[IMP] Apply suggested changes from FrankC013 to put price_extra to 0.0

product_variant_sale_price/models/product_product.py

@@ -27,10 +27,26 @@ def write(self, vals):
             template._update_fix_price(vals)
         return res
 
+    def _get_combination_info(self, combination=False, product_id=False, add_qty=1, pricelist=False,
+                              parent_combination=False, only_template=False):
+        res = super()._get_combination_info(combination, product_id, add_qty, pricelist,
+                                            parent_combination, only_template)
+        res['price_extra'] = 0.0
+        return res
+
 
 class ProductProduct(models.Model):
     _inherit = "product.product"
 
+    lst_price = fields.Float(
+        compute="_compute_lst_price",
+        inverse="_inverse_product_lst_price",
+    )
+    list_price = fields.Float(
+        compute="_compute_list_price",
+    )
+    fix_price = fields.Float()
+
     @api.depends("fix_price")
     def _compute_lst_price(self):
         uom_model = self.env["uom.uom"]
@@ -71,11 +87,8 @@ def _inverse_product_lst_price(self):
                 ).list_price = min(fix_prices)
             product.write(vals)
 
-    lst_price = fields.Float(
-        compute="_compute_lst_price",
-        inverse="_inverse_product_lst_price",
-    )
-    list_price = fields.Float(
-        compute="_compute_list_price",
-    )
-    fix_price = fields.Float()
+    def _compute_product_price_extra(self):
+        """the sale.order.line module calculates the price_unit by adding the value of price_extra and this can
+        generate inconsistencies if the field has old data stored."""
+        for product in self:
+            product.price_extra = 0.0