[FIX] point_of_sale: do not hide transactional errors

Catching and hiding database transactional errors can
sometimes cause a POS order to be entirely lost.

When it occurs, the transaction won't be committed
into the database, and if there is only one order
in the batch, the server won't return any error to
the frontend POS which will consider the order saved.

addons/point_of_sale/point_of_sale.py

@@ -24,6 +24,7 @@
 from decimal import Decimal
 import logging
 import pdb
+import psycopg2
 import time
 
 import openerp
@@ -537,6 +538,9 @@ def create_from_ui(self, cr, uid, orders, context=None):
             wf_service = netsvc.LocalService("workflow")
             try:
                 wf_service.trg_validate(uid, 'pos.order', order_id, 'paid', cr)
+            except psycopg2.OperationalError:
+                # do not hide transactional errors, the order(s) won't be saved!
+                raise
             except Exception:
                 _logger.error('ERROR: Could not fully process the POS Order', exc_info=True)
         return order_ids