Fix. Wrong return values.

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Add new test fixture.

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
Add more tests ...

Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>