Issue #3278883 by vhin0210, longwave: TypeError: Argument 1 passed to...

Issue #3278883 by vhin0210, longwave: TypeError: Argument 1 passed to Drupal\Core\Entity\EntityViewBuilder::view() must implement interface Drupal\Core\Entity\EntityInterface, null given, called in core/modules/node/node.module on line 559

(cherry picked from commit dd664245)

core/modules/node/node.module

@@ -586,9 +586,11 @@ function template_preprocess_node(&$variables) {
         // 'compact' view mode on the User entity. Note that the 'compact'
         // view mode might not be configured, so remember to always check the
         // theme setting first.
-        $variables['author_picture'] = \Drupal::entityTypeManager()
-          ->getViewBuilder('user')
-          ->view($node->getOwner(), 'compact');
+        if ($node_owner = $node->getOwner()) {
+          $variables['author_picture'] = \Drupal::entityTypeManager()
+            ->getViewBuilder('user')
+            ->view($node_owner, 'compact');
+        }
       }
     }
   }