t7409: make sure submodule is initialized and updated in more detail

The earlier test did not even make sure that the correct commit is
checked out in the submodule directory.  Inspect the result in a bit
more detail.

Signed-off-by: Daniel Graña <dangra@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7409-submodule-detached-worktree.sh

@@ -15,7 +15,11 @@ TEST_NO_CREATE_REPO=1
 test_expect_success 'submodule on detached working tree' '
 	git init --bare remote &&
 	test_create_repo bundle1 &&
-	(cd bundle1 && test_commit "shoot") &&
+	(
+		cd bundle1 &&
+		test_commit "shoot" &&
+		git rev-parse --verify HEAD >../expect
+	) &&
 	mkdir home &&
 	(
 		cd home &&
@@ -23,14 +27,27 @@ test_expect_success 'submodule on detached working tree' '
 		git clone --bare ../remote .dotfiles &&
 		git submodule add ../bundle1 .vim/bundle/sogood &&
 		test_commit "sogood" &&
+		(
+			unset GIT_WORK_TREE GIT_DIR &&
+			cd .vim/bundle/sogood &&
+			git rev-parse --verify HEAD >actual &&
+			test_cmp ../../../../expect actual
+		) &&
 		git push origin master
 	) &&
 	mkdir home2 &&
 	(
 		cd home2 &&
-		export GIT_WORK_TREE="$(pwd)" GIT_DIR="$(pwd)/.dotfiles" &&
 		git clone --bare ../remote .dotfiles &&
-		git submodule update --init
+		export GIT_WORK_TREE="$(pwd)" GIT_DIR="$(pwd)/.dotfiles" &&
+		git checkout master &&
+		git submodule update --init &&
+		(
+			unset GIT_WORK_TREE GIT_DIR &&
+			cd .vim/bundle/sogood &&
+			git rev-parse --verify HEAD >actual &&
+			test_cmp ../../../../expect actual
+		)
 	)
 '
 
@@ -42,6 +59,7 @@ test_expect_success 'submodule on detached working pointed by core.worktree' '
 		git clone --bare ../remote "$GIT_DIR" &&
 		git config core.bare false &&
 		git config core.worktree .. &&
+		git checkout master &&
 		git submodule add ../bundle1 .vim/bundle/dupe &&
 		test_commit "dupe" &&
 		git push origin master
@@ -52,9 +70,8 @@ test_expect_success 'submodule on detached working pointed by core.worktree' '
 		git config core.bare false &&
 		git config core.worktree .. &&
 		git pull &&
-		git submodule update &&
-		git submodule status &&
-		test -d .vim/bundle/dupe
+		git submodule update --init &&
+		test -f .vim/bundle/dupe/shoot.t
 	)
 '