diff --git a/odoo/addons/test_new_api/tests/test_onchange.py b/odoo/addons/test_new_api/tests/test_onchange.py
index 16144c266fc..fc72c500e50 100644
--- a/odoo/addons/test_new_api/tests/test_onchange.py
+++ b/odoo/addons/test_new_api/tests/test_onchange.py
@@ -149,10 +149,17 @@ class TestOnChange(common.TransactionCase):
             (5,),
             (1, message1.id, {
                 'name': "[%s] %s" % ("Foo", USER.name),
+                'body': "ABC",
+                'author': USER.name_get()[0],
+                'size': 3,
+                'important': False,
             }),
             (1, message2.id, {
                 'name': "[%s] %s" % ("Foo", USER.name),
                 'body': "XYZ",          # this must be sent back
+                'author': USER.name_get()[0],
+                'size': 3,
+                'important': False,
             }),
             (0, 0, {
                 'name': "[%s] %s" % ("Foo", USER.name),
@@ -262,11 +269,16 @@ class TestOnChange(common.TransactionCase):
             'name': partner2.name,
             'lines': [
                 (5,),
-                (1, line1.id, {'name': partner2.name,
-                               'partner': (partner2.id, partner2.name)}),
-                (0, 0, {'name': partner2.name,
-                        'partner': (partner2.id, partner2.name),
-                        'tags': [(5,)]}),
+                (1, line1.id, {
+                    'name': partner2.name,
+                    'partner': (partner2.id, partner2.name),
+                    'tags': [(5,)],
+                }),
+                (0, 0, {
+                    'name': partner2.name,
+                    'partner': (partner2.id, partner2.name),
+                    'tags': [(5,)],
+                }),
             ],
         })
 
@@ -286,11 +298,16 @@ class TestOnChange(common.TransactionCase):
             'name': partner2.name,
             'lines': [
                 (5,),
-                (1, line1.id, {'name': partner2.name,
-                               'partner': (partner2.id, partner2.name)}),
-                (0, 0, {'name': partner2.name,
-                        'partner': (partner2.id, partner2.name),
-                        'tags': [(5,), (0, 0, {'name': 'Tag'})]}),
+                (1, line1.id, {
+                    'name': partner2.name,
+                    'partner': (partner2.id, partner2.name),
+                    'tags': [(5,)],
+                }),
+                (0, 0, {
+                    'name': partner2.name,
+                    'partner': (partner2.id, partner2.name),
+                    'tags': [(5,), (0, 0, {'name': 'Tag'})],
+                }),
             ],
         }
         self.assertEqual(result['value'], expected_value)
@@ -439,7 +456,14 @@ class TestOnChange(common.TransactionCase):
 
         self.assertEqual(
             result['value']['important_emails'],
-            [(5,), (1, email.id, {'name': u'[Foo Bar] %s' % USER.name})],
+            [(5,), (1, email.id, {
+                'name': u'[Foo Bar] %s' % USER.name,
+                'body': BODY,
+                'author': USER.name_get()[0],
+                'size': len(BODY),
+                'important': True,
+                'email_to': demo.email,
+            })],
         )
 
     def test_onchange_related(self):
diff --git a/odoo/models.py b/odoo/models.py
index dc1a4b4f427..3266a763977 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -5100,10 +5100,13 @@ class BaseModel(MetaModel('DummyModel', (object,), {'_register': False})):
                                 line_diff = line_snapshot.diff({})
                                 commands.append((0, line.id.ref or 0, line_diff))
                             else:
-                                # existing line: send diff from database
+                                # existing line: check diff from database
                                 # (requires a clean record cache!)
                                 line_diff = line_snapshot.diff(Snapshot(line, subnames))
                                 if line_diff:
+                                    # send all fields because the web client
+                                    # might need them to evaluate modifiers
+                                    line_diff = line_snapshot.diff({})
                                     commands.append((1, line.id, line_diff))
                                 else:
                                     commands.append((4, line.id))