Error in return of account_voucher function

Move_ID True
Number d-01630223632233003511/2013/6055/1
[2013-07-03 11:42:08,999][20130701diana] ERROR:db.cursor:Programming error: operator does not exist: integer = boolean
LINE 1: ...='DP 369852',write_uid=1,write_date=now() where id IN (true)
                                                              ^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
, in query update account_move set "ref"=%s,write_uid=%s,write_date=now() where id IN %s
[2013-07-03 11:42:08,999][20130701diana] ERROR:web-services:Uncaught exception
Traceback (most recent call last):
  File "/home/jmoreno/instancia/6.0/server/bin/osv/osv.py", line 122, in wrapper
    return f(self, dbname, *args, **kwargs)
  File "/home/jmoreno/instancia/6.0/server/bin/osv/osv.py", line 176, in execute
    res = self.execute_cr(cr, uid, obj, method, *args, **kw)
  File "/home/jmoreno/instancia/6.0/server/bin/osv/osv.py", line 167, in execute_cr
    return getattr(object, method)(cr, uid, *args, **kw)
  File "/home/jmoreno/instancia/6.0/modules/sisb_banking/model/account_bank_statement.py", line 121, in button_confirm_bank
    uid, ids, context=context)
  File "/home/jmoreno/instancia/6.0/modules/account/account_bank_statement.py", line 355, in button_confirm_bank
    self.create_move_from_st_line(cr, uid, st_line.id, company_currency_id, st_line_number, context)
  File "/home/jmoreno/instancia/6.0/modules/sisb_banking/model/account_bank_statement.py", line 45, in create_move_from_st_line
    res = account_move_obj.write(cr, uid, mov_id, {'ref': st_line.name,}, context=context)
  File "/home/jmoreno/instancia/6.0/modules/account/account.py", line 1257, in write
    result = super(osv.osv, self).write(cr, uid, ids, vals, c)
  File "/home/jmoreno/instancia/6.0/server/bin/osv/orm.py", line 3443, in write
    'where id IN %s', upd1 + [sub_ids])
  File "/home/jmoreno/instancia/6.0/server/bin/sql_db.py", line 78, in wrapper
    return f(self, *args, **kwargs)
  File "/home/jmoreno/instancia/6.0/server/bin/sql_db.py", line 131, in execute
    res = self._obj.execute(query, params)
ProgrammingError: operator does not exist: integer = boolean
LINE 1: ...='DP 369852',write_uid=1,write_date=now() where id IN (true)
                                                              ^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.

[2013-07-03 11:42:09,002][20130701diana] DEBUG:web-services:netrpc: rpc-dispatching exception
Traceback (most recent call last):
  File "/home/jmoreno/instancia/6.0/server/bin/service/netrpc_server.py", line 70, in run
    result = self.dispatch(msg[0], msg[1], msg[2:])
  File "/home/jmoreno/instancia/6.0/server/bin/netsvc.py", line 499, in dispatch
    raise OpenERPDispatcherException(e, tb_s)
OpenERPDispatcherException

the function to run in account_voucher this overwriting the return value to a boolean should return an integer, as well was defined in the original function.

Original Inherit Fuction:

def create_move_from_st_line(self, cr, uid, st_line_id, company_currency_id, next_number, context=None):
        voucher_obj = self.pool.get('account.voucher')
        wf_service = netsvc.LocalService("workflow")
        move_line_obj = self.pool.get('account.move.line')
        bank_st_line_obj = self.pool.get('account.bank.statement.line')
        st_line = bank_st_line_obj.browse(cr, uid, st_line_id, context=context)
        if st_line.voucher_id:
            voucher_obj.write(cr, uid, [st_line.voucher_id.id],
                            {'number': next_number,
                            'date': st_line.date,
                            'period_id': st_line.statement_id.period_id.id},
                            context=context)
            if st_line.voucher_id.state == 'cancel':
                voucher_obj.action_cancel_draft(cr, uid, [st_line.voucher_id.id], context=context)
            wf_service.trg_validate(uid, 'account.voucher', st_line.voucher_id.id, 'proforma_voucher', cr)

            v = voucher_obj.browse(cr, uid, st_line.voucher_id.id, context=context)
            bank_st_line_obj.write(cr, uid, [st_line_id], {
                'move_ids': [(4, v.move_id.id, False)]
            })

            return move_line_obj.write(cr, uid, [x.id for x in v.move_ids], {'statement_id': st_line.statement_id.id}, context=context)
        return super(account_bank_statement, self).create_move_from_st_line(cr, uid, st_line.id, company_currency_id, next_number, context=context)

Proposal for the correction function:

def create_move_from_st_line(self, cr, uid, st_line_id, company_currency_id, next_number, context=None):
        voucher_obj = self.pool.get('account.voucher')
        wf_service = netsvc.LocalService("workflow")
        move_line_obj = self.pool.get('account.move.line')
        bank_st_line_obj = self.pool.get('account.bank.statement.line')
        st_line = bank_st_line_obj.browse(cr, uid, st_line_id, context=context)
        if st_line.voucher_id:
            voucher_obj.write(cr, uid, [st_line.voucher_id.id],
                            {'number': next_number,
                            'date': st_line.date,
                            'period_id': st_line.statement_id.period_id.id},
                            context=context)
            if st_line.voucher_id.state == 'cancel':
                voucher_obj.action_cancel_draft(cr, uid, [st_line.voucher_id.id], context=context)
            wf_service.trg_validate(uid, 'account.voucher', st_line.voucher_id.id, 'proforma_voucher', cr)

            v = voucher_obj.browse(cr, uid, st_line.voucher_id.id, context=context)
            bank_st_line_obj.write(cr, uid, [st_line_id], {
                'move_ids': [(4, v.move_id.id, False)]
            })

            move_line_obj.write(cr, uid, [x.id for x in v.move_ids], {'statement_id': st_line.statement_id.id}, context=context)
        return super(account_bank_statement, self).create_move_from_st_line(cr, uid, st_line.id, company_currency_id, next_number, context=context)