fatal error when trying to cancel a contribution recur payment

easy to reproduce in a test - ie

function testCancelRecur()

{ $contributionRecur = $this->callAPISuccess('contribution_recur', 'create', $this->_params); CRM_Contribute_BAO_ContributionRecur::cancelRecurContribution($contributionRecur['id'], CRM_Core_DAO::$_nullObject); }

Will put the full class in a PR but the crucial thing is that end_date is not null as this is a long running bug with the DAO - that when you do a FIND the date is returned in a way that is not valid for SAVE