WordPress アーカイブページの URL 自動補完リダイレクト

add_action( 'template_redirect', function() {
	global $wp_rewrite, $wp, $cat;

	if ( is_category() && $wp_rewrite->permalink_structure ) {
		$requested_url = home_url( $wp->request );
		$redirect_url  = get_category_link( $cat );
		if ( $requested_url !== untrailingslashit( $redirect_url ) ) {
			wp_safe_redirect( $redirect_url );
			exit();
		}
	}
} );

add_action( 'template_redirect', function() {
	global $wp_rewrite, $wp_query;

	if ( is_category() && $wp_rewrite->permalink_structure ) {
		$category_name = $wp_query->query_vars['category_name'];
		$category_path = $wp_query->query['category_name'];
		if ( $category_name !== $category_path ) {
			$category = get_category_by_path( $category_path );
			if ( ! $category || is_wp_error( $category ) ) {
				$wp_query->set_404();
				status_header( 404 );
				nocache_headers();
			}
		}
	}
} );