submodule update: learn `--[no-]recommend-shallow` option

Sometimes the history of a submodule is not considered important by
the projects upstream. To make it easier for downstream users, allow
a boolean field 'submodule.<name>.shallow' in .gitmodules, which can
be used to recommend whether upstream considers the history important.

This field is honored in the initial clone by default, it can be
ignored by giving the `--no-recommend-shallow` option.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/t/t5614-clone-submodules.sh b/t/t5614-clone-submodules.sh
index 62044c5..32d83e2 100755
--- a/t/t5614-clone-submodules.sh
+++ b/t/t5614-clone-submodules.sh
@@ -82,4 +82,56 @@ test_expect_success 'non shallow clone with shallow submodule' '
 	)
 '
 
+test_expect_success 'clone follows shallow recommendation' '
+	test_when_finished "rm -rf super_clone" &&
+	git config -f .gitmodules submodule.sub.shallow true &&
+	git add .gitmodules &&
+	git commit -m "recommed shallow for sub" &&
+	git clone --recurse-submodules --no-local "file://$pwd/." super_clone &&
+	(
+		cd super_clone &&
+		git log --oneline >lines &&
+		test_line_count = 4 lines
+	) &&
+	(
+		cd super_clone/sub &&
+		git log --oneline >lines &&
+		test_line_count = 1 lines
+	)
+'
+
+test_expect_success 'get unshallow recommended shallow submodule' '
+	test_when_finished "rm -rf super_clone" &&
+	git clone --no-local "file://$pwd/." super_clone &&
+	(
+		cd super_clone &&
+		git submodule update --init --no-recommend-shallow &&
+		git log --oneline >lines &&
+		test_line_count = 4 lines
+	) &&
+	(
+		cd super_clone/sub &&
+		git log --oneline >lines &&
+		test_line_count = 3 lines
+	)
+'
+
+test_expect_success 'clone follows non shallow recommendation' '
+	test_when_finished "rm -rf super_clone" &&
+	git config -f .gitmodules submodule.sub.shallow false &&
+	git add .gitmodules &&
+	git commit -m "recommed non shallow for sub" &&
+	git clone --recurse-submodules --no-local "file://$pwd/." super_clone &&
+	(
+		cd super_clone &&
+		git log --oneline >lines &&
+		test_line_count = 5 lines
+	) &&
+	(
+		cd super_clone/sub &&
+		git log --oneline >lines &&
+		test_line_count = 3 lines
+	)
+'
+
 test_done