From d7c0f27e9fac104f613dcb672c243d3dc7eaf655 Mon Sep 17 00:00:00 2001
From: Thomas Neidhart <tn@apache.org>
Date: Wed, 1 Aug 2012 21:24:27 +0000
Subject: [PATCH] [MATH-836] Improve overflow check for negative values in
 Fraction constructor.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1368253 13f79535-47bb-0310-9956-ffa450edef68
---
 src/main/java/org/apache/commons/math3/fraction/Fraction.java | 4 ++--
 .../java/org/apache/commons/math3/fraction/FractionTest.java  | 3 +++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/apache/commons/math3/fraction/Fraction.java b/src/main/java/org/apache/commons/math3/fraction/Fraction.java
index f81ff0a94..08d3b9556 100644
--- a/src/main/java/org/apache/commons/math3/fraction/Fraction.java
+++ b/src/main/java/org/apache/commons/math3/fraction/Fraction.java
@@ -178,7 +178,7 @@ public class Fraction
         long overflow = Integer.MAX_VALUE;
         double r0 = value;
         long a0 = (long)FastMath.floor(r0);
-        if (a0 > overflow) {
+        if (FastMath.abs(a0) > overflow) {
             throw new FractionConversionException(value, a0, 1l);
         }
 
@@ -206,7 +206,7 @@ public class Fraction
             long a1 = (long)FastMath.floor(r1);
             p2 = (a1 * p1) + p0;
             q2 = (a1 * q1) + q0;
-            if ((p2 > overflow) || (q2 > overflow)) {
+            if ((FastMath.abs(p2) > overflow) || (FastMath.abs(q2) > overflow)) {
                 throw new FractionConversionException(value, p2, q2);
             }
 
diff --git a/src/test/java/org/apache/commons/math3/fraction/FractionTest.java b/src/test/java/org/apache/commons/math3/fraction/FractionTest.java
index c112ab752..37e22d105 100644
--- a/src/test/java/org/apache/commons/math3/fraction/FractionTest.java
+++ b/src/test/java/org/apache/commons/math3/fraction/FractionTest.java
@@ -60,6 +60,7 @@ public class FractionTest {
         } catch (MathArithmeticException ex) {
             // success
         }
+
         assertFraction(0, 1, new Fraction(0.00000000000001));
         assertFraction(2, 5, new Fraction(0.40000000000001));
         assertFraction(15, 1, new Fraction(15.0000000000001));
@@ -134,6 +135,8 @@ public class FractionTest {
     public void testIntegerOverflow() {
         checkIntegerOverflow(0.75000000001455192);
         checkIntegerOverflow(1.0e10);
+        checkIntegerOverflow(-1.0e10);
+        checkIntegerOverflow(-43979.60679604749);
     }
 
     private void checkIntegerOverflow(double a) {