**Impacted versions:**
* 9.0

**Steps to reproduce:**
* Enable multi currencies
* Make sure that the current rate of a foreign currency (i.e. EUR) is not 1.0 (i.e. 0.84)
* Create a purchasable product with a cost (i.e. 33$)
* Create a vendor bill in a foreign currency (i.e. EUR)
* Add the product on the invoice

**Current behavior:**
* The unit price will be 23.28 == (33 * 0.84) * 0.84

**Expected behavior:**
* The unit price should be 27,72 == 33 * 0.84
* Probably due to this line of code: https://github.com/odoo/odoo/blob/9.0/addons/account/models/account_invoice.py#L1241

**Video/Screenshot link (optional):**
* On Runbot Community 9.0: https://www.youtube.com/watch?v=60qPmczo5vk


addons/account/models/account_invoice.py
TYPES = {
            'out_invoice': _('Invoice'),
            'in_invoice': _('Vendor Bill'),
            'out_refund': _('Refund'),
            'in_refund': _('Vendor Refund'),
        }
        result = []
        for inv in self:
            result.append((inv.id, "%s %s" % (inv.number or TYPES[inv.type], inv.name or '')))
        return result
    @api.model
    def name_search(self, name, args=None, operator='ilike', limit=100):