UserAction.inc.php

<?php
 
import('lib.pkp.classes.user.PKPUserAction');
 
class UserAction extends PKPUserAction {
   public function mergeUsers($oldUserId, $newUserId) {
      if (!parent::mergeUsers($oldUserId, $newUserId)) return false;
 
      // Transfer completed payments.
      $paymentDao = DAORegistry::getDAO('OMPCompletedPaymentDAO'); /* @var $paymentDao OMPCompletedPaymentDAO */
      $paymentFactory = $paymentDao->getByUserId($oldUserId);
      while ($payment = $paymentFactory->next()) {
         $payment->setUserId($newUserId);
         $paymentDao->updateObject($payment);
      }
 
      return true;
   }
}