19.0 vanilla

odoo-bringout-oca-ocb-purchase/purchase/models/account_tax.py

@@ -0,0 +1,30 @@
+# -*- coding: utf-8 -*-
+
+from odoo import models
+
+
+class AccountTax(models.Model):
+    _inherit = "account.tax"
+
+    def _hook_compute_is_used(self, taxes_to_compute):
+        # OVERRIDE in order to fetch taxes used in purchase
+
+        used_taxes = super()._hook_compute_is_used(taxes_to_compute)
+        taxes_to_compute -= used_taxes
+
+        if taxes_to_compute:
+            self.env['purchase.order.line'].flush_model(['tax_ids'])
+            self.env.cr.execute("""
+                SELECT id
+                FROM account_tax
+                WHERE EXISTS(
+                    SELECT 1
+                    FROM account_tax_purchase_order_line_rel AS pur
+                    WHERE account_tax_id IN %s
+                    AND account_tax.id = pur.account_tax_id
+                )
+            """, [tuple(taxes_to_compute)])
+
+            used_taxes.update([tax[0] for tax in self.env.cr.fetchall()])
+
+        return used_taxes