submodule: document failure to handle relative superproject origin URLs

This test case documents several cases where handling of relative
superproject origin URLs doesn't produce an expected result.

submodule.{sub}.url in the superproject is incorrect in these cases:
  foo
  ./foo
  ./foo/bar

The remote.origin.url of the submodule is incorrect in the above cases
and also when the superproject origin URL is like:
  foo/bar
  ../foo
  ../foo/bar

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7400-submodule-basic.sh

@@ -564,6 +564,18 @@ test_expect_success '../subrepo works with scp-style URL - user@host:path/to/rep
 	)
 '
 
+test_expect_failure '../subrepo works with relative local path - foo' '
+	(
+		cd reltest &&
+		cp pristine-.git-config .git/config &&
+		cp pristine-.gitmodules .gitmodules &&
+		git config remote.origin.url foo &&
+		# actual: fails with an error
+		git submodule init &&
+		test "$(git config submodule.sub.url)" = subrepo
+	)
+'
+
 test_expect_success '../subrepo works with relative local path - foo/bar' '
 	(
 		cd reltest &&
@@ -575,6 +587,28 @@ test_expect_success '../subrepo works with relative local path - foo/bar' '
 	)
 '
 
+test_expect_failure '../subrepo works with relative local path - ./foo' '
+	(
+		cd reltest &&
+		cp pristine-.git-config .git/config &&
+		cp pristine-.gitmodules .gitmodules &&
+		git config remote.origin.url ./foo &&
+		git submodule init &&
+		test "$(git config submodule.sub.url)" = subrepo
+	)
+'
+
+test_expect_failure '../subrepo works with relative local path - ./foo/bar' '
+	(
+		cd reltest &&
+		cp pristine-.git-config .git/config &&
+		cp pristine-.gitmodules .gitmodules &&
+		git config remote.origin.url ./foo/bar &&
+		git submodule init &&
+		test "$(git config submodule.sub.url)" = foo/subrepo
+	)
+'
+
 test_expect_success '../subrepo works with relative local path - ../foo' '
 	(
 		cd reltest &&

t/t7403-submodule-sync.sh

@@ -26,7 +26,9 @@ test_expect_success setup '
 	(cd super-clone && git submodule update --init) &&
 	git clone super empty-clone &&
 	(cd empty-clone && git submodule init) &&
-	git clone super top-only-clone
+	git clone super top-only-clone &&
+	git clone super relative-clone &&
+	(cd relative-clone && git submodule update --init)
 '
 
 test_expect_success 'change submodule' '
@@ -86,4 +88,90 @@ test_expect_success '"git submodule sync" should not vivify uninteresting submod
 	)
 '
 
+test_expect_failure '"git submodule sync" handles origin URL of the form foo' '
+	(cd relative-clone &&
+	 git remote set-url origin foo &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual fails with: "cannot strip off url foo
+	 test "$(git config remote.origin.url)" = "../submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form foo/bar' '
+	(cd relative-clone &&
+	 git remote set-url origin foo/bar &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual foo/submodule
+	 test "$(git config remote.origin.url)" = "../foo/submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form ./foo' '
+	(cd relative-clone &&
+	 git remote set-url origin ./foo &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual ./submodule
+	 test "$(git config remote.origin.url)" = "../submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form ./foo/bar' '
+	(cd relative-clone &&
+	 git remote set-url origin ./foo/bar &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual ./foo/submodule
+	 test "$(git config remote.origin.url)" = "../foo/submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form ../foo' '
+	(cd relative-clone &&
+	 git remote set-url origin ../foo &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual ../submodule
+	 test "$(git config remote.origin.url)" = "../../submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form ../foo/bar' '
+	(cd relative-clone &&
+	 git remote set-url origin ../foo/bar &&
+	 git submodule sync &&
+	(cd submodule &&
+	 #actual ../foo/submodule
+	 test "$(git config remote.origin.url)" = "../../foo/submodule"
+	)
+	)
+'
+
+test_expect_failure '"git submodule sync" handles origin URL of the form ../foo/bar with deeply nested submodule' '
+	(cd relative-clone &&
+	 git remote set-url origin ../foo/bar &&
+	 mkdir -p a/b/c &&
+	 ( cd a/b/c &&
+	   git init &&
+	   :> .gitignore &&
+	   git add .gitignore &&
+	   test_tick &&
+	   git commit -m "initial commit" ) &&
+	 git submodule add ../bar/a/b/c ./a/b/c &&
+	 git submodule sync &&
+	(cd a/b/c &&
+	 #actual ../foo/bar/a/b/c
+	 test "$(git config remote.origin.url)" = "../../../../foo/bar/a/b/c"
+	)
+	)
+'
+
+
 test_done