FULL PRODUCT VERSION :
java version "1.6.0-ea"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-ea-b52)
Java HotSpot(TM) Client VM (build 1.6.0-ea-b52, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
For some classes, a call to retransformClasses fails with the following error, even when no transformers are present.

java.lang.UnsupportedOperationException: class redefinition failed: attempted to delete a method


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Compile the class referenced below and package it as a java.lang.instrument Java agent with the provided manifest. Run the Java2D demo shipped with the 1.6.0_b52 jdk, using this java Agent:

java -javaagent:TestAgent.jar -jar Java2Demo.jar


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No UnsupportedOperationException errors during the retransformClasses calls since no transformers are present.

ACTUAL -
Two java.lang.UnsupportedOperationException errors occurred, even though no transformers were present.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Retransform failed for class java2d.demos.Paint.TextureAnim$AnimVal
java.lang.UnsupportedOperationException: class redefinition failed: attempted to delete a method
        at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
        at sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:116)
        at TestAgent.reloadClasses(TestAgent.java:47)
        at TestAgent.run(TestAgent.java:31)
        at java.lang.Thread.run(Thread.java:611)
Retransform failed for class java2d.Tools
java.lang.UnsupportedOperationException: class redefinition failed: attempted to delete a method
        at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
        at sun.instrument.InstrumentationImpl.retransformClasses(InstrumentationImpl.java:116)
        at TestAgent.reloadClasses(TestAgent.java:47)
        at TestAgent.run(TestAgent.java:31)
        at java.lang.Thread.run(Thread.java:611)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
TestAgent.java
------------------------------------------------------------------------------
import java.lang.instrument.*;

public class TestAgent
implements Runnable
{
private final Instrumentation fInstrumentation;

public static void
premain( String agentArgs,
Instrumentation instrumentation)
{
System.out.println("TestAgent started");
new Thread(new TestAgent(instrumentation)).start();
}

public
TestAgent( Instrumentation instrumentation)
{
fInstrumentation = instrumentation;
}

public void
run()
{
// wait for some classes to be loaded
try { Thread.sleep(5000); } catch (InterruptedException ie) {}
reloadClasses();
}

    public void
    reloadClasses()
    {
        Class[] allClasses = fInstrumentation.getAllLoadedClasses();
        for (int i = 0; i < allClasses.length; i++)
        {
            try
            {
                // ignore arrays, primitives and classes loaded from the bootstrap loader
                if (!allClasses[i].isArray() &&
                    !allClasses[i].isPrimitive() &&
                     allClasses[i].getClassLoader() != null)
                {
                 fInstrumentation.retransformClasses(new Class[] { allClasses[i] });
                }
            }
            catch (Exception e)
            {
             System.out.println("Retransform failed for " + allClasses[i]);
                e.printStackTrace();
            }
        }
    }
}
------------------------------------------------------------------------------


TestAgent.mf
------------------------------------------------------------------------------
Manifest-Version: 1.0
Premain-Class: TestAgent
------------------------------------------------------------------------------

---------- END SOURCE ----------
Response from filer:
Adding the Can-Retransform-Classes manifest entry appears to make the
problem go away for static agents (loaded using the -javaagent option).
The error message is still very misleading though. Something like
"retransform not enabled for this agent" would make more sense.

The problem still occurs when loading the Agent via the remote attach
feature, even with this new manifest attribute. I've attached an
updated TestAgent.jar with the new manifest attribute that also supports
remote attach.
It works using -javaagent but has the same problem when loaded via
remote attach.
--

I ran the test on Windows with b52 and it duplicates with -javaagent (not just a late-binding agent).