Ticket #51743: 51743.4.diff

src/wp-admin/includes/schema.php

@@ -535 +535 @@
                 'disallowed_keys'                 => '',
                 'comment_previously_approved'     => 1,
                 'auto_plugin_theme_update_emails' => array(),
+
+                // 5.6.0
+                'auto_update_core_dev'            => 'enabled',
+                'auto_update_core_minor'          => 'enabled',
+                // Default to enabled for new installs.
+                // See https://core.trac.wordpress.org/ticket/51742.
+                'auto_update_core_major'          => 'enabled',
         );
 
         // 3.3.0

src/wp-admin/includes/upgrade.php

@@ -2255 +2255 @@
         if ( ! is_null( $post_category_exists ) ) {
                 $wpdb->query( "ALTER TABLE $wpdb->posts DROP COLUMN `post_category`" );
         }
+
+        // When upgrading from WP < 5.6.0 set the core major auto-updates option to `unset` by default.
+        // This overrides the same option from populate_options() that is intended for new installs.
+        // See https://core.trac.wordpress.org/ticket/51742.
+        update_option( 'auto_update_core_major', 'unset' );
 }
 
 /**