**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)


if not self.contract_id.struct_id:
            return
        self.struct_id = self.contract_id.struct_id
        
        contracts = self.env['hr.contract'].browse(contract_ids)
        worked_days_line_ids = self.get_worked_day_lines(contracts, date_from, date_to)
        worked_days_lines = self.worked_days_line_ids.browse([])
        for r in worked_days_line_ids:
            worked_days_lines += worked_days_lines.new(r)
        self.worked_days_line_ids = worked_days_lines
        input_line_ids = self.get_inputs(contracts, date_from, date_to)
        input_lines = self.input_line_ids.browse([])
        for r in input_line_ids:
            input_lines += input_lines.new(r)
        self.input_line_ids = input_lines
        return
    @api.onchange('contract_id')
    def onchange_contract(self):
        if not self.contract_id:
            self.struct_id = False
        self.with_context(contract=True).onchange_employee()
        return
    def get_salary_line_total(self, code):
        self.ensure_one()
        line = self.line_ids.filtered(lambda line: line.code == code)
        if line:
            return line[0].total
        else:
            return 0.0
class HrPayslipLine(models.Model):