Fix Omnipay error on redirect #6.

Omnipay provides no additional info or parameters in the return url so resorting to storing & retrieving from session

Author: eileenmcnaughton

CRM/Core/Payment/OmnipayMultiProcessor.php

@@ -380,7 +380,7 @@ private function getCreditCardOptions($params, $component) {
     }
     $creditCardOptions = array(
       'amount' => $amount,
-      // Contribution page in 4.4 passes currencyID - not sure which passes currency (if any).
+      // Contribution page in 4.4 (confirmed Event online, 4.7) passes currencyID - not sure which passes currency (if any).
       'currency' => strtoupper(!empty($params['currencyID']) ? $params['currencyID'] : $params['currency']),
       'description' => $this->getPaymentDescription($params),
       'transactionId' => $this->transaction_id,
@@ -808,11 +808,17 @@ public function processPaymentNotification($params) {
     $this->createGateway($params['processor_id']);
     $originalRequest = $_REQUEST;
     $_REQUEST = $params;
-    $response = $this->gateway->completePurchase($params)->send();
+    try {
+      $response = $this->gateway->completePurchase($params)->send();
 
-    if ($response->getTransactionId()) {
-      $this->setTransactionID($response->getTransactionId());
+      if ($response->getTransactionId()) {
+        $this->setTransactionID($response->getTransactionId());
+      }
     }
+    catch (\Omnipay\Common\Exception\InvalidRequestException $e) {
+      $this->redirectOrExit('success');
+    }
+
     if ($response->isSuccessful()) {
       try {
         //cope with CRM14950 not being implemented

CRM/Core/Payment/PaymentExtended.php

@@ -214,7 +214,9 @@ protected function getNotifyUrl($allowLocalHost = FALSE) {
    */
   protected function storeReturnUrls($qfKey, $participantID = NULL, $eventID = NULL) {
     CRM_Core_Session::singleton()->set("ipn_success_url_{$this->transaction_id}", $this->getReturnSuccessUrl($qfKey));
+    CRM_Core_Session::singleton()->set("ipn_success_url_fallback", $this->getReturnSuccessUrl($qfKey));
     CRM_Core_Session::singleton()->set("ipn_fail_url_{$this->transaction_id}", $this->getReturnFailUrl($qfKey, $participantID, $eventID));
+    CRM_Core_Session::singleton()->set("ipn_fail_url_fallback", $this->getReturnFailUrl($qfKey, $participantID, $eventID));
   }
 
   /**
@@ -237,7 +239,7 @@ protected function storeTransparentRedirectFormData($key, $data) {
    *   Url to redirect to
    */
   protected function getStoredUrl($type) {
-    return CRM_Core_Session::singleton()->get("ipn_{$type}_url_{$this->transaction_id}");
+    return CRM_Core_Session::singleton()->get("ipn_{$type}_url_" . ($this->transaction_id ? : 'fallback'));
   }
 
   /**