Ticket #45933: 45933.4.diff

src/wp-includes/class-wp-shutdown-handler.php

@@ -122 +122 @@
          * Displays the PHP error template and sends the HTTP status code, typically 500.
          *
          * A drop-in 'php-error.php' can be used as a custom template. This drop-in should control the HTTP status code and
-         * print the HTML markup indicating that a PHP error occurred. Alternatively, {@see wp_die()} can be used. Note
-         * that this drop-in may potentially be executed very early in the WordPress bootstrap process, so any core
-         * functions used that are not part of `wp-includes/load.php` should be checked for before being called.
+         * print the HTML markup indicating that a PHP error occurred. Note that this drop-in may potentially be executed
+         * very early in the WordPress bootstrap process, so any core functions used that are not part of
+         * `wp-includes/load.php` should be checked for before being called.
          *
-         * The default template also displays a link to the admin in order to fix the problem, however doing so is not
-         * mandatory.
+         * If no such drop-in is available, this will call {@see WP_Shutdown_Handler::display_default_error_template()}.
          *
          * @since 5.1.0
          */
@@ -141 +140 @@
                         }
                 }
 
-                // Otherwise, fail with a `wp_die()` message.
-                $message = $this->get_error_message_markup();
-
-                // `wp_die()` wraps the message in paragraph tags, so let's just try working around that.
-                if ( substr( $message, 0, 3 ) === '<p>' && substr( $message, -4 ) === '</p>' ) {
-                        $message = substr( $message, 3, -4 );
-                }
-
-                wp_die( $message, '', 500 );
+                // Otherwise, display the default error template.
+                $this->display_default_error_template();
         }
 
         /**
-         * Returns the error message markup to display in the default error template.
+         * Displays the default PHP error template.
          *
+         * This method is called conditionally if no 'php-error.php' drop-in is available.
+         *
+         * It calls {@see wp_die()} with a message indicating that the site is experiencing technical difficulties and a
+         * login link to the admin backend. The {@see 'wp_php_error_message'} and {@see 'wp_php_error_args'} filters can
+         * be used to modify these parameters.
+         *
          * @since 5.1.0
-         *
-         * @return string Error message HTML output.
          */
-        protected function get_error_message_markup() {
+        protected function display_default_error_template() {
                 if ( ! function_exists( '__' ) ) {
                         wp_load_translations_early();
                 }
 
-                $message = sprintf(
-                        '<p>%s</p>',
-                        __( 'The site is experiencing technical difficulties.' )
-                );
+                if ( ! function_exists( 'wp_die' ) ) {
+                        require_once ABSPATH . WPINC . '/functions.php';
+                }
 
+                $message = __( 'The site is experiencing technical difficulties.' );
+
+                $args = array( 'response' => 500 );
                 if ( function_exists( 'admin_url' ) ) {
-                        $message .= sprintf(
-                                '<hr><p><em>%s <a href="%s">%s</a></em></p>',
-                                __( 'Are you the site owner?' ),
-                                admin_url(),
-                                __( 'Log into the admin backend to fix this.' )
-                        );
+                        $args['link_url']  = admin_url();
+                        $args['link_text'] = __( 'Log into the admin backend to fix this.' );
                 }
 
-                if ( function_exists( 'apply_filters' ) ) {
-                        /**
-                         * Filters the message that the default PHP error page displays.
-                         *
-                         * @since 5.1.0
-                         *
-                         * @param string $message HTML error message to display.
-                         */
-                        $message = apply_filters( 'wp_technical_issues_display', $message );
-                }
+                /**
+                 * Filters the message that the default PHP error template displays.
+                 *
+                 * @since 5.1.0
+                 *
+                 * @param string $message HTML error message to display.
+                 */
+                $message = apply_filters( 'wp_php_error_message', $message );
 
-                return $message;
+                /**
+                 * Filters the arguments passed to {@see wp_die()} for the default PHP error template.
+                 *
+                 * @since 5.1.0
+                 *
+                 * @param array $args Associative array of arguments passed to `wp_die()`. By default these contain a
+                 *                    'response' key, and optionally 'link_url' and 'link_text' keys.
+                 */
+                $args = apply_filters( 'wp_php_error_args', $args );
+
+                wp_die( $message, '', $args );
         }
 }

src/wp-includes/functions.php

@@ -2933 +2933 @@
  * @since 2.0.4
  * @since 4.1.0 The `$title` and `$args` parameters were changed to optionally accept
  *              an integer to be used as the response code.
+ * @since 5.1.0 The `$link_url` and `$link_text` arguments were added.
  *
  * @param string|WP_Error  $message Optional. Error message. If this is a WP_Error object,
  *                                  and not an Ajax or XML-RPC request, the error's messages are used.
@@ -2946 +2947 @@
  *     as the response code. Default empty array.
  *
  *     @type int    $response       The HTTP response code. Default 200 for Ajax requests, 500 otherwise.
+ *     @type string $link_url       A URL to include a link to. Only works in combination with $link_text.
+ *                                  Default empty string.
+ *     @type string $link_text      A label for the link to include. Only works in combination with $link_url.
+ *                                  Default empty string.
  *     @type bool   $back_link      Whether to include a link to go back. Default false.
  *     @type string $text_direction The text direction. This is only useful internally, when WordPress
  *                                  is still loading and the site's locale is not set up yet. Accepts 'rtl'.
@@ -2970 +2975 @@
                  * @param callable $function Callback function name.
                  */
                 $function = apply_filters( 'wp_die_ajax_handler', '_ajax_wp_die_handler' );
+        } elseif ( wp_is_json_request() ) {
+                /**
+                 * Filters the callback for killing WordPress execution for JSON requests.
+                 *
+                 * @since 5.1.0
+                 *
+                 * @param callable $function Callback function name.
+                 */
+                $function = apply_filters( 'wp_die_json_handler', '_json_wp_die_handler' );
         } elseif ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) {
                 /**
                  * Filters the callback for killing WordPress execution for XML-RPC requests.
@@ -3035 +3049 @@
                 $message = "<p>$message</p>";
         }
 
+        if ( ! empty( $r['link_url'] ) && ! empty( $r['link_text'] ) ) {
+                $link_url = $r['link_url'];
+                if ( function_exists( 'esc_url' ) ) {
+                        $link_url = esc_url( $link_url );
+                }
+                $link_text = $r['link_text'];
+                $message  .= "\n<p><a href='{$link_url}'>{$link_text}</a></p>";
+        }
+
         if ( isset( $r['back_link'] ) && $r['back_link'] ) {
                 $back_text = $have_gettext ? __( '&laquo; Back' ) : '&laquo; Back';
                 $message  .= "\n<p><a href='javascript:history.back()'>$back_text</a></p>";
@@ -3202 +3225 @@
 }
 
 /**
+ * Kill WordPress execution and display JSON message with error message.
+ *
+ * This is the handler for wp_die when processing JSON requests.
+ *
+ * @since 5.1.0
+ * @access private
+ *
+ * @param string       $message Error message.
+ * @param string       $title   Optional. Error title. Default empty.
+ * @param string|array $args    Optional. Arguments to control behavior. Default empty array.
+ */
+function _json_wp_die_handler( $message, $title = '', $args = array() ) {
+        $defaults = array( 'response' => 500 );
+
+        $r = wp_parse_args( $args, $defaults );
+
+        $data = array(
+                'code'    => 'wp_die',
+                'message' => $message,
+                'status'  => $r['response'],
+        );
+
+        if ( ! headers_sent() ) {
+                header( 'Content-Type: application/json; charset=utf-8' );
+                if ( null !== $r['response'] ) {
+                        status_header( $r['response'] );
+                }
+        }
+
+        echo wp_json_encode( $data );
+        die();
+}
+
+/**
  * Kill WordPress execution and display XML message with error message.
  *
  * This is the handler for wp_die when processing XMLRPC requests.