Merge pull request #7270 from eileenmcnaughton/CRM-17611

CRM-17611 do not set dummy trxn_id on declines and do not attempt to …

diff --cc CRM/Core/Payment/AuthorizeNetIPN.php
index 9443bc683c5643fb1a565783e7b762d3f479810a,2eaff45073e74e137834ad042fd9ff83c5427cd4..f808053b922a3789182641a2ddd96f90815a994b
--- 1/CRM/Core/Payment/AuthorizeNetIPN.php
--- 2/CRM/Core/Payment/AuthorizeNetIPN.php
+++ b/CRM/Core/Payment/AuthorizeNetIPN.php
@@@ -331,16 -333,16 +333,20 @@@ INNER JOIN civicrm_membership_payment m
    }
  
    /**
 -   * @param $ids
 -   * @param $input
 +   * Check that the MDs is valid.
     *
 -   * @return bool
 +   * Note that this only checks if it is provided.
 +   *
 +   * @param array $ids
 +   * @param array $input
 +   *
 +   * @throws CRM_Core_Exception
     */
    public function checkMD5($ids, $input) {
+     if (empty($input['trxn_id'])) {
+       // For decline we have nothing to check against.
+       return;
+     }
      $paymentProcessor = CRM_Financial_BAO_PaymentProcessor::getPayment($ids['paymentProcessor'],
        $input['is_test'] ? 'test' : 'live'
      );