This was an issue with the old version as well, but putting it like this makes it more explicit: I'm wondering if this case should return a DecodingError instead of nil,nil. The Kafka spec simply says "These will always be encoded as an int32 size containing the length N followed by N repetitions of the structure". I let negative values map to nil because that's what the Kafka spec does for string and byte types, but it doesn't actually say that for array types.

@burke @fw42 thoughts?