Re: [PATCH 3/3] t7406: make a test_must_fail call fail for the right reason

["SZEDER Gábor" <szeder.dev@gmail.com>]

> A test making use of test_must_fail was failing like this:
>   fatal: ambiguous argument '|': unknown revision or path not in the working tree.
> when the intent was to verify that a specific string was not found
> in the output of the git diff command, i.e. that grep returned
> non-zero.  Fix the test to do that.
> 
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
>  t/t7406-submodule-update.sh | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
> index c8971abd07..f65049ec73 100755
> --- a/t/t7406-submodule-update.sh
> +++ b/t/t7406-submodule-update.sh
> @@ -603,7 +603,8 @@ test_expect_success 'submodule update - update=none in .git/config but --checkou
>  	 git diff --name-only >out &&
>  	 grep submodule out &&
>  	 git submodule update --checkout &&
> -	 test_must_fail git diff --name-only \| grep submodule &&
> +	 git diff --name-only >out &&
> +	 ! grep submodule out &&
>  	 (cd submodule &&
>  	  test_must_fail compare_head

May I suggest a while-at-it cleanup? :)
Here 'test_must_fail' is used in front of a shell function, which
should be written as '! compare_head', and indeed in all other places
in this test script it's written that way.

>  	 ) &&
> --
> 2.18.0.548.gd57a518419
> 
>