Chinese/Japanese rendering issue

Because of the following code, the font engine renders several Chinese/Japanese characters to the same position (the position of the first character).

    bool design = (default_hint_style == HintNone ||
             default_hint_style == HintLight ||
             (flags & HB_ShaperFlag_UseDesignMetrics)) && FT_IS_SCALABLE(freetype->face);

Please run i18n example to reproduce this bug. A screenshot attached.