TezGroupedSplits fails with empty (zero length) file

Running hive on a directory with some 0 length files in it:

2013-12-17 23:01:35,868 ERROR [AsyncDispatcher event handler] org.apache.tez.dag.app.dag.impl.VertexImpl: Vertex Input: bucket1_1 initializer failed
java.lang.NullPointerException
at org.apache.hadoop.io.Text.encode(Text.java:443)
at org.apache.hadoop.io.Text.encode(Text.java:424)
at org.apache.hadoop.io.Text.writeString(Text.java:476)
at org.apache.hadoop.mapred.split.TezGroupedSplit.write(TezGroupedSplit.java:87)
at org.apache.tez.mapreduce.hadoop.MRHelpers.createSplitProto(MRHelpers.java:446)
at org.apache.tez.mapreduce.common.MRInputAMSplitGenerator.initialize(MRInputAMSplitGenerator.java:129)
at org.apache.tez.dag.app.dag.RootInputInitializerRunner$InputInitializerCallable.call(RootInputInitializerRunner.java:121)
at org.apache.tez.dag.app.dag.RootInputInitializerRunner$InputInitializerCallable.call(RootInputInitializerRunner.java:97)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:695)

Deleting the empty files makes the error disappear.