**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
if report_pages[-1] and report_pages[-1][-1]['pagebreak']:
                report_pages.append([])
            
            report_pages[-1].append({
                'name': category and category.name or _('Uncategorized'),
                'subtotal': category and category.subtotal,
                'pagebreak': category and category.pagebreak,
                'lines': list(lines)
            })
        return report_pages
    @api.multi
    def _get_tax_amount_by_group(self):
        self.ensure_one()
        res = {}
        for line in self.order_line:
            price_reduce = line.price_unit * (1.0 - line.discount / 100.0)
            taxes = line.tax_id.compute_all(price_reduce, quantity=line.product_uom_qty, product=line.product_id, partner=self.partner_shipping_id)['taxes']
            for tax in line.tax_id:
                group = tax.tax_group_id
                res.setdefault(group, {'amount': 0.0, 'base': 0.0})
                for t in taxes:
                    if t['id'] == tax.id or t['id'] in tax.children_tax_ids.ids:
                        res[group]['amount'] += t['amount']
                        res[group]['base'] += t['base']
        res = sorted(res.items(), key=lambda l: l[0].sequence)
        res = [(l[0].name, l[1]['amount'], l[1]['base'], len(res)) for l in res]
        return res
    @api.multi
    def get_access_action(self, access_uid=None):