[TRY 2] user32: Add test to check the MDI child switching

[Dmitry Timoshkov]

"Ilya Shpigor" <shpigor at etersoft.ru> wrote:

> +    trace("creating maximized visible MDI child window 3\n");
> +    mdi_child3 = CreateWindowExA(WS_EX_MDICHILD, "MDI_child_class", "MDI child",
> +                                WS_CHILD | WS_VISIBLE | WS_MAXIMIZEBOX | WS_MAXIMIZE,
> +                                0, 0, CW_USEDEFAULT, CW_USEDEFAULT,
> +                                mdi_client, 0, GetModuleHandleA(0), NULL);
> +    assert(mdi_child3);
> +
> +    active_child = (HWND)SendMessageW(mdi_client, WM_MDIGETACTIVE, 0, 0);
> +    SendMessageW(mdi_client, WM_MDINEXT, 0, 0);
> +    SendMessageW(mdi_client, WM_MDINEXT, 0, 0);
> +    ok(active_child != (HWND)SendMessageW(mdi_client, WM_MDIGETACTIVE, 0, 0), "wrong active MDI child %p\n", 
> active_child);
> +
> +    trace("destroying maximized visible MDI child window 3\n");
> +    DestroyWindow(mdi_child3);

What's the purpose of creating the 3rd MDI child if you don't care about
values returned by WM_MDIGETACTIVE, nor about intermediate results of
WM_MDINEXT? Apparently you have all MDI children handles in your hands and
can use them in the tests.

-- 
Dmitry.