make_site_theme()

function make_site_theme() {
	// Name the theme after the blog.
	$theme_name = __get_option('blogname');
	$template = sanitize_title($theme_name);
	$site_dir = WP_CONTENT_DIR . "/themes/$template";

	// If the theme already exists, nothing to do.
	if ( is_dir($site_dir)) {
		return false;
	}

	// We must be able to write to the themes dir.
	if (! is_writable(WP_CONTENT_DIR . "/themes")) {
		return false;
	}

	umask(0);
	if (! mkdir($site_dir, 0777)) {
		return false;
	}

	if (file_exists(ABSPATH . 'wp-layout.css')) {
		if (! make_site_theme_from_oldschool($theme_name, $template)) {
			// TODO: rm -rf the site theme directory.
			return false;
		}
	} else {
		if (! make_site_theme_from_default($theme_name, $template))
			// TODO: rm -rf the site theme directory.
			return false;
	}

	// Make the new site theme active.
	$current_template = __get_option('template');
	if ($current_template == WP_DEFAULT_THEME) {
		update_option('template', $template);
		update_option('stylesheet', $template);
	}
	return $template;
}