Re: [RFC/PATCH 3/9] for-each-ref: add '--points-at' option

> Add the '--points-at' option provided by 'ref-filter'. The
> option lets the user to pick only refs which point to a particular
> commit.
>
> Add Documentation for the same.
>
> Based-on-patch-by: Jeff King <peff@peff.net>
> Mentored-by: Christian Couder <christian.couder@gmail.com>
> Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
> ---
>  Documentation/git-for-each-ref.txt | 3 +++
>  builtin/for-each-ref.c             | 6 +++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/git-for-each-ref.txt b/Documentation/git-for-each-ref.txt
> index 7f8d9a5..e9f6a8a 100644
> --- a/Documentation/git-for-each-ref.txt
> +++ b/Documentation/git-for-each-ref.txt
> @@ -10,6 +10,7 @@ SYNOPSIS
>  [verse]
>  'git for-each-ref' [--count=<count>] [--shell|--perl|--python|--tcl]
>  		   [(--sort=<key>)...] [--format=<format>] [<pattern>...]
> +		   [--points-at <object>]
>  
>  DESCRIPTION
>  -----------
> @@ -62,6 +63,8 @@ OPTIONS
>  	the specified host language.  This is meant to produce
>  	a scriptlet that can directly be `eval`ed.
>  
> +--points-at <object>::
> +	Only list tags of the given object.

>  
>  FIELD NAMES
>  -----------
> diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
> index 4d2d024..b9d180a 100644
> --- a/builtin/for-each-ref.c
> +++ b/builtin/for-each-ref.c
> @@ -7,6 +7,7 @@
>  
>  static char const * const for_each_ref_usage[] = {
>  	N_("git for-each-ref [<options>] [<pattern>]"),
> +	N_("git for-each-ref [--points-at <object>]"),
>  	NULL
>  };
>  
> @@ -17,6 +18,7 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
>  	struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
>  	int maxcount = 0, quote_style = 0;
>  	struct ref_filter_cbdata ref_cbdata;
> +	memset(&ref_cbdata, 0, sizeof(ref_cbdata));
>  
>  	struct option opts[] = {
>  		OPT_BIT('s', "shell", &quote_style,
> @@ -33,6 +35,9 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
>  		OPT_STRING(  0 , "format", &format, N_("format"), N_("format to use for the output")),
>  		OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
>  			    N_("field name to sort on"), &parse_opt_ref_sorting),
> +		OPT_CALLBACK(0, "points-at", &ref_cbdata.filter.points_at,
> +			     N_("object"), N_("print only tags of the object"),
> +			     parse_opt_points_at),
>  		OPT_END(),
>  	};
>  
> @@ -54,7 +59,6 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
>  	/* for warn_ambiguous_refs */
>  	git_config(git_default_config, NULL);
>  
> -	memset(&ref_cbdata, 0, sizeof(ref_cbdata));