[FIX] purchase: vendor currency

When defined, the vendor currency should be the default on vendor bills.

Fixes #13017
Closes #13016
opw-685016

addons/purchase/invoice.py

@@ -87,6 +87,22 @@ class AccountInvoice(models.Model):
         if purchase_ids:
             self.origin = ', '.join(purchase_ids.mapped('name'))
 
+    @api.onchange('partner_id', 'company_id')
+    def _onchange_partner_id(self):
+        res = super(AccountInvoice, self)._onchange_partner_id()
+        if not self.env.context.get('default_journal_id') and self.partner_id and self.currency_id and\
+                self.type in ['in_invoice', 'in_refund'] and\
+                self.currency_id != self.partner_id.property_purchase_currency_id:
+            journal_domain = [
+                ('type', '=', 'purchase'),
+                ('company_id', '=', self.company_id.id),
+                ('currency_id', '=', self.partner_id.property_purchase_currency_id.id),
+            ]
+            default_journal_id = self.env['account.journal'].search(journal_domain, limit=1)
+            if default_journal_id:
+                self.journal_id = default_journal_id
+        return res
+
     @api.model
     def invoice_line_move_line_get(self):
         res = super(AccountInvoice, self).invoice_line_move_line_get()