clone: add `--remote-submodules` flag

When using `git clone --recurse-submodules` there was previously no way to
pass a `--remote` switch to the implicit `git submodule update` command for
any use case where you want the submodules to be checked out on their
remote-tracking branch rather than with the SHA-1 recorded in the superproject.

This patch rectifies this situation. It actually passes `--no-fetch` to
`git submodule update` as well on the grounds they the submodule has only just
been cloned, so fetching from the remote again only serves to slow things down.

Signed-off-by: Ben Avison <bavison@riscosopen.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/t/t5617-clone-submodules-remote.sh b/t/t5617-clone-submodules-remote.sh
new file mode 100755
index 0000000000..37fcce9c40
--- /dev/null
+++ b/t/t5617-clone-submodules-remote.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+
+test_description='Test cloning repos with submodules using remote-tracking branches'
+
+. ./test-lib.sh
+
+pwd=$(pwd)
+
+test_expect_success 'setup' '
+	git checkout -b master &&
+	test_commit commit1 &&
+	mkdir sub &&
+	(
+		cd sub &&
+		git init &&
+		test_commit subcommit1 &&
+		git tag sub_when_added_to_super
+	) &&
+	git submodule add "file://$pwd/sub" sub &&
+	git commit -m "add submodule" &&
+	(
+		cd sub &&
+		test_commit subcommit2
+	)
+'
+
+test_expect_success 'clone with --no-remote-submodules' '
+	test_when_finished "rm -rf super_clone" &&
+	git clone --recurse-submodules --no-remote-submodules "file://$pwd/." super_clone &&
+	(
+		cd super_clone/sub &&
+		git diff --exit-code sub_when_added_to_super
+	)
+'
+
+test_expect_success 'clone with --remote-submodules' '
+	test_when_finished "rm -rf super_clone" &&
+	git clone --recurse-submodules --remote-submodules "file://$pwd/." super_clone &&
+	(
+		cd super_clone/sub &&
+		git diff --exit-code remotes/origin/master
+	)
+'
+
+test_expect_success 'check the default is --no-remote-submodules' '
+	test_when_finished "rm -rf super_clone" &&
+	git clone --recurse-submodules "file://$pwd/." super_clone &&
+	(
+		cd super_clone/sub &&
+		git diff --exit-code sub_when_added_to_super
+	)
+'
+
+test_done