Issue #3193771 by larowlan, sk_10, quietone:...

Issue #3193771 by larowlan, sk_10, quietone: Drupal\Component\Plugin\Exception\PluginNotFoundException: The "'"--><" entity type does not exist

(cherry picked from commit 26130ff2)

core/lib/Drupal/Core/ParamConverter/AdminPathConfigEntityConverter.php

@@ -63,7 +63,9 @@ public function __construct(EntityTypeManagerInterface $entity_type_manager, Con
    */
   public function convert($value, $definition, $name, array $defaults) {
     $entity_type_id = $this->getEntityTypeFromDefaults($definition, $name, $defaults);
-
+    if (!$this->entityTypeManager->hasDefinition($entity_type_id)) {
+      return NULL;
+    }
     // If the entity type is dynamic, confirm it to be a config entity. Static
     // entity types will have performed this check in self::applies().
     if (strpos($definition['type'], 'entity:{') === 0) {

core/modules/comment/tests/src/Functional/CommentInterfaceTest.php

@@ -53,6 +53,10 @@ public function testCommentInterface() {
     $comment = $this->postComment($this->node, $comment_text);
     $this->assertTrue($this->commentExists($comment), 'Comment found.');
 
+    // Test that using an invalid entity-type does not raise an error.
+    $this->drupalGet('comment/reply/yeah-this-is-not-an-entity-type/' . $this->node->id() . '/comment/' . $comment->id());
+    $this->assertSession()->statusCodeEquals(404);
+
     // Test the comment field title is displayed when there's comments.
     $this->drupalGet($this->node->toUrl());
     $this->assertSession()->responseMatches('@<h2[^>]*>Comments</h2>@');