Fixed: Incorrect discount amount when using fixed discount amount for whole cart

Author: Aasim Goriya

app/code/Magento/SalesRule/Model/Validator.php

@@ -478,6 +478,9 @@ public function initTotals($items, Address $address)
             $validItemsCount = 0;
 
             foreach ($items as $item) {
+                if($item->getHasChildren()){
+                    continue;
+                }
                 if (!$this->isValidItemForRule($item, $rule)
                     || ($item->getChildren() && $item->isChildrenCalculated())
                     || $item->getNoDiscount()