**Impacted versions:**
11.0

**Steps to reproduce:**

- Create a SO with two lines:
-  - _LIne1_: Product: product50, Ordered Quantity: 1.000, Unit Price: 50.0
-  - _Line2_: Product: product12, Ordered Quantity: 1.000, Unit Price: 12.0

- Confirm the SO
- Click on "Create Invoice" (choosing for example "Invoiceable lines")
- Validate the invoice
- Click on "Add Credit Note" (choosing for example "Create a draft credit note")
- Validate the Credit Note

- Go to Reporting->Sales and open the Pivot view
- Enable the following measures:
- - Amount Invoiced
- - Amount To Invoice

- Expand the rows by Product


**Current behavior:**

- Amount Invoiced for product12 is 50.0
- Amount Invoiced for product50 is 12.0


**Expected behavior:**

- Amount Invoiced for product12 is 0.0
- Amount Invoiced for product50 is 0.0

addons/sale/models/sale.py
invoice.type = 'out_refund'
                for line in invoice.invoice_line_ids:
                    line.quantity = -line.quantity
            
            for line in invoice.invoice_line_ids:
                line._set_additional_fields(invoice)
            
            
            invoice.compute_taxes()
            invoice.message_post_with_view('mail.message_origin_link',
                values={'self': invoice, 'origin': references[invoice]},
                subtype_id=self.env.ref('mail.mt_note').id)
        return [inv.id for inv in invoices.values()]
    @api.multi
    def action_draft(self):
        orders = self.filtered(lambda s: s.state in ['cancel', 'sent'])
        return orders.write({
            'state': 'draft',
        })
    @api.multi
    def action_cancel(self):
        return self.write({'state': 'cancel'})
    @api.multi
    def action_quotation_send(self):
        '''
        This function opens a window to compose an email, with the edi sale template message loaded by default
        '''
        self.ensure_one()
        ir_model_data = self.env['ir.model.data']
        try: