From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 13 Mar 2026 17:54:41 GMT
Subject: Re: [PATCH v1] builtin/mktree: remove USE_THE_REPOSITORY_VARIABLE
Message-ID: <xmqqzf4b4ntq.fsf@gitster.g>
In-Reply-To: <4fb9c915-7246-4c55-b7c6-b4ef7ca91230@malon.dev>

Tian Yuchen <cat@malon.dev> writes:

> On 3/14/26 00:03, Junio C Hamano wrote:
>
>> There is one corner case; upon "git foo -h", your cmd_foo() will get
>> repo==NULL when the command is run outside a repository.  As long as
>> your cmd_foo() asks parse_options() to react to "-h" (which gives
>> the help message and then exits) before it uses repo assuming it
>> cannot be NULL, you are safe.
>
> I was completely blown away Σ( ° △ °)
>
> Thanks for pointing that out. Otherwise, I wouldn’t have been able to 
> figure it out no matter how hard I try.
>
> I just took a quick look at the code:
>
>> 	const struct option option[] = {
>> 		OPT_BOOL('z', NULL, &nul_term_line, N_("input is NUL terminated")),
>> 		OPT_SET_INT( 0 , "missing", &allow_missing, N_("allow missing objects"), 1),
>> 		OPT_SET_INT( 0 , "batch", &is_batch_mode, N_("allow creation of more than one tree"), 1),
>> 		OPT_END()
>> 	};
>> 
>> 	ac = parse_options(ac, av, prefix, option, mktree_usage, 0);
>> 	getline_fn = nul_term_line ? strbuf_getline_nul : strbuf_getline_lf;
>> 
>> 	while (!got_eof) {
>> 		while (1) { ...
>
> I think if there's a '-h' parameter, it gets intercepted in 
> parse_options() and the process exits before repo is called. So there’s 
> nothing to worry about, right?

Correct.  The function calls parse_options() before it looks at "repo".

> By the way, I find it a bit confusing that the'`-h' parameter — which is 
> solely used for documentation query — is parsed and intercepted within a 
> function that handles actual business logic.

I strongly disagree your idea that 'z' is more business logic than
'h' is.  Both are equally relevant.