Re: [Outreachy PATCH v4 1/3] parse-options: answer --git-completion-helper before command runs

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

Tanga Joris <tangajoris@gmail.com> writes:

> diff --git a/parse-options.h b/parse-options.h
> index f68b51ceca..7ad33801fe 100644
> --- a/parse-options.h
> +++ b/parse-options.h
> @@ -427,6 +427,12 @@ int parse_options(int argc, const char **argv, const char *prefix,
>  NORETURN void usage_with_options(const char * const *usagestr,
>  				 const struct option *options);
>  
> +/*
> + * If the only argument is -h, --help-all, --git-completion-helper or
> + * --git-completion-helper-all, print the answer and exit. Call this
> + * before the command does any work. Then asking for help or for the
> + * completion list does not wait for input or leave files behind.
> + */

This is a very strange thing to say as a comment for this function.

There is no reason to expect any normal program to "wait for input"
or "leave files behind" unless the program has some strange trait.
What is it?

I think what you want to describe is

 - A program that uses parse_options() early in the program has no
   reason to use this function.

 - If there is a reason why you may have to react to help request
   from the command line before the control hits parse_options(),
   you may want to call this function to react to such a request.


"wait for input" and "leave files behind" are peculiarity that
exists only in fast-import, that is shared with nobody else, no?
The fact that it does not call parse_options() until it gets an
input, and that you want it to react to "-h", is what makes this
function useful in that context.