hpcc-systems/HPCC-Platform — pull request #2107 by ghalliday (2012-04-16 10:04:59+00:00)
Title: Common up null datasets with minor differences

A record with or without an associated named symbol could make two null
datasets appear difference when they are infact identical.
(Had a minor effect on a couple of queries).

Signed-off-by: Gavin Halliday