Subject: Re: [PATCH v5 1/2] add-patch: classify '@' as a synonym for 'HEAD'

From: Junio C Hamano <[email-masked]>
Date: Mon, 12 Feb 2024 13:45:25 -0800

Ghanshyam Thakkar <[email-masked]> writes:

>  add-patch.c                |  8 -------
>  builtin/checkout.c         |  4 +++-
>  builtin/reset.c            |  4 +++-
>  t/t2016-checkout-patch.sh  | 46 +++++++++++++++++++++-----------------
>  t/t2020-checkout-detach.sh | 12 ++++++++++
>  t/t2071-restore-patch.sh   | 18 +++++++++------
>  t/t7105-reset-patch.sh     | 15 ++++++++-----
>  7 files changed, 64 insertions(+), 43 deletions(-)
>
> diff --git a/add-patch.c b/add-patch.c
> index 79eda168eb..68f525b35c 100644
> --- a/add-patch.c
> +++ b/add-patch.c
> @@ -1729,14 +1729,6 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
>  	if (mode == ADD_P_STASH)
>  		s.mode = &patch_mode_stash;
>  	else if (mode == ADD_P_RESET) {
> -		/*
> -		 * NEEDSWORK: Instead of comparing to the literal "HEAD",
> -		 * compare the commit objects instead so that other ways of
> -		 * saying the same thing (such as "@") are also handled
> -		 * appropriately.
> -		 *
> -		 * This applies to the cases below too.
> -		 */
>  		if (!revision || !strcmp(revision, "HEAD"))
>  			s.mode = &patch_mode_reset_head;
>  		else
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> index a6e30931b5..067c251933 100644
> --- a/builtin/checkout.c
> +++ b/builtin/checkout.c
> @@ -1224,7 +1224,9 @@ static void setup_new_branch_info_and_source_tree(
>  	struct tree **source_tree = &opts->source_tree;
>  	struct object_id branch_rev;
>  
> -	new_branch_info->name = xstrdup(arg);
> +	/* treat '@' as a shortcut for 'HEAD' */
> +	new_branch_info->name = !strcmp(arg, "@") ? xstrdup("HEAD") :
> +						    xstrdup(arg);
>  	setup_branch_path(new_branch_info);
>  
>  	if (!check_refname_format(new_branch_info->path, 0) &&
> diff --git a/builtin/reset.c b/builtin/reset.c
> index 8390bfe4c4..f0bf29a478 100644
> --- a/builtin/reset.c
> +++ b/builtin/reset.c
> @@ -281,7 +281,9 @@ static void parse_args(struct pathspec *pathspec,
>  			verify_filename(prefix, argv[0], 1);
>  		}
>  	}
> -	*rev_ret = rev;
> +
> +	/* treat '@' as a shortcut for 'HEAD' */
> +	*rev_ret = !strcmp("@", rev) ? "HEAD" : rev;
>  
>  	parse_pathspec(pathspec, 0,
>  		       PATHSPEC_PREFER_FULL |

Nice.  Things have become so much simpler, without having to touch
millions of strcmp() with "HEAD" everywhere in the code paths.

Will queue.  Thanks.