Hello,

when i duplicate the purchase request it return this error

Odoo Server Error

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 544, in _handle_exception
    return super(JsonRequest, self)._handle_exception(exception)
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 581, in dispatch
    result = self._call_function(**self.params)
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 317, in _call_function
    return checked_call(self.db, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/service/model.py", line 118, in wrapper
    return f(dbname, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 314, in checked_call
    return self.endpoint(*a, **kw)
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 810, in __call__
    return self.method(*args, **kw)
  File "/usr/lib/python2.7/dist-packages/openerp/http.py", line 410, in response_wrap
    response = f(*args, **kw)
  File "/usr/lib/python2.7/dist-packages/openerp/addons/web/controllers/main.py", line 944, in call_kw
    return self._call_kw(model, method, args, kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/addons/web/controllers/main.py", line 936, in _call_kw
    return getattr(request.registry.get(model), method)(request.cr, request.uid, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/addons/purchase/purchase.py", line 368, in copy
    new_id = super(purchase_order, self).copy(cr, uid, id, default=default, context=context)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/models.py", line 4890, in copy
    data = self.copy_data(cr, uid, id, default, context)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/addons/mail/mail_thread.py", line 464, in copy_data
    return super(mail_thread, self).copy_data(cr, uid, id, default=default, context=context)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/models.py", line 4788, in copy_data
    data = self.read(cr, uid, [id], fields_to_copy.keys(), context=context)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 268, in wrapper
    return old_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/models.py", line 3144, in read
    result = BaseModel.read(records, fields, load=load)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 266, in wrapper
    return new_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/models.py", line 3179, in read
    self._read_from_database(stored, inherited)
  File "/usr/lib/python2.7/dist-packages/openerp/api.py", line 266, in wrapper
    return new_api(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/models.py", line 3311, in _read_from_database
    cr.execute(query_str, [tuple(sub_ids)] + where_params)
  File "/usr/lib/python2.7/dist-packages/openerp/sql_db.py", line 158, in wrapper
    return f(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/openerp/sql_db.py", line 234, in execute
    res = self._obj.execute(query, params)
IndexError: list index out of range