[RFC PATCH v2 04/12] submodule--helper: add a new 'config' subcommand

[Antonio Ospite <ao2@ao2.it>]

Add a new 'config' subcommand to 'submodule--helper', this extra level
of indirection makes it possible to add some flexibility to how the
submodules configuration is handled.

Signed-off-by: Antonio Ospite <ao2@ao2.it>
---

Note that the tests follow the predominant style in the file: subshell and cd
right at the start of the sub-shell opening.

 builtin/submodule--helper.c | 17 +++++++++++++++++
 t/t7411-submodule-config.sh | 26 ++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index a3c4564c6c..14f0845d30 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -2029,6 +2029,22 @@ static int connect_gitdir_workingtree(int argc, const char **argv, const char *p
 	return 0;
 }
 
+static int module_config(int argc, const char **argv, const char *prefix)
+{
+	if (argc < 2 || argc > 3)
+		die("submodule--helper config takes 1 or 2 arguments: name [value]");
+
+	/* Equivalent to ACTION_GET in builtin/config.c */
+	if (argc == 2)
+		return print_config_from_gitmodules(argv[1]);
+
+	/* Equivalent to ACTION_SET in builtin/config.c */
+	if (argc == 3)
+		return config_set_in_gitmodules_file_gently(argv[1], argv[2]);
+
+	return 0;
+}
+
 #define SUPPORT_SUPER_PREFIX (1<<0)
 
 struct cmd_struct {
@@ -2057,6 +2073,7 @@ static struct cmd_struct commands[] = {
 	{"absorb-git-dirs", absorb_git_dirs, SUPPORT_SUPER_PREFIX},
 	{"is-active", is_active, 0},
 	{"check-name", check_name, 0},
+	{"config", module_config, 0},
 };
 
 int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
diff --git a/t/t7411-submodule-config.sh b/t/t7411-submodule-config.sh
index 248da0bc4f..bbca4b421d 100755
--- a/t/t7411-submodule-config.sh
+++ b/t/t7411-submodule-config.sh
@@ -141,4 +141,30 @@ test_expect_success 'error in history in fetchrecursesubmodule lets continue' '
 	)
 '
 
+test_expect_success 'reading submodules config with "submodule--helper config"' '
+	(cd super &&
+		echo "../submodule" >expected &&
+		git submodule--helper config submodule.submodule.url >actual &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'writing submodules config with "submodule--helper config"' '
+	(cd super &&
+		echo "new_url" >expected &&
+		git submodule--helper config submodule.submodule.url "new_url" &&
+		git submodule--helper config submodule.submodule.url >actual &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success 'overwriting unstaged submodules config with "submodule--helper config"' '
+	(cd super &&
+		echo "newer_url" >expected &&
+		git submodule--helper config submodule.submodule.url "newer_url" &&
+		git submodule--helper config submodule.submodule.url >actual &&
+		test_cmp expected actual
+	)
+'
+
 test_done
-- 
2.18.0