wp/wp-includes/load.php
changeset 9 177826044cd9
parent 7 cf61fcea0001
child 16 a86126ab1dd4
--- a/wp/wp-includes/load.php	Mon Oct 14 18:06:33 2019 +0200
+++ b/wp/wp-includes/load.php	Mon Oct 14 18:28:13 2019 +0200
@@ -27,20 +27,23 @@
  * @access private
  */
 function wp_unregister_GLOBALS() {
-	if ( !ini_get( 'register_globals' ) )
+	if ( ! ini_get( 'register_globals' ) ) {
 		return;
+	}
 
-	if ( isset( $_REQUEST['GLOBALS'] ) )
+	if ( isset( $_REQUEST['GLOBALS'] ) ) {
 		die( 'GLOBALS overwrite attempt detected' );
+	}
 
 	// Variables that shouldn't be unset
 	$no_unset = array( 'GLOBALS', '_GET', '_POST', '_COOKIE', '_REQUEST', '_SERVER', '_ENV', '_FILES', 'table_prefix' );
 
 	$input = array_merge( $_GET, $_POST, $_COOKIE, $_SERVER, $_ENV, $_FILES, isset( $_SESSION ) && is_array( $_SESSION ) ? $_SESSION : array() );
-	foreach ( $input as $k => $v )
-		if ( !in_array( $k, $no_unset ) && isset( $GLOBALS[$k] ) ) {
-			unset( $GLOBALS[$k] );
+	foreach ( $input as $k => $v ) {
+		if ( ! in_array( $k, $no_unset ) && isset( $GLOBALS[ $k ] ) ) {
+			unset( $GLOBALS[ $k ] );
 		}
+	}
 }
 
 /**
@@ -57,7 +60,7 @@
 
 	$default_server_values = array(
 		'SERVER_SOFTWARE' => '',
-		'REQUEST_URI' => '',
+		'REQUEST_URI'     => '',
 	);
 
 	$_SERVER = array_merge( $default_server_values, $_SERVER );
@@ -65,24 +68,25 @@
 	// Fix for IIS when running with PHP ISAPI
 	if ( empty( $_SERVER['REQUEST_URI'] ) || ( PHP_SAPI != 'cgi-fcgi' && preg_match( '/^Microsoft-IIS\//', $_SERVER['SERVER_SOFTWARE'] ) ) ) {
 
-		// IIS Mod-Rewrite
 		if ( isset( $_SERVER['HTTP_X_ORIGINAL_URL'] ) ) {
+			// IIS Mod-Rewrite
 			$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_ORIGINAL_URL'];
-		}
-		// IIS Isapi_Rewrite
-		elseif ( isset( $_SERVER['HTTP_X_REWRITE_URL'] ) ) {
+		} elseif ( isset( $_SERVER['HTTP_X_REWRITE_URL'] ) ) {
+			// IIS Isapi_Rewrite
 			$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_REWRITE_URL'];
 		} else {
 			// Use ORIG_PATH_INFO if there is no PATH_INFO
-			if ( !isset( $_SERVER['PATH_INFO'] ) && isset( $_SERVER['ORIG_PATH_INFO'] ) )
+			if ( ! isset( $_SERVER['PATH_INFO'] ) && isset( $_SERVER['ORIG_PATH_INFO'] ) ) {
 				$_SERVER['PATH_INFO'] = $_SERVER['ORIG_PATH_INFO'];
+			}
 
 			// Some IIS + PHP configurations puts the script-name in the path-info (No need to append it twice)
 			if ( isset( $_SERVER['PATH_INFO'] ) ) {
-				if ( $_SERVER['PATH_INFO'] == $_SERVER['SCRIPT_NAME'] )
+				if ( $_SERVER['PATH_INFO'] == $_SERVER['SCRIPT_NAME'] ) {
 					$_SERVER['REQUEST_URI'] = $_SERVER['PATH_INFO'];
-				else
+				} else {
 					$_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME'] . $_SERVER['PATH_INFO'];
+				}
 			}
 
 			// Append the query string if it exists and isn't null
@@ -93,17 +97,20 @@
 	}
 
 	// Fix for PHP as CGI hosts that set SCRIPT_FILENAME to something ending in php.cgi for all requests
-	if ( isset( $_SERVER['SCRIPT_FILENAME'] ) && ( strpos( $_SERVER['SCRIPT_FILENAME'], 'php.cgi' ) == strlen( $_SERVER['SCRIPT_FILENAME'] ) - 7 ) )
+	if ( isset( $_SERVER['SCRIPT_FILENAME'] ) && ( strpos( $_SERVER['SCRIPT_FILENAME'], 'php.cgi' ) == strlen( $_SERVER['SCRIPT_FILENAME'] ) - 7 ) ) {
 		$_SERVER['SCRIPT_FILENAME'] = $_SERVER['PATH_TRANSLATED'];
+	}
 
 	// Fix for Dreamhost and other PHP as CGI hosts
-	if ( strpos( $_SERVER['SCRIPT_NAME'], 'php.cgi' ) !== false )
+	if ( strpos( $_SERVER['SCRIPT_NAME'], 'php.cgi' ) !== false ) {
 		unset( $_SERVER['PATH_INFO'] );
+	}
 
 	// Fix empty PHP_SELF
 	$PHP_SELF = $_SERVER['PHP_SELF'];
-	if ( empty( $PHP_SELF ) )
-		$_SERVER['PHP_SELF'] = $PHP_SELF = preg_replace( '/(\?.*)?$/', '', $_SERVER["REQUEST_URI"] );
+	if ( empty( $PHP_SELF ) ) {
+		$_SERVER['PHP_SELF'] = $PHP_SELF = preg_replace( '/(\?.*)?$/', '', $_SERVER['REQUEST_URI'] );
+	}
 }
 
 /**
@@ -129,16 +136,23 @@
 		header( sprintf( '%s 500 Internal Server Error', $protocol ), true, 500 );
 		header( 'Content-Type: text/html; charset=utf-8' );
 		/* translators: 1: Current PHP version number, 2: WordPress version number, 3: Minimum required PHP version number */
-		die( sprintf( __( 'Your server is running PHP version %1$s but WordPress %2$s requires at least %3$s.' ), $php_version, $wp_version, $required_php_version ) );
+		printf( __( 'Your server is running PHP version %1$s but WordPress %2$s requires at least %3$s.' ), $php_version, $wp_version, $required_php_version );
+		exit( 1 );
 	}
 
 	if ( ! extension_loaded( 'mysql' ) && ! extension_loaded( 'mysqli' ) && ! extension_loaded( 'mysqlnd' ) && ! file_exists( WP_CONTENT_DIR . '/db.php' ) ) {
+		require_once( ABSPATH . WPINC . '/functions.php' );
 		wp_load_translations_early();
-
-		$protocol = wp_get_server_protocol();
-		header( sprintf( '%s 500 Internal Server Error', $protocol ), true, 500 );
-		header( 'Content-Type: text/html; charset=utf-8' );
-		die( __( 'Your PHP installation appears to be missing the MySQL extension which is required by WordPress.' ) );
+		$args = array(
+			'exit' => false,
+			'code' => 'mysql_not_found',
+		);
+		wp_die(
+			__( 'Your PHP installation appears to be missing the MySQL extension which is required by WordPress.' ),
+			__( 'Insufficient Requirements' ),
+			$args
+		);
+		exit( 1 );
 	}
 }
 
@@ -151,7 +165,7 @@
  */
 function wp_favicon_request() {
 	if ( '/favicon.ico' == $_SERVER['REQUEST_URI'] ) {
-		header('Content-Type: image/vnd.microsoft.icon');
+		header( 'Content-Type: image/vnd.microsoft.icon' );
 		exit;
 	}
 }
@@ -173,15 +187,17 @@
  * @global int $upgrading the unix timestamp marking when upgrading WordPress began.
  */
 function wp_maintenance() {
-	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() )
+	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() ) {
 		return;
+	}
 
 	global $upgrading;
 
 	include( ABSPATH . '.maintenance' );
 	// If the $upgrading timestamp is older than 10 minutes, don't die.
-	if ( ( time() - $upgrading ) >= 600 )
+	if ( ( time() - $upgrading ) >= 600 ) {
 		return;
+	}
 
 	/**
 	 * Filters whether to enable maintenance mode.
@@ -205,26 +221,16 @@
 		die();
 	}
 
+	require_once( ABSPATH . WPINC . '/functions.php' );
 	wp_load_translations_early();
 
-	$protocol = wp_get_server_protocol();
-	header( "$protocol 503 Service Unavailable", true, 503 );
-	header( 'Content-Type: text/html; charset=utf-8' );
 	header( 'Retry-After: 600' );
-?>
-	<!DOCTYPE html>
-	<html xmlns="http://www.w3.org/1999/xhtml"<?php if ( is_rtl() ) echo ' dir="rtl"'; ?>>
-	<head>
-	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
-		<title><?php _e( 'Maintenance' ); ?></title>
 
-	</head>
-	<body>
-		<h1><?php _e( 'Briefly unavailable for scheduled maintenance. Check back in a minute.' ); ?></h1>
-	</body>
-	</html>
-<?php
-	die();
+	wp_die(
+		__( 'Briefly unavailable for scheduled maintenance. Check back in a minute.' ),
+		__( 'Maintenance' ),
+		503
+	);
 }
 
 /**
@@ -261,11 +267,12 @@
  */
 function timer_stop( $display = 0, $precision = 3 ) {
 	global $timestart, $timeend;
-	$timeend = microtime( true );
+	$timeend   = microtime( true );
 	$timetotal = $timeend - $timestart;
-	$r = ( function_exists( 'number_format_i18n' ) ) ? number_format_i18n( $timetotal, $precision ) : number_format( $timetotal, $precision );
-	if ( $display )
+	$r         = ( function_exists( 'number_format_i18n' ) ) ? number_format_i18n( $timetotal, $precision ) : number_format( $timetotal, $precision );
+	if ( $display ) {
 		echo $r;
+	}
 	return $r;
 }
 
@@ -292,12 +299,13 @@
  * from changing the global configuration setting. Defining `WP_DEBUG_DISPLAY`
  * as false will force errors to be hidden.
  *
- * When `WP_DEBUG_LOG` is true, errors will be logged to debug.log in the content
- * directory.
+ * When `WP_DEBUG_LOG` is true, errors will be logged to `wp-content/debug.log`.
+ * When `WP_DEBUG_LOG` is a valid path, errors will be logged to the specified file.
  *
  * Errors are never displayed for XML-RPC, REST, and Ajax requests.
  *
  * @since 3.0.0
+ * @since 5.1.0 `WP_DEBUG_LOG` can be a file path.
  * @access private
  */
 function wp_debug_mode() {
@@ -313,27 +321,36 @@
 	 *
 	 * @param bool $enable_debug_mode Whether to enable debug mode checks to occur. Default true.
 	 */
-	if ( ! apply_filters( 'enable_wp_debug_mode_checks', true ) ){
+	if ( ! apply_filters( 'enable_wp_debug_mode_checks', true ) ) {
 		return;
 	}
 
 	if ( WP_DEBUG ) {
 		error_reporting( E_ALL );
 
-		if ( WP_DEBUG_DISPLAY )
+		if ( WP_DEBUG_DISPLAY ) {
 			ini_set( 'display_errors', 1 );
-		elseif ( null !== WP_DEBUG_DISPLAY )
+		} elseif ( null !== WP_DEBUG_DISPLAY ) {
 			ini_set( 'display_errors', 0 );
+		}
 
-		if ( WP_DEBUG_LOG ) {
+		if ( in_array( strtolower( (string) WP_DEBUG_LOG ), array( 'true', '1' ), true ) ) {
+			$log_path = WP_CONTENT_DIR . '/debug.log';
+		} elseif ( is_string( WP_DEBUG_LOG ) ) {
+			$log_path = WP_DEBUG_LOG;
+		} else {
+			$log_path = false;
+		}
+
+		if ( $log_path ) {
 			ini_set( 'log_errors', 1 );
-			ini_set( 'error_log', WP_CONTENT_DIR . '/debug.log' );
+			ini_set( 'error_log', $log_path );
 		}
 	} else {
 		error_reporting( E_CORE_ERROR | E_CORE_WARNING | E_COMPILE_ERROR | E_ERROR | E_WARNING | E_PARSE | E_USER_ERROR | E_USER_WARNING | E_RECOVERABLE_ERROR );
 	}
 
-	if ( defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) || wp_doing_ajax() ) {
+	if ( defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || ( defined( 'WP_INSTALLING' ) && WP_INSTALLING ) || wp_doing_ajax() || wp_is_json_request() ) {
 		@ini_set( 'display_errors', 0 );
 	}
 }
@@ -352,8 +369,8 @@
  * @access private
  */
 function wp_set_lang_dir() {
-	if ( !defined( 'WP_LANG_DIR' ) ) {
-		if ( file_exists( WP_CONTENT_DIR . '/languages' ) && @is_dir( WP_CONTENT_DIR . '/languages' ) || !@is_dir(ABSPATH . WPINC . '/languages') ) {
+	if ( ! defined( 'WP_LANG_DIR' ) ) {
+		if ( file_exists( WP_CONTENT_DIR . '/languages' ) && @is_dir( WP_CONTENT_DIR . '/languages' ) || ! @is_dir( ABSPATH . WPINC . '/languages' ) ) {
 			/**
 			 * Server path of the language directory.
 			 *
@@ -362,7 +379,7 @@
 			 * @since 2.1.0
 			 */
 			define( 'WP_LANG_DIR', WP_CONTENT_DIR . '/languages' );
-			if ( !defined( 'LANGDIR' ) ) {
+			if ( ! defined( 'LANGDIR' ) ) {
 				// Old static relative path maintained for limited backward compatibility - won't work in some cases.
 				define( 'LANGDIR', 'wp-content/languages' );
 			}
@@ -375,7 +392,7 @@
 			 * @since 2.1.0
 			 */
 			define( 'WP_LANG_DIR', ABSPATH . WPINC . '/languages' );
-			if ( !defined( 'LANGDIR' ) ) {
+			if ( ! defined( 'LANGDIR' ) ) {
 				// Old relative path maintained for backward compatibility.
 				define( 'LANGDIR', WPINC . '/languages' );
 			}
@@ -394,14 +411,20 @@
 	global $wpdb;
 
 	require_once( ABSPATH . WPINC . '/wp-db.php' );
-	if ( file_exists( WP_CONTENT_DIR . '/db.php' ) )
+	if ( file_exists( WP_CONTENT_DIR . '/db.php' ) ) {
 		require_once( WP_CONTENT_DIR . '/db.php' );
+	}
 
 	if ( isset( $wpdb ) ) {
 		return;
 	}
 
-	$wpdb = new wpdb( DB_USER, DB_PASSWORD, DB_NAME, DB_HOST );
+	$dbuser     = defined( 'DB_USER' ) ? DB_USER : '';
+	$dbpassword = defined( 'DB_PASSWORD' ) ? DB_PASSWORD : '';
+	$dbname     = defined( 'DB_NAME' ) ? DB_NAME : '';
+	$dbhost     = defined( 'DB_HOST' ) ? DB_HOST : '';
+
+	$wpdb = new wpdb( $dbuser, $dbpassword, $dbname, $dbhost );
 }
 
 /**
@@ -418,15 +441,46 @@
  */
 function wp_set_wpdb_vars() {
 	global $wpdb, $table_prefix;
-	if ( !empty( $wpdb->error ) )
+	if ( ! empty( $wpdb->error ) ) {
 		dead_db();
+	}
 
-	$wpdb->field_types = array( 'post_author' => '%d', 'post_parent' => '%d', 'menu_order' => '%d', 'term_id' => '%d', 'term_group' => '%d', 'term_taxonomy_id' => '%d',
-		'parent' => '%d', 'count' => '%d','object_id' => '%d', 'term_order' => '%d', 'ID' => '%d', 'comment_ID' => '%d', 'comment_post_ID' => '%d', 'comment_parent' => '%d',
-		'user_id' => '%d', 'link_id' => '%d', 'link_owner' => '%d', 'link_rating' => '%d', 'option_id' => '%d', 'blog_id' => '%d', 'meta_id' => '%d', 'post_id' => '%d',
-		'user_status' => '%d', 'umeta_id' => '%d', 'comment_karma' => '%d', 'comment_count' => '%d',
+	$wpdb->field_types = array(
+		'post_author'      => '%d',
+		'post_parent'      => '%d',
+		'menu_order'       => '%d',
+		'term_id'          => '%d',
+		'term_group'       => '%d',
+		'term_taxonomy_id' => '%d',
+		'parent'           => '%d',
+		'count'            => '%d',
+		'object_id'        => '%d',
+		'term_order'       => '%d',
+		'ID'               => '%d',
+		'comment_ID'       => '%d',
+		'comment_post_ID'  => '%d',
+		'comment_parent'   => '%d',
+		'user_id'          => '%d',
+		'link_id'          => '%d',
+		'link_owner'       => '%d',
+		'link_rating'      => '%d',
+		'option_id'        => '%d',
+		'blog_id'          => '%d',
+		'meta_id'          => '%d',
+		'post_id'          => '%d',
+		'user_status'      => '%d',
+		'umeta_id'         => '%d',
+		'comment_karma'    => '%d',
+		'comment_count'    => '%d',
 		// multisite:
-		'active' => '%d', 'cat_id' => '%d', 'deleted' => '%d', 'lang_id' => '%d', 'mature' => '%d', 'public' => '%d', 'site_id' => '%d', 'spam' => '%d',
+		'active'           => '%d',
+		'cat_id'           => '%d',
+		'deleted'          => '%d',
+		'lang_id'          => '%d',
+		'mature'           => '%d',
+		'public'           => '%d',
+		'site_id'          => '%d',
+		'spam'             => '%d',
 	);
 
 	$prefix = $wpdb->set_prefix( $table_prefix );
@@ -434,8 +488,9 @@
 	if ( is_wp_error( $prefix ) ) {
 		wp_load_translations_early();
 		wp_die(
-			/* translators: 1: $table_prefix 2: wp-config.php */
-			sprintf( __( '<strong>ERROR</strong>: %1$s in %2$s can only contain numbers, letters, and underscores.' ),
+			/* translators: 1: $table_prefix, 2: wp-config.php */
+			sprintf(
+				__( '<strong>ERROR</strong>: %1$s in %2$s can only contain numbers, letters, and underscores.' ),
 				'<code>$table_prefix</code>',
 				'<code>wp-config.php</code>'
 			)
@@ -457,8 +512,9 @@
 function wp_using_ext_object_cache( $using = null ) {
 	global $_wp_using_ext_object_cache;
 	$current_using = $_wp_using_ext_object_cache;
-	if ( null !== $using )
+	if ( null !== $using ) {
 		$_wp_using_ext_object_cache = $using;
+	}
 	return $current_using;
 }
 
@@ -475,34 +531,43 @@
  */
 function wp_start_object_cache() {
 	global $wp_filter;
-
-	$first_init = false;
- 	if ( ! function_exists( 'wp_cache_init' ) ) {
-		if ( file_exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
-			require_once ( WP_CONTENT_DIR . '/object-cache.php' );
-			if ( function_exists( 'wp_cache_init' ) ) {
-				wp_using_ext_object_cache( true );
-			}
+	static $first_init = true;
 
-			// Re-initialize any hooks added manually by object-cache.php
-			if ( $wp_filter ) {
-				$wp_filter = WP_Hook::build_preinitialized_hooks( $wp_filter );
-			}
-		}
+	// Only perform the following checks once.
+	if ( $first_init ) {
+		if ( ! function_exists( 'wp_cache_init' ) ) {
+			/*
+			 * This is the normal situation. First-run of this function. No
+			 * caching backend has been loaded.
+			 *
+			 * We try to load a custom caching backend, and then, if it
+			 * results in a wp_cache_init() function existing, we note
+			 * that an external object cache is being used.
+			 */
+			if ( file_exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
+				require_once( WP_CONTENT_DIR . '/object-cache.php' );
+				if ( function_exists( 'wp_cache_init' ) ) {
+					wp_using_ext_object_cache( true );
+				}
 
-		$first_init = true;
-	} elseif ( ! wp_using_ext_object_cache() && file_exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
-		/*
-		 * Sometimes advanced-cache.php can load object-cache.php before
-		 * it is loaded here. This breaks the function_exists check above
-		 * and can result in `$_wp_using_ext_object_cache` being set
-		 * incorrectly. Double check if an external cache exists.
-		 */
-		wp_using_ext_object_cache( true );
+				// Re-initialize any hooks added manually by object-cache.php
+				if ( $wp_filter ) {
+					$wp_filter = WP_Hook::build_preinitialized_hooks( $wp_filter );
+				}
+			}
+		} elseif ( ! wp_using_ext_object_cache() && file_exists( WP_CONTENT_DIR . '/object-cache.php' ) ) {
+			/*
+			 * Sometimes advanced-cache.php can load object-cache.php before
+			 * this function is run. This breaks the function_exists() check
+			 * above and can result in wp_using_ext_object_cache() returning
+			 * false when actually an external cache is in use.
+			 */
+			wp_using_ext_object_cache( true );
+		}
 	}
 
 	if ( ! wp_using_ext_object_cache() ) {
-		require_once ( ABSPATH . WPINC . '/cache.php' );
+		require_once( ABSPATH . WPINC . '/cache.php' );
 	}
 
 	/*
@@ -517,9 +582,11 @@
 	}
 
 	if ( function_exists( 'wp_cache_add_global_groups' ) ) {
-		wp_cache_add_global_groups( array( 'users', 'userlogins', 'usermeta', 'user_meta', 'useremail', 'userslugs', 'site-transient', 'site-options', 'blog-lookup', 'blog-details', 'site-details', 'rss', 'global-posts', 'blog-id-cache', 'networks', 'sites' ) );
+		wp_cache_add_global_groups( array( 'users', 'userlogins', 'usermeta', 'user_meta', 'useremail', 'userslugs', 'site-transient', 'site-options', 'blog-lookup', 'blog-details', 'site-details', 'rss', 'global-posts', 'blog-id-cache', 'networks', 'sites', 'blog_meta' ) );
 		wp_cache_add_non_persistent_groups( array( 'counts', 'plugins' ) );
 	}
+
+	$first_init = false;
 }
 
 /**
@@ -542,7 +609,6 @@
 
 		require( ABSPATH . WPINC . '/kses.php' );
 		require( ABSPATH . WPINC . '/pluggable.php' );
-		require( ABSPATH . WPINC . '/formatting.php' );
 
 		$link = wp_guess_url() . '/wp-admin/install.php';
 
@@ -565,13 +631,16 @@
  */
 function wp_get_mu_plugins() {
 	$mu_plugins = array();
-	if ( !is_dir( WPMU_PLUGIN_DIR ) )
+	if ( ! is_dir( WPMU_PLUGIN_DIR ) ) {
 		return $mu_plugins;
-	if ( ! $dh = opendir( WPMU_PLUGIN_DIR ) )
+	}
+	if ( ! $dh = opendir( WPMU_PLUGIN_DIR ) ) {
 		return $mu_plugins;
+	}
 	while ( ( $plugin = readdir( $dh ) ) !== false ) {
-		if ( substr( $plugin, -4 ) == '.php' )
+		if ( substr( $plugin, -4 ) == '.php' ) {
 			$mu_plugins[] = WPMU_PLUGIN_DIR . '/' . $plugin;
+		}
 	}
 	closedir( $dh );
 	sort( $mu_plugins );
@@ -584,17 +653,17 @@
  *
  * While upgrading or installing WordPress, no plugins are returned.
  *
- * The default directory is wp-content/plugins. To change the default
+ * The default directory is `wp-content/plugins`. To change the default
  * directory manually, define `WP_PLUGIN_DIR` and `WP_PLUGIN_URL`
- * in wp-config.php.
+ * in `wp-config.php`.
  *
  * @since 3.0.0
  * @access private
  *
- * @return array Files.
+ * @return string[] $plugin_file Array of paths to plugin files relative to the plugins directory.
  */
 function wp_get_active_and_valid_plugins() {
-	$plugins = array();
+	$plugins        = array();
 	$active_plugins = (array) get_option( 'active_plugins', array() );
 
 	// Check for hacks file if the option is enabled
@@ -603,8 +672,9 @@
 		array_unshift( $plugins, ABSPATH . 'my-hacks.php' );
 	}
 
-	if ( empty( $active_plugins ) || wp_installing() )
+	if ( empty( $active_plugins ) || wp_installing() ) {
 		return $plugins;
+	}
 
 	$network_plugins = is_multisite() ? wp_get_active_network_plugins() : false;
 
@@ -614,10 +684,214 @@
 			&& file_exists( WP_PLUGIN_DIR . '/' . $plugin ) // $plugin must exist
 			// not already included as a network plugin
 			&& ( ! $network_plugins || ! in_array( WP_PLUGIN_DIR . '/' . $plugin, $network_plugins ) )
-			)
-		$plugins[] = WP_PLUGIN_DIR . '/' . $plugin;
+			) {
+			$plugins[] = WP_PLUGIN_DIR . '/' . $plugin;
+		}
+	}
+
+	/*
+	 * Remove plugins from the list of active plugins when we're on an endpoint
+	 * that should be protected against WSODs and the plugin is paused.
+	 */
+	if ( wp_is_recovery_mode() ) {
+		$plugins = wp_skip_paused_plugins( $plugins );
+	}
+
+	return $plugins;
+}
+
+/**
+ * Filters a given list of plugins, removing any paused plugins from it.
+ *
+ * @since 5.2.0
+ *
+ * @param array $plugins List of absolute plugin main file paths.
+ * @return array Filtered value of $plugins, without any paused plugins.
+ */
+function wp_skip_paused_plugins( array $plugins ) {
+	$paused_plugins = wp_paused_plugins()->get_all();
+
+	if ( empty( $paused_plugins ) ) {
+		return $plugins;
+	}
+
+	foreach ( $plugins as $index => $plugin ) {
+		list( $plugin ) = explode( '/', plugin_basename( $plugin ) );
+
+		if ( array_key_exists( $plugin, $paused_plugins ) ) {
+			unset( $plugins[ $index ] );
+
+			// Store list of paused plugins for displaying an admin notice.
+			$GLOBALS['_paused_plugins'][ $plugin ] = $paused_plugins[ $plugin ];
+		}
+	}
+
+	return $plugins;
+}
+
+/**
+ * Retrieves an array of active and valid themes.
+ *
+ * While upgrading or installing WordPress, no themes are returned.
+ *
+ * @since 5.1.0
+ * @access private
+ *
+ * @return array Array of paths to theme directories.
+ */
+function wp_get_active_and_valid_themes() {
+	global $pagenow;
+
+	$themes = array();
+
+	if ( wp_installing() && 'wp-activate.php' !== $pagenow ) {
+		return $themes;
+	}
+
+	if ( TEMPLATEPATH !== STYLESHEETPATH ) {
+		$themes[] = STYLESHEETPATH;
+	}
+
+	$themes[] = TEMPLATEPATH;
+
+	/*
+	 * Remove themes from the list of active themes when we're on an endpoint
+	 * that should be protected against WSODs and the theme is paused.
+	 */
+	if ( wp_is_recovery_mode() ) {
+		$themes = wp_skip_paused_themes( $themes );
+
+		// If no active and valid themes exist, skip loading themes.
+		if ( empty( $themes ) ) {
+			add_filter( 'wp_using_themes', '__return_false' );
+		}
+	}
+
+	return $themes;
+}
+
+/**
+ * Filters a given list of themes, removing any paused themes from it.
+ *
+ * @since 5.2.0
+ *
+ * @param array $themes List of absolute theme directory paths.
+ * @return array Filtered value of $themes, without any paused themes.
+ */
+function wp_skip_paused_themes( array $themes ) {
+	$paused_themes = wp_paused_themes()->get_all();
+
+	if ( empty( $paused_themes ) ) {
+		return $themes;
 	}
-	return $plugins;
+
+	foreach ( $themes as $index => $theme ) {
+		$theme = basename( $theme );
+
+		if ( array_key_exists( $theme, $paused_themes ) ) {
+			unset( $themes[ $index ] );
+
+			// Store list of paused themes for displaying an admin notice.
+			$GLOBALS['_paused_themes'][ $theme ] = $paused_themes[ $theme ];
+		}
+	}
+
+	return $themes;
+}
+
+/**
+ * Is WordPress in Recovery Mode.
+ *
+ * In this mode, plugins or themes that cause WSODs will be paused.
+ *
+ * @since 5.2.0
+ *
+ * @return bool
+ */
+function wp_is_recovery_mode() {
+	return wp_recovery_mode()->is_active();
+}
+
+/**
+ * Determines whether we are currently on an endpoint that should be protected against WSODs.
+ *
+ * @since 5.2.0
+ *
+ * @return bool True if the current endpoint should be protected.
+ */
+function is_protected_endpoint() {
+	// Protect login pages.
+	if ( isset( $GLOBALS['pagenow'] ) && 'wp-login.php' === $GLOBALS['pagenow'] ) {
+		return true;
+	}
+
+	// Protect the admin backend.
+	if ( is_admin() && ! wp_doing_ajax() ) {
+		return true;
+	}
+
+	// Protect AJAX actions that could help resolve a fatal error should be available.
+	if ( is_protected_ajax_action() ) {
+		return true;
+	}
+
+	/**
+	 * Filters whether the current request is against a protected endpoint.
+	 *
+	 * This filter is only fired when an endpoint is requested which is not already protected by
+	 * WordPress core. As such, it exclusively allows providing further protected endpoints in
+	 * addition to the admin backend, login pages and protected AJAX actions.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param bool $is_protected_endpoint Whether the currently requested endpoint is protected. Default false.
+	 */
+	return (bool) apply_filters( 'is_protected_endpoint', false );
+}
+
+/**
+ * Determines whether we are currently handling an AJAX action that should be protected against WSODs.
+ *
+ * @since 5.2.0
+ *
+ * @return bool True if the current AJAX action should be protected.
+ */
+function is_protected_ajax_action() {
+	if ( ! wp_doing_ajax() ) {
+		return false;
+	}
+
+	if ( ! isset( $_REQUEST['action'] ) ) {
+		return false;
+	}
+
+	$actions_to_protect = array(
+		'edit-theme-plugin-file', // Saving changes in the core code editor.
+		'heartbeat',              // Keep the heart beating.
+		'install-plugin',         // Installing a new plugin.
+		'install-theme',          // Installing a new theme.
+		'search-plugins',         // Searching in the list of plugins.
+		'search-install-plugins', // Searching for a plugin in the plugin install screen.
+		'update-plugin',          // Update an existing plugin.
+		'update-theme',           // Update an existing theme.
+	);
+
+	/**
+	 * Filters the array of protected AJAX actions.
+	 *
+	 * This filter is only fired when doing AJAX and the AJAX request has an 'action' property.
+	 *
+	 * @since 5.2.0
+	 *
+	 * @param array $actions_to_protect Array of strings with AJAX actions to protect.
+	 */
+	$actions_to_protect = (array) apply_filters( 'wp_protected_ajax_actions', $actions_to_protect );
+
+	if ( ! in_array( $_REQUEST['action'], $actions_to_protect, true ) ) {
+		return false;
+	}
+
+	return true;
 }
 
 /**
@@ -632,8 +906,9 @@
 function wp_set_internal_encoding() {
 	if ( function_exists( 'mb_internal_encoding' ) ) {
 		$charset = get_option( 'blog_charset' );
-		if ( ! $charset || ! @mb_internal_encoding( $charset ) )
+		if ( ! $charset || ! @mb_internal_encoding( $charset ) ) {
 			mb_internal_encoding( 'UTF-8' );
+		}
 	}
 }
 
@@ -649,14 +924,14 @@
 function wp_magic_quotes() {
 	// If already slashed, strip.
 	if ( get_magic_quotes_gpc() ) {
-		$_GET    = stripslashes_deep( $_GET    );
-		$_POST   = stripslashes_deep( $_POST   );
+		$_GET    = stripslashes_deep( $_GET );
+		$_POST   = stripslashes_deep( $_POST );
 		$_COOKIE = stripslashes_deep( $_COOKIE );
 	}
 
 	// Escape with wpdb.
-	$_GET    = add_magic_quotes( $_GET    );
-	$_POST   = add_magic_quotes( $_POST   );
+	$_GET    = add_magic_quotes( $_GET );
+	$_POST   = add_magic_quotes( $_POST );
 	$_COOKIE = add_magic_quotes( $_COOKIE );
 	$_SERVER = add_magic_quotes( $_SERVER );
 
@@ -696,11 +971,15 @@
 }
 
 /**
- * Whether the current request is for an administrative interface page.
+ * Determines whether the current request is for an administrative interface page.
  *
- * Does not check if the user is an administrator; current_user_can()
+ * Does not check if the user is an administrator; use current_user_can()
  * for checking roles and capabilities.
  *
+ * For more information on this and similar theme functions, check out
+ * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
+ * Conditional Tags} article in the Theme Developer Handbook.
+ *
  * @since 1.5.1
  *
  * @global WP_Screen $current_screen
@@ -708,10 +987,11 @@
  * @return bool True if inside WordPress administration interface, false otherwise.
  */
 function is_admin() {
-	if ( isset( $GLOBALS['current_screen'] ) )
+	if ( isset( $GLOBALS['current_screen'] ) ) {
 		return $GLOBALS['current_screen']->in_admin();
-	elseif ( defined( 'WP_ADMIN' ) )
+	} elseif ( defined( 'WP_ADMIN' ) ) {
 		return WP_ADMIN;
+	}
 
 	return false;
 }
@@ -721,7 +1001,7 @@
  *
  * e.g. `/wp-admin/`
  *
- * Does not check if the user is an administrator; current_user_can()
+ * Does not check if the user is an administrator; use current_user_can()
  * for checking roles and capabilities.
  *
  * @since 3.1.0
@@ -731,10 +1011,11 @@
  * @return bool True if inside WordPress blog administration pages.
  */
 function is_blog_admin() {
-	if ( isset( $GLOBALS['current_screen'] ) )
+	if ( isset( $GLOBALS['current_screen'] ) ) {
 		return $GLOBALS['current_screen']->in_admin( 'site' );
-	elseif ( defined( 'WP_BLOG_ADMIN' ) )
+	} elseif ( defined( 'WP_BLOG_ADMIN' ) ) {
 		return WP_BLOG_ADMIN;
+	}
 
 	return false;
 }
@@ -744,7 +1025,7 @@
  *
  * e.g. `/wp-admin/network/`
  *
- * Does not check if the user is an administrator; current_user_can()
+ * Does not check if the user is an administrator; use current_user_can()
  * for checking roles and capabilities.
  *
  * @since 3.1.0
@@ -754,10 +1035,11 @@
  * @return bool True if inside WordPress network administration pages.
  */
 function is_network_admin() {
-	if ( isset( $GLOBALS['current_screen'] ) )
+	if ( isset( $GLOBALS['current_screen'] ) ) {
 		return $GLOBALS['current_screen']->in_admin( 'network' );
-	elseif ( defined( 'WP_NETWORK_ADMIN' ) )
+	} elseif ( defined( 'WP_NETWORK_ADMIN' ) ) {
 		return WP_NETWORK_ADMIN;
+	}
 
 	return false;
 }
@@ -767,9 +1049,8 @@
  *
  * e.g. `/wp-admin/user/`
  *
- * Does not inform on whether the user is an admin! Use capability
- * checks to tell if the user should be accessing a section or not
- * current_user_can().
+ * Does not check if the user is an administrator; use current_user_can()
+ * for checking roles and capabilities.
  *
  * @since 3.1.0
  *
@@ -778,10 +1059,11 @@
  * @return bool True if inside WordPress user administration pages.
  */
 function is_user_admin() {
-	if ( isset( $GLOBALS['current_screen'] ) )
+	if ( isset( $GLOBALS['current_screen'] ) ) {
 		return $GLOBALS['current_screen']->in_admin( 'user' );
-	elseif ( defined( 'WP_USER_ADMIN' ) )
+	} elseif ( defined( 'WP_USER_ADMIN' ) ) {
 		return WP_USER_ADMIN;
+	}
 
 	return false;
 }
@@ -794,11 +1076,13 @@
  * @return bool True if Multisite is enabled, false otherwise.
  */
 function is_multisite() {
-	if ( defined( 'MULTISITE' ) )
+	if ( defined( 'MULTISITE' ) ) {
 		return MULTISITE;
+	}
 
-	if ( defined( 'SUBDOMAIN_INSTALL' ) || defined( 'VHOST' ) || defined( 'SUNRISE' ) )
+	if ( defined( 'SUBDOMAIN_INSTALL' ) || defined( 'VHOST' ) || defined( 'SUNRISE' ) ) {
 		return true;
+	}
 
 	return false;
 }
@@ -814,7 +1098,7 @@
  */
 function get_current_blog_id() {
 	global $blog_id;
-	return absint($blog_id);
+	return absint( $blog_id );
 }
 
 /**
@@ -859,12 +1143,14 @@
 	global $wp_locale;
 
 	static $loaded = false;
-	if ( $loaded )
+	if ( $loaded ) {
 		return;
+	}
 	$loaded = true;
 
-	if ( function_exists( 'did_action' ) && did_action( 'init' ) )
+	if ( function_exists( 'did_action' ) && did_action( 'init' ) ) {
 		return;
+	}
 
 	// We need $wp_local_package
 	require ABSPATH . WPINC . '/version.php';
@@ -882,31 +1168,39 @@
 
 	while ( true ) {
 		if ( defined( 'WPLANG' ) ) {
-			if ( '' == WPLANG )
+			if ( '' == WPLANG ) {
 				break;
+			}
 			$locales[] = WPLANG;
 		}
 
-		if ( isset( $wp_local_package ) )
+		if ( isset( $wp_local_package ) ) {
 			$locales[] = $wp_local_package;
+		}
 
-		if ( ! $locales )
+		if ( ! $locales ) {
 			break;
+		}
 
-		if ( defined( 'WP_LANG_DIR' ) && @is_dir( WP_LANG_DIR ) )
+		if ( defined( 'WP_LANG_DIR' ) && @is_dir( WP_LANG_DIR ) ) {
 			$locations[] = WP_LANG_DIR;
+		}
 
-		if ( defined( 'WP_CONTENT_DIR' ) && @is_dir( WP_CONTENT_DIR . '/languages' ) )
+		if ( defined( 'WP_CONTENT_DIR' ) && @is_dir( WP_CONTENT_DIR . '/languages' ) ) {
 			$locations[] = WP_CONTENT_DIR . '/languages';
+		}
 
-		if ( @is_dir( ABSPATH . 'wp-content/languages' ) )
+		if ( @is_dir( ABSPATH . 'wp-content/languages' ) ) {
 			$locations[] = ABSPATH . 'wp-content/languages';
+		}
 
-		if ( @is_dir( ABSPATH . WPINC . '/languages' ) )
+		if ( @is_dir( ABSPATH . WPINC . '/languages' ) ) {
 			$locations[] = ABSPATH . WPINC . '/languages';
+		}
 
-		if ( ! $locations )
+		if ( ! $locations ) {
 			break;
+		}
 
 		$locations = array_unique( $locations );
 
@@ -914,8 +1208,9 @@
 			foreach ( $locations as $location ) {
 				if ( file_exists( $location . '/' . $locale . '.mo' ) ) {
 					load_textdomain( 'default', $location . '/' . $locale . '.mo' );
-					if ( defined( 'WP_SETUP_CONFIG' ) && file_exists( $location . '/admin-' . $locale . '.mo' ) )
+					if ( defined( 'WP_SETUP_CONFIG' ) && file_exists( $location . '/admin-' . $locale . '.mo' ) ) {
 						load_textdomain( 'default', $location . '/admin-' . $locale . '.mo' );
+					}
 					break 2;
 				}
 			}
@@ -951,7 +1246,7 @@
 
 	if ( ! is_null( $is_installing ) ) {
 		$old_installing = $installing;
-		$installing = $is_installing;
+		$installing     = $is_installing;
 		return (bool) $old_installing;
 	}
 
@@ -975,7 +1270,7 @@
 		if ( '1' == $_SERVER['HTTPS'] ) {
 			return true;
 		}
-	} elseif ( isset($_SERVER['SERVER_PORT'] ) && ( '443' == $_SERVER['SERVER_PORT'] ) ) {
+	} elseif ( isset( $_SERVER['SERVER_PORT'] ) && ( '443' == $_SERVER['SERVER_PORT'] ) ) {
 		return true;
 	}
 	return false;
@@ -1030,7 +1325,7 @@
 		if ( function_exists( 'ini_get_all' ) ) {
 			$ini_all = ini_get_all();
 		}
- 	}
+	}
 
 	// Bit operator to workaround https://bugs.php.net/bug.php?id=44936 which changes access level to 63 in PHP 5.2.6 - 5.2.17.
 	if ( isset( $ini_all[ $setting ]['access'] ) && ( INI_ALL === ( $ini_all[ $setting ]['access'] & 7 ) || INI_USER === ( $ini_all[ $setting ]['access'] & 7 ) ) ) {
@@ -1064,6 +1359,24 @@
 }
 
 /**
+ * Determines whether the current request should use themes.
+ *
+ * @since 5.1.0
+ *
+ * @return bool True if themes should be used, false otherwise.
+ */
+function wp_using_themes() {
+	/**
+	 * Filters whether the current request should use themes.
+	 *
+	 * @since 5.1.0
+	 *
+	 * @param bool $wp_using_themes Whether the current request should use themes.
+	 */
+	return apply_filters( 'wp_using_themes', defined( 'WP_USE_THEMES' ) && WP_USE_THEMES );
+}
+
+/**
  * Determines whether the current request is a WordPress cron request.
  *
  * @since 4.8.0
@@ -1124,18 +1437,23 @@
 	if ( ! isset( $_REQUEST['wp_scrape_key'] ) || ! isset( $_REQUEST['wp_scrape_nonce'] ) ) {
 		return;
 	}
-	$key = substr( sanitize_key( wp_unslash( $_REQUEST['wp_scrape_key'] ) ), 0, 32 );
+	$key   = substr( sanitize_key( wp_unslash( $_REQUEST['wp_scrape_key'] ) ), 0, 32 );
 	$nonce = wp_unslash( $_REQUEST['wp_scrape_nonce'] );
 
 	if ( get_transient( 'scrape_key_' . $key ) !== $nonce ) {
 		echo "###### wp_scraping_result_start:$key ######";
-		echo wp_json_encode( array(
-			'code' => 'scrape_nonce_failure',
-			'message' => __( 'Scrape nonce check failed. Please try again.' ),
-		) );
+		echo wp_json_encode(
+			array(
+				'code'    => 'scrape_nonce_failure',
+				'message' => __( 'Scrape nonce check failed. Please try again.' ),
+			)
+		);
 		echo "###### wp_scraping_result_end:$key ######";
 		die();
 	}
+	if ( ! defined( 'WP_SANDBOX_SCRAPING' ) ) {
+		define( 'WP_SANDBOX_SCRAPING', true );
+	}
 	register_shutdown_function( 'wp_finalize_scraping_edited_file_errors', $key );
 }
 
@@ -1157,3 +1475,84 @@
 	}
 	echo "\n###### wp_scraping_result_end:$scrape_key ######\n";
 }
+
+/**
+ * Checks whether current request is a JSON request, or is expecting a JSON response.
+ *
+ * @since 5.0.0
+ *
+ * @return bool True if Accepts or Content-Type headers contain application/json, false otherwise.
+ */
+function wp_is_json_request() {
+
+	if ( isset( $_SERVER['HTTP_ACCEPT'] ) && false !== strpos( $_SERVER['HTTP_ACCEPT'], 'application/json' ) ) {
+		return true;
+	}
+
+	if ( isset( $_SERVER['CONTENT_TYPE'] ) && 'application/json' === $_SERVER['CONTENT_TYPE'] ) {
+		return true;
+	}
+
+	return false;
+
+}
+
+/**
+ * Checks whether current request is a JSONP request, or is expecting a JSONP response.
+ *
+ * @since 5.2.0
+ *
+ * @return bool True if JSONP request, false otherwise.
+ */
+function wp_is_jsonp_request() {
+	if ( ! isset( $_GET['_jsonp'] ) ) {
+		return false;
+	}
+
+	if ( ! function_exists( 'wp_check_jsonp_callback' ) ) {
+		require_once ABSPATH . WPINC . '/functions.php';
+	}
+
+	$jsonp_callback = $_GET['_jsonp'];
+	if ( ! wp_check_jsonp_callback( $jsonp_callback ) ) {
+		return false;
+	}
+
+	/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
+	$jsonp_enabled = apply_filters( 'rest_jsonp_enabled', true );
+
+	return $jsonp_enabled;
+
+}
+
+/**
+ * Checks whether current request is an XML request, or is expecting an XML response.
+ *
+ * @since 5.2.0
+ *
+ * @return bool True if Accepts or Content-Type headers contain xml, false otherwise.
+ */
+function wp_is_xml_request() {
+	$accepted = array(
+		'text/xml',
+		'application/rss+xml',
+		'application/atom+xml',
+		'application/rdf+xml',
+		'text/xml+oembed',
+		'application/xml+oembed',
+	);
+
+	if ( isset( $_SERVER['HTTP_ACCEPT'] ) ) {
+		foreach ( $accepted as $type ) {
+			if ( false !== strpos( $_SERVER['HTTP_ACCEPT'], $type ) ) {
+				return true;
+			}
+		}
+	}
+
+	if ( isset( $_SERVER['CONTENT_TYPE'] ) && in_array( $_SERVER['CONTENT_TYPE'], $accepted, true ) ) {
+		return true;
+	}
+
+	return false;
+}