From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bryce McKinlay <bryce@albatross.co.nz>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org
Subject: Re: libgcj/2357: HashMap does not handle initialCapacity=0 correctly
Date: Sat, 24 Mar 2001 00:16:00 -0000
Message-id: <20010324081601.4355.qmail@sourceware.cygnus.com>
X-SW-Source: 2001-03/msg00248.html
List-Id: <gcc-prs.sourceware.org>

The following reply was made to PR libgcj/2357; it has been noted by GNATS.

From: Bryce McKinlay <bryce@albatross.co.nz>
To: mark@klomp.org
Cc: gcc-gnats@gcc.gnu.org, java-patches@gcc.gnu.org
Subject: Re: libgcj/2357: HashMap does not handle initialCapacity=0 correctly
Date: Sat, 24 Mar 2001 20:10:23 +1200

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 mark@klomp.org wrote:
 
 > >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.
 
 I've checked in this fix. It seems better to simply bump the initialCapacity to 1 if 0 is given, than to add a special case in hash(), making it slower.
 
 regards
 
   [ bryce ]
 
 
 
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 2001-03-24  Bryce McKinlay  <bryce@albatross.co.nz>
 
 	* java/util/HashMap.java (HashMap): If 0 is given for initialCapacity 
 	paramater, bump it to 1.
 	* java/util/Hashtable.java (Hashtable): Likewise.
 
 Index: Hashtable.java
 ===================================================================
 RCS file: /cvs/gcc/egcs/libjava/java/util/Hashtable.java,v
 retrieving revision 1.10.4.1
 diff -u -r1.10.4.1 Hashtable.java
 --- Hashtable.java	2001/02/22 04:26:06	1.10.4.1
 +++ Hashtable.java	2001/03/24 08:00:18
 @@ -179,7 +179,9 @@
        					 + initialCapacity);    
      if (loadFactor <= 0)
        throw new IllegalArgumentException("Illegal Load Factor: " + loadFactor);
 -     
 +    
 +    if (initialCapacity == 0)
 +      initialCapacity = 1;    
      buckets = new Entry[initialCapacity];
      this.loadFactor = loadFactor;
      this.threshold = (int) (initialCapacity * loadFactor);
 Index: HashMap.java
 ===================================================================
 RCS file: /cvs/gcc/egcs/libjava/java/util/HashMap.java,v
 retrieving revision 1.4.4.2
 diff -u -r1.4.4.2 HashMap.java
 --- HashMap.java	2001/02/22 04:26:06	1.4.4.2
 +++ HashMap.java	2001/03/24 08:00:18
 @@ -157,7 +157,7 @@
     * @param   loadFactor       the load factor
     * 
     * @throws   IllegalArgumentException    if (initialCapacity < 0) ||
 -   *                                          (initialLoadFactor > 1.0) ||
 +   *                                          (loadFactor <= 0)
     */
    public HashMap(int initialCapacity, float loadFactor)
      throws IllegalArgumentException
 @@ -167,7 +167,9 @@
        					 + initialCapacity);    
      if (loadFactor <= 0)
        throw new IllegalArgumentException("Illegal Load Factor: " + loadFactor);
 -  
 +
 +    if (initialCapacity == 0)
 +      initialCapacity = 1;
      buckets = new Entry[initialCapacity];
      this.loadFactor = loadFactor;
      this.threshold = (int) (initialCapacity * loadFactor);
 
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