The NPE was a result of not following defensive programming practices and that is fixed.
Also, we already support both reader and writer schema being null where new ReflectDatumReader(type) is used in getDatumReader(..) operation.
That said there may still be conditions which are not supported and that is okay since in the end it's a MessageConverter and as such it is one
of the extension points of the framework allowing user to provide a custom one follwing instructions in 'User-defined Message Converters' of the reference guide.
Resolves#1294
e319fe8c02