From 48401aa9a0d40db1e0711063ed27e6a9f761e89e Mon Sep 17 00:00:00 2001
From: Yannick Tivisse <yti@odoo.com>
Date: Mon, 22 Nov 2021 13:21:48 +0100
Subject: [PATCH] [IMP] sale: Convert _onchange_partner_shipping_id into
 computed field

---
 addons/account/models/account_move.py |  6 +++---
 addons/sale/models/account_move.py    | 24 ++++++++++++++----------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index 05e1b70f524..b62213a584a 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -284,9 +284,9 @@ class AccountMove(models.Model):
     # =========================================================
 
     # ==== Business fields ====
-    fiscal_position_id = fields.Many2one('account.fiscal.position', string='Fiscal Position', readonly=True,
-        states={'draft': [('readonly', False)]},
-        check_company=True,
+    fiscal_position_id = fields.Many2one(
+        'account.fiscal.position', string='Fiscal Position', readonly=True,
+        states={'draft': [('readonly', False)]}, check_company=True,
         domain="[('company_id', '=', company_id)]", ondelete="restrict",
         help="Fiscal positions are used to adapt taxes and accounts for particular customers or sales orders/invoices. "
              "The default value comes from the customer.")
diff --git a/addons/sale/models/account_move.py b/addons/sale/models/account_move.py
index ba9fb504bdc..5b12b143188 100644
--- a/addons/sale/models/account_move.py
+++ b/addons/sale/models/account_move.py
@@ -4,6 +4,7 @@
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError
 
+
 class AccountMove(models.Model):
     _name = 'account.move'
     _inherit = ['account.move', 'utm.mixin']
@@ -24,22 +25,25 @@ class AccountMove(models.Model):
         states={'draft': [('readonly', False)]},
         domain="['|', ('company_id', '=', False), ('company_id', '=', company_id)]",
         help="Delivery address for current invoice.")
+
     # UTMs - enforcing the fact that we want to 'set null' when relation is unlinked
     campaign_id = fields.Many2one(ondelete='set null')
     medium_id = fields.Many2one(ondelete='set null')
     source_id = fields.Many2one(ondelete='set null')
 
-    @api.onchange('partner_shipping_id', 'company_id')
-    def _onchange_partner_shipping_id(self):
-        """
-        Trigger the change of fiscal position when the shipping address is modified.
-        """
-        delivery_partner = self.env['res.partner'].browse(self._get_invoice_delivery_partner_id())
-        fiscal_position = self.env['account.fiscal.position'].with_company(self.company_id)._get_fiscal_position(
-            self.partner_id, delivery=delivery_partner)
+    fiscal_position_id = fields.Many2one(
+        compute='_compute_fiscal_position_id', store=True, pre_compute=True)
 
-        if fiscal_position:
-            self.fiscal_position_id = fiscal_position
+
+    @api.depends('partner_shipping_id', 'company_id')
+    def _compute_fiscal_position_id(self):
+        # Trigger the change of fiscal position when the shipping address is modified.
+        for move in self:
+            delivery_partner = self.env['res.partner'].browse(move._get_invoice_delivery_partner_id())
+            fiscal_position = self.env['account.fiscal.position'].with_company(
+                move.company_id)._get_fiscal_position(move.partner_id, delivery=delivery_partner)
+            if fiscal_position:
+                move.fiscal_position_id = fiscal_position
 
     def unlink(self):
         downpayment_lines = self.mapped('line_ids.sale_line_ids').filtered(lambda line: line.is_downpayment and line.invoice_lines <= self.mapped('line_ids'))