JDK-6371401 : java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError
  • Type: Bug
  • Component: core-libs
  • Sub-Component: java.math
  • Affected Version: 5.0,6
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: linux
  • CPU: x86
  • Submitted: 2006-01-11
  • Updated: 2017-05-16
  • Resolved: 2009-11-24
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JDK 7
7 b77Fixed
Related Reports
Duplicate :  
JDK-6590391 - BigInteger.ONE.shiftLeft(Integer.MIN_VALUE) Recurses Infinitely
Relates :  
JDK-6910473 - java.math.BigInteger.bitLength() may return negative "int" on large numbers
Description
FULL PRODUCT VERSION :
java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Client VM (build 1.5.0_05-b05, mixed mode, sharing)


ADDITIONAL OS VERSION INFORMATION :
2.6.11-6mdk #1 Tue Mar 22 16:04:32 CET 2005 i686 Intel(R) Pentium(R) 4 CPU 2.26GHz unknown GNU/Linux


A DESCRIPTION OF THE PROBLEM :
If you shift a BigInteger by Integer.MIN_VALUE, it throws StackOverflowError (probably because Integer.MIN_VALUE == -Integer.MIN_VALUE

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
BigInteger.ONE.shiftRight(Intger.MIN_VALUE)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
BigInteger.ZERO
ACTUAL -
an Error: StackOverflowError

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.math.BigInteger;
public class BugShift{
    public static void main(String[] args){
        System.out.println(BigInteger.ONE.shiftRight(Integer.MIN_VALUE));
    }
}
---------- END SOURCE ----------
Comments
SUGGESTED FIX # HG changeset patch # User darcy # Date 1256057488 25200 # Node ID 0dd3d16e81836f39485d436e6e088bc23d4483da # Parent 052f056f7ba193b303f6c84a5523e40f58dd8c42 6371401: java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError Reviewed-by: alanb --- a/src/share/classes/java/math/BigInteger.java Tue Oct 20 15:35:55 2009 +0100 +++ b/src/share/classes/java/math/BigInteger.java Tue Oct 20 09:51:28 2009 -0700 @@ -2051,6 +2051,8 @@ public class BigInteger extends Number i * * @param n shift distance, in bits. * @return {@code this << n} + * @throws ArithmeticException if the shift distance is {@code + * Integer.MIN_VALUE}. * @see #shiftRight */ public BigInteger shiftLeft(int n) { @@ -2058,8 +2060,13 @@ public class BigInteger extends Number i return ZERO; if (n==0) return this; - if (n<0) - return shiftRight(-n); + if (n<0) { + if (n == Integer.MIN_VALUE) { + throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported."); + } else { + return shiftRight(-n); + } + } int nInts = n >>> 5; int nBits = n & 0x1f; @@ -2097,13 +2104,20 @@ public class BigInteger extends Number i * * @param n shift distance, in bits. * @return {@code this >> n} + * @throws ArithmeticException if the shift distance is {@code + * Integer.MIN_VALUE}. * @see #shiftLeft */ public BigInteger shiftRight(int n) { if (n==0) return this; - if (n<0) - return shiftLeft(-n); + if (n<0) { + if (n == Integer.MIN_VALUE) { + throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported."); + } else { + return shiftLeft(-n); + } + } int nInts = n >>> 5; int nBits = n & 0x1f; --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/java/math/BigInteger/ExtremeShiftingTests.java Tue Oct 20 09:51:28 2009 -0700 @@ -0,0 +1,48 @@ +/* + * Copyright 2009 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + */ + +/* + * @test + * @bug 6371401 + * @summary Tests of shiftLeft and shiftRight on Integer.MIN_VALUE + * @author Joseph D. Darcy + */ +import static java.math.BigInteger.*; + +public class ExtremeShiftingTests { + public static void main(String... args) { + try { + ONE.shiftLeft(Integer.MIN_VALUE); + throw new RuntimeException("Should not reach here."); + } catch (ArithmeticException ae) { + ; // Expected + } + + try { + ONE.shiftRight(Integer.MIN_VALUE); + throw new RuntimeException("Should not reach here."); + } catch (ArithmeticException ae) { + ; // Expected + } + } +}
20-10-2009
PUBLIC COMMENTS See 6371401: java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError
20-10-2009
EVALUATION The BigInteger shift methods do not properly check for Integer.MIN_VALUE and should be updated to do so.
11-01-2006