Re: [PATCHv6 1/2] submodule tests: don't use itself as a submodule

[Junio C Hamano <gitster@pobox.com>]

Stefan Beller <sbeller@google.com> writes:

> This provides an easier way to have submodules in tests, by just setting
> TEST_CREATE_SUBMODULE to a non empty string, similar to
> TEST_NO_CREATE_REPO.

Yuck.  

I find it doubtful that it is a good idea to create two submodule
repositories by merely dot-including the test-lib.sh; I find it
doubly doubtful that it is a good idea to make test_create_repo
pay attention to the special variable to implement that.

I am OK with a solution where callers that set TEST_CREATE_SUBMODULE
variable in this patch to instead have an explicit call

	test_create_repo --submodule pretzel

That would be a lot more obvious.

The primary reason why I hate the implementation in this patch is
that it is very easy for a test that says TEST_CREATE_SUBMODULE
upfront, only to get the initial test repository (which everybody
else gets) with two test submodules, to later gain a test that wants
to use a separate repository and call "test_create_repo".  It will
always get the pretzel submodules, which may or may not match what
the test writer who adds a new test needs.

> Make use of it in those tests that add a submodule from ./. except for
> the occurrence in create_lib_submodule_repo as there it seems we craft
> a repository deliberately for both inside as well as outside use.

But isn't the point of this change that use of ./. cannot be
mimicking any real-world use, hence pointless for the purpose of
really testing the components of the system?  If "we craft
deliberately for both inside and outside use" indeed _IS_ a good
thing, then perhaps use of ./. has practical real-world use---if
not, wouldn't we want to fix the scripts that include the
lib-submodule-repo helper not to test such an unrealistic layout?