Ticket #10399: 0001-Fixed-10399-Tested-that-o2o-field-updates-are-not-co.patch

django/test/testcases.py

@@ -168 +168 @@
             transaction.rollback_unless_managed(using=conn)
 
 
-class _AssertNumQueriesContext(object):
-    def __init__(self, test_case, num, connection):
-        self.test_case = test_case
-        self.num = num
+class CaptureQueriesContext(object):
+    def __init__(self, connection):
         self.connection = connection
 
+    def __iter__(self):
+        return iter(self.captured_queries)
+
+    def __getitem__(self, key):
+        return self.captured_queries[key]
+
+    @property
+    def captured_queries(self):
+        return self.connection.queries[self.initial_queries:self.final_queries]
+
     def __enter__(self):
-        self.old_debug_cursor = self.connection.use_debug_cursor
+        self.use_debug_cursor = self.connection.use_debug_cursor
         self.connection.use_debug_cursor = True
-        self.starting_queries = len(self.connection.queries)
+        self.initial_queries = len(self.connection.queries)
+        self.final_queries = None
         request_started.disconnect(reset_queries)
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
-        self.connection.use_debug_cursor = self.old_debug_cursor
+        self.connection.use_debug_cursor = self.use_debug_cursor
         request_started.connect(reset_queries)
         if exc_type is not None:
             return
 
-        final_queries = len(self.connection.queries)
-        executed = final_queries - self.starting_queries
+        self.final_queries = len(self.connection.queries)
 
+
+class _AssertNumQueriesContext(CaptureQueriesContext):
+    def __init__(self, test_case, num, connection):
+        self.test_case = test_case
+        self.num = num
+        super(_AssertNumQueriesContext, self).__init__(connection)
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        super(_AssertNumQueriesContext, self).__exit__(exc_type, exc_value, traceback)
+        executed = len(self.captured_queries)
         self.test_case.assertEqual(
             executed, self.num, "%d queries executed, %d expected" % (
                 executed, self.num

tests/model_inheritance/tests.py

@@ -1 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from operator import attrgetter
 
 from django.core.exceptions import FieldError
+from django.db import connection
 from django.test import TestCase
+from django.test.testcases import CaptureQueriesContext
 from django.utils import six
 
 from .models import (Chef, CommonInfo, ItalianRestaurant, ParkingLot, Place,
@@ -294 +296 @@
         )
         with self.assertNumQueries(6):
             ir.save()
+
+    def test_update_parent_filtering(self):
+        """
+        Test that updating a field of a model subclass doesn't issue an UPDATE
+        query constrained by an inner query.
+        Refs #10399
+        """
+        supplier = Supplier.objects.create(
+            name='Central market',
+            address='610 some street'
+        )
+        # Capture the expected query in a database agnostic way
+        with CaptureQueriesContext(connection) as captured_queries:
+            Place.objects.filter(pk=supplier.pk).update(name=supplier.name)
+        expected_sql = captured_queries[0]['sql']
+        # Capture the queries executed when a subclassed model instance is saved.
+        with CaptureQueriesContext(connection) as captured_queries:
+            supplier.save(update_fields=('name',))
+        for query in captured_queries:
+            sql = query['sql']
+            if 'UPDATE' in sql:
+                self.assertEqual(expected_sql, sql)