POC: Handler for preventing the load of incompatible "for Core" plugins

src/wp-admin/includes/admin-filters.php

@@ -133,6 +133,8 @@
 
 add_action( 'admin_notices', 'update_nag', 3 );
 add_action( 'admin_notices', 'deactivated_plugins_notice', 5 );
+add_action( 'admin_init', '_deactivate_incompatible_for_core_plugins', 5 );
+add_action( 'admin_notices', '_render_admin_notice_for_incompatible_plugins', 5 );
 add_action( 'admin_notices', 'paused_plugins_notice', 5 );
 add_action( 'admin_notices', 'paused_themes_notice', 5 );
 add_action( 'admin_notices', 'maintenance_nag', 10 );

src/wp-admin/includes/plugin.php

@@ -2596,3 +2596,97 @@ function deactivated_plugins_notice() {
 		update_site_option( 'wp_force_deactivated_plugins', array() );
 	}
 }
+
+/**
+ * Deactivate incompatible for-core plugins.
+ *
+ * @since 6.5.0
+ */
+function _deactivate_incompatible_for_core_plugins() {
+	$blog_plugins = get_option( 'found_incompatible_for_core_plugins' );
+	$site_plugins = array();
+
+	// Option not in database, add an empty array to avoid extra DB queries on subsequent loads.
+	if ( false === $blog_plugins ) {
+		update_option( 'found_incompatible_for_core_plugins', array() );
+	}
+
+	if ( is_multisite() ) {
+		$site_plugins = get_site_option( 'found_incompatible_for_core_plugins' );
+		// Option not in database, add an empty array to avoid extra DB queries on subsequent loads.
+		if ( false === $site_plugins ) {
+			update_site_option( 'found_incompatible_for_core_plugins', array() );
+		}
+	}
+
+	// No incompatible plugins. Bail out.
+	if ( empty( $blog_plugins ) && empty( $site_plugins ) ) {
+		return;
+	}
+
+	$incompatible_plugins = array_merge( $blog_plugins, $site_plugins );
+
+	// Deactivate.
+	$plugins_to_deactivate = array_keys( $incompatible_plugins );
+	deactivate_plugins( $plugins_to_deactivate, true );
+}
+
+/**
+ * Renders an admin notice for each incompatible plugin.
+ *
+ * These plugins were not loaded during WordPress' early loading
+ * due to incompatibility with the current version of WordPress.
+ *
+ * @since 6.5.0
+ * @access private
+ *
+ * @global string $wp_version The WordPress version string.
+ */
+function _render_admin_notice_for_incompatible_plugins() {
+
+	if ( ! current_user_can( 'activate_plugins' ) ) {
+		return;
+	}
+
+	$blog_plugins = get_option( 'found_incompatible_for_core_plugins' );
+	$site_plugins = is_multisite()
+		? get_site_option( 'found_incompatible_for_core_plugins' )
+		: array();
+
+	// No incompatible plugins. Bail out.
+	if ( empty( $blog_plugins ) && empty( $site_plugins ) ) {
+		return;
+	}
+
+	$incompatible_plugins = array_merge( $blog_plugins, $site_plugins );
+
+	foreach ( $incompatible_plugins as $plugin ) {
+		// Skip if information is missing.
+		if ( empty( $plugin['version_compatible'] ) || empty( $plugin['version_deactivated'] ) ) {
+			continue;
+		}
+
+		$explanation = sprintf(
+			/* translators: 1: Name of deactivated plugin, 2: Plugin version deactivated, 3: Current WP version, 4: Compatible plugin version. */
+			__( '%1$s %2$s was deactivated due to incompatibility with WordPress %3$s, please upgrade to %1$s %4$s or later.' ),
+			$plugin['plugin_name'],
+			$plugin['version_deactivated'],
+			$GLOBALS['wp_version'],
+			$plugin['version_compatible']
+		);
+
+		$message = sprintf(
+			'%s</p><p><a href="%s">%s</a>',
+			$explanation,
+			esc_url( admin_url( 'plugins.php?plugin_status=inactive' ) ),
+			__( 'Go to the Plugins screen' )
+		);
+		wp_admin_notice( $message, array( 'type' => 'warning' ) );
+	}
+
+	// Empty the options.
+	update_option( 'found_incompatible_for_core_plugins', array() );
+	if ( is_multisite() ) {
+		update_site_option( 'found_incompatible_for_core_plugins', array() );
+	}
+}

src/wp-includes/load.php

@@ -919,6 +919,30 @@ function wp_not_installed() {
 	die();
 }
 
+/**
+ * Gets the for-core plugin's minimum compatible version.
+ *
+ * @since 6.5.0
+ * @access private
+ *
+ * @param string $plugin Plugin path relative to the plugins' directory.
+ * @return string Returns the minimum version on success, otherwise an empty string.
+ */
+function _get_plugin_wp_min_compatible_version( $plugin ) {
+	static $plugin_data = array(
+		'gutenberg/gutenberg.php' => array(
+			'name'                       => 'Gutenberg',
+			'minimum_compatible_version' => '17.6',
+		),
+	);
+
+	if ( ! isset( $plugin_data[ $plugin ] ) ) {
+		return '';
+	}
+
+	return $plugin_data[ $plugin ]['minimum_compatible_version'];
+}
+
 /**
  * Retrieves an array of must-use plugin files.
  *

src/wp-settings.php

@@ -412,6 +412,117 @@
 
 $GLOBALS['wp_plugin_paths'] = array();
 
+/*
+ * Compatibility handler for for-core plugins.
+ *
+ * "For-core" are approved plugins being developed specifically to be merged into
+ * Core, e.g. Gutenberg and feature plugins.
+ *
+ * As these "for-core" plugins are frequently released, the handler identifies
+ * each's minimum compatible version, detects the version of each that is activated,
+ * and deactivates and does not load each incompatible plugin.
+ *
+ * This handler is done at the activated plugin loading loops to ensure
+ * sites stay running (to avoid fatal errors) and experiences are expected (by
+ * not loading older versions of features).
+ *
+ * @since 6.5.0
+ */
+global $_found_incompatible_for_core_plugins, $_is_plugin_compatible_with_wp, $_handle_incompatible_for_core_plugins;
+
+// Found incompatible for-core plugins.
+$_found_incompatible_for_core_plugins = array(
+	'sitewide_plugins' => array(),
+	'single_plugins'   => array(),
+);
+
+/**
+ * Checks if the given plugin is compatible with this WordPress version.
+ *
+ * @since 6.5.0
+ *
+ * @global $_found_incompatible_for_core_plugins
+ *
+ * @param string $plugin_absolute_path Absolute path to the plugin's file.
+ * @param bool   $is_network           Optional. Whether the plugin is activated sitewide. Default false.
+ */
+$_is_plugin_compatible_with_wp = static function ( $plugin_absolute_path, $is_network = false ) {
+	global $_found_incompatible_for_core_plugins;
+
+	static $plugins_dir_strlen;
+	if ( empty( $plugins_dir_strlen ) ) {
+		$plugins_dir_strlen = strlen( WP_PLUGIN_DIR . '/' );
+	}
+
+	$plugin = substr( $plugin_absolute_path, $plugins_dir_strlen );
+
+	// Not a for-core plugin.
+	$min_compat_version = _get_plugin_wp_min_compatible_version( $plugin );
+	if ( ! $min_compat_version ) {
+		return true;
+	}
+
+	// The plugin is already marked as incompatible.
+	if ( isset( $_found_incompatible_for_core_plugins[ $plugin ] ) ) {
+		return false;
+	}
+
+	// Get the Name and Version from the plugin's header.
+	require_once ABSPATH . 'wp-admin/includes/plugin.php';
+	$plugin_data = get_plugin_data(
+		$plugin_absolute_path,
+		array(
+			'Name'    => 'Plugin Name',
+			'Version' => 'Version',
+		),
+		'plugin'
+	);
+
+	// Whoops, something went wrong. Bail out.
+	if ( ! ( isset( $plugin_data['Version'] ) && isset( $plugin_data['Name'] ) ) ) {
+		return true;
+	}
+
+	// Plugin is compatible.
+	if ( version_compare( $plugin_data['Version'], $min_compat_version, '>=' ) ) {
+		return true;
+	}
+
+	// Found an incompatible for-core plugin. Add it to the found global for later batch processing.
+	$key                                                     = $is_network ? 'sitewide_plugins' : 'single_plugins';
+	$_found_incompatible_for_core_plugins[ $key ][ $plugin ] = array(
+		'plugin_absolute_path' => $plugin_absolute_path,
+		'plugin_name'          => $plugin_data['Name'],
+		'version_deactivated'  => $plugin_data['Version'],
+		'version_compatible'   => $min_compat_version,
+	);
+
+	return false;
+};
+
+/**
+ * Handle incompatible for-core plugins.
+ *
+ * The handler does adds a 'found_incompatible_for_core_plugins' option for single site
+ * and multisites. The option is used in wp-admin to deactivate and render a notice.
+ *
+ * @since 6.5.0
+ *
+ * @global $_found_incompatible_for_core_plugins
+ */
+$_handle_incompatible_for_core_plugins = static function () {
+	global $_found_incompatible_for_core_plugins;
+
+	if ( ! empty( $_found_incompatible_for_core_plugins['sitewide_plugins'] ) ) {
+		update_site_option( 'found_incompatible_for_core_plugins', $_found_incompatible_for_core_plugins['sitewide_plugins'] );
+	}
+
+	if ( ! empty( $_found_incompatible_for_core_plugins['single_plugins'] ) ) {
+		update_option( 'found_incompatible_for_core_plugins', $_found_incompatible_for_core_plugins['single_plugins'] );
+	}
+};
+// End of the for-core plugins compatibility handler.
+
 // Load must-use plugins.
 foreach ( wp_get_mu_plugins() as $mu_plugin ) {
 	$_wp_plugin_file = $mu_plugin;
@@ -432,6 +543,16 @@
 // Load network activated plugins.
 if ( is_multisite() ) {
 	foreach ( wp_get_active_network_plugins() as $network_plugin ) {
+
+		/*
+		 * If the plugin is incompatible with this WordPress version, skip loading it.
+		 *
+		 * @since 6.5.0
+		 */
+		if ( ! $_is_plugin_compatible_with_wp( $network_plugin, true ) ) {
+			continue;
+		}
+
 		wp_register_plugin_realpath( $network_plugin );
 
 		$_wp_plugin_file = $network_plugin;
@@ -487,6 +608,16 @@
 
 // Load active plugins.
 foreach ( wp_get_active_and_valid_plugins() as $plugin ) {
+
+	/*
+	 * If the plugin is incompatible with this WordPress version, skip loading it.
+	 *
+	 * @since 6.5.0
+	 */
+	if ( ! $_is_plugin_compatible_with_wp( $plugin ) ) {
+		continue;
+	}
+
 	wp_register_plugin_realpath( $plugin );
 
 	$_wp_plugin_file = $plugin;
@@ -502,7 +633,15 @@
 	 */
 	do_action( 'plugin_loaded', $plugin );
 }
-unset( $plugin, $_wp_plugin_file );
+$_handle_incompatible_for_core_plugins();
+unset(
+	$plugin,
+	$_wp_plugin_file,
+	// Remove the for-core compatibility handler.
+	$_wp_activated_plugins_to_compat_check,
+	$_is_plugin_compatible_with_wp,
+	$_handle_incompatible_for_core_plugins
+);
 
 // Load pluggable functions.
 require ABSPATH . WPINC . '/pluggable.php';