[REVERT] sale: Fix fiscal pos. mapping taxes to price included

This reverts commit d89562e8fe473692296cb209651beb2ce7a715e4.

Since this commit, the taxes mapped by fiscal position wasn't managed by the _fix_tax_included_price_company method anymore.
Otherwise, some customizations exist on this method that are no longer called.
The 2527940 issue is also due to a remaining bug: the total_excluded price should be divided by the quantity but:
- what if the quantity & price_unit are both signed?
- what if the number of digits for price_unit and the currency are different? Should we skip the rounding of taxes?
Since this commit is not perfect and has a lot of dependencies in others modules, we decided to revert it.

Original PR: https://github.com/odoo/odoo/pull/68997
Revert PR: https://github.com/odoo/odoo/pull/70858

closes odoo/odoo#70883

Issue: 2527940
X-original-commit: c9330e4af5b034fd81090478723ee3c18be58733
Signed-off-by: Victor Feyens (vfe) <vfe@odoo.com>
Signed-off-by: Laurent Smet <smetl@users.noreply.github.com>

3 files changed, 3 insertions, 172 deletions

diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index 3cd616616b7..9c28c66a593 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -1648,43 +1648,6 @@ class SaleOrderLine(models.Model):
         # negative discounts (= surcharge) are included in the display price
         return max(base_price, final_price)
 
-    def _get_default_price_unit_from_product(self, product):
-        self.ensure_one()
-
-        currency = self.order_id.currency_id
-        fiscal_position = self.order_id.fiscal_position_id or self.order_id.partner_id.property_account_position_id
-        product_taxes = self.product_id.taxes_id.filtered(lambda r: r.company_id == self.order_id.company_id)
-        product_taxes_after_fp = fiscal_position.map_tax(product_taxes, partner=self.order_id.partner_id)
-        price_unit = self._get_display_price(product)
-
-        if set(product_taxes.ids) != set(product_taxes_after_fp.ids):
-            flattened_taxes = product_taxes._origin.flatten_taxes_hierarchy()
-            if any(tax.price_include for tax in flattened_taxes):
-                taxes_res = flattened_taxes.compute_all(
-                    price_unit,
-                    quantity=self.product_uom_qty,
-                    currency=currency,
-                    product=self.product_id,
-                    partner=self.order_id.partner_id,
-                )
-                price_unit = currency.round(taxes_res['total_excluded'])
-
-            flattened_taxes = product_taxes_after_fp._origin.flatten_taxes_hierarchy()
-            if any(tax.price_include for tax in flattened_taxes):
-                taxes_res = flattened_taxes.compute_all(
-                    price_unit,
-                    quantity=self.product_uom_qty,
-                    currency=currency,
-                    product=self.product_id,
-                    partner=self.order_id.partner_id,
-                    handle_price_include=False,
-                )
-                for tax_res in taxes_res['taxes']:
-                    tax = self.env['account.tax'].browse(tax_res['id'])
-                    if tax.price_include:
-                        price_unit += tax_res['amount']
-        return price_unit
-
     @api.onchange('product_id')
     def product_id_change(self):
         if not self.product_id:
@@ -1713,13 +1676,13 @@ class SaleOrderLine(models.Model):
             pricelist=self.order_id.pricelist_id.id,
             uom=self.product_uom.id
         )
+
         vals.update(name=self.get_sale_order_line_multiline_description_sale(product))
 
         self._compute_tax_id()
 
         if self.order_id.pricelist_id and self.order_id.partner_id:
-            vals['price_unit'] = self._get_default_price_unit_from_product(product)
-
+            vals['price_unit'] = self.env['account.tax']._fix_tax_included_price_company(self._get_display_price(product), product.taxes_id, self.tax_id, self.company_id)
         self.update(vals)
 
         title = False
@@ -1752,7 +1715,7 @@ class SaleOrderLine(models.Model):
                 uom=self.product_uom.id,
                 fiscal_position=self.env.context.get('fiscal_position')
             )
-            self.price_unit = self._get_default_price_unit_from_product(product)
+            self.price_unit = self.env['account.tax']._fix_tax_included_price_company(self._get_display_price(product), product.taxes_id, self.tax_id, self.company_id)
 
     def name_get(self):
         result = []
diff --git a/addons/sale/tests/__init__.py b/addons/sale/tests/__init__.py
index b6629c7082a..88bf481bf04 100644
--- a/addons/sale/tests/__init__.py
+++ b/addons/sale/tests/__init__.py
@@ -12,4 +12,3 @@ from . import test_sale_refund
 from . import test_sale_signature
 from . import test_sale_transaction
 from . import test_sale_flow
-from . import test_sale_fiscal_position
diff --git a/addons/sale/tests/test_sale_fiscal_position.py b/addons/sale/tests/test_sale_fiscal_position.py
deleted file mode 100644
index 2bc1e8c5126..00000000000
--- a/addons/sale/tests/test_sale_fiscal_position.py
+++ /dev/null
@@ -1,131 +0,0 @@
-# -*- coding: utf-8 -*-
-from odoo import fields
-from odoo.addons.account.tests.common import AccountTestInvoicingCommon
-from odoo.tests import tagged
-from odoo.tests.common import Form
-
-
-@tagged('post_install', '-at_install')
-class TestSaleFiscalPosition(AccountTestInvoicingCommon):
-
-    def test_fiscal_pos_taxes_mapping_price_included_to_price_excluded(self):
-        ''' Test mapping a price-included tax (10%) with a price-excluded tax (20%) on a price_unit of 110.0.
-        The price_unit should be 100.0 after applying the fiscal position.
-        '''
-        tax_price_include = self.env['account.tax'].create({
-            'name': '10% incl',
-            'type_tax_use': 'sale',
-            'amount_type': 'percent',
-            'amount': 10,
-            'price_include': True,
-            'include_base_amount': True,
-        })
-        tax_price_exclude = self.env['account.tax'].create({
-            'name': '15% excl',
-            'type_tax_use': 'sale',
-            'amount_type': 'percent',
-            'amount': 15,
-        })
-
-        fiscal_position = self.env['account.fiscal.position'].create({
-            'name': 'fiscal_pos_a',
-            'tax_ids': [
-                (0, None, {
-                    'tax_src_id': tax_price_include.id,
-                    'tax_dest_id': tax_price_exclude.id,
-                }),
-            ],
-        })
-
-        product = self.env['product.product'].create({
-            'name': 'product',
-            'uom_id': self.env.ref('uom.product_uom_unit').id,
-            'lst_price': 110.0,
-            'taxes_id': [(6, 0, tax_price_include.ids)],
-        })
-
-        so_form = Form(self.env['sale.order'])
-        so_form.partner_id = self.partner_a
-        so_form.date_order = fields.Date.from_string('2019-01-01')
-        so_form.fiscal_position_id = fiscal_position
-        so_form.pricelist_id = self.env.ref('product.list0')
-        with so_form.order_line.new() as line:
-            line.product_id = product
-        so = so_form.save()
-
-        self.assertRecordValues(so.order_line, [{
-            'price_unit': 100.0,
-            'tax_id': tax_price_exclude.ids,
-        }])
-
-        uom_dozen = self.env.ref('uom.product_uom_dozen')
-        with Form(so) as so_form:
-            with so_form.order_line.edit(0) as line_form:
-                line_form.product_uom = uom_dozen
-
-        self.assertRecordValues(so.order_line, [{
-            'price_unit': 1200.0,
-            'tax_id': tax_price_exclude.ids,
-        }])
-
-    def test_fiscal_pos_taxes_mapping_price_included_to_price_included(self):
-        ''' Test mapping a price-included tax (10%) with another price-included tax (20%) on a price_unit of 110.0.
-        The price_unit should be 120.0 after applying the fiscal position.
-        '''
-        tax_price_include_1 = self.env['account.tax'].create({
-            'name': '10% incl',
-            'type_tax_use': 'sale',
-            'amount_type': 'percent',
-            'amount': 10,
-            'price_include': True,
-            'include_base_amount': True,
-        })
-        tax_price_include_2 = self.env['account.tax'].create({
-            'name': '20% incl',
-            'type_tax_use': 'sale',
-            'amount_type': 'percent',
-            'amount': 20,
-            'price_include': True,
-            'include_base_amount': True,
-        })
-
-        fiscal_position = self.env['account.fiscal.position'].create({
-            'name': 'fiscal_pos_a',
-            'tax_ids': [
-                (0, None, {
-                    'tax_src_id': tax_price_include_1.id,
-                    'tax_dest_id': tax_price_include_2.id,
-                }),
-            ],
-        })
-
-        product = self.env['product.product'].create({
-            'name': 'product',
-            'uom_id': self.env.ref('uom.product_uom_unit').id,
-            'lst_price': 110.0,
-            'taxes_id': [(6, 0, tax_price_include_1.ids)],
-        })
-
-        so_form = Form(self.env['sale.order'])
-        so_form.partner_id = self.partner_a
-        so_form.date_order = fields.Date.from_string('2019-01-01')
-        so_form.fiscal_position_id = fiscal_position
-        so_form.pricelist_id = self.env.ref('product.list0')
-        with so_form.order_line.new() as line:
-            line.product_id = product
-        so = so_form.save()
-
-        self.assertRecordValues(so.order_line, [{
-            'price_unit': 120.0,
-            'tax_id': tax_price_include_2.ids,
-        }])
-
-        uom_dozen = self.env.ref('uom.product_uom_dozen')
-        with Form(so) as so_form:
-            with so_form.order_line.edit(0) as line_form:
-                line_form.product_uom = uom_dozen
-
-        self.assertRecordValues(so.order_line, [{
-            'price_unit': 1440.0,
-            'tax_id': tax_price_include_2.ids,
-        }])