[Doc] MessageFormat null locale generates NullPointerException

FULL PRODUCT VERSION :
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
The MessageFormat can be created with a null locale however, the SimpleDateFormat,ChoiceFormat, and NumberFormat objects used by the MessageFormat seem to be hostile towards a null locale.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Create a PropertiesResourceBundle loaded with a key/value.
2. Create a new MessageFormat("{0}", prb.getLocale()).
3. Try to format the key/value.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The behavior should align with java.util.Formatter which is not hostile towards a null locale.
ACTUAL -
NullPointerException is thrown when the MessageFormat tries to create the subformat objects.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.NullPointerException
at java.text.SimpleDateFormat.<init>(SimpleDateFormat.java:614)
at java.text.DateFormat.get(DateFormat.java:772)
at java.text.DateFormat.getDateInstance(DateFormat.java:508)
at java.text.MessageFormat.makeFormat(MessageFormat.java:1487)
at java.text.MessageFormat.applyPattern(MessageFormat.java:479)
at java.text.MessageFormat.<init>(MessageFormat.java:381)
at Main.testLongAsDate(Main.java:23)
at Main.main(Main.java:17)
java.lang.NullPointerException
at java.util.Hashtable.hash(Hashtable.java:239)
at java.util.Hashtable.get(Hashtable.java:434)
at java.text.NumberFormat.getInstance(NumberFormat.java:759)
at java.text.NumberFormat.getInstance(NumberFormat.java:393)
at java.text.MessageFormat.subformat(MessageFormat.java:1262)
at java.text.MessageFormat.format(MessageFormat.java:860)
at java.text.Format.format(Format.java:157)
at Main.testLongAsNumber(Main.java:32)
at Main.main(Main.java:18)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class Main {

    public static void main(String[] args) throws Exception {
        testStringAsString();
        testLongAsDate();
        testLongAsNumber();
        testLongAsNone();
    }
    
    private static void testLongAsDate() {
        try {
            new MessageFormat("{0, date}", (Locale) null).format(new Object[]{42});
            System.err.println("Pass long as date");
        } catch(RuntimeException fail) {
            fail.printStackTrace();
        }
    }
    
    private static void testLongAsNumber() {
        try {
            new MessageFormat("{0, integer}", (Locale) null).format(new Object[]{42});
            System.err.println("Pass long as number");
        } catch(RuntimeException fail) {
            fail.printStackTrace();
        }
    }
    
    private static void testLongAsNone() {
        try {
            new MessageFormat("{0}", (Locale) null).format(new Object[]{42});
            System.err.println("Pass long as none");
        } catch(RuntimeException fail) {
            fail.printStackTrace();
        }
    }
    
    private static void testStringAsString() {
        try {
            new MessageFormat("{0}", (Locale) null).format(new Object[]{"hello"});
            System.err.println("Pass string as string");
        } catch(RuntimeException fail) {
            fail.printStackTrace();
        }
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
If the locale is null, use the single argument constructor.

ResourceBundle rb = getFooBundleFromBarLoader();
Locale l = rb.getLocale();
if (l == null) {
  new MessageFormat(pattern);
} else {
  new MessageFormat(pattern, l);
}