Re: [PATCH v2 1/2] remote: drop "explicit" parameter from remote_ref_for_branch()

From: Jeff King <peff@peff.net>
Date: Mar 3, 2020, 21:11 UTC
Message-ID: <20200303211142.GA36275@coredump.intra.peff.net>
In-Reply-To: <xmqqzhcx8gz8.fsf@gitster-ct.c.googlers.com>

On Tue, Mar 03, 2020 at 09:51:07AM -0800, Junio C Hamano wrote:

Show 16 quoted lines

> > But unlike remote names, there's no default case for the remote branch
> > name.
> 
> Up to this point, it is well written and easy to read.  I think
> "there is no case where a default name for the remoate branch is
> used" would be even more easy to read.
> 
> In any case, if there is no case that default name, I understand
> that explicit is always set to 1?
> 
> > In any case where we don't set "explicit", we'd just an empty
> > string anyway.
> 
> Sorry, but I cannot parse this.  But earlier, you established that
> there is no case that a default is used, so is there any case where
> we don't set "explicit"?  I don't get it.

Maybe more clear:

For remote names, we will always return one of two things:

  - a remote name based on user config, in which case explicit=1

  - the default string "origin", in which case explicit=0

For remote branches, we will return either:

  - the remote branch name from config, in which case explicit=1

  - the empty string, in which case explicit=0

But nobody ever looks at that empty string. For the second case, we could just as well return NULL. At which point we don't need an explicit flag at all, as the caller can just check for NULL.

(written before reading what you wrote below)

Show 12 quoted lines

> After reading the code through, I think "there's no default case"
> was what caused my confusion.
> 
>     But unlike remote names, there is no default name when the user
>     didn't configure one.  The only way the "explicit" parameter is
>     used by the caller is to use the value returned from the helper
>     when it is set, and use an empty string otherwise, ignoring the
>     returned value from the helper.
> 
>     Let's drop the "explicit" out-parameter, and return NULL when
>     the returned value from the helper should be ignored, to
>     simplify the function interface.

Yes, that looks fine to me.

-Peff