Hi, As I said in the discussion on the Jira issue, I’m in favour of this change!
This is the Jira Issue, for reference: https://issues.apache.org/jira/browse/FLINK-15424 Best, Aljoscha > On 8. Jan 2020, at 15:16, Congxian Qiu <qcx978132...@gmail.com> wrote: > > Dear All > > > Currently, we found the implementations of AppendingState#add are not the > same, taking some as example: > > - HeapReducingState will clear state if add null element > - RocksDBReducingState will add null element if serializer can serialize > null > - Both HeapListState and RocksDBListState refuse to add null element — > will throw NullPointException > > > we think this need to be fixed, and possible solutions include: > > 1. Respect the current java doc, which said “If null is passed in, the > state value will remain unchanged” > 2. Make all AppendingState#add refuse to add null element > > > We propose to apply the second solution, following the recommendation in > Guava[1]. > > > Would love to hear your thoughts. Thanks. > > > Regards, > > Congxian > > > [1] https://github.com/google/guava/wiki/UsingAndAvoidingNullExplained