Fixed implicit conversion from float to int in Mage_SalesRule_Model_V…

…alidator (#3345)

Co-authored-by: Ng Kiat Siong <kiatsiong.ng@gmail.com>
Co-authored-by: Fabrizio Balliano <fabrizio.balliano@gmail.com>

app/code/core/Mage/SalesRule/Model/Validator.php

@@ -465,10 +465,10 @@ public function process(Mage_Sales_Model_Quote_Item_Abstract $item)
             $discountAmount = $result->getDiscountAmount();
             $baseDiscountAmount = $result->getBaseDiscountAmount();
 
-            $percentKey = $item->getDiscountPercent();
             /**
              * Process "delta" rounding
              */
+            $percentKey = (string) $item->getDiscountPercent();
             if ($percentKey) {
                 $delta      = $this->_roundingDeltas[$percentKey] ?? 0;
                 $baseDelta  = $this->_baseRoundingDeltas[$percentKey] ?? 0;