Subject: Re: [PATCH v2 9/9] fetch: allow explicit --refmap to override configuration

From: Marc Branchaud <[email-masked]>
Date: Wed, 04 Jun 2014 11:01:53 -0400

On 14-06-03 06:16 PM, Junio C Hamano wrote:
> Since the introduction of opportunisitic updates of remote-tracking
> branches, started at around f2690487 (fetch: opportunistically
> update tracking refs, 2013-05-11) with a few updates in v1.8.4 era,
> the remote.*.fetch configuration always kicks in even when a refspec
> to specify what to fetch is given on the command line, and there is
> no way to disable or override it per-invocation.
> 
> Teach the command to pay attention to the --refmap=<lhs>:<rhs>
> command-line options that can be used to override the use of
> configured remote.*.fetch as the refmap.

(Your 0/9 message merely said "The new patches at the
end clarifies how remote.*.fetch configuration variables are used in
two conceptually different ways." so I was not expecting fetch to get a new
option.)

> Signed-off-by: Junio C Hamano <[email-masked]>
> ---
> ---
>  Documentation/fetch-options.txt |  8 ++++++++
>  Documentation/git-fetch.txt     |  3 +++
>  builtin/fetch.c                 | 35 ++++++++++++++++++++++++++++++++---
>  t/t5510-fetch.sh                | 37 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 80 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt
> index 92c68c3..d5c6289 100644
> --- a/Documentation/fetch-options.txt
> +++ b/Documentation/fetch-options.txt
> @@ -72,6 +72,14 @@ endif::git-pull[]
>  	setting. See linkgit:git-config[1].
>  
>  ifndef::git-pull[]
> +--refmap=<refspec>::
> +	When fetching refs listed on the command line, use the
> +	specified refspec (can be given more than once) to map the
> +	refs to remote-tracking branches, instead of values of

s/values/the values/

> +	`remote.*.fetch` configuration variable for the remote

s/variable/variables/

> +	repository.  See section on "Configured Remote-tracking
> +	Branches" for details.
> +
>  -t::
>  --tags::
>  	Fetch all tags from the remote (i.e., fetch remote tags
> diff --git a/Documentation/git-fetch.txt b/Documentation/git-fetch.txt
> index d09736a..96c44f9 100644
> --- a/Documentation/git-fetch.txt
> +++ b/Documentation/git-fetch.txt
> @@ -93,6 +93,9 @@ This configuration is used in two ways:
>    only used to decide _where_ the refs that are fetched are stored
>    by acting as a mapping.
>  
> +The latter use of the configured values can be overridden by giving

For consistency with my suggestions on 8/9:

s/configured values/`remote.<repository>.fetch` values/

		M.

> +the `--refmap=<refspec>` parameter(s) on the command line.
> +
>  
>  EXAMPLES
>  --------
> diff --git a/builtin/fetch.c b/builtin/fetch.c
> index 55f457c..dd46b61 100644
> --- a/builtin/fetch.c
> +++ b/builtin/fetch.c
> @@ -45,6 +45,8 @@ static struct transport *gsecondary;
>  static const char *submodule_prefix = "";
>  static const char *recurse_submodules_default;
>  static int shown_url = 0;
> +static int refmap_alloc, refmap_nr;
> +static const char **refmap_array;
>  
>  static int option_parse_recurse_submodules(const struct option *opt,
>  				   const char *arg, int unset)
> @@ -69,6 +71,19 @@ static int git_fetch_config(const char *k, const char *v, void *cb)
>  	return 0;
>  }
>  
> +static int parse_refmap_arg(const struct option *opt, const char *arg, int unset)
> +{
> +	ALLOC_GROW(refmap_array, refmap_nr + 1, refmap_alloc);
> +
> +	/*
> +	 * "git fetch --refmap='' origin foo"
> +	 * can be used to tell the command not to store anywhere
> +	 */
> +	if (*arg)
> +		refmap_array[refmap_nr++] = arg;
> +	return 0;
> +}
> +
>  static struct option builtin_fetch_options[] = {
>  	OPT__VERBOSITY(&verbosity),
>  	OPT_BOOL(0, "all", &all,
> @@ -107,6 +122,8 @@ static struct option builtin_fetch_options[] = {
>  		   N_("default mode for recursion"), PARSE_OPT_HIDDEN },
>  	OPT_BOOL(0, "update-shallow", &update_shallow,
>  		 N_("accept refs that update .git/shallow")),
> +	{ OPTION_CALLBACK, 0, "refmap", NULL, N_("refmap"),
> +	  N_("specify fetch refmap"), PARSE_OPT_NONEG, parse_refmap_arg },
>  	OPT_END()
>  };
>  
> @@ -278,6 +295,9 @@ static struct ref *get_ref_map(struct transport *transport,
>  	const struct ref *remote_refs = transport_get_remote_refs(transport);
>  
>  	if (refspec_count) {
> +		struct refspec *fetch_refspec;
> +		int fetch_refspec_nr;
> +
>  		for (i = 0; i < refspec_count; i++) {
>  			get_fetch_map(remote_refs, &refspecs[i], &tail, 0);
>  			if (refspecs[i].dst && refspecs[i].dst[0])
> @@ -307,12 +327,21 @@ static struct ref *get_ref_map(struct transport *transport,
>  		 * by ref_remove_duplicates() in favor of one of these
>  		 * opportunistic entries with FETCH_HEAD_IGNORE.
>  		 */
> -		for (i = 0; i < transport->remote->fetch_refspec_nr; i++)
> -			get_fetch_map(ref_map, &transport->remote->fetch[i],
> -				      &oref_tail, 1);
> +		if (refmap_array) {
> +			fetch_refspec = parse_fetch_refspec(refmap_nr, refmap_array);
> +			fetch_refspec_nr = refmap_nr;
> +		} else {
> +			fetch_refspec = transport->remote->fetch;
> +			fetch_refspec_nr = transport->remote->fetch_refspec_nr;
> +		}
> +
> +		for (i = 0; i < fetch_refspec_nr; i++)
> +			get_fetch_map(ref_map, &fetch_refspec[i], &oref_tail, 1);
>  
>  		if (tags == TAGS_SET)
>  			get_fetch_map(remote_refs, tag_refspec, &tail, 0);
> +	} else if (refmap_array) {
> +		die("--refmap option is only meaningful with command-line refspec(s).");
>  	} else {
>  		/* Use the defaults */
>  		struct remote *remote = transport->remote;
> diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh
> index 29d59ef..d78f320 100755
> --- a/t/t5510-fetch.sh
> +++ b/t/t5510-fetch.sh
> @@ -447,6 +447,43 @@ test_expect_success 'explicit pull should update tracking' '
>  	)
>  '
>  
> +test_expect_success 'explicit --refmap is allowed only with command-line refspec' '
> +	cd "$D" &&
> +	(
> +		cd three &&
> +		test_must_fail git fetch --refmap="*:refs/remotes/none/*"
> +	)
> +'
> +
> +test_expect_success 'explicit --refmap option overrides remote.*.fetch' '
> +	cd "$D" &&
> +	git branch -f side &&
> +	(
> +		cd three &&
> +		git update-ref refs/remotes/origin/master base-origin-master &&
> +		o=$(git rev-parse --verify refs/remotes/origin/master) &&
> +		git fetch --refmap="refs/heads/*:refs/remotes/other/*" origin master &&
> +		n=$(git rev-parse --verify refs/remotes/origin/master) &&
> +		test "$o" = "$n" &&
> +		test_must_fail git rev-parse --verify refs/remotes/origin/side &&
> +		git rev-parse --verify refs/remotes/other/master
> +	)
> +'
> +
> +test_expect_success 'explicitly empty --refmap option disables remote.*.fetch' '
> +	cd "$D" &&
> +	git branch -f side &&
> +	(
> +		cd three &&
> +		git update-ref refs/remotes/origin/master base-origin-master &&
> +		o=$(git rev-parse --verify refs/remotes/origin/master) &&
> +		git fetch --refmap="" origin master &&
> +		n=$(git rev-parse --verify refs/remotes/origin/master) &&
> +		test "$o" = "$n" &&
> +		test_must_fail git rev-parse --verify refs/remotes/origin/side
> +	)
> +'
> +
>  test_expect_success 'configured fetch updates tracking' '
>  
>  	cd "$D" &&
>