dmcompos/tests: Fix a failing test on Windows 8.

[Michael Stefaniuc]

On 02/03/2017 02:33 PM, Huw Davies wrote:
> On Fri, Feb 03, 2017 at 02:24:49PM +0100, Michael Stefaniuc wrote:
>> On 02/03/2017 12:45 PM, Huw Davies wrote:
>>> The dirty bit is most likely uninitialized, so sometimes this returns S_OK.
>> Interesting, that seems to be only newtb-w8 that does that.
> 
> Yes.  FWIW, I tried calling IPersistStream_Save() in order to clear the
> dirty bit, but that returned E_NOTIMPL on all Windows versions...
Yes, that's the default for the dmusic COM objects that implement
IPersistStream. Afair there are less than a handful of them having
IPersistStream_Save() but
    git grep unimpl_IPersistStream_Save, | wc -l
    23

bye
	michael