multi-store refund support

pxpost-multi-store-refunds.diff

diff --git a/app/code/community/MageBase/DpsPaymentExpress/Model/Method/Pxpost.php b/app/code/community/MageBase/DpsPaymentExpress/Model/Method/Pxpost.php
index 96dde32..5b30bab 100644
--- a/app/code/community/MageBase/DpsPaymentExpress/Model/Method/Pxpost.php
+++ b/app/code/community/MageBase/DpsPaymentExpress/Model/Method/Pxpost.php
@@ -48,6 +48,28 @@ class MageBase_DpsPaymentExpress_Model_Method_Pxpost extends Mage_Payment_Model_
     protected $_canSaveCc               = false;
 
     protected $_order;
+    protected $_store;
+
+    /**
+     * retrieve store for this payment
+     *
+     * @return Mage_Core_Model_Store
+     **/
+    protected function _getStore()
+    {
+        if ( ! $this->_store ) $this->_store = $this->_getOrder()->getStore();
+        return $this->_store;
+    }
+
+    /**
+     * retrieve config applicable to this payment
+     *
+     * @return string|null
+     **/
+    protected function _getConfig($value)
+    {
+        return $this->_getStore()->getConfig($value);
+    }
 
     /**
      * retrieve PostUsername from database
@@ -56,7 +78,7 @@ class MageBase_DpsPaymentExpress_Model_Method_Pxpost extends Mage_Payment_Model_
      */
     public function getPostUsername()
     {
-        return Mage::helper('core')->decrypt(Mage::getStoreConfig('payment/'.$this->_code.'/postusername'));
+        return Mage::helper('core')->decrypt($this->_getConfig('payment/'.$this->_code.'/postusername'));
     }
 
     /**
@@ -66,7 +88,7 @@ class MageBase_DpsPaymentExpress_Model_Method_Pxpost extends Mage_Payment_Model_
      */
     public function getPostPassword()
     {
-        return Mage::helper('core')->decrypt(Mage::getStoreConfig('payment/'.$this->_code.'/postpassword'));
+        return Mage::helper('core')->decrypt($this->_getConfig('payment/'.$this->_code.'/postpassword'));
     }
 
     /**
@@ -77,7 +99,7 @@ class MageBase_DpsPaymentExpress_Model_Method_Pxpost extends Mage_Payment_Model_
      */
     protected function _getPxPostPaymentAction()
     {
-        switch(Mage::getStoreConfig('payment/'.$this->_code.'/payment_action')) {
+        switch($this->_getConfig('payment/'.$this->_code.'/payment_action')) {
             case Mage_Payment_Model_Method_Abstract::ACTION_AUTHORIZE:
                 return MageBase_DpsPaymentExpress_Model_Method_Common::ACTION_AUTHORIZE;
                 break;
@@ -395,7 +417,7 @@ class MageBase_DpsPaymentExpress_Model_Method_Pxpost extends Mage_Payment_Model_
      */
     public function debugToDb()
     {
-        return Mage::getStoreConfig('payment/'.$this->_code.'/debug');
+        return $this->_getConfig('payment/'.$this->_code.'/debug');
     }
 
     /**