Test for filtering records across multiple blocks

I added a test that currently fails. I don't understand why it should fail though.

Please see this thread on the discussion forum for more info: https://groups.google.com/d/msg/parquet-dev/eMoVUXxY044/RzaoK2LykbYJ
if you are filtering out a third of the records, wouldn't this iteration stop working around  i == 6666? I am guessing you need to bail out when you see null, and not keep going 10000 times.