Incorrect qty to ship after few creditmemos

qty_refunded should decrease items qty to ship

Author: bka

app/code/Magento/Sales/Model/Order/Item.php

@@ -234,7 +234,7 @@ public function getQtyToShip()
      */
     public function getSimpleQtyToShip()
     {
-        $qty = $this->getQtyOrdered() - max($this->getQtyShipped(), $this->getQtyRefunded()) - $this->getQtyCanceled();
+        $qty = $this->getQtyOrdered() - $this->getQtyShipped() - $this->getQtyRefunded() - $this->getQtyCanceled();
         return max(round($qty, 8), 0);
     }
 

app/code/Magento/Sales/Test/Unit/Model/Order/ItemTest.php

@@ -321,7 +321,7 @@ public static function getItemQtyVariants()
                     'qty_ordered' => 12, 'qty_invoiced' => 12, 'qty_refunded' => 5, 'qty_shipped' => 4,
                     'qty_canceled' => 0
                 ],
-                'expectedResult' => ['to_ship' => 7.0, 'to_invoice' => 0.0]
+                'expectedResult' => ['to_ship' => 3.0, 'to_invoice' => 0.0]
             ],
             'complete' => [
                 'options' => [
@@ -339,10 +339,10 @@ public static function getItemQtyVariants()
             ],
             'completely_shipped_using_decimals' => [
                 'options' => [
-                    'qty_ordered' => 4.4, 'qty_invoiced' => 0.4, 'qty_refunded' => 0.4, 'qty_shipped' => 4,
+                    'qty_ordered' => 4.8, 'qty_invoiced' => 0.4, 'qty_refunded' => 0.4, 'qty_shipped' => 4,
                     'qty_canceled' => 0,
                 ],
-                'expectedResult' => ['to_ship' => 0.4, 'to_invoice' => 4.0]
+                'expectedResult' => ['to_ship' => 0.4, 'to_invoice' => 4.4]
             ],
             'completely_invoiced_using_decimals' => [
                 'options' => [