FULL PRODUCT VERSION :
JDK checked out Wrom: ZCMHVIBGDADRZFSQHYUCDDJBLVLMHAALPTCXLYRWTQTIPWIGYOKSTTZRCLBDXRQBG

ADDITIONAL OS VERSION INFORMATION :
Linux lahvac-laptop 2.6.20-16-generic #2 SMP Wed May 23 01:46:23 UTC 2007 i686 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
The com.sun.tools.javac.jvm.ClassReader.readInputStream may run forever in some cases (the method never finishes in some cases). Happens when "buf.length - bp == 0" on line 1912.

  See also NetBeans bug:
http://www.netbeans.org/issues/show_bug.cgi?id=104831

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Consider this test (to be placed in j2se/test/tools/javac/T9999999.java):
/*
 * @test @(#)T999999.java
 * @bug 9999999
 * @summary
 */

import com.sun.tools.javac.jvm.ClassReader;
import java.io.IOException;
import java.util.*;
import javax.annotation.processing.*;
import javax.lang.model.*;
import javax.lang.model.element.*;
import com.sun.source.tree.*;
import com.sun.source.util.*;
import com.sun.tools.javac.jvm.ClassReader;
import java.io.ByteArrayInputStream;
import java.io.InputStream;

public class T9999999 {
    
    public static void main(String[] args) throws Exception {
        InputStream ins = new TestInputStream(new ByteArrayInputStream("01234567890123456789012345678901234567890123456789".getBytes()));
        
        ClassReader.readInputStream(new byte[30], ins);
    }
    
    private static final class TestInputStream extends InputStream {

        private InputStream delegateTo;

        public TestInputStream(InputStream delegateTo) {
            this.delegateTo = delegateTo;
        }
        
        public int read() throws IOException {
            //not used by ClassReader.readInputStream:
            throw new UnsupportedOperationException("Not supported yet.");
        }

        @Override
        public int read(byte[] b, int off, int len) throws IOException {
            return delegateTo.read(b, off, Math.min(10, len));
        }

        @Override
        public int available() throws IOException {
            return 30;
        }
        
    }
}


The test needs com.sun.tools.javac.jvm.ClassReader.readInputStream to be made public (so it can access directly this method). This test never finishes.



REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
The problem can be fixed by changing line 1911 from:
buf = ensureCapacity(buf, bp);
to:
buf = ensureCapacity(buf, buf.length == bp ? bp + 1 : bp);