Bootstrap/Load: Add support for JSONP requests to `wp_die()`.

In addition to AJAX, XML-RPC, and JSON requests, `wp_die()` now handles JSONP requests correctly, returning information in the expected content type.

Props spacedmonkey, TimothyBlynJacobs.
Fixes #46025. See #44458.
Built from https://develop.svn.wordpress.org/trunk@45015


git-svn-id: http://core.svn.wordpress.org/trunk@44824 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/functions.php

@@ -2989,6 +2989,15 @@ function wp_die( $message = '', $title = '', $args = array() ) {
 		 * @param callable $function Callback function name.
 		 */
 		$function = apply_filters( 'wp_die_json_handler', '_json_wp_die_handler' );
+	} elseif ( wp_is_jsonp_request() ) {
+		/**
+		 * Filters the callback for killing WordPress execution for JSONP requests.
+		 *
+		 * @since 5.2.0
+		 *
+		 * @param callable $function Callback function name.
+		 */
+		$function = apply_filters( 'wp_die_jsonp_handler', '_jsonp_wp_die_handler' );
 	} elseif ( defined( 'XMLRPC_REQUEST' ) && XMLRPC_REQUEST ) {
 		/**
 		 * Filters the callback for killing WordPress execution for XML-RPC requests.
@@ -3247,6 +3256,48 @@ function _json_wp_die_handler( $message, $title = '', $args = array() ) {
 	}
 }
 
+/**
+ * Kill WordPress execution and display JSONP message with error message.
+ *
+ * This is the handler for wp_die when processing JSONP requests.
+ *
+ * @since 5.2.0
+ * @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 _jsonp_wp_die_handler( $message, $title = '', $args = array() ) {
+	list( $message, $title, $r ) = _wp_die_process_input( $message, $title, $args );
+
+	$data = array(
+		'code'              => $r['code'],
+		'message'           => $message,
+		'data'              => array(
+			'status' => $r['response'],
+		),
+		'additional_errors' => $r['additional_errors'],
+	);
+
+	if ( ! headers_sent() ) {
+		header( 'Content-Type: application/javascript; charset=utf-8' );
+		header( 'X-Content-Type-Options: nosniff' );
+		header( 'X-Robots-Tag: noindex' );
+		if ( null !== $r['response'] ) {
+			status_header( $r['response'] );
+		}
+		nocache_headers();
+	}
+
+	$result         = wp_json_encode( $data );
+	$jsonp_callback = $_GET['_jsonp'];
+	echo '/**/' . $jsonp_callback . '(' . $result . ')';
+	if ( $r['exit'] ) {
+		die();
+	}
+}
+
 /**
  * Kills WordPress execution and displays XML response with an error message.
  *

wp-includes/load.php

@@ -1501,3 +1501,31 @@ function wp_is_json_request() {
 	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;
+
+}

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.2-alpha-45014';
+$wp_version = '5.2-alpha-45015';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.