+/**
+ * Default filter attached to pingback_ping_source_uri to validate the pingback's Source URI
+ *
+ * @since 3.5.1
+ * @see wp_http_validate_url()
+ *
+ * @param string $source_uri
+ * @return string
+ */
+function pingback_ping_source_uri( $source_uri ) {
+ return (string) wp_http_validate_url( $source_uri );
+}
+
+/**
+ * Default filter attached to xmlrpc_pingback_error.
+ *
+ * Returns a generic pingback error code unless the error code is 48,
+ * which reports that the pingback is already registered.
+ *
+ * @since 3.5.1
+ * @link http://www.hixie.ch/specs/pingback/pingback#TOC3
+ *
+ * @param IXR_Error $ixr_error
+ * @return IXR_Error
+ */
+function xmlrpc_pingback_error( $ixr_error ) {
+ if ( $ixr_error->code === 48 )
+ return $ixr_error;
+ return new IXR_Error( 0, '' );
+}
+