(commons-lang) branch master updated: LANG-1834 Fix Fraction reduction for Integer.MIN_VALUE (#1794)

[ggregory]

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garydgregory pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
     new e992a498d LANG-1834 Fix Fraction reduction for Integer.MIN_VALUE 
(#1794)
e992a498d is described below

commit e992a498d711fc4302d5ad89e80511db41db2f11
Author: Indy <109909013+makarandhi...@users.noreply.github.com>
AuthorDate: Sat Sep 19 01:37:24 2026 +0530

    LANG-1834 Fix Fraction reduction for Integer.MIN_VALUE (#1794)
---
 .../org/apache/commons/lang3/math/Fraction.java    |  4 ++--
 .../apache/commons/lang3/math/FractionTest.java    | 24 ++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/apache/commons/lang3/math/Fraction.java 
b/src/main/java/org/apache/commons/lang3/math/Fraction.java
index 3ba548fac..a57845dd2 100644
--- a/src/main/java/org/apache/commons/lang3/math/Fraction.java
+++ b/src/main/java/org/apache/commons/lang3/math/Fraction.java
@@ -328,8 +328,8 @@ public static Fraction getReducedFraction(int numerator, 
int denominator) {
         if (numerator == 0) {
             return ZERO; // normalize zero.
         }
-        // allow 2^k/-2^31 as a valid fraction (where k>0)
-        if (denominator == Integer.MIN_VALUE && (numerator & 1) == 0) {
+        // Reduce common powers of two before sign normalization to avoid 
negating Integer.MIN_VALUE.
+        while ((numerator & 1) == 0 && (denominator & 1) == 0) {
             numerator /= 2;
             denominator /= 2;
         }
diff --git a/src/test/java/org/apache/commons/lang3/math/FractionTest.java 
b/src/test/java/org/apache/commons/lang3/math/FractionTest.java
index 7affb71cd..aac15b782 100644
--- a/src/test/java/org/apache/commons/lang3/math/FractionTest.java
+++ b/src/test/java/org/apache/commons/lang3/math/FractionTest.java
@@ -1114,6 +1114,30 @@ void testReducedFactory_int_int() {
         assertEquals(1, f.getDenominator());
     }
 
+    @Test
+    void testReducedFactoryIntegerMinValue() {
+        Fraction f = Fraction.getReducedFraction(Integer.MIN_VALUE, -2);
+        assertEquals(1073741824, f.getNumerator());
+        assertEquals(1, f.getDenominator());
+
+        f = Fraction.getReducedFraction(Integer.MIN_VALUE, -6);
+        assertEquals(1073741824, f.getNumerator());
+        assertEquals(3, f.getDenominator());
+
+        f = Fraction.getReducedFraction(Integer.MIN_VALUE, Integer.MIN_VALUE);
+        assertEquals(1, f.getNumerator());
+        assertEquals(1, f.getDenominator());
+
+        assertThrows(ArithmeticException.class, () -> 
Fraction.getReducedFraction(Integer.MIN_VALUE, -1));
+        assertThrows(ArithmeticException.class, () -> 
Fraction.getReducedFraction(Integer.MIN_VALUE, -3));
+
+        f = Fraction.getReducedFraction(-2, Integer.MIN_VALUE);
+        assertEquals(1, f.getNumerator());
+        assertEquals(1073741824, f.getDenominator());
+
+        assertThrows(ArithmeticException.class, () -> 
Fraction.getReducedFraction(-7, Integer.MIN_VALUE));
+    }
+
     @Test
     void testSubtract() {
         Fraction f;