t1409: check that `packed-refs` is not rewritten unnecessarily
There is no need to rewrite the `packed-refs` file except for the case
that we are deleting a reference that has a packed version. Verify
that `packed-refs` is not rewritten when it shouldn't be.
In fact, two of these tests fail:
* A new (empty) `packed-refs` file is created when deleting any loose
reference and no `packed-refs` file previously existed.
* The `packed-refs` file is rewritten unnecessarily when deleting a
loose reference that has no packed counterpart.
Both problems will be fixed in the next commit.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>