Ticket #45933: 45933.7.diff

src/wp-includes/functions.php

@@ -2993 +2993 @@
                  * @param callable $function Callback function name.
                  */
                 $function = apply_filters( 'wp_die_xmlrpc_handler', '_xmlrpc_wp_die_handler' );
-        } else {
+        } elseif ( wp_is_xml_request() ) {
+                /**
+                 * Filters the callback for killing WordPress execution for XML requests.
+                 *
+                 * @since 5.1.0
+                 *
+                 * @param callable $function Callback function name.
+                 */
+                $function = apply_filters( 'wp_die_xml_handler', '_xml_wp_die_handler' );
+        }else {
                 /**
                  * Filters the callback for killing WordPress execution for all non-Ajax, non-XML-RPC requests.
                  *
@@ -3258 +3267 @@
         die();
 }
 
+/**
+ * Kill WordPress execution and display XML message with error message.
+ *
+ * This is the handler for wp_die when processing XML 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 _xml_wp_die_handler( $message, $title = '', $args = array() ) {
+        $defaults = array( 'response' => 500 );
+
+        $r = wp_parse_args( $args, $defaults );
+
+        $data = array(
+                'error' => array(
+                        'code'    => 'wp_die',
+                        'message' => $message,
+                        'status'  => $r['response'],
+                )
+        );
+
+        if ( ! headers_sent() ) {
+                header( 'Content-Type: text/xml; charset=utf-8' );
+                if ( null !== $r['response'] ) {
+                        status_header( $r['response'] );
+                }
+                nocache_headers();
+        }
+        echo '<?xml version="1.0" encoding="UTF-8"?>';
+        array_walk( $data, '_wp_wrap_xml' );
+        die();
+}
+
+
 /**
  * Kill WordPress execution and display XML message with error message.
  *
@@ -3330 +3377 @@
         die();
 }
 
+/**
+ * Helper function to walk through array and echo xml elements
+ *
+ * @since 5.1.0
+ * @access private
+ *
+ * @param $value
+ * @param $element
+ */
+function _wp_wrap_xml( $value, $element ) {
+
+        if ( ! is_string( $element ) ) {
+                $element = 'item';
+        }
+        if ( is_object( $value ) ) {
+                $value = (array) $value;
+        }
+
+        echo "<$element>";
+        if ( is_array( $value ) ) {
+                array_walk( $value, '_wp_wrap_xml' );
+        } elseif ( is_scalar( $value ) ) {
+                echo $value;
+        }
+        echo "</$element>";
+}
+
 /**
  * Encode a variable into JSON, with some sanity checks.
  *

src/wp-includes/load.php

@@ -1488 +1488 @@
         return false;
 
 }
+
+/**
+ * Checks whether current request is a XML request, or is expecting a XML response.
+ *
+ * @since 5.1.0
+ *
+ * @return bool True if Accepts or Content-Type headers contain xml, false otherwise.
+ */
+function wp_is_xml_request() {
+
+        $accepted = array(
+                'application/rss+xml',
+                'application/rss+xml',
+                'text/xml',
+                'application/atom+xml',
+                'application/rdf+xml',
+        );
+
+        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;
+}