+ if ($entity_type->isRevisionable()) {
+ // Disable the BC layer to prevent a recursion, this only needs the
+ // revision_default key that is always set.
+ $field_name = $entity_type->getRevisionMetadataKeys(FALSE)['revision_default'];
+ $base_field_definitions[$field_name] = BaseFieldDefinition::create('boolean')
+ ->setLabel($this->t('Default revision'))
+ ->setDescription($this->t('A flag indicating whether this was a default revision when it was saved.'))
+ ->setStorageRequired(TRUE)
+ ->setInternal(TRUE)
+ ->setTranslatable(FALSE)
+ ->setRevisionable(TRUE);
+ }
+
+ // Make sure that revisionable and translatable entity types are correctly
+ // defined.