magento#7372: Product images gets removed from "Images And Videos" af…

…ter validation alert.

- Add check for product in case of not initialized product.

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';
  }