Fix type error in Creditmemo qty validator

Author: mfickers

app/code/Magento/Sales/Model/Order/Creditmemo/Validation/QuantityValidator.php

@@ -132,16 +132,17 @@ private function validateTotalQuantityRefundable(
             );
         }
         $orderItem = $orderItemsById[$item->getOrderItemId()];
+        $qtyRequested = (float)$item->getQty();
 
-        if (!$this->isValidDecimalRefundQty($orderItem->getIsQtyDecimal(), $item->getQty())) {
+        if (!$this->isValidDecimalRefundQty($orderItem->getIsQtyDecimal(), $qtyRequested)) {
             return __(
                 'We found an invalid quantity to refund item "%1".',
                 $orderItem->getSku()
             );
         }
 
-        if (!$this->canRefundItem($orderItem, $item->getQty(), $invoiceQtysRefundLimits) ||
-            !$this->isQtyAvailable($orderItem, $item->getQty())
+        if (!$this->canRefundItem($orderItem, $qtyRequested, $invoiceQtysRefundLimits) ||
+            !$this->isQtyAvailable($orderItem, $qtyRequested)
         ) {
             return __(
                 'The quantity to creditmemo must not be greater than the unrefunded quantity'

app/code/Magento/Sales/Test/Unit/Model/Order/Creditmemo/Validation/QuantityValidatorTest.php

@@ -284,6 +284,17 @@ public static function dataProviderForValidateQty()
                 'isQtyDecimalAllowed' => false,
                 'isAllowZeroGrandTotal' => true
             ],
+            [
+                'orderId' => 1,
+                'orderItemId' => 1,
+                'qtyToRequest' => '1.0000',
+                'qtyToRefund' => '1.0000',
+                'sku',
+                'total' => 15,
+                'expected' => [],
+                'isQtyDecimalAllowed' => false,
+                'isAllowZeroGrandTotal' => true
+            ],
             [
                 'orderId' => 1,
                 'orderItemId' => 1,