Re: [PATCH v1 1/2] implement test_might_fail using a refactored test_must_fail

> From: Lars Schneider <larsxschneider@gmail.com>
> 
> Add an (optional) first parameter "ok=<special case>" to test_must_fail
> and return success for "<special case>". Add "success" as
> "<special case>" and use it to implement "test_might_fail". This removes
> redundancies in test-lib-function.sh.
> 
> You can pass multiple <special case> arguments divided by comma (e.g.
> "test_must_fail ok=success,something")
> 
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Jeff King <peff@peff.net>
> Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
> Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
> ---
>  t/test-lib-functions.sh | 47 +++++++++++++++++++++++++++++++++--------------
>  1 file changed, 33 insertions(+), 14 deletions(-)
> 
> diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
> index 73e37a1..94c449a 100644
> --- a/t/test-lib-functions.sh
> +++ b/t/test-lib-functions.sh
> @@ -569,6 +569,21 @@ test_line_count () {
>  	fi
>  }
>  
> +# Returns success if a comma separated string of keywords ($1) contains a
> +# given keyword ($2).
> +# Examples:
> +# `list_contains "foo,bar" bar` returns 0
> +# `list_contains "foo" bar` returns 1
> +
> +list_contains () {
> +	case ",$1," in
> +	*,$2,*)
> +		return 0
> +		;;
> +	esac
> +	return 1
> +}
> +
>  # This is not among top-level (test_expect_success | test_expect_failure)
>  # but is a prefix that can be used in the test script, like:
>  #
> @@ -582,18 +597,31 @@ test_line_count () {
>  # the failure could be due to a segv.  We want a controlled failure.
>  
>  test_must_fail () {
> +	case "$1" in
> +	ok=*)
> +		_test_ok=${1#ok=}
> +		shift
> +		;;
> +	*)
> +		_test_ok=
> +		;;
> +	esac
>  	"$@"
>  	exit_code=$?
> -	if test $exit_code = 0; then
> +	if ! list_contains "$_test_ok" success && test "$exit_code" -eq 0
> +	then