From 695de8cc9145e139c2b22e05aa44f5ac04da6f85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Honza=20Kr=C3=A1l?= <honza.kral@gmail.com>
Date: Sun, 13 Dec 2009 21:39:46 +0000
Subject: [PATCH] [soc2009/model-validation] Fixed #12132: unneccessary
 unique_check for primary key when not adding model

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/model-validation@11856 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/models/base.py                   |  4 ++++
 tests/modeltests/validation/test_unique.py | 27 +++++++++++++++++++++-
 tests/modeltests/validation/tests.py       |  2 +-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/django/db/models/base.py b/django/db/models/base.py
index a348cf6de7..04c802a04b 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -678,6 +678,10 @@ class Model(object):
                 f = self._meta.get_field(field_name)
                 lookup_value = getattr(self, f.attname)
                 if f.null and lookup_value is None:
+                    # no value, skip the lookup
+                    continue
+                if f.primary_key and not getattr(self, '_adding', False):
+                    # no need to check for unique primary key when editting 
                     continue
                 lookup_kwargs[str(field_name)] = lookup_value
 
diff --git a/tests/modeltests/validation/test_unique.py b/tests/modeltests/validation/test_unique.py
index 98c9615927..2790d378c6 100644
--- a/tests/modeltests/validation/test_unique.py
+++ b/tests/modeltests/validation/test_unique.py
@@ -1,6 +1,9 @@
 import unittest
 
-from models import CustomPKModel, UniqueTogetherModel, UniqueFieldsModel, UniqueForDateModel
+from django.conf import settings
+from django.db import connection
+
+from models import CustomPKModel, UniqueTogetherModel, UniqueFieldsModel, UniqueForDateModel, ModelToValidate
 
 class GetUniqueCheckTests(unittest.TestCase):
     def test_unique_fields_get_collected(self):
@@ -24,4 +27,26 @@ class GetUniqueCheckTests(unittest.TestCase):
         )
 
 
+class PerformUniqueChecksTest(unittest.TestCase):
+    def setUp(self):
+        self._old_debug, settings.DEBUG = settings.DEBUG, True
+        super(PerformUniqueChecksTest, self).setUp()
 
+    def tearDown(self):
+        settings.DEBUG = self._old_debug
+        super(PerformUniqueChecksTest, self).tearDown()
+
+    def test_primary_key_unique_check_performed_when_adding(self):
+        "Check#12132"
+        l = len(connection.queries)
+        mtv = ModelToValidate(number=10, name='Some Name')
+        setattr(mtv, '_adding', True)
+        mtv.clean()
+        self.assertEqual(l+1, len(connection.queries))
+
+    def test_primary_key_unique_check_not_performed_when_not_adding(self):
+        "Check#12132"
+        l = len(connection.queries)
+        mtv = ModelToValidate(number=10, name='Some Name')
+        mtv.clean()
+        self.assertEqual(l, len(connection.queries))
diff --git a/tests/modeltests/validation/tests.py b/tests/modeltests/validation/tests.py
index 25f9d0c005..656e9d8216 100644
--- a/tests/modeltests/validation/tests.py
+++ b/tests/modeltests/validation/tests.py
@@ -5,7 +5,7 @@ from modeltests.validation import ValidationTestCase
 from models import *
 
 from validators import TestModelsWithValidators
-from test_unique import GetUniqueCheckTests
+from test_unique import GetUniqueCheckTests, PerformUniqueChecksTest
 from test_custom_messages import CustomMessagesTest
 
 class BaseModelValidationTests(ValidationTestCase):