E:\alcatel\borsotti\jtest>java -version
java version "1.6.0_07"
Java(TM) SE Runtime Environment (build 1.6.0_07-b06)
Java HotSpot(TM) Client VM (build 10.0-b23, mixed mode, sharing)

Does this problem occur on J2SE 1.4.x or 5.0.x ? Yes / No (pick one)
Not known

Operating System Configuration Information (be specific):
Windows Vista
SP1


Hardware Configuration Information (be specific):
AMD Athlon X2-64 2Gb RAM


Bug Description:
The Rhino scripting engine embedded in Java 6 recreates the "print" and "println" functions each time eva() is called.

Compile the following program:

import java.util.*;
import java.io.*;
import javax.script.*;

public class ScriptPrint {
    public static void main(String[] args) throws Exception {

        ScriptEngineManager factory = new ScriptEngineManager();
        ScriptEngine engine = factory.getEngineByName("JavaScript");
        ScriptContext cxt = engine.getContext();
        Bindings bin = cxt.getBindings(ScriptContext.ENGINE_SCOPE);

        System.out.println("scope----first----");
        for (Map.Entry<String,Object> e : bin.entrySet()){
            System.out.printf("ent: %s %s%n",e,e.getValue().getClass());
        }


        engine.eval("");
        System.out.println("scope----second----");
        for (Map.Entry<String,Object> e : bin.entrySet()){
            System.out.printf("ent: %s %s%n",e,e.getValue().getClass());

        }

        engine.eval("");
        System.out.println("scope----third----");
        for (Map.Entry<String,Object> e : bin.entrySet()){
            System.out.printf("ent: %s %s%n",e,e.getValue().getClass());

        }
    }
}

Then run it:

E:\alcatel\borsotti\jtest>java ScriptPrint
scope----first----
scope----second----
ent: println=sun.org.mozilla.javascript.internal.InterpretedFunction@133f1d7 class sun.org.mozilla.javascript.internal.I

nterpretedFunction
ent: context=javax.script.SimpleScriptContext@14a9972 class javax.script.SimpleScriptContext
ent: print=sun.org.mozilla.javascript.internal.InterpretedFunction@a01335 class sun.org.mozilla.javascript.internal.Inte

rpretedFunction
scope----third----
ent: println=sun.org.mozilla.javascript.internal.InterpretedFunction@14d3343 class sun.org.mozilla.javascript.internal.I
nterpretedFunction
ent: context=javax.script.SimpleScriptContext@14a9972 class javax.script.SimpleScriptContext

ent: print=sun.org.mozilla.javascript.internal.InterpretedFunction@1608e05 class sun.org.mozilla.javascript.internal.Int
erpretedFunction

Note that the execution of an eval(""), which should produce nothing, makes the

engine re-create the "print" and "println" functions.
It does this even when the calling program has deleted them (either with
bin.remove("print") or with engine.eval("delete print")).

This means that a script cannot redefine these functions.

Remedy: refrain from creating these functions in the engine, or make it
create them only once.