Fixed #17671 - Cursors are now context managers.

3 files changed, 14 insertions, 1 deletions

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index 131a73715d..74046a0d9b 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -1,7 +1,7 @@
 import datetime
 import time
 
-from django.db.utils import DatabaseError
+from django.db.utils import DatabaseError, ProgrammingError
 
 try:
     from django.utils.six.moves import _thread as thread
@@ -664,6 +664,9 @@ class BaseDatabaseFeatures(object):
     # Does the backend require a connection reset after each material schema change?
     connection_persists_old_columns = False
 
+    # What kind of error does the backend throw when accessing closed cursor?
+    closed_cursor_error_class = ProgrammingError
+
     def __init__(self, connection):
         self.connection = connection
 
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 71ff2811e2..b22c653bd7 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -15,6 +15,7 @@ from django.db.backends.postgresql_psycopg2.creation import DatabaseCreation
 from django.db.backends.postgresql_psycopg2.version import get_version
 from django.db.backends.postgresql_psycopg2.introspection import DatabaseIntrospection
 from django.db.backends.postgresql_psycopg2.schema import DatabaseSchemaEditor
+from django.db.utils import InterfaceError
 from django.utils.encoding import force_str
 from django.utils.functional import cached_property
 from django.utils.safestring import SafeText, SafeBytes
@@ -60,6 +61,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     can_rollback_ddl = True
     supports_combined_alters = True
     nulls_order_largest = True
+    closed_cursor_error_class = InterfaceError
 
 
 class DatabaseWrapper(BaseDatabaseWrapper):
diff --git a/django/db/backends/utils.py b/django/db/backends/utils.py
index 0e2aa4503e..ccda77f658 100644
--- a/django/db/backends/utils.py
+++ b/django/db/backends/utils.py
@@ -36,6 +36,14 @@ class CursorWrapper(object):
     def __iter__(self):
         return iter(self.cursor)
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        # Ticket #17671 - Close instead of passing thru to avoid backend
+        # specific behavior.
+        self.close()
+
 
 class CursorDebugWrapper(CursorWrapper):