Se permite fusionar solicitudes de compra realizadas

El SISB permite realizar fusiones de solicitudes de compra cuya orden de compra han sido aprobadas.

Verificar a que cuando una de las solicitudes de compra no tiene al menos una línea con un producto, genera el siguiente error:

Traceback (most recent call last):
  File "/home/edgar/bzr_diana/6.0/server/bin/netsvc.py", line 489, in dispatch
    result = ExportService.getService(service_name).dispatch(method, auth, params)
  File "/home/edgar/bzr_diana/6.0/server/bin/service/web_services.py", line 599, in dispatch
    res = fn(db, uid, *params)
  File "/home/edgar/bzr_diana/6.0/modules/audittrail/audittrail.py", line 522, in execute
    res = my_fct(db, uid, model, method, *args)
  File "/home/edgar/bzr_diana/6.0/modules/audittrail/audittrail.py", line 506, in my_fct
    return fct_src(db, uid_orig, model, method, *args)
  File "/home/edgar/bzr_diana/6.0/server/bin/osv/osv.py", line 122, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/edgar/bzr_diana/6.0/server/bin/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/edgar/bzr_diana/6.0/server/bin/osv/osv.py", line 167, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/edgar/bzr_diana/6.0/modules/sisb_merge_purchase_requisition/wizard/purchase_requisition_merge.py", line 64, in merge_requisitions
    product = self.pool.get('purchase.requisition.line').browse(cr, uid, prl_id)[0].product_id
IndexError: list index out of range