acquisitions: sort lines in order

Line sorting is now done on the PID to keep the same order as the command.

* Closes #2653.

Co-Authored-by: Bertrand Zuchuat <[email protected]>

rero_ils/modules/acquisition/acq_orders/api.py

@@ -350,16 +350,26 @@ def get_order_lines(self, output=None, includes=None):
         :param includes: a list of statuses to include order lines.
         :return a generator of related order lines (or length).
         """
+
+        def preserve_order(query):
+            """Keep results in order.
+
+            :param: query: the es query.
+            :return the es query.
+            """
+            return query.params(preserve_order=True) \
+                .sort({'pid': {"order": "asc"}})
+
         query = AcqOrderLinesSearch().filter('term', acq_order__pid=self.pid)
         if includes:
             query = query.filter('terms', status=includes)
 
         if output == 'count':
             return query.count()
         elif output == 'query':
-            return query
+            return preserve_order(query)
         else:
-            return get_objects(AcqOrderLine, query)
+            return get_objects(AcqOrderLine, preserve_order(query))
 
     def get_order_provisional_total_amount(self):
         """Get provisional total amount of this order."""