Updated Drupal to 8.6. This goes with the following updates because it's possible...

[yaffs-website] / web / core / modules / book / src / Form / BookRemoveForm.php

diff --git a/web/core/modules/book/src/Form/BookRemoveForm.php b/web/core/modules/book/src/Form/BookRemoveForm.php
index f61aa775a5abd2ee9a42a1307f6e49f44b50b50d..2d5a91982f7c6dd5c77393db371aff1401f25153 100644 (file)
--- a/web/core/modules/book/src/Form/BookRemoveForm.php
+++ b/web/core/modules/book/src/Form/BookRemoveForm.php
@@ -103,7 +103,7 @@ class BookRemoveForm extends ConfirmFormBase {
   public function submitForm(array &$form, FormStateInterface $form_state) {
     if ($this->bookManager->checkNodeIsRemovable($this->node)) {
       $this->bookManager->deleteFromBook($this->node->id());
-      drupal_set_message($this->t('The post has been removed from the book.'));
+      $this->messenger()->addStatus($this->t('The post has been removed from the book.'));
     }
     $form_state->setRedirectUrl($this->getCancelUrl());
   }