Fix silent int overflow in Fraction.getFraction(double)

src/main/java/org/apache/commons/lang3/math/Fraction.java

@@ -174,7 +174,10 @@ public static Fraction getFraction(double value) {
         if (i == 25) {
             throw new ArithmeticException("Unable to convert double to fraction");
         }
-        return getReducedFraction((numer0 + wholeNumber * denom0) * sign, denom0);
+        // wholeNumber can be up to Integer.MAX_VALUE while denom0 > 1 for any non-integer value,
+        // so the int product overflows for values near the limit; check it instead of wrapping silently.
+        final int numerator = Math.addExact(numer0, mulAndCheck(wholeNumber, denom0));
+        return getReducedFraction(numerator * sign, denom0);
     }
 
     /**

src/test/java/org/apache/commons/lang3/math/FractionTest.java

@@ -334,6 +334,10 @@ void testFactory_double() {
         assertThrows(ArithmeticException.class, () -> Fraction.getFraction(Double.POSITIVE_INFINITY));
         assertThrows(ArithmeticException.class, () -> Fraction.getFraction(Double.NEGATIVE_INFINITY));
         assertThrows(ArithmeticException.class, () -> Fraction.getFraction((double) Integer.MAX_VALUE + 1));
+        // near Integer.MAX_VALUE with a fractional part: numerator overflows an int, so it must throw
+        // rather than silently return a wrong fraction (previously -3/2 and -2147483647/2 respectively)
+        assertThrows(ArithmeticException.class, () -> Fraction.getFraction(2147483646.5d));
+        assertThrows(ArithmeticException.class, () -> Fraction.getFraction(1073741824.5d));
 
         // zero
         Fraction f = Fraction.getFraction(0.0d);