Re: [PATCH v3 1/7] git-compat-util: introduce skip_to_optional_arg()

From: Jeff King <peff@peff.net>
Date: Dec 10, 2017, 14:31 UTC
Message-ID: <20171210143118.GB19453@sigill.intra.peff.net>
In-Reply-To: <20171209204013.10997-1-chriscool@tuxfamily.org>

On Sat, Dec 09, 2017 at 09:40:07PM +0100, Christian Couder wrote:

Show 5 quoted lines

> The changes compared to v2 are:
> 
>   - s/_val/_arg/ in the name of the functions
>   - s/val/arg/ in the name of the third argument of the functions
>   - works with NULL as third argument of the functions

This whole series looks OK to me, but this third point made me wonder: what would be the use of allowing NULL for the "arg" parameter?

I didn't see any use of this in the series, and I'm having trouble figuring out how it would be useful. E.g., if I do:

  if (skip_to_optional_arg(arg, "--foo", NULL))
     ...

what can I do in "..."? I know we matched _some_ type of "--foo", but I cannot know whether it was "--foo" or "--foo=bar", nor what "bar" is. It could only be used by some kind of vague validator to say "well, at least this looks like an option that I _could_ parse if I wanted to".

So I guess I don't mind it, as it does the most reasonable thing it can when passed NULL, but I would be surprised if we ever actually exercise the code path.

-Peff