Ticket #44458: 44458-2.diff

src/wp-admin/css/list-tables.css

@@ -1301 +1301 @@
         text-decoration: underline;
 }
 
+.plugins tr.paused th.check-column {
+        border-left: 4px solid #d54e21;
+}
+
+.plugins tr.paused th,
+.plugins tr.paused td {
+        background-color: #fef7f1;
+}
+
+.plugins tr.paused .plugin-title,
+.plugins .paused .dashicons-warning {
+        color: #dc3232;
+}
+
+.plugins .resume-link {
+        color: #dc3232;
+}
+
 .plugin-card .update-now:before {
         color: #f56e28;
         content: "\f463";

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

@@ -119 +119 @@
 add_action( 'load-themes.php', 'wp_theme_update_rows', 20 ); // After wp_update_themes() is called.
 
 add_action( 'admin_notices', 'update_nag', 3 );
+add_action( 'admin_notices', 'paused_plugins_notice', 5 );
 add_action( 'admin_notices', 'maintenance_nag', 10 );
 
 add_filter( 'update_footer', 'core_update_footer' );

src/wp-admin/includes/class-wp-plugins-list-table.php

@@ -99 +99 @@
                         'upgrade'            => array(),
                         'mustuse'            => array(),
                         'dropins'            => array(),
+                        'paused'            => isset( $GLOBALS['_paused_plugins'] ) ? $GLOBALS['_paused_plugins'] : array(),
                 );
 
                 $screen = $this->screen;
@@ -647 +648 @@
                                                 /* translators: %s: plugin name */
                                                 $actions['deactivate'] = '<a href="' . wp_nonce_url( 'plugins.php?action=deactivate&amp;plugin=' . urlencode( $plugin_file ) . '&amp;plugin_status=' . $context . '&amp;paged=' . $page . '&amp;s=' . $s, 'deactivate-plugin_' . $plugin_file ) . '" aria-label="' . esc_attr( sprintf( _x( 'Deactivate %s', 'plugin' ), $plugin_data['Name'] ) ) . '">' . __( 'Deactivate' ) . '</a>';
                                         }
+                                        if ( current_user_can( 'resume_plugin' ) && is_plugin_paused( $plugin_file ) ) {
+                                                /* translators: %s: plugin name */
+                                                $actions['resume'] = '<a class="resume-link" href="' . wp_nonce_url( 'plugins.php?action=resume&amp;plugin=' . urlencode( $plugin_file ) . '&amp;plugin_status=' . $context . '&amp;paged=' . $page . '&amp;s=' . $s, 'resume-plugin_' . $plugin_file ) . '" aria-label="' . esc_attr( sprintf( _x( 'Resume execution of %s', 'plugin' ), $plugin_data['Name'] ) ) . '">' . __( 'Resume execution' ) . '</a>';
+                                        }
                                 } else {
                                         if ( current_user_can( 'activate_plugin', $plugin_file ) ) {
                                                 /* translators: %s: plugin name */
@@ -753 +758 @@
                         $class .= ' update';
                 }
 
+                $paused = is_plugin_paused( $plugin_file );
+                if ( $paused ) {
+                        $class .= ' paused';
+                }
+
                 $plugin_slug = isset( $plugin_data['slug'] ) ? $plugin_data['slug'] : sanitize_title( $plugin_name );
                 printf(
                         '<tr class="%s" data-slug="%s" data-plugin="%s">',
@@ -836 +846 @@
                                         $plugin_meta = apply_filters( 'plugin_row_meta', $plugin_meta, $plugin_file, $plugin_data, $status );
                                         echo implode( ' | ', $plugin_meta );
 
-                                        echo '</div></td>';
+                                        echo '</div>';
+
+                                        if ( $paused ) {
+                                                echo sprintf(
+                                                        '<p><span class="dashicons dashicons-warning"></span> <strong>%s</strong></p>',
+                                                        __( 'This plugin failed to load properly and was paused within the admin backend.' )
+                                                );
+                                        }
+
+                                        echo '</td>';
                                         break;
                                 default:
                                         $classes = "$column_name column-$column_name $class";

src/wp-admin/includes/plugin.php

@@ -444 +444 @@
                 'install.php'        => array( __( 'Custom installation script.' ), true ), // auto on installation
                 'maintenance.php'    => array( __( 'Custom maintenance message.' ), true ), // auto on maintenance
                 'object-cache.php'   => array( __( 'External object cache.' ), true ), // auto on load
+                'php-error.php'      => array( __( 'Custom PHP error message.' ), true ), // auto on error
+                'shutdown-handler'   => array( __( 'Custom PHP shutdown handler.' ), true ), // auto on error
         );
 
         if ( is_multisite() ) {
@@ -496 +498 @@
         return ! is_plugin_active( $plugin );
 }
 
+/**
+ * Determines whether a plugin is technically active but was paused while
+ * loading.
+ *
+ * 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 5.0.0
+ *
+ * @param string $plugin Path to the plugin file relative to the plugins directory.
+ *
+ * @return bool True, if in the active plugins list. False, not in the list.
+ */
+function is_plugin_paused( $plugin ) {
+        if ( ! isset( $GLOBALS['_paused_plugins'] ) ) {
+                return false;
+        }
+
+        if ( ! is_plugin_active( $plugin ) || is_plugin_active_for_network( $plugin ) ) {
+                return false;
+        }
+
+        $plugin_path = WP_CONTENT_DIR . '/plugins/' . $plugin;
+
+        return in_array( $plugin_path, $GLOBALS['_paused_plugins'], true );
+}
+
 /**
  * Determines whether the plugin is active for the entire network.
  *
@@ -693 +723 @@
                         continue;
                 }
 
+                // Clean up the database before deactivating the plugin.
+                if ( is_plugin_paused( $plugin ) ) {
+                        resume_plugin( $plugin );
+                }
+
                 $network_deactivating = false !== $network_wide && is_plugin_active_for_network( $plugin );
 
                 if ( ! $silent ) {
@@ -887 +922 @@
                         uninstall_plugin( $plugin_file );
                 }
 
+                // Clean up the database before removing the plugin.
+                if ( is_plugin_paused( $plugin_file ) ) {
+                        resume_plugin( $plugin_file );
+                }
+
                 /**
                  * Fires immediately before a plugin deletion attempt.
                  *
@@ -959 +999 @@
         return true;
 }
 
+/**
+ * Resumes a single plugin.
+ *
+ * Resuming the plugin basically means removing its entry from the
+ * `pause_on_admin` database option.
+ *
+ * @since 5.0.0
+ *
+ * @param string $plugin Single plugin to resume.
+ *
+ * @return bool|WP_Error True on success, false if `$plugin` was not paused, `WP_Error` on failure.
+ */
+function resume_plugin( $plugin ) {
+        $pause_on_admin = get_option( 'pause_on_admin', array() );
+
+        if ( ! array_key_exists( 'plugin', $pause_on_admin ) ) {
+                return false;
+        }
+
+        list( $plugin ) = explode( '/', $plugin );
+
+        if ( ( $index = array_search( $plugin, $pause_on_admin['plugin'], true ) ) !== false ) {
+                unset( $pause_on_admin['plugin'][ $index ] );
+        }
+
+        if ( count( $pause_on_admin['plugin'] ) === 0 ) {
+                unset( $pause_on_admin['plugin'] );
+        }
+
+        $result = update_option( 'pause_on_admin', $pause_on_admin );
+
+        if ( ! $result ) {
+                return new WP_Error( 'could_not_resume_plugin', __( 'Could not resume execution of the plugin.' ) );
+        }
+
+        return true;
+}
+
 /**
  * Validate active plugins
  *
@@ -2066 +2144 @@
 
         WP_Privacy_Policy_Content::add( $plugin_name, $policy_text );
 }
+
+/**
+ * Renders an admin notice in case some plugins have been paused due to errors.
+ *
+ * @since 5.0.0
+ *
+ * @return void
+ */
+function paused_plugins_notice() {
+        if ( 'plugins.php' === $GLOBALS['pagenow'] ) {
+                return;
+        }
+
+        if ( ! current_user_can( 'deactivate_plugins' ) ) {
+                return;
+        }
+
+        if ( ! isset( $GLOBALS['_paused_plugins'] ) || empty( $GLOBALS['_paused_plugins'] ) ) {
+                return;
+        }
+
+
+        echo sprintf(
+                '<div class="notice notice-error"><p><strong>%s</strong><br>%s</p><p>%s</p></div>',
+                __( 'One or more plugins failed to load properly.' ),
+                __( 'You can find more details and make changes on the Plugins screen.' ),
+                sprintf(
+                        '<a href="%s">%s</a>',
+                        admin_url( 'plugins.php' ),
+                        'Go to the Plugins screen'
+                )
+        );
+}

src/wp-admin/plugins.php

@@ -389 +389 @@
                         }
                         break;
 
+                case 'resume':
+                        if ( ! current_user_can( 'resume_plugin', $plugin ) ) {
+                                wp_die( __( 'Sorry, you are not allowed to resume execution of this plugin.' ) );
+                        }
+
+                        if ( is_multisite() && ! is_network_admin() && is_network_only_plugin( $plugin ) ) {
+                                wp_redirect( self_admin_url( "plugins.php?plugin_status=$status&paged=$page&s=$s" ) );
+                                exit;
+                        }
+
+                        check_admin_referer( 'resume-plugin_' . $plugin );
+
+                        $result = resume_plugin( $plugin );
+
+                        if ( is_wp_error( $result ) ) {
+                                wp_die( $result );
+                        }
+
+                        wp_redirect( self_admin_url( "plugins.php?resume=true&plugin_status=$status&paged=$page&s=$s" ) );
+                        exit;
+
                 default:
                         if ( isset( $_POST['checked'] ) ) {
                                 check_admin_referer( 'bulk-plugins' );
@@ -532 +553 @@
         <div id="message" class="updated notice is-dismissible"><p><?php _e( 'Selected plugins <strong>deactivated</strong>.' ); ?></p></div>
 <?php elseif ( 'update-selected' == $action ) : ?>
         <div id="message" class="updated notice is-dismissible"><p><?php _e( 'All selected plugins are up to date.' ); ?></p></div>
+<?php elseif ( isset( $_GET['resume'] ) ) : ?>
+        <div id="message" class="updated notice is-dismissible"><p><?php _e( 'Execution of plugin <strong>resumed</strong>.' ); ?></p></div>
 <?php endif; ?>
 
 <div class="wrap">

src/wp-includes/capabilities.php

@@ -455 +455 @@
                 case 'deactivate_plugins':
                 case 'activate_plugin':
                 case 'deactivate_plugin':
+                case 'resume_plugin':
                         $caps[] = 'activate_plugins';
                         if ( is_multisite() ) {
                                 // update_, install_, and delete_ are handled above with is_super_admin().

src/wp-includes/load.php

@@ -687 +687 @@
                         $plugins[] = WP_PLUGIN_DIR . '/' . $plugin;
                 }
         }
+
+        /*
+         * Remove plugins from the list of active plugins when we're on an admin or
+         * login screen and the plugin appears in the `pause_on_admin` list.
+         */
+        if ( 'wp-login.php' === $GLOBALS['pagenow']
+             || ( is_admin() && ! wp_doing_ajax() ) ) {
+                $pause_on_admin  = (array) get_option( 'pause_on_admin', array() );
+
+                if ( ! array_key_exists( 'plugin', $pause_on_admin ) ) {
+                        return $plugins;
+                }
+
+                foreach ( $plugins as $index => $plugin ) {
+                        $parts = explode(
+                                '/',
+                                str_replace( WP_CONTENT_DIR . '/', '', $plugin )
+                        );
+
+                        if ( in_array( $parts[1], $pause_on_admin['plugin'], true ) ) {
+                                unset( $plugins[ $index ] );
+                                // Store list of paused plugins for displaying an admin notice.
+                                $GLOBALS['_paused_plugins'][] = $plugin;
+                        }
+                }
+        }
+
         return $plugins;
 }
 
@@ -1250 +1277 @@
         }
         echo "\n###### wp_scraping_result_end:$scrape_key ######\n";
 }
+
+/**
+ * Wraps the shutdown handler function so it can be made pluggable at a later
+ * stage.
+ *
+ * @since 5.0.0
+ *
+ * @return void
+ */
+function wp_shutdown_handler_wrapper() {
+        if ( defined( 'WP_EXECUTION_SUCCEEDED' ) && WP_EXECUTION_SUCCEEDED ) {
+                return;
+        }
+
+        // Load the pluggable shutdown handler in case we found one.
+        if ( function_exists( 'wp_handle_shutdown' ) ) {
+                $stop_propagation = (bool) wp_handle_shutdown();
+
+                if ( $stop_propagation ) {
+                        return;
+                }
+        }
+
+        $error = error_get_last();
+
+        // No error, just skip the error handling code.
+        if ( null === $error ) {
+                return;
+        }
+
+        /*
+         * If the option API has not been loaded yet, we cannot persist our
+         * discovery, so there's no point in moving forward.
+         */
+        if ( ! function_exists( 'get_option' ) ) {
+                return;
+        }
+
+        // For now, we only trigger our safe mode on parse errors.
+        if ( ! isset( $error['type'] ) || E_PARSE !== $error['type'] ) {
+                return;
+        }
+
+        try {
+                $path = str_replace( WP_CONTENT_DIR . '/', '', $error['file'] );
+
+                $parts     = explode( '/', $path );
+                $type      = rtrim( array_shift( $parts ), 's' );
+                $extension = array_shift( $parts );
+
+                $pause_on_admin   = get_option( 'pause_on_admin', array() );
+
+                if ( ! array_key_exists( $type, $pause_on_admin ) ) {
+                        $pause_on_admin[ $type ] = array();
+                }
+
+                if ( ! in_array( $extension, $pause_on_admin[ $type ], true ) ) {
+                        $pause_on_admin[ $type ][] = $extension;
+                }
+
+                update_option( 'pause_on_admin', $pause_on_admin );
+
+                // Load custom PHP error template, if present.
+                if ( is_readable( WP_CONTENT_DIR . '/php-error.php' ) ) {
+                        include WP_CONTENT_DIR . '/php-error.php';
+                        die();
+                }
+
+                $message = sprintf(
+                        '<p>%s</p>',
+                        __( 'The site is experiencing technical difficulties.' )
+                );
+
+                if ( function_exists( 'get_admin_url' ) ) {
+                        $url = get_admin_url();
+                        $message .= sprintf(
+                                '<hr><p><em>%s <a href="%s">%s</a></em></p>',
+                                __( 'Are you the site owner?' ),
+                                $url,
+                                __( 'Log into the admin backend to fix this.' )
+                        );
+                }
+
+                if ( function_exists( 'apply_filters' ) ) {
+                        /**
+                         * Filters the message that the default PHP error page displays.
+                         *
+                         * @since 5.0.0
+                         *
+                         * @param string $message HTML error message to display.
+                         */
+                        $message = apply_filters( 'wp_technical_issues_display', $message );
+                }
+
+                wp_die( $message );
+        } catch ( Exception $exception ) {
+                // Catch exceptions and remain silent.
+        }
+}
+
+/**
+ * Registers the WordPress premature shutdown handler.
+ *
+ * @since 5.0.0
+ *
+ * @return void
+ */
+function wp_register_premature_shutdown_handler() {
+        register_shutdown_function( 'wp_shutdown_handler_wrapper' );
+}

src/wp-settings.php

@@ -20 +20 @@
 require( ABSPATH . WPINC . '/default-constants.php' );
 require_once( ABSPATH . WPINC . '/plugin.php' );
 
+// Make sure we register the premature shutdown handler as soon as possible.
+wp_register_premature_shutdown_handler();
+
 /*
  * These can't be directly globalized in version.php. When updating,
  * we're including version.php from another installation and don't want
@@ -40 +43 @@
 // Set initial default constants including WP_MEMORY_LIMIT, WP_MAX_MEMORY_LIMIT, WP_DEBUG, SCRIPT_DEBUG, WP_CONTENT_DIR and WP_CACHE.
 wp_initial_constants();
 
+/*
+ * Allow an optional shutdown handler to be included through a pluggable file.
+ * This file should register a function `wp_handle_shutdown( $context )` that
+ * returns a boolean value. If the return value evaluates to false, the default
+ * shutdown handler will not be executed.
+ */
+if ( is_readable( WP_CONTENT_DIR . '/shutdown-handler.php' ) ) {
+        include WP_CONTENT_DIR . '/shutdown-handler.php';
+}
+
 // Check for the required PHP version and for the MySQL extension or a database drop-in.
 wp_check_php_mysql_versions();
 
@@ -482 +495 @@
  * @since 3.0.0
  */
 do_action( 'wp_loaded' );
+
+/*
+ * Store the fact that we could successfully execute the entire WordPress
+ * lifecycle. This is used to skip the premature shutdown handler, as it cannot
+ * be unregistered.
+ */
+if ( ! defined( 'WP_EXECUTION_SUCCEEDED' ) ) {
+        define( 'WP_EXECUTION_SUCCEEDED', true );
+}