Re: [PATCH v2 1/2] fsexcludes: add a programmatic way to exclude files from git's working directory traversal logic

[Junio C Hamano <gitster@pobox.com>]

I haven't studied and thought about the motivation behind these two
patches, but one thing I noticed...

Ben Peart <Ben.Peart@microsoft.com> writes:

> diff --git a/dir.c b/dir.c
> index 63a917be45..1aa639b9f4 100644
> --- a/dir.c
> +++ b/dir.c
> @@ -1102,6 +1103,12 @@ int is_excluded_from_list(const char *pathname,
>  			  struct exclude_list *el, struct index_state *istate)
>  {
>  	struct exclude *exclude;
> +
> +	if (*dtype == DT_UNKNOWN)
> +		*dtype = get_dtype(NULL, istate, pathname, pathlen);
> +	if (fsexcludes_is_excluded_from(istate, pathname, pathlen, *dtype) > 0)
> +		return 1;
> +
>  	exclude = last_exclude_matching_from_list(pathname, pathlen, basename,
>  						  dtype, el, istate);
>  	if (exclude)
> @@ -1317,8 +1324,15 @@ struct exclude *last_exclude_matching(struct dir_struct *dir,
>  int is_excluded(struct dir_struct *dir, struct index_state *istate,
>  		const char *pathname, int *dtype_p)
>  {
> -	struct exclude *exclude =
> -		last_exclude_matching(dir, istate, pathname, dtype_p);
> +	struct exclude *exclude;
> +	int pathlen = strlen(pathname);
> +
> +	if (*dtype_p == DT_UNKNOWN)
> +		*dtype_p = get_dtype(NULL, istate, pathname, pathlen);
> +	if (fsexcludes_is_excluded_from(istate, pathname, pathlen, *dtype_p) > 0)
> +		return 1;
> +
> +	exclude = last_exclude_matching(dir, istate, pathname, dtype_p);
>  	if (exclude)
>  		return exclude->flags & EXC_FLAG_NEGATIVE ? 0 : 1;
>  	return 0;

A piece of impression I am getting from the above two hunks is that
the fsexcludes_is_excluded_from() function requires a real dtype in
its last parameter (i.e. DT_UNKNOWN is not acceptable).

> @@ -1671,6 +1685,9 @@ static enum path_treatment treat_one_path(struct dir_struct *dir,
>  	if (dtype != DT_DIR && has_path_in_index)
>  		return path_none;
>  
> +	if (fsexcludes_is_excluded_from(istate, path->buf, path->len, dtype) > 0)
> +		return path_excluded;
> +

And this hunk reinforces that impression (we are comparing dtype
with DT_DIR, so we know we cannot be passing DT_UNKNOWN to it).

> @@ -2011,6 +2028,8 @@ static enum path_treatment read_directory_recursive(struct dir_struct *dir,
>  		/* add the path to the appropriate result list */
>  		switch (state) {
>  		case path_excluded:
> +			if (fsexcludes_is_excluded_from(istate, path.buf, path.len, DTYPE(cdir.de)) > 0)
> +				break;

Then the use of DTYPE() looks a bit odd here.  On
NO_D_TYPE_IN_DIRENT platforms, we would get DT_UNKNOWN out of it and
then end up passing DT_UNKNOWN to the function.