d3d8/tests: make sure to use return values (LLVM/Clang)

[Henri Verbeet]

On 26 July 2011 16:08, Jacek Caban <jacek at codeweavers.com> wrote:
> If there is no cost of having tests more strict (like code
> complication), it is a good principle IMO. In this case it's a matter of
> choosing the right way for testing results, so it should be preferable.
>
We're not testing return codes here, so IMO we don't care about them
beyond detecting failures early. As a general principle though, the
point has always been to test behaviour that actual applications
depend on, not finding the most obscure implementation details of
native. Also, it's not unheard of for some of those details to change
between Windows versions. If applications don't care, we don't either.

>>  (Not that it matters a lot here anyway, for most of these
>> D3D_OK is the only possible sucessful return value.)
>
> How can you be sure without tests?
>
Well, aside from disassembling the entire thing for every single
Windows version, you can't, even with tests. I mean, native D3D could
do something obscure like switching all return codes to S_FALSE after
drawing a green icosahedron, but I think it's somewhat unlikely.