Author: bayard
Date: Mon Jan 17 04:30:05 2011
New Revision: 1059749
URL: http://svn.apache.org/viewvc?rev=1059749&view=rev
Log:
Adding first method check from Math's MathUtils.gcd method; and unit tests
showing that this was needed. Bug reported and solved by Christian Semrau
[LANG-662]
Modified:
commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/math/Fraction.java
commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/math/FractionTest.java
Modified:
commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/math/Fraction.java
URL:
http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/math/Fraction.java?rev=1059749&r1=1059748&r2=1059749&view=diff
==============================================================================
---
commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/math/Fraction.java
(original)
+++
commons/proper/lang/trunk/src/main/java/org/apache/commons/lang3/math/Fraction.java
Mon Jan 17 04:30:05 2011
@@ -579,8 +579,15 @@ public final class Fraction extends Numb
* @return the greatest common divisor, never zero
*/
private static int greatestCommonDivisor(int u, int v) {
- //if either op. is abs 0 or 1, return 1:
- if (Math.abs(u) <= 1 || Math.abs(v) <= 1) {
+ // From Commons Math:
+ if ((u == 0) || (v == 0)) {
+ if ((u == Integer.MIN_VALUE) || (v == Integer.MIN_VALUE)) {
+ throw new ArithmeticException("overflow: gcd is 2^31");
+ }
+ return Math.abs(u) + Math.abs(v);
+ }
+ //if either operand is abs 1, return 1:
+ if (Math.abs(u) == 1 || Math.abs(v) == 1) {
return 1;
}
// keep u and v negative, as negative integers range down to
Modified:
commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/math/FractionTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/math/FractionTest.java?rev=1059749&r1=1059748&r2=1059749&view=diff
==============================================================================
---
commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/math/FractionTest.java
(original)
+++
commons/proper/lang/trunk/src/test/java/org/apache/commons/lang3/math/FractionTest.java
Mon Jan 17 04:30:05 2011
@@ -330,6 +330,11 @@ public class FractionTest extends TestCa
f = Fraction.getReducedFraction(-7, Integer.MIN_VALUE);
fail("Expecting ArithmeticException");
} catch (ArithmeticException ex) {}
+
+ // LANG-662
+ f = Fraction.getReducedFraction(Integer.MIN_VALUE, 2);
+ assertEquals(Integer.MIN_VALUE / 2, f.getNumerator());
+ assertEquals(1, f.getDenominator());
}
public void testFactory_double() {
@@ -643,6 +648,11 @@ public class FractionTest extends TestCa
assertEquals(0, result.getNumerator());
assertEquals(1, result.getDenominator());
assertSame(result, Fraction.ZERO);
+
+ f = Fraction.getFraction(Integer.MIN_VALUE, 2);
+ result = f.reduce();
+ assertEquals(Integer.MIN_VALUE / 2, result.getNumerator());
+ assertEquals(1, result.getDenominator());
}
public void testInvert() {
