Re: [PATCH v3 09/16] index-helper: use watchman to avoid refreshing index with lstat()

> diff --git a/read-cache.c b/read-cache.c
> index 59d892e..b6e9244 100644
> --- a/read-cache.c
> +++ b/read-cache.c
> @@ -1407,10 +1472,24 @@ static int read_watchman_ext(struct index_state *istate, const void *data,
>  	ewah_each_bit(bitmap, mark_no_watchman, istate);
>  	ewah_free(bitmap);
>  
> -	/*
> -	 * TODO: update the untracked cache from the untracked data in this
> -	 * extension.
> -	 */
> +	if (istate->untracked && istate->untracked->root) {
> +		int i;
> +		const char *untracked;
> +
> +		untracked = data + len + 8 + bitmap_size;