Issue #3285631: Make it impossible to call CronUpdater::begin() directly

src/CronUpdater.php

@@ -96,12 +96,12 @@ class CronUpdater extends Updater {
   /**
    * {@inheritdoc}
    */
-  public function begin(array $project_versions, ?int $timeout = 300): string {
+  final public function begin(array $project_versions, ?int $timeout = 300): string {
     // Prevent mischievous callers from starting an update even if unattended
     // updates are disabled. To start an update programmatically, use
     // \Drupal\automatic_updates\Updater::begin().
     if ($this->getMode() === static::DISABLED) {
-      throw new \LogicException('Unattended updates are disabled.');
+      throw new \BadMethodCallException(__METHOD__ . '() cannot be called directly.');
     }
     return parent::begin($project_versions, $timeout);
   }
@@ -126,7 +126,7 @@ class CronUpdater extends Updater {
     // handle any exceptions or validation errors consistently, and destroy the
     // stage regardless of whether the update succeeds.
     try {
-      $this->begin(['drupal' => $target_version], $timeout);
+      parent::begin(['drupal' => $target_version], $timeout);
       $this->stage();
       $this->apply();