Re: [PATCH v2 0/1] MR2068: Draft: comdlg32: Enable visual styles when showing IFileDialog.

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about dlls/comdlg32/itemdlg.c:
> static HRESULT create_dialog(FileDialogImpl *This, HWND parent)
>  {
>      INT_PTR res;
> -
>
> ULONG_PTR actctx_cookie = 0;
> -
> -
>
> GetCurrentActCtx(&This->user_actctx);
> -
>
> if (!ActivateActCtx(COMDLG32_hActCtx, &actctx_cookie))
> -
>    ERR("failed to activate activation context, last error %lx\n", GetLastError());
>
> SetLastError(0);
>    res = DialogBoxParamW(COMDLG32_hInstance,
>                          MAKEINTRESOURCEW(NEWFILEOPENV3ORD),
>                          parent, itemdlg_dlgproc, (LPARAM)This);
>    This->dlg_hwnd = NULL;
> -
> -
>
> if (actctx_cookie != 0)

You shouldn't rely on `0` being an invalid cookie value.