Try the following example in Rhino's shell: /* runnable.js Demonstrates use of JavaScript from JShell, implementing the interface java.lang.Runnable using the new syntax. by Patrick C. Beard. */ var runnableDate = new Date(); runnableDate.run = function() { print('runnableDate.run() here.'); } // create a java.lang.Runnable. var runnable = new java.lang.Runnable(runnableDate); Store this in "runnable.js" and type this in the shell: js> load('runnable.js') js> runnable adapter0@bb070d js> runnable.self java.lang.NullPointerException java.lang.NullPointerException at org.mozilla.javascript.ScriptableObject.getTopLevelScope(ScriptableObject.java:12 89) at org.mozilla.javascript.ScriptableObject.getClassPrototype(ScriptableObject.java:1 263) at org.mozilla.javascript.ScriptableObject.getFunctionPrototype(ScriptableObject.jav a:1242) at org.mozilla.javascript.JavaMembers.reflectMethod(JavaMembers.java:305) at org.mozilla.javascript.JavaMembers.reflect(JavaMembers.java:319) at org.mozilla.javascript.JavaMembers.<init>(JavaMembers.java:58) at org.mozilla.javascript.JavaMembers.lookupClass(JavaMembers.java:488) at org.mozilla.javascript.NativeJavaObject.<init>(NativeJavaObject.java:72) at org.mozilla.javascript.NativeJavaObject.wrap(NativeJavaObject.java:191) at org.mozilla.javascript.NativeJavaMethod.call(NativeJavaMethod.java:215) at org.mozilla.javascript.ScriptableObject.getDefaultValue(ScriptableObject.java:528 ) at org.mozilla.javascript.NativeDate.getDefaultValue(NativeDate.java:101) at org.mozilla.javascript.ScriptRuntime.toString(ScriptRuntime.java:408) at org.mozilla.javascript.Context.toString(Context.java:1108) at org.mozilla.javascript.tools.shell.Main.processSource(Main.java:287) at org.mozilla.javascript.tools.shell.Main.exec(Main.java:146) at org.mozilla.javascript.tools.shell.Main.main(Main.java:74) at org.jxe.tools.java.Java.main(Java.java:113) at org.jxe.kernel.Tool$ToolThread.run(Tool.java:215) The problem seems to be that org.mozilla.javascript.ScriptableObject.getTopLevelScope() is getting passed a null scope to begin with.

Reassign to my other account

I checked in the fix and removed the negative tests that started failing as a result (see thread in n.p.m.jseng)