Re: [PATCH v2 19/20] builtin/stash.c: let parse-options parse subcommands

> 'git stash' parses its subcommands with a long list of if-else if
> statements.  parse-options has just learned to parse subcommands, so
> let's use that facility instead, with the benefits of shorter code,
> and listing subcommands for Bash completion.
>
> Note that the push_stash() function implementing the 'push' subcommand
> accepts an extra flag parameter to indicate whether push was assumed,
> so add a wrapper function with the standard subcommand function
> signature.
>
> Note also that this change "hides" the '-h' option in 'git stash push
> -h' from the parse_option() call in cmd_stash(), as it comes after the
> subcommand.  Consequently, from now on it will emit the usage of the
> 'push' subcommand instead of the usage of 'git stash'.  We had a
> failing test for this case, which can now be flipped to expect
> success.
>
> Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
> ---
>  builtin/stash.c  | 53 ++++++++++++++++++++++--------------------------
>  t/t3903-stash.sh |  2 +-
>  2 files changed, 25 insertions(+), 30 deletions(-)
>
> diff --git a/builtin/stash.c b/builtin/stash.c
> index a14e832e9f..1ba24c1173 100644
> --- a/builtin/stash.c
> +++ b/builtin/stash.c
> @@ -1739,6 +1739,11 @@ static int push_stash(int argc, const char **argv, const char *prefix,
>  			     include_untracked, only_staged);
>  }
>  
> +static int push_stash_unassumed(int argc, const char **argv, const char *prefix)
> +{
> +	return push_stash(argc, argv, prefix, 0);
> +}
> +
>  static int save_stash(int argc, const char **argv, const char *prefix)
>  {
>  	int keep_index = -1;
> @@ -1787,15 +1792,28 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
>  	pid_t pid = getpid();
>  	const char *index_file;
>  	struct strvec args = STRVEC_INIT;
> -
> +	parse_opt_subcommand_fn *fn = NULL;
>  	struct option options[] = {
> +		OPT_SUBCOMMAND("apply", &fn, apply_stash),
> +		OPT_SUBCOMMAND("clear", &fn, clear_stash),
> +		OPT_SUBCOMMAND("drop", &fn, drop_stash),
> +		OPT_SUBCOMMAND("pop", &fn, pop_stash),
> +		OPT_SUBCOMMAND("branch", &fn, branch_stash),
> +		OPT_SUBCOMMAND("list", &fn, list_stash),
> +		OPT_SUBCOMMAND("show", &fn, show_stash),
> +		OPT_SUBCOMMAND("store", &fn, store_stash),
> +		OPT_SUBCOMMAND("create", &fn, create_stash),
> +		OPT_SUBCOMMAND("push", &fn, push_stash_unassumed),
> +		OPT_SUBCOMMAND_F("save", &fn, save_stash, PARSE_OPT_NOCOMPLETE),
>  		OPT_END()
>  	};
>  
>  	git_config(git_stash_config, NULL);
>  
>  	argc = parse_options(argc, argv, prefix, options, git_stash_usage,
> -			     PARSE_OPT_KEEP_UNKNOWN_OPT | PARSE_OPT_KEEP_DASHDASH);
> +			     PARSE_OPT_SUBCOMMAND_OPTIONAL |
> +			     PARSE_OPT_KEEP_UNKNOWN_OPT |
> +			     PARSE_OPT_KEEP_DASHDASH);
>  
>  	prepare_repo_settings(the_repository);
>  	the_repository->settings.command_requires_full_index = 0;
> @@ -1804,33 +1822,10 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
>  	strbuf_addf(&stash_index_path, "%s.stash.%" PRIuMAX, index_file,
>  		    (uintmax_t)pid);
>  
> -	if (!argc)
> -		return !!push_stash(0, NULL, prefix, 0);
> -	else if (!strcmp(argv[0], "apply"))
> -		return !!apply_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "clear"))
> -		return !!clear_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "drop"))
> -		return !!drop_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "pop"))
> -		return !!pop_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "branch"))
> -		return !!branch_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "list"))
> -		return !!list_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "show"))
> -		return !!show_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "store"))
> -		return !!store_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "create"))
> -		return !!create_stash(argc, argv, prefix);
> -	else if (!strcmp(argv[0], "push"))
> -		return !!push_stash(argc, argv, prefix, 0);
> -	else if (!strcmp(argv[0], "save"))
> -		return !!save_stash(argc, argv, prefix);
> -	else if (*argv[0] != '-')
> -		usage_msg_optf(_("unknown subcommand: %s"),
> -			       git_stash_usage, options, argv[0]);
> +	if (fn)
> +		return !!fn(argc, argv, prefix);
> +	else if (!argc)
> +		return !!push_stash_unassumed(0, NULL, prefix);
>  
>  	/* Assume 'stash push' */
>  	strvec_push(&args, "push");
> diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
> index 2a4c3fd61c..376cc8f4ab 100755
> --- a/t/t3903-stash.sh
> +++ b/t/t3903-stash.sh
> @@ -25,7 +25,7 @@ test_expect_success 'usage on main command -h emits a summary of subcommands' '
>  	grep -F "or: git stash show" usage
>  '
>  
> -test_expect_failure 'usage for subcommands should emit subcommand usage' '
> +test_expect_success 'usage for subcommands should emit subcommand usage' '
>  	test_expect_code 129 git stash push -h >usage &&
>  	grep -F "usage: git stash [push" usage
>  '