Upgrade/Install: Delay automatic updates after installation.

After installation, the user is directed to the `Log In` page. This triggers the `wp_schedule_update_checks()` function which is hooked to `init` and schedules updates to run immediately if no other events exist. As a result of more robust use of maintenance mode for automatic updates added in [58128], the user may be presented with a maintenance mode screen just after installing WordPress.

To improve the user experience, this schedules core updates for 1 hour, plugin updates for 1.5 hours, and theme updates for 2 hours after installation.

Follow-up to [58128], [58139], [58308], [58309].

Props afragen, hellofromTonya, peterwilsoncc, nithi22, dd32.
Fixes #61457. See #58281, #61391.

git-svn-id: https://develop.svn.wordpress.org/trunk@58435 602fd350-edb4-49c9-b593-d223f7449a82

Author: costdev

src/wp-admin/includes/upgrade.php

@@ -52,6 +52,21 @@ function wp_install( $blog_title, $user_name, $user_email, $is_public, $deprecat
 		wp_check_mysql_version();
 		wp_cache_flush();
 		make_db_current_silent();
+
+		/*
+		 * Ensure update checks are delayed after installation.
+		 *
+		 * This prevents users being presented with a maintenance mode screen
+		 * immediately after installation.
+		 */
+		wp_unschedule_hook( 'wp_version_check' );
+		wp_unschedule_hook( 'wp_update_plugins' );
+		wp_unschedule_hook( 'wp_update_themes' );
+
+		wp_schedule_event( time() + HOUR_IN_SECONDS, 'twicedaily', 'wp_version_check' );
+		wp_schedule_event( time() + ( 1.5 * HOUR_IN_SECONDS ), 'twicedaily', 'wp_update_plugins' );
+		wp_schedule_event( time() + ( 2 * HOUR_IN_SECONDS ), 'twicedaily', 'wp_update_themes' );
+
 		populate_options();
 		populate_roles();