Fixed #19707 -- Reset transaction state after requests

tests/regressiontests/middleware/tests.py

@@ -9,9 +9,9 @@ import warnings
 
 from django.conf import settings
 from django.core import mail
-from django.db import transaction
-from django.http import HttpRequest
-from django.http import HttpResponse, StreamingHttpResponse
+from django.db import (transaction, connections, DEFAULT_DB_ALIAS,
+                       IntegrityError)
+from django.http import HttpRequest, HttpResponse, StreamingHttpResponse
 from django.middleware.clickjacking import XFrameOptionsMiddleware
 from django.middleware.common import CommonMiddleware, BrokenLinkEmailsMiddleware
 from django.middleware.http import ConditionalGetMiddleware
@@ -710,3 +710,22 @@ class TransactionMiddlewareTest(TransactionTestCase):
         TransactionMiddleware().process_exception(self.request, None)
         self.assertEqual(Band.objects.count(), 0)
         self.assertFalse(transaction.is_dirty())
+
+    def test_failing_commit(self):
+        # It is possible that connection.commit() fails. Check that
+        # TransactionMiddleware handles such cases correctly.
+        try:
+            def raise_exception():
+                raise IntegrityError()
+            connections[DEFAULT_DB_ALIAS].commit = raise_exception
+            transaction.enter_transaction_management()
+            transaction.managed(True)
+            Band.objects.create(name='The Beatles')
+            self.assertTrue(transaction.is_dirty())
+            with self.assertRaises(IntegrityError):
+                TransactionMiddleware().process_response(self.request, None)
+            self.assertEqual(Band.objects.count(), 0)
+            self.assertFalse(transaction.is_dirty())
+            self.assertFalse(transaction.is_managed())
+        finally:
+            del connections[DEFAULT_DB_ALIAS].commit

tests/regressiontests/requests/tests.py

@@ -6,9 +6,12 @@ import warnings
 from datetime import datetime, timedelta
 from io import BytesIO
 
+from django.db import connection, connections, DEFAULT_DB_ALIAS
+from django.core import signals
 from django.core.exceptions import SuspiciousOperation
 from django.core.handlers.wsgi import WSGIRequest, LimitedStream
 from django.http import HttpRequest, HttpResponse, parse_cookie, build_request_repr, UnreadablePostError
+from django.test import TransactionTestCase
 from django.test.client import FakePayload
 from django.test.utils import override_settings, str_prefix
 from django.utils import six
@@ -524,3 +527,42 @@ class RequestsTests(unittest.TestCase):
 
         with self.assertRaises(UnreadablePostError):
             request.body
+
+class TransactionRequestTests(TransactionTestCase):
+    def test_request_finished_db_state(self):
+        # The GET below will not succeed, but it will give a response with
+        # defined ._handler_class. That is needed for sending the
+        # request_finished signal.
+        response = self.client.get('/')
+        # Make sure there is an open connection
+        connection.cursor()
+        connection.enter_transaction_management()
+        connection.managed(True)
+        signals.request_finished.send(sender=response._handler_class)
+        # In-memory sqlite doesn't actually close connections.
+        if connection.vendor != 'sqlite':
+            self.assertIs(connection.connection, None)
+        self.assertEqual(len(connection.transaction_state), 0)
+
+    @unittest.skipIf(connection.vendor == 'sqlite',
+                     'This test will close the connection, in-memory '
+                     'sqlite connections must not be closed.')
+    def test_request_finished_failed_connection(self):
+        # See comments in test_request_finished_db_state() for the self.client
+        # usage.
+        response = self.client.get('/')
+        conn = connections[DEFAULT_DB_ALIAS]
+        conn.enter_transaction_management()
+        conn.managed(True)
+        conn.set_dirty()
+        # Test that the rollback doesn't succeed (for example network failure
+        # could cause this).
+        def fail_horribly():
+            raise Exception("Horrible failure!")
+        conn._rollback = fail_horribly
+        signals.request_finished.send(sender=response._handler_class)
+        # As even rollback wasn't possible the connection wrapper itself was
+        # abandoned. Accessing the connections[alias] will create a new
+        # connection wrapper, whch must be different than the original one.
+        self.assertIsNot(conn, connections[DEFAULT_DB_ALIAS])
+        self.assertEqual(len(connection.transaction_state), 0)