Re: [PATCH 1/2] git remote add: allow re-adding remotes with the same URL

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 22, 2014, 17:49 UTC
Message-ID: <xmqq1tnrbmn1.fsf@gitster.dls.corp.google.com>
In-Reply-To: <9c0c693efe68b1c0b080c14104bb6c5f7bf74097.1419267895.git.johannes.schindelin@gmx.de>

Johannes Schindelin <johannes.schindelin@gmx.de> writes:

Show 31 quoted lines

> When adding a remote, we make sure that the remote does not exist
> already.
>
> For convenience, we allow re-adding remotes with the same URLs.
> This also handles the case that there is an "[url ...] insteadOf"
> setting in the config.
>
> It might seem like a mistake to compare against remote->url[0] without
> verifying that remote->url_nr >=1, but at this point a missing URL has
> been filled by the name already, therefore url_nr cannot be zero.
>
> Noticed by Anastas Dancha.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  builtin/remote.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/builtin/remote.c b/builtin/remote.c
> index 46ecfd9..9168c83 100644
> --- a/builtin/remote.c
> +++ b/builtin/remote.c
> @@ -180,7 +180,8 @@ static int add(int argc, const char **argv)
>  	url = argv[1];
>  
>  	remote = remote_get(name);
> -	if (remote && (remote->url_nr > 1 || strcmp(name, remote->url[0]) ||
> +	if (remote && (remote->url_nr > 1 || (strcmp(name, remote->url[0]) &&
> +				strcmp(url, remote->url[0])) ||
>  			remote->fetch_refspec_nr))
>  		die(_("remote %s already exists."), name);

When we need to fold an overlong line, it is easier to read if the line is folded at an operator with higher precedence, i.e. this line

        if (A && (B || (C && D) || E))

folded like this

        if (A && (B || (C &&
                   D) ||
            E))

is harder to read than when folded like this

        if (A && (B ||
                  (C && D) ||
                   E))

So, it is an error if we have "remote" and if

 (1) URL for the remote is defined already twice or more; or
 (2) we are adding a nickname (i.e. not a URL) and it is different
     from what we already have; or
 (3) we already have fetch_refspec

The way I read the log message's rationale was that this is to allow replacing an existing remote's URL; wouldn't checking the existence of fetch_refspec go against that goal?

Puzzled. Either the code is wrong or I am mislead by the explanation in the log.