Issue #2978320 by quietone, Ivan616, daffie: rdf comment storage load should not load NULL comments

core/modules/rdf/rdf.module

@@ -237,12 +237,13 @@ function rdf_comment_storage_load($comments) {
       ->getPreparedFieldMapping('created');
     /** @var \Drupal\comment\CommentInterface $comment*/
     $comment->rdf_data['date'] = rdf_rdfa_attributes($created_mapping, $comment->get('created')->first()->toArray());
-    $entity = $comment->getCommentedEntity();
-    // The current function is a storage level hook, so avoid to bubble
-    // bubbleable metadata, because it can be outside of a render context.
-    $comment->rdf_data['entity_uri'] = $entity->toUrl()->toString(TRUE)->getGeneratedUrl();
-    if ($comment->hasParentComment()) {
-      $comment->rdf_data['pid_uri'] = $comment->getParentComment()->toUrl()->toString(TRUE)->getGeneratedUrl();
+    if ($entity = $comment->getCommentedEntity()) {
+      // The current function is a storage level hook, so avoid to bubble
+      // bubbleable metadata, because it can be outside of a render context.
+      $comment->rdf_data['entity_uri'] = $entity->toUrl()->toString(TRUE)->getGeneratedUrl();
+    }
+    if ($parent = $comment->getParentComment()) {
+      $comment->rdf_data['pid_uri'] = $parent->toUrl()->toString(TRUE)->getGeneratedUrl();
     }
   }
 }

core/modules/rdf/tests/src/Kernel/RdfCommentStorageLoadTest.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Drupal\Tests\rdf\Kernel;
+
+use Drupal\Core\Field\FieldItemList;
+use Drupal\Core\Field\Plugin\Field\FieldType\CreatedItem;
+use Drupal\KernelTests\Core\Entity\EntityKernelTestBase;
+use Drupal\comment\Entity\Comment;
+
+/**
+ * Tests rdf_comment_storage_load.
+ *
+ * @group rdf
+ */
+class RdfCommentStorageLoadTest extends EntityKernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['comment', 'rdf'];
+
+  /**
+   * Tests rdf_comment_storage_load.
+   */
+  public function testRdfCommentStorageLoad() {
+    $field_created_item = $this->prophesize(CreatedItem::class);
+    $field_created_item->setValue([time()]);
+
+    $field_list = $this->prophesize(FieldItemList::class);
+    $field_list->reveal();
+    $field_list->first()->willReturn($field_created_item->reveal());
+
+    $comment = $this->prophesize(Comment::class);
+    $comment->bundle()->willReturn('page');
+    $comment->get('created')->willReturn($field_list);
+    $comment->getFieldDefinitions()->willReturn(NULL);
+    // Set commented entity and parent entity to NULL.
+    $comment->getCommentedEntity()->willReturn(NULL);
+    $comment->getParentComment()->willReturn(NULL);
+
+    /** @var \Drupal\Core\Extension\ModuleHandler $module_handler */
+    $module_handler = \Drupal::service('module_handler');
+    $module_handler->invoke('rdf', 'comment_storage_load', [[$comment->reveal()]]);
+  }
+
+}