None.

源文件：

/**
 * Checks that current theme files 'index.php' and 'style.css' exists.
 *
 * Does not check the default theme, which is the fallback and should always exist.
 * Will switch theme to the fallback theme if current theme does not validate.
 * You can use the 'validate_current_theme' filter to return false to
 * disable this functionality.
 *
 * @since 1.5.0
 * @see WP_DEFAULT_THEME
 *
 * @return bool
 */
function validate_current_theme() {
	/**
	 * Filter whether to validate the current theme.
	 *
	 * @since 2.7.0
	 *
	 * @param bool true Validation flag to check the current theme.
	 */
	if ( defined('WP_INSTALLING') || ! apply_filters( 'validate_current_theme', true ) )
		return true;

	if ( get_template() != WP_DEFAULT_THEME && !file_exists(get_template_directory() . '/index.php') ) {
		switch_theme( WP_DEFAULT_THEME );
		return false;
	}

	if ( get_stylesheet() != WP_DEFAULT_THEME && !file_exists(get_template_directory() . '/style.css') ) {
		switch_theme( WP_DEFAULT_THEME );
		return false;
	}

	if ( is_child_theme() && ! file_exists( get_stylesheet_directory() . '/style.css' ) ) {
		switch_theme( WP_DEFAULT_THEME );
		return false;
	}

	return true;
}