstants, FSNamesystemMBean, FSClusterSt
           blocksMap.removeINode(b);
           corruptReplicas.removeFromCorruptReplicasMap(b);
           // Remove the block from pendingReplications
-          pendingReplications.remove(b);
+          if (pendingReplications != null) {
+            pendingReplications.remove(b);
+          }
           addToInvalidates(b);
         }
       }