ENGCOM-2670: Save configurable product options after validation error #16597

 - Merge Pull Request #16597 from swnsma/magento2-1:Save-Configurable-Product-Options-After-Validation-Error
 - Merged commits:
   1. d866b18
   2. bc00d8e

Author: magento-engcom-team

app/code/Magento/Catalog/Controller/Adminhtml/Product/Save.php

@@ -147,13 +147,13 @@ public function execute()
             } catch (\Magento\Framework\Exception\LocalizedException $e) {
                 $this->_objectManager->get(\Psr\Log\LoggerInterface::class)->critical($e);
                 $this->messageManager->addExceptionMessage($e);
-                $data = $this->persistMediaData($product, $data);
+                $data = isset($product) ? $this->persistMediaData($product, $data) : $data;
                 $this->getDataPersistor()->set('catalog_product', $data);
                 $redirectBack = $productId ? true : 'new';
             } catch (\Exception $e) {
                 $this->_objectManager->get(\Psr\Log\LoggerInterface::class)->critical($e);
                 $this->messageManager->addErrorMessage($e->getMessage());
-                $data = $this->persistMediaData($product, $data);
+                $data = isset($product) ? $this->persistMediaData($product, $data) : $data;
                 $this->getDataPersistor()->set('catalog_product', $data);
                 $redirectBack = $productId ? true : 'new';
             }

app/code/Magento/ConfigurableProduct/view/adminhtml/web/js/variations/variations.js

@@ -407,15 +407,17 @@ define([
          *   - associated_product_ids_serialized.
          */
         serializeData: function () {
-            this.source.data['configurable-matrix-serialized'] =
-                JSON.stringify(this.source.data['configurable-matrix']);
-
-            delete this.source.data['configurable-matrix'];
-
-            this.source.data['associated_product_ids_serialized'] =
-                JSON.stringify(this.source.data['associated_product_ids']);
+            if (this.source.data['configurable-matrix']) {
+                this.source.data['configurable-matrix-serialized'] =
+                    JSON.stringify(this.source.data['configurable-matrix']);
+                delete this.source.data['configurable-matrix'];
+            }
 
-            delete this.source.data['associated_product_ids'];
+            if (this.source.data['associated_product_ids']) {
+                this.source.data['associated_product_ids_serialized'] =
+                    JSON.stringify(this.source.data['associated_product_ids']);
+                delete this.source.data['associated_product_ids'];
+            }
         },
 
         /**