Issue1546

I tried to run web.py with modjy and got this exception.
I tried moving jython.jar from the WEB-INF/lib directory
to tomcat lib directory but it didn't help.

java.lang.NullPointerException
       org.python.core.PyType.computeLinearMro(PyType.java:487)
       org.python.core.PyJavaType.init(PyJavaType.java:187)
       org.python.core.PyType.createType(PyType.java:1175)
       org.python.core.PyType.addFromClass(PyType.java:1116)
       org.python.core.PyType.fromClass(PyType.java:1192)
       org.python.core.PyObject.<init>(PyObject.java:67)
       org.python.core.PyMethod.<init>(PyMethod.java:30)
       org.python.core.PyReflectedFunction._doget(PyReflectedFunction.java:46)
       org.python.core.PyObject.__get__(PyObject.java:3672)
       org.python.core.PyObject.object___findattr__(PyObject.java:3716)
       org.python.core.PyObject.object___getattribute__(PyObject.java:3688)
       org.python.core.PyObject$object___getattribute___exposer.__call__(Unknown
Source)
       org.python.core.PyObjectDerived.__findattr_ex__(PyObjectDerived.java:993)
       org.python.core.PyObject.__getattr__(PyObject.java:929)
       modjy.modjy_publish$py.get_app_object$4(C:\java\jython2.5.1\Lib\modjy\modjy_publish.py:63)
       modjy.modjy_publish$py.call_function(C:\java\jython2.5.1\Lib\modjy\modjy_publish.py)
       org.python.core.PyTableCode.call(PyTableCode.java:165)
       org.python.core.PyBaseCode.call(PyBaseCode.java:297)
       org.python.core.PyBaseCode.call(PyBaseCode.java:191)
       org.python.core.PyFunction.__call__(PyFunction.java:385)
       org.python.core.PyFunction.__call__(PyFunction.java:380)
       org.python.modules.SynchronizedCallable.__call__(synchronize.java:53)
       org.python.core.PyObject.__call__(PyObject.java:355)
       org.python.core.PyMethod.__call__(PyMethod.java:215)
       org.python.core.PyMethod.instancemethod___call__(PyMethod.java:221)
       org.python.core.PyMethod.__call__(PyMethod.java:206)
       org.python.core.PyObject.__call__(PyObject.java:414)
       org.python.core.PyObject.__call__(PyObject.java:418)
       modjy.modjy$py.dispatch_to_application$9(C:\java\jython2.5.1\Lib\modjy\modjy.py:103)
       modjy.modjy$py.call_function(C:\java\jython2.5.1\Lib\modjy\modjy.py)
       org.python.core.PyTableCode.call(PyTableCode.java:165)
       org.python.core.PyBaseCode.call(PyBaseCode.java:297)
       org.python.core.PyBaseCode.call(PyBaseCode.java:191)
       org.python.core.PyFunction.__call__(PyFunction.java:385)
       org.python.core.PyMethod.__call__(PyMethod.java:215)
       org.python.core.PyMethod.instancemethod___call__(PyMethod.java:221)
       org.python.core.PyMethod.__call__(PyMethod.java:206)
       org.python.core.PyObject.__call__(PyObject.java:432)
       org.python.core.PyObject.__call__(PyObject.java:436)
       modjy.modjy$py.service$7(C:\java\jython2.5.1\Lib\modjy\modjy.py:80)
       modjy.modjy$py.call_function(C:\java\jython2.5.1\Lib\modjy\modjy.py)
       org.python.core.PyTableCode.call(PyTableCode.java:165)
       org.python.core.PyBaseCode.call(PyBaseCode.java:297)
       org.python.core.PyBaseCode.call(PyBaseCode.java:191)
       org.python.core.PyFunction.__call__(PyFunction.java:385)
       org.python.core.PyMethod.__call__(PyMethod.java:215)
       org.python.core.PyMethod.instancemethod___call__(PyMethod.java:221)
       org.python.core.PyMethod.__call__(PyMethod.java:206)
       org.python.core.PyObject.__call__(PyObject.java:367)
       org.python.core.PyObject._jcallexc(PyObject.java:3500)
       org.python.proxies.modjy.modjy$modjy_servlet$2.service(Unknown Source)
       com.xhaus.modjy.ModjyJServlet.service(ModjyJServlet.java:126)
       javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
note The full stack trace of the root cause is available in the Apache
Tomcat/6.0.18 logs.

We really need to isolate the problem more, ideally with a reproducible script. Though if this can only be reproduced within modjy, the script case could be more difficult to produce

We've had a variety of problems running jython under tomcat, and other containers. They are not necessarily modjy specific. The following bug, for example,

Jython crashes in unknown circumstances when running on some servlet containers.
http://bugs.jython.org/issue1489

can be reproduced with a very small piece of code that doesn't use modjy.

Please can I ask you to try running the attached java code, from the above bug, and see if that recreates the problem you're seeing? That should give us a good starting point.

Lastly, what version of jython are you running? Leo made some fixes to the classloading system back in January. 

http://fisheye3.atlassian.com/changelog/jython/?cs=6970

I think that this problem is related to classloading, or related classloading configuration for the container.

It would be good if you try out Leo's fixes by running the latest code. Can you build from trunk and try that to see if it fixes the problem?

Philip, we really need to get a 2.5.2 out the door; there's too many outstanding bug fixes unreleased.

Is this still an issue?