dmime: Fix handling of NULL out pointer in QI.

dlls/dmime/segmentstate.c

@@ -37,6 +37,9 @@ static HRESULT WINAPI DirectMusicSegmentState8_QueryInterface(IDirectMusicSegmen
 
     TRACE("(%p, %s, %p)\n", This, debugstr_dmguid(riid), ppobj);
 
+    if (!ppobj)
+        return E_POINTER;
+
     *ppobj = NULL;
 
     if (IsEqualIID(riid, &IID_IUnknown) ||

dlls/dmime/tests/dmime.c

@@ -293,6 +293,9 @@ static void test_COM_segmentstate(void)
     ok(refcount == 4, "refcount == %u, expected 4\n", refcount);
     refcount = IUnknown_Release(unk);
 
+    hr = IDirectMusicSegmentState8_QueryInterface(dmss8, &IID_IUnknown, NULL);
+    ok(hr == E_POINTER, "got %08x\n", hr);
+
     while (IDirectMusicSegmentState8_Release(dmss8));
 }