Introduce filters for skipping parts of the bootstrap process

Non web interfaces with WordPress (such as wp-cli) need to be able to bypass certain checks in the bootstrap process. This introduces three new filters to allow for those checks to be skipped.

1. Provides a way of forcefully bypassing wp_maintenance().
2. Provides a way of forcefully bypassing wp_debug_mode(). See https://github.com/wp-cli/wp-cli/issues/177
3. Provide a way of forcefully skipping loading wp-content/advance-cache.php. See https://github.com/wp-cli/wp-cli/pull/164

These filters should not be used by plugins (in fact, they run before plugins are loaded, so they can't be used by plugins). In general, they should only be used in non-web interactions with WordPress.

See #34936.
Props jorbin, DrewAPicture.

Built from https://develop.svn.wordpress.org/trunk@37626


git-svn-id: http://core.svn.wordpress.org/trunk@37594 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/load.php

@@ -183,6 +183,21 @@ function wp_maintenance() {
 	// If the $upgrading timestamp is older than 10 minutes, don't die.
 	if ( ( time() - $upgrading ) >= 600 )
 		return;
+	
+	/**
+	 * Bypass the maintenance mode check
+	 *
+	 * This filter should *NOT* be used by plugins. It is designed for non-web
+	 * runtimes. If this filter returns true, maintenance mode will not be  
+	 * active which can cause problems during updates for web site views.
+	 *
+	 * @since 4.6.0
+	 *
+	 * @param bool True to bypass maintenance
+	 */
+	if ( apply_filters( 'bypass_maintenance_mode', false ) ){
+		return;	
+	}
 
 	if ( file_exists( WP_CONTENT_DIR . '/maintenance.php' ) ) {
 		require_once( WP_CONTENT_DIR . '/maintenance.php' );
@@ -285,6 +300,22 @@ function timer_stop( $display = 0, $precision = 3 ) {
  * @access private
  */
 function wp_debug_mode() {
+	/**
+	 * Bypass the debug mode check
+	 *
+	 * This filter should *NOT* be used by plugins. It is designed for non-web
+	 * runtimes. Returning true causes the WP_DEBUG and related constants to
+	 * not be checked and the default php values for errors will be used unless
+	 * you take care to update them yourself.
+	 *
+	 * @since 4.6.0
+	 *
+	 * @param bool True to bypass debug mode 
+	 */
+	if ( apply_filters( 'bypass_debug_mode', false ) ){
+		return;	
+	}
+
 	if ( WP_DEBUG ) {
 		error_reporting( E_ALL );
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-alpha-37625';
+$wp_version = '4.6-alpha-37626';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-settings.php

@@ -70,8 +70,18 @@ timer_start();
 // Check if we're in WP_DEBUG mode.
 wp_debug_mode();
 
+/**
+ * Bypass the loading of advanced-cache.php
+ *
+ * This filter should *NOT* be used by plugins. It is designed for non-web
+ * runtimes. If true is returned, advance-cache.php will never be loaded.
+ *
+ * @since 4.6.0
+ *
+ * @param bool True to bypass advanced-cache.php
+ */
+if ( WP_CACHE && ! apply_filters( 'bypass_advanced_cache', false )  ) {
 // For an advanced caching plugin to use. Uses a static drop-in because you would only want one.
-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();