While playing with jython roundup tracker (http://bugs.jython.org/) 
locally, I hit a problem during user login.

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Traceback (most recent call last):
  File "/opt/tracker-roundup//lib/python2.6/site-
packages/roundup/cgi/client.py", line 442, in inner_main
    html = self.handle_action()
  File "/opt/tracker-roundup//lib/python2.6/site-
packages/roundup/cgi/client.py", line 1121, in handle_action
    action = self.form['@action'].value.lower()
AttributeError: 'list' object has no attribute 'value'
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On investigating the problem, I found one earlier issue similar to this 
one: http://issues.roundup-tracker.org/issue2550504

I am attaching a patch that fixed the problem for me. Note that my test 
was against 1.4.10 (which jython tracker uses) even though I generated 
the patch against trunk.

This bug usually indicates the <form> for login has somehow managed to get two <input> 
fields with the name "@action". This is usually due to an error.

I will modify Roundup to detect multiple @action values and raise a more useful error.