NPE in taskReporter in specific scenarios

java.lang.NullPointerException
	at org.apache.tez.runtime.task.TaskReporter$HeartbeatCallable.access$300(TaskReporter.java:120)
	at org.apache.tez.runtime.task.TaskReporter.taskFailed(TaskReporter.java:382)
	at org.apache.tez.runtime.task.TezTaskRunner.signalFatalError(TezTaskRunner.java:298)
	at org.apache.tez.runtime.api.impl.TezTaskContextImpl.signalFatalError(TezTaskContextImpl.java:209)
	at org.apache.tez.runtime.api.impl.TezInputContextImpl.fatalError(TezInputContextImpl.java:129)
	at org.apache.tez.runtime.library.common.shuffle.orderedgrouped.Shuffle$ShuffleRunnerFutureCallback.onFailure(Shuffle.java:490)
	at com.google.common.util.concurrent.Futures$6.run(Futures.java:977)
	at com.google.common.util.concurrent.MoreExecutors$SameThreadExecutorService.execute(MoreExecutors.java:253)
	at com.google.common.util.concurrent.ExecutionList$RunnableExecutorPair.execute(ExecutionList.java:149)
	at com.google.common.util.concurrent.ExecutionList.execute(ExecutionList.java:134)
	at com.google.common.util.concurrent.ListenableFutureTask.done(ListenableFutureTask.java:86)
	at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:380)
	at java.util.concurrent.FutureTask.setException(FutureTask.java:247)
	at java.util.concurrent.FutureTask.run(FutureTask.java:267)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)