From 65d7cc524d9f3a5dc833cb483ccaaf86fab4819d Mon Sep 17 00:00:00 2001
From: Denis Ledoux <dle@openerp.com>
Date: Wed, 28 May 2014 18:00:11 +0200
Subject: [PATCH] [FIX] purchase: Do not allow to delete a purchase order line
 which is validated

This restriction behavior copied from the sale.order model
Moreover, the purchase.order lines state were not set to cancel when the purchase order was cancelled.
This is now the case, this behavior is also coped from the sale.order model
When the purchase order is reset to draft, we also reset the order lines state to draft
---
 addons/purchase/purchase.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 6767f9185ac..d258eee7431 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -499,6 +499,8 @@ class purchase_order(osv.osv):
         if not len(ids):
             return False
         self.write(cr, uid, ids, {'state':'draft','shipped':0})
+        for purchase in self.browse(cr, uid, ids, context=context):
+            self.pool['purchase.order.line'].write(cr, uid, [l.id for l in  purchase.order_line], {'state': 'draft'})
         wf_service = netsvc.LocalService("workflow")
         for p_id in ids:
             # Deleting the existing instance of workflow for PO
@@ -596,6 +598,8 @@ class purchase_order(osv.osv):
                         _('You must first cancel all receptions related to this purchase order.'))
                 if inv:
                     wf_service.trg_validate(uid, 'account.invoice', inv.id, 'invoice_cancel', cr)
+            self.pool['purchase.order.line'].write(cr, uid, [l.id for l in  purchase.order_line],
+                    {'state': 'cancel'})
         self.write(cr,uid,ids,{'state':'cancel'})
 
         for (id, name) in self.name_get(cr, uid, ids):
@@ -901,6 +905,8 @@ class purchase_order_line(osv.osv):
     def unlink(self, cr, uid, ids, context=None):
         procurement_ids_to_cancel = []
         for line in self.browse(cr, uid, ids, context=context):
+            if line.state not in ['draft', 'cancel']:
+                raise osv.except_osv(_('Invalid Action!'), _('Cannot delete a purchase order line which is in state \'%s\'.') %(line.state,))
             if line.move_dest_id:
                 procurement_ids_to_cancel.extend(procurement.id for procurement in line.move_dest_id.procurements)
         if procurement_ids_to_cancel: