[LANG-380]

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@599500 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/math/Fraction.java

@@ -463,6 +463,9 @@ public final class Fraction extends Number implements Comparable {
      * @return a new reduced fraction instance, or this if no simplification possible
      */
     public Fraction reduce() {
+        if (numerator == 0) {
+            return equals(ZERO) ? this : ZERO;
+        }
         int gcd = greatestCommonDivisor(Math.abs(numerator), denominator);
         if (gcd == 1) {
             return this;