Difference in behaviour is:

* dp1 / dp2 = null -> date fields come back empty if there are no results
* dp1 / dp2 = $dp1 / $dp2 -> date fields come back with dates entered by user 

Lines 473-375 close #1010 issue. :)

(Sorry if I'm breaking the commit freeze here. I'm not sure if that fits it and only had a chance to look at this now...)