A DESCRIPTION OF THE PROBLEM :
DateFormatSymbols(locale) doesn't check for null, causing an NPE when finding a null key in a map.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
MissingResourceException – if the resources for the specified locale cannot be found or cannot be loaded.
ACTUAL -
Exception in thread "main" java.lang.NullPointerException: Cannot invoke "Object.hashCode()" because "key" is null
at java.base/java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:948)
at java.base/java.text.DateFormatSymbols.initializeData(DateFormatSymbols.java:725)
at java.base/java.text.DateFormatSymbols.<init>(DateFormatSymbols.java:151)

---------- BEGIN SOURCE ----------
    public static void main(String[] args)
    {
        DateFormatSymbols defaultSymbols = new DateFormatSymbols(null);
    }
---------- END SOURCE ----------