Re: [PATCH] submodule helper: convert relative URL to absolute URL if needed

From: Jonathan Nieder <jrnieder@gmail.com>
To: Stefan Beller <sbeller@google.com>
Cc: gitster@pobox.com, git@vger.kernel.org,
	Jaewoong Jung <jungjw@google.com>
Subject: Re: [PATCH] submodule helper: convert relative URL to absolute URL if needed
Date: Mon, 15 Oct 2018 17:33:24 -0700	[thread overview]
Message-ID: <20181016003324.GA104911@aiede.svl.corp.google.com> (raw)
In-Reply-To: <20181016001949.173333-1-sbeller@google.com>

Hi,

Stefan Beller wrote:

> The submodule helper update_clone called by "git submodule update",
> clones submodules if needed. As submodules used to have the URL indicating
> if they were active, the step to resolve relative URLs was done in the
> "submodule init" step. Nowadays submodules can be configured active without
> calling an explicit init, e.g. via configuring submodule.active.
>
> When trying to obtain submodules that are set active this way, we'll
> fallback to the URL found in the .gitmodules, which may be relative to the
> superproject, but we do not resolve it, yet:
> 
>     git clone https://gerrit.googlesource.com/gerrit
>     cd gerrit && grep url .gitmodules
> 	url = ../plugins/codemirror-editor
> 	...
>     git config submodule.active .
>     git submodule update
> fatal: repository '../plugins/codemirror-editor' does not exist
> fatal: clone of '../plugins/codemirror-editor' into submodule path '/tmp/gerrit/plugins/codemirror-editor' failed
> Failed to clone 'plugins/codemirror-editor'. Retry scheduled
> [...]
> fatal: clone of '../plugins/codemirror-editor' into submodule path '/tmp/gerrit/plugins/codemirror-editor' failed
> Failed to clone 'plugins/codemirror-editor' a second time, aborting
> [...]

Thanks.

"git log" and other tools have the ability to rewrap lines and will get
confused by this transcript.  Can you indent it to unconfuse them?

> Signed-off-by: Stefan Beller <sbeller@google.com>

Please also credit the bug reporter:

Reported-by: Jaewoong Jung <jungjw@google.com>

[...]
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -584,6 +584,27 @@ static int module_foreach(int argc, const char **argv, const char *prefix)
>  	return 0;
>  }
>  
> +

nit: inconsistent vertical whitespace (extra blank line?)

> +static char *compute_submodule_clone_url(const char *rel_url)
> +{
> +	char *remoteurl, *relurl;
> +	char *remote = get_default_remote();
> +	struct strbuf remotesb = STRBUF_INIT;
> +
> +	strbuf_addf(&remotesb, "remote.%s.url", remote);
> +	free(remote);
> +
> +	if (git_config_get_string(remotesb.buf, &remoteurl)) {
> +		warning(_("could not lookup configuration '%s'. Assuming this repository is its own authoritative upstream."), remotesb.buf);
> +		remoteurl = xgetcwd();
> +	}
> +	relurl = relative_url(remoteurl, rel_url, NULL);
> +	strbuf_release(&remotesb);
> +	free(remoteurl);
> +
> +	return relurl;
> +}

I think this would be easier to read with all the release commands
together:

	...

	free(remote);
	free(remoteurl);
	strbuf_release(&remotesb);
	return relurl;

[...]
> @@ -634,21 +655,9 @@ static void init_submodule(const char *path, const char *prefix,
[...]
> -			relurl = relative_url(remoteurl, url, NULL);
> -			strbuf_release(&remotesb);
> -			free(remoteurl);
> -			free(url);
> -			url = relurl;
> +			char *to_free = url;
> +			url = compute_submodule_clone_url(url);
> +			free(to_free);

I still think this would be easier to read with a style that makes
the ownership passing clearer:

			char *oldurl = url;
			url = compute_submodule_clone_url(oldurl);
			free(oldurl);

With whatever subset of the above tweaks makes sense,
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

Thanks.