Magento_Customer-M2.3.x-Checked-quote-object-contains-id-before-looking-quote-items.patch

--- Block/Adminhtml/Edit/Tab/Cart.orig.php	2020-04-13 17:35:40.000000000 +0300
+++ Block/Adminhtml/Edit/Tab/Cart.php	2020-07-13 13:19:45.000000000 +0300
@@ -105,14 +105,13 @@
     {
         $quote = $this->getQuote();
 
-        if ($quote) {
+        if ($quote && $quote->getId()) {
             $collection = $quote->getItemsCollection(false);
+            $collection->addFieldToFilter('parent_item_id', ['null' => true]);
         } else {
             $collection = $this->_dataCollectionFactory->create();
         }
 
-        $collection->addFieldToFilter('parent_item_id', ['null' => true]);
-
         $this->setCollection($collection);
 
         return parent::_prepareCollection();