For the region specific data, we would get the data from CLDR only regards to the region settings in locale. In current implementation, if we use an "invalid" locale, e.g. "zh-ES", as this locale hasn't been handled correctly when need to search the region specific information, so we would get the data from root resource bundle.

===== Code
    public static void main(String[] args) {
        Locale normLocale = Locale.forLanguageTag("es-ES");
        Locale oddLocale = Locale.forLanguageTag("zh-ES");
        print(normLocale);
        print(oddLocale);
    }

    private static void print(Locale loc) {
        Calendar ca = Calendar.getInstance(loc);
        int minDayInFirstWeek = ca.getMinimalDaysInFirstWeek();
        int firstDayOfWeek = ca.getFirstDayOfWeek();
        System.out.println("minDay: "+minDayInFirstWeek +" firstDay: "+firstDayOfWeek);
    }
===== Output
minDay: 4 firstDay: 2
minDay: 1 firstDay: 1

===== Expected:
minDay: 4 firstDay: 2
minDay: 4 firstDay: 2