Bootstrap/Load: Load plugin.php earlier in wp-settings.php

In order to allow non-web initializations of WordPress (such as through wp-cli) to modify things like the check for maintenance mode, plugins.php and the associated functions must be available much earlier. The use of these functions earlier than the loading of plugins is not recommended in most use cases.

Fixes #36819. See #34936.
Props jorbin, danielbachhuber for documentation.


git-svn-id: https://develop.svn.wordpress.org/trunk@37588 602fd350-edb4-49c9-b593-d223f7449a82

Author: jorbin

src/wp-includes/plugin.php

@@ -946,3 +946,65 @@ function _wp_filter_build_unique_id($tag, $function, $priority) {
 		return $function[0] . '::' . $function[1];
 	}
 }
+
+/**
+ * Back up global variables used for actions and filters.
+ *
+ * Prevents redefinition of these globals in advanced-cache.php from accidentally
+ * destroying existing data.
+ *
+ * @since 4.6.0
+ * @access private
+ *
+ * @global array $wp_filter         Stores all filters and actions.
+ * @global array $wp_actions        Stores the amount of times an action was triggered.
+ * @global array $merged_filters    Merges the filter hooks using this function.
+ * @global array $wp_current_filter Stores the list of current filters with the current one last.
+ * @staticvar array $backup_globals Backed up globals.
+ * @return array the staticvar from the first time it is set.
+ */
+function _backup_plugin_globals(){
+	global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
+	static $backup_globals = array();
+	if ( empty( $backup_globals ) ) {
+		$backup_globals = array(
+			'backup_wp_filter'         => $wp_filter,
+			'backup_wp_actions'        => $wp_actions,
+			'backup_merged_filters'    => $merged_filters,
+			'backup_wp_current_filter' => $wp_current_filter,
+		);
+	};
+	return $backup_globals;
+}
+
+/**
+ * Safely restore backed up global variables used for actions and filters.
+ *
+ * @since 4.6.0
+ * @access private
+ *
+ * @global array $wp_filter         Stores all filters and actions.
+ * @global array $wp_actions        Stores the amount of times an action was triggered.
+ * @global array $merged_filters    Merges the filter hooks using this function.
+ * @global array $wp_current_filter Stores the list of current filters with the current one last.
+ * @staticvar array $backup_globals Backed up globals.
+ */
+function _restore_plugin_globals(){
+	global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
+	$backup_globals = _backup_plugin_globals();
+	if ( $wp_filter !== $backup_globals['backup_wp_filter'] ){
+		$wp_filter = array_merge_recursive( $wp_filter, $backup_globals['backup_wp_filter'] );
+	}
+
+	if ( $wp_actions !== $backup_globals['backup_wp_actions'] ){
+		$wp_actions = array_merge_recursive( $wp_actions, $backup_globals['backup_wp_actions'] );
+	}
+
+	if ( $merged_filters !== $backup_globals['backup_merged_filters'] ){
+		$merged_filters = array_merge_recursive( $merged_filters, $backup_globals['backup_merged_filters'] );
+	}
+
+	if ( $wp_current_filter !== $backup_globals['backup_wp_current_filter'] ){
+		$wp_current_filter = array_merge_recursive( $wp_current_filter, $backup_globals['backup_wp_current_filter'] );
+	}
+}

src/wp-settings.php

@@ -20,6 +20,7 @@
 // Include files required for initialization.
 require( ABSPATH . WPINC . '/load.php' );
 require( ABSPATH . WPINC . '/default-constants.php' );
+require( ABSPATH . WPINC . '/plugin.php' );
 
 /*
  * These can't be directly globalized in version.php. When updating,
@@ -70,8 +71,11 @@
 wp_debug_mode();
 
 // For an advanced caching plugin to use. Uses a static drop-in because you would only want one.
-if ( WP_CACHE )
+if ( WP_CACHE ) {
+	_backup_plugin_globals();
 	WP_DEBUG ? include( WP_CONTENT_DIR . '/advanced-cache.php' ) : @include( WP_CONTENT_DIR . '/advanced-cache.php' );
+	_restore_plugin_globals();
+}
 
 // Define WP_LANG_DIR if not set.
 wp_set_lang_dir();
@@ -81,7 +85,6 @@
 require( ABSPATH . WPINC . '/functions.php' );
 require( ABSPATH . WPINC . '/class-wp.php' );
 require( ABSPATH . WPINC . '/class-wp-error.php' );
-require( ABSPATH . WPINC . '/plugin.php' );
 require( ABSPATH . WPINC . '/pomo/mo.php' );
 
 // Include the wpdb class and, if present, a db.php database drop-in.

tests/phpunit/tests/actions.php

@@ -328,6 +328,69 @@ function test_doing_filter_real() {
 		$this->assertFalse( doing_filter( 'testing' ) ); // No longer doing this filter
 	}
 
+	/**
+	 * @ticket 36819
+	 */
+	function test_backup_plugin_globals_returns_filters() {
+		$backup = _backup_plugin_globals();
+		$this->assertArrayHasKey( 'backup_wp_filter',         $backup );
+		$this->assertArrayHasKey( 'backup_wp_actions',        $backup );
+		$this->assertArrayHasKey( 'backup_wp_current_filter', $backup );
+		$this->assertArrayHasKey( 'backup_merged_filters', $backup );
+	}
+
+	/**
+	 * @ticket 36819
+	 */
+	function test_backup_plugin_globals_returns_filters_from_first_time_called() {
+		$backup = _backup_plugin_globals();
+
+		$a = new MockAction();
+		$tag = rand_str();
+
+		add_action($tag, array(&$a, 'action'));
+
+		$new_backup = _backup_plugin_globals();
+		$this->assertEquals( $backup, $new_backup );
+	}
+
+	/**
+	 * @ticket 36819
+	 */
+	function test_restore_plugin_globals_from_stomp() {
+		global $wp_actions;
+		$original_actions = $wp_actions;
+
+		_backup_plugin_globals();
+
+		$wp_actions = array();
+		
+		$this->assertEmpty( $wp_actions );
+		_restore_plugin_globals();
+
+		$this->assertEquals( $GLOBALS['wp_actions'], $original_actions );
+	}
+
+	/**
+	 * @ticket 36819
+	 */
+	function test_restore_plugin_globals_includes_additions() {
+		global $wp_filter;
+		$original_filter = $wp_filter;
+
+		$backup = _backup_plugin_globals();
+
+		$a = new MockAction();
+		$tag = rand_str();
+		add_action($tag, array(&$a, 'action'));
+		
+		$this->assertNotEquals( $GLOBALS['wp_filter'], $original_filter );
+
+		_restore_plugin_globals();
+
+		$this->assertNotEquals( $GLOBALS['wp_filter'], $original_filter );
+	}
+
 	function apply_testing_filter() {
 		$this->apply_testing_filter = true;