#6284 removing the "WTF" part of the logic - an association cache entry should never ever reach metadata

lib/Doctrine/ORM/Mapping/ClassMetadataInfo.php

@@ -715,6 +715,9 @@ class ClassMetadataInfo implements ClassMetadata
      */
     public function getIdentifierValues($entity)
     {
+        if ($entity instanceof AssociationCacheEntry) {
+            throw new \InvalidArgumentException('WTF DUDE: ' . $entity->class . ' - ' . \serialize($entity->identifier));
+        }
         if ($this->isIdentifierComposite) {
             $id = [];