Re: [PATCH 1/2] t3507: pin CHERRY_PICK_HEAD absence for a conflicting --no-commit

Phillip Wood [off-list ref] writes:

In this case I think it is worth checking as we can do it by adding a
single call to test_ref_missing to an existing test and the logic
around when we do and do not write CHERRY_PICK_HEAD is a bit tricky.

That is the justification I should have given. Whether the ref is
written depends on the command, on whether the merge started, and on
--no-commit, all in one condition, and the conflicting --no-commit case
is the one nothing checks. v3 states it that way.