Re: [PATCH v4 6/6] tests: don't lose misc "git" exit codes

> Fix a few miscellaneous cases where:
> 
> - We lost the "git" exit code via "git ... | grep"
> - Likewise by having a $(git) argument to git itself
> - Used "test -z" to check that a command emitted no output, we can use
>    "test_must_be_empty" and &&-chaining instead.
> 
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> [...]
> diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
> index 5841f280fb2..f1fe5d60677 100755
> --- a/t/t3701-add-interactive.sh
> +++ b/t/t3701-add-interactive.sh
> @@ -296,9 +296,11 @@ test_expect_success FILEMODE 'stage mode and hunk' '
>   	echo content >>file &&
>   	chmod +x file &&
>   	printf "y\\ny\\n" | git add -p &&
> -	git diff --cached file | grep "new mode" &&
> -	git diff --cached file | grep "+content" &&
> -	test -z "$(git diff file)"
> +	git diff --cached file >out &&
> +	grep "new mode" out &&
> +	grep "+content" out &&
> +	git diff file >out &&
> +	test_must_be_empty out