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Bug ID: JDK-6371401 java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError
JDK-6371401 : java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError

Details
Type:
Bug
Submit Date:
2006-01-11
Status:
Resolved
Updated Date:
2014-03-21
Project Name:
JDK
Resolved Date:
2009-11-24
Component:
core-libs
OS:
linux
Sub-Component:
java.math
CPU:
x86
Priority:
P4
Resolution:
Fixed
Affected Versions:
5.0,6
Fixed Versions:

Related Reports
Duplicate:
Relates:

Sub Tasks

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
EVALUATION

The BigInteger shift methods do not properly check for Integer.MIN_VALUE and should be updated to do so.
                                     
2006-01-11
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
+        }
+    }
+}
                                     
2009-10-20
PUBLIC COMMENTS

See
6371401: java.math.BigInteger.shift(Integer.MIN_VALUE) throws StackOverflowError
                                     
2009-10-20



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