FULL PRODUCT VERSION :
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
java.lang.ConditionalSpecialCasing uses the old (Unicode 4.0) casing condition for Greek sigma, i.e. "Final_Cased":
---
Final_Cased

Within the closest word boundaries containing C, there is a cased letter before C, and there is no cased letter after C.
---

Unicode 5.0 changed this to "Final_Sigma":
---
Final_Sigma

C is preceded by a sequence consisting of a cased letter and a case-ignorable sequence, and C is not followed by a sequence consisting of a case ignorable sequence and then a cased letter.
---


Specification: Unicode 5.0 (or later), 3.13 Default Case Operations

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Execute the attached test case.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
`lower` is the same string value as `expected`.
ACTUAL -
`lower` is not the same string value as `expected`.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Locale;

public class TestFinalSigma {
    public static void main(String[] args) {
        /*
         * DerivedCoreProperties.txt
         *
         * 0041 ; Cased # Lu LATIN CAPITAL LETTER A
         * 0042 ; Cased # Lu LATIN CAPITAL LETTER B
         * 003A ; Case_Ignorable # Po COLON
         */

        /*
         * SpecialCasing.txt
         *
         * <code>; <lower>; <title>; <upper>; (<condition_list>;)? # <comment>
         * 03A3; 03C2; 03A3; 03A3; Final_Sigma; # GREEK CAPITAL LETTER SIGMA
         * 03A3; 03C3; 03A3; 03A3; # GREEK CAPITAL LETTER SIGMA
         */

        String s = "A\u03A3:B";
        String lower = s.toLowerCase(Locale.ROOT);
        String expected = "a\u03C3:b";

        System.out.println(lower);
        System.out.println(expected);
        System.out.println("Same? " + expected.equals(lower));
    }
}
---------- END SOURCE ----------