From mboxrd@z Thu Jan  1 00:00:00 1970
From: mark@klomp.org
To: gcc-gnats@gcc.gnu.org
Subject: libgcj/2357: HashMap does not handle initialCapacity=0 correctly
Date: Fri, 23 Mar 2001 04:26:00 -0000
Message-id: <20010323121731.25071.qmail@sourceware.cygnus.com>
X-SW-Source: 2001-03/msg00227.html
List-Id: <gcc-prs.sourceware.org>

>Number:         2357
>Category:       libgcj
>Synopsis:       HashMap does not handle initialCapacity=0 correctly
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Mar 23 04:26:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     mark@klomp.org
>Release:        gcc version 3.0 20010323 (prerelease)
>Organization:
>Environment:

>Description:
When the initialCapacity of a HashMap is zero then bucket.length will be zero and then you will get a ArithmetichException in the hash() method.

import java.util.HashMap;

public class HashMapTest {
    public static void main(String args[]) {
        HashMap map = new HashMap(0);
        map.get(new Object());
    }
}

Exception in thread "main" java.lang.ArithmeticException: / by zero
   at 0x4016836d: _Jv_ThrowSignal (/usr/local/gcc/lib/libgcj.so.1)
   at 0x40168402: _Jv_ThrowSignal (/usr/local/gcc/lib/libgcj.so.1)
   at 0x401dc840: java.util.HashMap.hash(java.lang.Object) (/usr/local/gcc/lib/libgcj.so.1)
   at 0x401dc0a4: java.util.HashMap.get(java.lang.Object) (/usr/local/gcc/lib/libgcj.so.1)
   at 0x08048a82: HashMapTest.main(java.lang.String[]) (/tmp/HashMapTest.java:6)   at 0x4017f0a5: gnu.gcj.runtime.FirstThread.run() (/usr/local/gcc/lib/libgcj.so.1)
   at 0x40189d92: java.lang.Thread.run_(java.lang.Object) (/usr/local/gcc/lib/libgcj.so.1)
   at 0x402a2e68: _Jv_ThreadSetPriority(_Jv_Thread_t, int) (/usr/local/gcc/lib/libgcj.so.1)
   at 0x4045653d: GC_start_routine (/usr/local/gcc/lib/libgcjgc.so.1)
   at 0x4046fc75: pthread_detach (/lib/libpthread.so.0)
   at 0x40559eba: __clone (/lib/libc.so.6)
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: