Fixed #25353 -- Changed LogEntry.action_time to a "date created".

django/contrib/admin/migrations/0002_logentry_remove_auto_add.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.utils import timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('admin', '0001_initial'),
+    ]
+
+    # No database changes; removes auto_add and adds default/editable.
+    operations = [
+        migrations.AlterField(
+            model_name='logentry',
+            name='action_time',
+            field=models.DateTimeField(
+                verbose_name='action time',
+                default=timezone.now,
+                editable=False,
+            ),
+        ),
+    ]

django/contrib/admin/models.py

@@ -5,6 +5,7 @@ from django.contrib.admin.utils import quote
 from django.contrib.contenttypes.models import ContentType
 from django.core.urlresolvers import NoReverseMatch, reverse
 from django.db import models
+from django.utils import timezone
 from django.utils.encoding import python_2_unicode_compatible, smart_text
 from django.utils.translation import ugettext, ugettext_lazy as _
 
@@ -17,16 +18,23 @@ class LogEntryManager(models.Manager):
     use_in_migrations = True
 
     def log_action(self, user_id, content_type_id, object_id, object_repr, action_flag, change_message=''):
-        e = self.model(
-            None, None, user_id, content_type_id, smart_text(object_id),
-            object_repr[:200], action_flag, change_message
+        self.model.objects.create(
+            user_id=user_id,
+            content_type_id=content_type_id,
+            object_id=smart_text(object_id),
+            object_repr=object_repr[:200],
+            action_flag=action_flag,
+            change_message=change_message,
         )
-        e.save()
 
 
 @python_2_unicode_compatible
 class LogEntry(models.Model):
-    action_time = models.DateTimeField(_('action time'), auto_now=True)
+    action_time = models.DateTimeField(
+        _('action time'),
+        default=timezone.now,
+        editable=False,
+    )
     user = models.ForeignKey(
         settings.AUTH_USER_MODEL,
         models.CASCADE,

tests/admin_views/tests.py

@@ -2405,6 +2405,16 @@ class AdminViewStringPrimaryKeyTest(TestCase):
         edited_obj = logentry.get_edited_object()
         self.assertEqual(logentry.object_id, str(edited_obj.pk))
 
+    def test_logentry_save(self):
+        """"
+        LogEntry.action_time is a timestamp of the date when the entry was
+        created. It shouldn't be updated on a subsequent save().
+        """
+        logentry = LogEntry.objects.get(content_type__model__iexact="modelwithstringprimarykey")
+        action_time = logentry.action_time
+        logentry.save()
+        self.assertEqual(logentry.action_time, action_time)
+
     def test_deleteconfirmation_link(self):
         "The link from the delete confirmation page referring back to the changeform of the object should be quoted"
         response = self.client.get(reverse('admin:admin_views_modelwithstringprimarykey_delete', args=(quote(self.pk),)))