function wp_kses_normalize_entities3($matches)
{
    if (empty($matches[1])) {
        return '';
    }
    $hexchars = $matches[1];
    return !valid_unicode(hexdec($hexchars)) ? "&#x{$hexchars};" : '&#x' . ltrim($hexchars, '0') . ';';
}

/**
 * Callback for wp_kses_normalize_entities() for regular expression.
 *
 * This function helps wp_kses_normalize_entities() to only accept valid Unicode
 * numeric entities in hex form.
 *
 * @access private
 *
 * @param array $matches preg_replace_callback() matches array
 * @return string Correctly encoded entity
 */
function wp_kses_normalize_entities3($matches)
{
    if (!isset($matches[2]) || empty($matches[2])) {
        return '';
    }
    $hexchars = $matches[2];
    return !valid_unicode(hexdec($hexchars)) ? "&#x{$hexchars};" : "&#x{$hexchars};";
}

/**
 * Callback for wp_kses_normalize_entities() for regular expression.
 *
 * This function helps wp_kses_normalize_entities() to only accept valid Unicode
 * numeric entities in hex form.
 *
 * @access private
 *
 * @param array $matches preg_replace_callback() matches array
 * @return string Correctly encoded entity
 */
function wp_kses_normalize_entities3($matches) {
	if ( ! isset($matches[2]) || empty($matches[2]) )
		return '';

	$hexchars = $matches[2];
	return ( ( ! valid_unicode(hexdec($hexchars)) ) ? "&#x$hexchars;" : "&#x$hexchars;" );
}