4 files changed, 66 insertions, 0 deletions
diff --git a/t/helper/test-submodule-nested-repo-config.c b/t/helper/test-submodule-nested-repo-config.c
new file mode 100644
index 0000000000..a31e2a9bea
--- /dev/null
+++ b/t/helper/test-submodule-nested-repo-config.c
@@ -0,0 +1,30 @@
+#include "test-tool.h"
+#include "submodule-config.h"
+
+static void die_usage(int argc, const char **argv, const char *msg)
+{
+	fprintf(stderr, "%s\n", msg);
+	fprintf(stderr, "Usage: %s <submodulepath> <config name>\n", argv[0]);
+	exit(1);
+}
+
+int cmd__submodule_nested_repo_config(int argc, const char **argv)
+{
+	struct repository submodule;
+
+	if (argc < 3)
+		die_usage(argc, argv, "Wrong number of arguments.");
+
+	setup_git_directory();
+
+	if (repo_submodule_init(&submodule, the_repository, argv[1])) {
+		die_usage(argc, argv, "Submodule not found.");
+	}
+
+	/* Read the config of _child_ submodules. */
+	print_config_from_gitmodules(&submodule, argv[2]);
+
+	submodule_free(the_repository);
+
+	return 0;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index 0edafcfd65..a25fa80ca2 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -40,6 +40,7 @@ static struct test_cmd cmds[] = {
 	{ "strcmp-offset", cmd__strcmp_offset },
 	{ "string-list", cmd__string_list },
 	{ "submodule-config", cmd__submodule_config },
+	{ "submodule-nested-repo-config", cmd__submodule_nested_repo_config },
 	{ "subprocess", cmd__subprocess },
 	{ "urlmatch-normalization", cmd__urlmatch_normalization },
 	{ "wildmatch", cmd__wildmatch },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index e954e8c522..9462e38fb5 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -36,6 +36,7 @@ int cmd__sigchain(int argc, const char **argv);
 int cmd__strcmp_offset(int argc, const char **argv);
 int cmd__string_list(int argc, const char **argv);
 int cmd__submodule_config(int argc, const char **argv);
+int cmd__submodule_nested_repo_config(int argc, const char **argv);
 int cmd__subprocess(int argc, const char **argv);
 int cmd__urlmatch_normalization(int argc, const char **argv);
 int cmd__wildmatch(int argc, const char **argv);
diff --git a/t/t7411-submodule-config.sh b/t/t7411-submodule-config.sh
index 2cfabb18bc..89690b7adb 100755
--- a/t/t7411-submodule-config.sh
+++ b/t/t7411-submodule-config.sh
@@ -216,4 +216,38 @@ test_expect_success 'reading submodules config from the current branch when .git
 	)
 '
 
+test_expect_success 'reading nested submodules config' '
+	(cd super &&
+		git init submodule/nested_submodule &&
+		echo "a" >submodule/nested_submodule/a &&
+		git -C submodule/nested_submodule add a &&
+		git -C submodule/nested_submodule commit -m "add a" &&
+		git -C submodule submodule add ./nested_submodule &&
+		git -C submodule add nested_submodule &&
+		git -C submodule commit -m "added nested_submodule" &&
+		git add submodule &&
+		git commit -m "updated submodule" &&
+		echo "./nested_submodule" >expect &&
+		test-tool submodule-nested-repo-config \
+			submodule submodule.nested_submodule.url >actual &&
+		test_cmp expect actual
+	)
+'
+
+# When this test eventually passes, before turning it into
+# test_expect_success, remember to replace the test_i18ngrep below with
+# a "test_must_be_empty warning" to be sure that the warning is actually
+# removed from the code.
+test_expect_failure 'reading nested submodules config when .gitmodules is not in the working tree' '
+	test_when_finished "git -C super/submodule checkout .gitmodules" &&
+	(cd super &&
+		echo "./nested_submodule" >expect &&
+		rm submodule/.gitmodules &&
+		test-tool submodule-nested-repo-config \
+			submodule submodule.nested_submodule.url >actual 2>warning &&
+		test_i18ngrep "nested submodules without %s in the working tree are not supported yet" warning &&
+		test_cmp expect actual
+	)
+'
+
 test_done