hpcc-systems/HPCC-Platform — pull request #3727 by jakesmith (2012-11-26 14:52:30+00:00)
Title: HPCC-7983 Avoid circular link leak for null inputs

Null activities that were created whilst tying up the graph, e.g.
when it was detected that a projectfilter had no matches, caused
a leak due to a circular leak

Signed-off-by: Jake Smith