apache/spark — pull request #2856 by zsxwing (2014-10-20 11:38:31+00:00)
Title: [SPARK-4008] Fix "kryo with fold" in KryoSerializerSuite

`zeroValue` will be serialized by `spark.closure.serializer` but `spark.closure.serializer` only supports the default Java serializer. So it must not be `ClassWithoutNoArgConstructor`, which can not be serialized by the Java serializer.

This PR changed `zeroValue` to null and updated the test to make it work correctly.