errors=0

f() {
	result=
	case $1 in
	a) result=${result}a ;;
	b) result=${result}b ;&
	c) result=${result}c ;&
	d) result=${result}d ;;
	e) result=${result}e ;&
	esac
}

check() {
	f "$1"
	if [ "$result" != "$2" ]; then
		printf "For %s, expected %s got %s\n" "$1" "$2" "$result"
		errors=$((errors + 1))
	fi
}

check '' ''
check a a
check b bcd
check c cd
check d d
check e e

if ! (case 1 in
	1) false ;&
	2) true ;;
esac) then
	echo "Subshell bad"
	errors=$((errors + 1))
fi

exit $((errors != 0))