Re: [PATCH v3 2/7] repo: add path.superproject-working-tree with absolute and relative suffixes

> Scripts working in multi-repository setups often need to identify the
> top-level working tree of a superproject from within a submodule.
> Currently, this is only exposed via `git rev-parse
> --show-superproject-working-tree`.
> 
> Introduce `path.superproject-working-tree.absolute` and
> `path.superproject-working-tree.relative` keys to `git repo info`.
> This exposes the core submodule context via a scriptable config-like key
> using standard format rules.

> If requested when not inside a submodule, the command returns an empty
> string.
> 
> Mentored-by: Justin Tobler <jltobler@gmail.com>
> Mentored-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
> Signed-off-by: K Jayatheerth <jayatheerthkulkarni2005@gmail.com>
> ---
>  Documentation/git-repo.adoc | 10 ++++++++++
>  builtin/repo.c              | 33 +++++++++++++++++++++++++++++++++
>  t/t1900-repo-info.sh        | 34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 77 insertions(+)
> 
> diff --git a/Documentation/git-repo.adoc b/Documentation/git-repo.adoc
> index e34abe5fea..03aa57942f 100644
> --- a/Documentation/git-repo.adoc
> +++ b/Documentation/git-repo.adoc
> @@ -119,6 +119,16 @@ values that they return:
>  `path.gitdir.relative`::
>  	The path to the Git repository directory relative to the current working directory.
>  
> +`path.superproject-working-tree.absolute`::
> +	The canonical absolute path to the working tree root of the superproject
> +	if the current repository is an initialized submodule. Outputs an empty
> +	string if not in a submodule.
> +
> +`path.superproject-working-tree.relative`::
> +	The path to the working tree root of the superproject relative to the
> +	current working directory if the current repository is an initialized
> +	submodule. Outputs an empty string if not in a submodule.
> +
>  `path.toplevel.absolute`::
>  	The canonical absolute path to the top-level directory of the
>  	repository's working tree. Outputs an empty string if the repository
> diff --git a/builtin/repo.c b/builtin/repo.c
> index 194757eb18..82359473e9 100644
> --- a/builtin/repo.c
> +++ b/builtin/repo.c
> @@ -18,6 +18,7 @@
>  #include "strbuf.h"
>  #include "string-list.h"
>  #include "shallow.h"
> +#include "submodule.h"
>  #include "tree.h"
>  #include "tree-walk.h"
>  #include "utf8.h"
> @@ -121,6 +122,36 @@ static int get_path_gitdir_relative(struct repository *repo, struct strbuf *buf)
>  	return 0;
>  }
>  
> +static int get_path_superproject_absolute(struct repository *repo UNUSED, struct strbuf *buf)
> +{
> +	struct strbuf superproject = STRBUF_INIT;
> +
> +	if (!get_superproject_working_tree(&superproject)) {
> +		strbuf_release(&superproject);
> +		strbuf_addstr(buf, "");

> +		return 0;
> +	}
> +
> +	format_path(buf, superproject.buf, startup_info->prefix, PATH_FORMAT_CANONICAL);
> +	strbuf_release(&superproject);
> +	return 0;
> +}
> +
> +static int get_path_superproject_relative(struct repository *repo UNUSED, struct strbuf *buf)
> +{
> +	struct strbuf superproject = STRBUF_INIT;
> +
> +	if (!get_superproject_working_tree(&superproject)) {
> +		strbuf_release(&superproject);
> +		strbuf_addstr(buf, "");

> +		return 0;
> +	}
> +
> +	format_path(buf, superproject.buf, startup_info->prefix, PATH_FORMAT_RELATIVE);
> +	strbuf_release(&superproject);
> +	return 0;
> +}
> +
>  static int get_path_toplevel_absolute(struct repository *repo, struct strbuf *buf)
>  {
>  	const char *work_tree = repo_get_work_tree(repo);
> @@ -163,6 +194,8 @@ static const struct repo_info_field repo_info_field[] = {
>  	{ "path.commondir.relative", get_path_commondir_relative },
>  	{ "path.gitdir.absolute", get_path_gitdir_absolute },
>  	{ "path.gitdir.relative", get_path_gitdir_relative },
> +	{ "path.superproject-working-tree.absolute", get_path_superproject_absolute },
> +	{ "path.superproject-working-tree.relative", get_path_superproject_relative },
>  	{ "path.toplevel.absolute", get_path_toplevel_absolute },
>  	{ "path.toplevel.relative", get_path_toplevel_relative },
>  	{ "references.format", get_references_format },
> diff --git a/t/t1900-repo-info.sh b/t/t1900-repo-info.sh
> index fbb9063ee5..220b3d4d3d 100755
> --- a/t/t1900-repo-info.sh
> +++ b/t/t1900-repo-info.sh
> @@ -213,6 +213,40 @@ test_repo_info_path 'gitdir with explicit GIT_DIR' 'gitdir' \
>  	'.git' \
>  	'GIT_DIR="../.git" && export GIT_DIR'
>  
> +test_expect_success 'path.superproject-working-tree absolute and relative' '
> +	test_when_finished "rm -rf sub super" &&
> +	git init sub &&
> +	test_commit -C sub initial &&
> +	git init super &&
> +	(
> +		cd super &&
> +		git -c protocol.file.allow=always submodule add "../sub" sub &&
> +		git commit -m "add submodule" &&
> +
> +		cd sub &&
> +		ROOT="$(test-tool path-utils real_path ..)" &&
> +
> +		echo "path.superproject-working-tree.absolute=$ROOT" >expect.abs &&
> +		git repo info path.superproject-working-tree.absolute >actual.abs &&
> +		test_cmp expect.abs actual.abs &&
> +
> +		echo "path.superproject-working-tree.relative=../" >expect.rel &&
> +		git repo info path.superproject-working-tree.relative >actual.rel &&
> +		test_cmp expect.rel actual.rel
> +	)
> +'
> +
> +test_expect_success 'path.superproject-working-tree returns empty when not in a submodule' '
> +	test_when_finished "rm -rf repo" &&
> +	git init repo &&
> +	(
> +		cd repo &&
> +		echo "path.superproject-working-tree.absolute=" >expect &&
> +		git repo info path.superproject-working-tree.absolute >actual &&
> +		test_cmp expect actual