Account Fiscal Position Allowed Journal Purchase

This module links purchase orders and fiscal positions to the journal used on vendor bills. It only changes what happens when a bill is created from a purchase order.

• On the vendor bill form, when you select a purchase order (or a vendor bill to reverse), Odoo fills in the bill details as usual. If the purchase order has a fiscal position, and that fiscal position allows exactly one purchase journal, that journal is set on the bill automatically.
• If the fiscal position allows no journal, or more than one, nothing is changed and you keep the journal Odoo would normally use.
• The rule is applied through the existing automatic completion of vendor bills from purchase orders, so it happens as soon as the purchase order is chosen, before you save.

The module extends the accounting entry model account.move and relies on the fiscal position's allowed journals configured by the companion module. It adds no new menus, screens, reports or scheduled actions; it only refines the default journal on vendor bills created from purchase orders.