svn merge -c 1565478 FIXES: MAPREDUCE-5744. Job hangs because RMContainerAllocator$AssignedRequests.preemptReduce() violates the comparator contract. Contributed by Gera Shegalov


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1573087 13f79535-47bb-0310-9956-ffa450edef68