[FIX] purchase_requisition: vendor name management from purchase agreements.

Purchase orders created from purchase agreement behave differently depending on
the agreement type.
On one hand, if the agreement is a blanket order, the vendor must be set automatically on the
purchase order and be the same as the BO. Changing the vendor is forbidden.
On the other hand, if the agreement is a call for tender, multiple purchase order can be
created with different vendors. It that case, the vendor field must be editable in RfQ states.

This commit is related to task ID 1866975.

addons/purchase_requisition/models/purchase_requisition.py

@@ -291,6 +291,7 @@ class PurchaseOrder(models.Model):
     _inherit = "purchase.order"
 
     requisition_id = fields.Many2one('purchase.requisition', string='Purchase Agreement', copy=False)
+    is_quantity_copy = fields.Selection(related='requisition_id.is_quantity_copy')
 
     @api.onchange('requisition_id')
     def _onchange_requisition_id(self):

addons/purchase_requisition/views/purchase_requisition_views.xml

@@ -79,9 +79,8 @@
         <field name="inherit_id" ref="purchase.purchase_order_form"/>
         <field name="arch" type="xml">
           <field name="partner_id" position="replace">
-            <field name="partner_id" context="{'search_default_supplier':1, 'default_supplier':1, 'default_customer':0}"
-              domain="[('supplier','=',True)]"
-              attrs="{'readonly': ['&amp;', ('partner_id', '!=', False), ('requisition_id','!=', False)]}" force_save="1"/>
+            <field name="is_quantity_copy" invisible="1"/>
+            <field name="partner_id" context="{'search_default_supplier':1, 'default_supplier':1, 'default_customer':0}" domain="[('supplier','=',True)]" attrs="{'readonly': ['|', ('is_quantity_copy', '=', 'none'), ('state', 'in', ['purchase', 'done', 'cancel'])]}" force_save="1"/>
             </field>
             <field name="partner_ref" position="after">
                 <field name="requisition_id"