Re: [PATCH v2] clone: respect configured fetch respecs during initial fetch

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

SZEDER Gábor <szeder@ira.uka.de> writes:

> Conceptually 'git clone' should behave as if the following commands
> were run:
>
>   git init
>   git config ... # set default configuration and origin remote
>   git fetch
>   git checkout   # unless '--bare' is given
>
> However, that initial 'git fetch' behaves differently from any
> subsequent fetches, because it takes only the default fetch refspec
> into account and ignores all other fetch refspecs that might have
> been explicitly specified on the command line (e.g. 'git -c
> remote.origin.fetch=<refspec> clone' or 'git clone -c ...').

Is it really 'git fetch' behaves differently?

What is missing in the above description is your expected behaviour
of "git -c var=val clone", and without it we cannot tell if your
expectation is sane to begin with.

Is the expectation like this?

    git init
    git config ... # set default configuration and origin remote
    git config var val # update with what "-c var=val" told us
    git fetch
    git checkout   # unless '--bare' is given

or is it something else?

Is "-c var=val" adding to the config variables set by default, or is
it replacing them?  Does the choice depend on the nature of
individual variables, and if so what is the criteria?

Are all "-c var=val" update the configuration of the resulting
repository?  Or are certain "var"s treated as special and placed in
the config but not other "var"s?  If the latter, what makes these
certain "var"s special?

These design decisions need to be explained so that they will serve
to guide people to decide what other variables to propagate and how
when they have to add new configuration variables in the future.
Otherwise we'd end up with an inconsistent mess.

> Check whether there are any fetch refspecs configured for the origin
> remote and take all of them into account during the initial fetch as
> well.
>
> Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
> ---
> Changes since previous (RFC) version:
>  - new commit message
>  - additional configured fetch refspecs are taken into account with
>    '--single-branch' as well
>
>  builtin/clone.c         | 36 ++++++++++++++++++++++++++++--------
>  t/t5708-clone-config.sh | 24 ++++++++++++++++++++++++
>  2 files changed, 52 insertions(+), 8 deletions(-)
>
> diff --git a/builtin/clone.c b/builtin/clone.c
> index 661639255c56..5e2d2c21e456 100644
> --- a/builtin/clone.c
> +++ b/builtin/clone.c
> @@ -515,7 +515,7 @@ static struct ref *find_remote_branch(const struct ref *refs, const char *branch
>  }
>  
>  static struct ref *wanted_peer_refs(const struct ref *refs,
> -		struct refspec *refspec)
> +		struct refspec *refspec, unsigned int refspec_count)
>  {
>  	struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
>  	struct ref *local_refs = head;
> @@ -536,13 +536,18 @@ static struct ref *wanted_peer_refs(const struct ref *refs,
>  			warning(_("Could not find remote branch %s to clone."),
>  				option_branch);
>  		else {
> -			get_fetch_map(remote_head, refspec, &tail, 0);
> +			unsigned int i;
> +			for (i = 0; i < refspec_count; i++)
> +				get_fetch_map(remote_head, &refspec[i], &tail, 0);
>  
>  			/* if --branch=tag, pull the requested tag explicitly */
>  			get_fetch_map(remote_head, tag_refspec, &tail, 0);
>  		}
> -	} else
> -		get_fetch_map(refs, refspec, &tail, 0);
> +	} else {
> +		unsigned int i;
> +		for (i = 0; i < refspec_count; i++)
> +			get_fetch_map(refs, &refspec[i], &tail, 0);
> +	}
>  
>  	if (!option_mirror && !option_single_branch)
>  		get_fetch_map(refs, tag_refspec, &tail, 0);
> @@ -840,7 +845,9 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  	int err = 0, complete_refs_before_fetch = 1;
>  
>  	struct refspec *refspec;
> -	const char *fetch_pattern;
> +	unsigned int refspec_count = 1;
> +	const char **fetch_patterns;
> +	const struct string_list *config_fetch_patterns;
>  
>  	packet_trace_identity("clone");
>  	argc = parse_options(argc, argv, prefix, builtin_clone_options,
> @@ -967,9 +974,21 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  	if (option_reference.nr)
>  		setup_reference();
>  
> -	fetch_pattern = value.buf;
> -	refspec = parse_fetch_refspec(1, &fetch_pattern);
> +	strbuf_addf(&key, "remote.%s.fetch", option_origin);
> +	config_fetch_patterns = git_config_get_value_multi(key.buf);
> +	if (config_fetch_patterns)
> +		refspec_count = 1 + config_fetch_patterns->nr;
> +	fetch_patterns = xcalloc(refspec_count, sizeof(*fetch_patterns));
> +	fetch_patterns[0] = value.buf;
> +	if (config_fetch_patterns) {
> +		struct string_list_item *fp;
> +		unsigned int i = 1;
> +		for_each_string_list_item(fp, config_fetch_patterns)
> +			fetch_patterns[i++] = fp->string;
> +	}
> +	refspec = parse_fetch_refspec(refspec_count, fetch_patterns);
>  
> +	strbuf_reset(&key);
>  	strbuf_reset(&value);
>  
>  	remote = remote_get(option_origin);
> @@ -1013,7 +1032,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  	refs = transport_get_remote_refs(transport);
>  
>  	if (refs) {
> -		mapped_refs = wanted_peer_refs(refs, refspec);
> +		mapped_refs = wanted_peer_refs(refs, refspec, refspec_count);
>  		/*
>  		 * transport_get_remote_refs() may return refs with null sha-1
>  		 * in mapped_refs (see struct transport->get_refs_list
> @@ -1094,6 +1113,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
>  	strbuf_release(&value);
>  	junk_mode = JUNK_LEAVE_ALL;
>  
> +	free(fetch_patterns);
>  	free(refspec);
>  	return err;
>  }
> diff --git a/t/t5708-clone-config.sh b/t/t5708-clone-config.sh
> index 27d730c0a720..136a8611c7f3 100755
> --- a/t/t5708-clone-config.sh
> +++ b/t/t5708-clone-config.sh
> @@ -37,4 +37,28 @@ test_expect_success 'clone -c config is available during clone' '
>  	test_cmp expect child/file
>  '
>  
> +test_expect_success 'clone -c remote.origin.fetch=<refspec> works' '
> +	rm -rf child &&
> +	git update-ref refs/grab/it refs/heads/master &&
> +	git update-ref refs/keep/out refs/heads/master &&
> +	git clone -c "remote.origin.fetch=+refs/grab/*:refs/grab/*" . child &&
> +	(
> +		cd child &&
> +		git for-each-ref --format="%(refname)" refs/grab/ >../actual
> +	) &&
> +	echo refs/grab/it >expect &&
> +	test_cmp expect actual
> +'
> +
> +test_expect_success 'git -c remote.origin.fetch=<refspec> clone works' '
> +	rm -rf child &&
> +	git -c "remote.origin.fetch=+refs/grab/*:refs/grab/*" clone . child &&
> +	(
> +		cd child &&
> +		git for-each-ref --format="%(refname)" refs/grab/ >../actual
> +	) &&
> +	echo refs/grab/it >expect &&
> +	test_cmp expect actual
> +'
> +
>  test_done