first commit

core/modules/update/update.post_update.php

@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * @file
+ * Post update functions for Update Manager.
+ */
+
+/**
+ * Implements hook_removed_post_updates().
+ */
+function update_remove_post_updates() {
+  return [
+    'update_post_update_add_view_update_notifications_permission' => '10.0.0',
+  ];
+}
+
+/**
+ * Updates update.settings:fetch.url config if it's still at the default.
+ */
+function update_post_update_set_blank_fetch_url_to_null() {
+  $update_settings = \Drupal::configFactory()->getEditable('update.settings');
+  if ($update_settings->get('fetch.url') === '') {
+    $update_settings
+      ->set('fetch.url', NULL)
+      ->save(TRUE);
+  }
+}