Group records written with the same values when saved

trytond/trytond/model/modelstorage.py

@@ -2278,7 +2278,9 @@ class ModelStorage(Model):
                             record._ids.append(record.id)
                     if to_write:
                         cls.write(*sum(
-                                (([r], save_values[r]) for r in to_write), ()))
+                                ((list(gr), v) for v, gr in groupby(
+                                        to_write, lambda r: save_values[r])),
+                                ()))
             except Exception:
                 for record in chain(to_create, to_write):
                     record._values = values.get(record)

trytond/trytond/tests/test_modelstorage.py

@@ -2,6 +2,7 @@
 # repository contains the full copyright notices and license terms.
 
 import warnings
+from unittest.mock import patch
 
 from trytond.model import BrowseList, EvalEnvironment
 from trytond.model.exceptions import (
@@ -124,6 +125,22 @@ class ModelStorageTestCase(TestCase):
 
         self.assertNotEqual(foo._context, bar._context)
 
+    @with_transaction()
+    def test_save_same_write_values(self):
+        "Test save with same write values"
+        pool = Pool()
+        ModelStorage = pool.get('test.modelstorage')
+
+        records = ModelStorage.create([{}, {}])
+
+        with patch.object(
+                ModelStorage, 'write', wraps=ModelStorage.write) as mock:
+            for record in records:
+                record.name = "test"
+            ModelStorage.save(records)
+
+            mock.assert_called_once_with(records, {'name': "test"})
+
     @with_transaction()
     def test_fail_saving_mixed_context1(self):
         'Test fail saving with mixed context '