# HG changeset patch
# User Brodie Rao <brodie@sf.io>
# Date 1331584552 25200
# Node ID c0b83639098449a3e1acc538bb8d83602d4449d6
# Parent  95cddfdbec66b6851789d8bce7257b46de1dec41
psycopg2: restore autocommit when leaving transaction management

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -108,12 +108,15 @@ class BaseDatabaseWrapper(object):
         over to the surrounding block, as a commit will commit all changes, even
         those from outside. (Commits are on connection level.)
         """
-        self._leave_transaction_management(self.is_managed())
         if self.transaction_state:
             del self.transaction_state[-1]
         else:
             raise TransactionManagementError("This code isn't under transaction "
                 "management")
+        # Note that it is intentional we pop first one entry from the
+        # transaction_state stack, and then use the topmost entry (given by
+        # is_managed()) for _leave_transaction_management(). Refs #16047.
+        self._leave_transaction_management(self.is_managed())
         if self._dirty:
             self.rollback()
             raise TransactionManagementError("Transaction managed block ended with "
diff --git a/tests/regressiontests/transactions_regress/tests.py b/tests/regressiontests/transactions_regress/tests.py
--- a/tests/regressiontests/transactions_regress/tests.py
+++ b/tests/regressiontests/transactions_regress/tests.py
@@ -1,11 +1,11 @@
 from __future__ import absolute_import
 
 from django.core.exceptions import ImproperlyConfigured
-from django.db import connection, transaction
+from django.db import connection, connections, transaction, DEFAULT_DB_ALIAS
 from django.db.transaction import commit_on_success, commit_manually, TransactionManagementError
 from django.test import TransactionTestCase, skipUnlessDBFeature
 from django.test.utils import override_settings
-from django.utils.unittest import skipIf
+from django.utils.unittest import skipIf, skipUnless
 
 from .models import Mod, M2mA, M2mB
 
@@ -175,6 +175,60 @@ class TestTransactionClosing(Transaction
         self.test_failing_query_transaction_closed()
 
 
+class TestPostgresAutocommit(TransactionTestCase):
+    """
+    Tests to make sure psycopg2's autocommit mode is restored after entering
+    and leaving transaction management. Refs #16047.
+    """
+    def setUp(self):
+        from psycopg2.extensions import (ISOLATION_LEVEL_AUTOCOMMIT,
+                                         ISOLATION_LEVEL_READ_COMMITTED)
+        self._autocommit = ISOLATION_LEVEL_AUTOCOMMIT
+        self._read_committed = ISOLATION_LEVEL_READ_COMMITTED
+
+        # We want a clean backend with autocommit = True, so
+        # first we need to do a bit of work to have that.
+        self._old_backend = connections[DEFAULT_DB_ALIAS]
+        settings = self._old_backend.settings_dict.copy()
+        settings['OPTIONS']['autocommit'] = True
+        new_backend = self._old_backend.__class__(settings, DEFAULT_DB_ALIAS)
+        connections[DEFAULT_DB_ALIAS] = new_backend
+
+    def test_initial_autocommit_state(self):
+        self.assertTrue(connection.features.uses_autocommit)
+        self.assertEqual(connection.isolation_level, self._autocommit)
+
+    def test_transaction_management(self):
+        transaction.enter_transaction_management()
+        transaction.managed(True)
+        self.assertEqual(connection.isolation_level, self._read_committed)
+
+        transaction.leave_transaction_management()
+        self.assertEqual(connection.isolation_level, self._autocommit)
+
+    def test_transaction_stacking(self):
+        transaction.enter_transaction_management()
+        transaction.managed(True)
+        self.assertEqual(connection.isolation_level, self._read_committed)
+
+        transaction.enter_transaction_management()
+        self.assertEqual(connection.isolation_level, self._read_committed)
+
+        transaction.leave_transaction_management()
+        self.assertEqual(connection.isolation_level, self._read_committed)
+
+        transaction.leave_transaction_management()
+        self.assertEqual(connection.isolation_level, self._autocommit)
+
+    def tearDown(self):
+        connections[DEFAULT_DB_ALIAS] = self._old_backend
+
+TestPostgresAutocommit = skipUnless(connection.vendor == 'postgresql',
+    "This test only valid for PostgreSQL")(TestPostgresAutocommit)
+TestPostgresAutoCommit = skipUnlessDBFeature('supports_transactions')(
+    TestPostgresAutocommit)
+
+
 class TestManyToManyAddTransaction(TransactionTestCase):
     def test_manyrelated_add_commit(self):
         "Test for https://code.djangoproject.com/ticket/16818"