[Bug 39852] 3DMark03: Mother Nature test: waterfall has no transparency if AllwaysOffScreen=disabled

https://bugs.winehq.org/show_bug.cgi?id=39852

--- Comment #2 from Sergey Isakov  ---
It is easy to see that wined3d_settings.always_offscreen used only in two
places:
wined3d/context.c
~~~
    if (wined3d_settings.offscreen_rendering_mode != ORM_BACKBUFFER
            && wined3d_settings.always_offscreen)
    {
        color_format = wined3d_get_format(gl_info, WINED3DFMT_B8G8R8A8_UNORM);
        ds_format = wined3d_get_format(gl_info, WINED3DFMT_UNKNOWN);
    }
~~~
and wined3d/swapchain.c
~~~
    if (!wined3d_settings.always_offscreen && !swapchain->desc.multisample_type
            && swapchain->desc.backbuffer_width == client_rect.right
            && swapchain->desc.backbuffer_height == client_rect.bottom)
    {
        TRACE("Backbuffer dimensions match window dimensions, rendering
onscreen.\n");
        swapchain->render_to_fbo = FALSE;
        return;
    }
~~~
Second place is the key for this bug.
If I set TRUE then the picture is good.
Also affected test "Pixel shaders".
tracing +d3d didn't reveal more differences.