Issue 15467 where a configuration sku gets deleted but is still saved in a customer cart

Author: jonshipman

app/code/Magento/ConfigurableProduct/Block/Cart/Item/Renderer/Configurable.php

@@ -65,7 +65,7 @@ public function getProductForThumbnail()
             self::CONFIG_THUMBNAIL_SOURCE,
             \Magento\Store\Model\ScopeInterface::SCOPE_STORE
         ) == ThumbnailSource::OPTION_USE_PARENT_IMAGE ||
-            !($this->getChildProduct()->getThumbnail() && $this->getChildProduct()->getThumbnail() != 'no_selection')
+            !($this->getChildProduct() && $this->getChildProduct()->getThumbnail() && $this->getChildProduct()->getThumbnail() != 'no_selection')
         ) {
             $product = $this->getProduct();
         } else {

app/code/Magento/ConfigurableProduct/CustomerData/ConfigurableItem.php

@@ -63,7 +63,7 @@ protected function getProductForThumbnail()
         );
 
         $product = $config == ThumbnailSource::OPTION_USE_PARENT_IMAGE
-            || (!$this->getChildProduct()->getThumbnail() || $this->getChildProduct()->getThumbnail() == 'no_selection')
+            || (!$this->getChildProduct() || !$this->getChildProduct()->getThumbnail() || $this->getChildProduct()->getThumbnail() == 'no_selection')
             ? $this->getProduct()
             : $this->getChildProduct();