Links:
------
  [1] https://docs.oracle.com/javase/6/docs/api/java/util/Locale.html#getISO3Country%28%29
  [2] https://docs.oracle.com/javase/7/docs/api/java/util/Locale.html#getISO3Country%28%29
  [3] http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html
  [4] https://docs.oracle.com/javase/6/docs/api/java/util/Locale.html
  [5] https://www.iso.org/obp/ui/#search
  [6] http://web.archive.org/web/20061205090748/http://www.iso.ch/iso/en/prods-services/iso3166ma/02iso-3166-code-lists/list-en1.html

Issue description:
------------------

The Locale.getISO3Country() javadoc states as follows:
 
Java SE 6 [1]:
    Returns a three-letter abbreviation for this locale's country. If the locale
    doesn't specify a country, this will be the empty string. Otherwise, this
    will be an uppercase ISO 3166 3-letter country code. The ISO 3166-2 country
    codes can be found on-line at http://www.davros.org/misc/iso3166.txt.
    Throws:
      MissingResourceException - Throws MissingResourceException if the
      three-letter country abbreviation is not available for this locale.
 
Java SE 7 [2]:
    Returns a three-letter abbreviation for this locale's country. If the
    country matches an ISO 3166-1 alpha-2 code, the corresponding ISO 3166-1 alpha-3
    uppercase code is returned. If the locale doesn't specify a country, this will
    be the empty string.The ISO 3166-1 codes can be found on-line.
    Returns:
      A three-letter abbreviation of this locale's country.
    Throws:
      MissingResourceException - Throws MissingResourceException if the
      three-letter country abbreviation is not available for this locale.
 
(Notice that the link [3], mentioned in the class javadoc for [4], makes a redirection
to [5] (official ISO site), but it still can be found at [6].)
 

The above javadocs do not say anything concrete about the "Status" field for
country codes in ISO-3166 standard, so someone can expect that getISOCountries() in 
the specific Java SE release has consistent behaviour for all countries with
"Transitionally Reserved" status. Unfortunately, there is a contradiction between
JDK6 vs JDK7(and 8), as demonstrated by the minimized test below. 
 

Minimized test:
---------------

$ cat TestTRISOs.java 
import java.util.*;
 
public class TestTRISOs {
 
    public static void main(String... args) {
        final String[] trCodes = {"AN", "BU", "CS"};
 
        for (String trc : trCodes) {
            Locale loc = new Locale("", trc);
            try {
                String ic = loc.getISO3Country();
                System.out.println(trc + " => " + ic);
            } catch(MissingResourceException e) {
                System.out.println("(" + trc +") Unexpected exception thrown " + e);
            }
        }
    }
}
 
 
$ /cygdrive/c/java/6/binaries/windows-x64/bin/java TestTRISOs
AN => ANT
(BU) Unexpected exception thrown java.util.MissingResourceException: Couldn't find 3-letter country code for BU
CS => SCG
 
$ /cygdrive/c/java/7/binaries/windows-x64/bin/java TestTRISOs
AN => ANT
(BU) Unexpected exception thrown java.util.MissingResourceException: Couldn't find 3-letter country code for BU
(CS) Unexpected exception thrown java.util.MissingResourceException: Couldn't find 3-letter country code for CS
 
$ /cygdrive/c/java/8/binaries/windows-x64/bin/java TestTRISOs
AN => ANT
(BU) Unexpected exception thrown java.util.MissingResourceException: Couldn't find 3-letter country code for BU
(CS) Unexpected exception thrown java.util.MissingResourceException: Couldn't find 3-letter country code for CS
 
Such behaviour looks inconsistent and can be fixed or at least documented.