**Impacted versions:**
11.0 
**Steps to reproduce:**
  - Create payslip
  - Add a contract with any structure
  - Add a structure in payslip, different from the one defined in step 2
  - Confirm or compute sheet

**Current behavior:**
Payslip is computed using the contract structure

**Expected behavior:**
Payslip should be computed using the payslip structure

**FYI:**  This is an issue because, sometimes, it's necessary to pay the employee using a structure different from their contract, e.g. in case of Christmas bonuses

**Video/Screenshot link (optional):**
[Video](https://www.youtube.com/watch?v=32H01n503uU&feature=youtu.be)


"""a class that will be used into the python code, mainly for usability purposes"""
            def sum(self, code, from_date, to_date=None):
                if to_date is None:
                    to_date = fields.Date.today()
                self.env.cr.execute("""SELECT sum(case when hp.credit_note = False then (pl.total) else (-pl.total) end)
                            FROM hr_payslip as hp, hr_payslip_line as pl
                            WHERE hp.employee_id = %s AND hp.state = 'done'
                            AND hp.date_from >= %s AND hp.date_to <= %s AND hp.id = pl.slip_id AND pl.code = %s""",
                            (self.employee_id, from_date, to_date, code))
                res = self.env.cr.fetchone()
                return res and res[0] or 0.0
        
        result_dict = {}
        rules_dict = {}
        worked_days_dict = {}
        inputs_dict = {}
        blacklist = []
        payslip = self.env['hr.payslip'].browse(payslip_id)
        for worked_days_line in payslip.worked_days_line_ids:
            worked_days_dict[worked_days_line.code] = worked_days_line
        for input_line in payslip.input_line_ids:
            inputs_dict[input_line.code] = input_line
        categories = BrowsableObject(payslip.employee_id.id, {}, self.env)
        inputs = InputLine(payslip.employee_id.id, inputs_dict, self.env)
        worked_days = WorkedDays(payslip.employee_id.id, worked_days_dict, self.env)
        payslips = Payslips(payslip.employee_id.id, payslip, self.env)
        rules = BrowsableObject(payslip.employee_id.id, rules_dict, self.env)
        baselocaldict = {'categories': categories, 'rules': rules, 'payslip': payslips, 'worked_days': worked_days, 'inputs': inputs}