Fixed #21453 -- Enabled autocommit before calling init_connection_state.

Also ensured the transaction state is clean on Oracle while I was there.

This change cannot be backported to 1.6 because it's
backwards-incompatible for custom database backends.

django/db/backends/__init__.py

@@ -110,9 +110,8 @@ class BaseDatabaseWrapper(object):
         # Establish the connection
         conn_params = self.get_connection_params()
         self.connection = self.get_new_connection(conn_params)
+        self.set_autocommit(self.settings_dict['AUTOCOMMIT'])
         self.init_connection_state()
-        if self.settings_dict['AUTOCOMMIT']:
-            self.set_autocommit(True)
         connection_created.send(sender=self.__class__, connection=self)
 
     def ensure_connection(self):

django/db/backends/oracle/base.py

@@ -627,6 +627,9 @@ class DatabaseWrapper(BaseDatabaseWrapper):
             # Django docs specify cx_Oracle version 4.3.1 or higher, but
             # stmtcachesize is available only in 4.3.2 and up.
             pass
+        # Ensure all changes are preserved even when AUTOCOMMIT is False.
+        if not self.get_autocommit():
+            self.commit()
 
     def create_cursor(self):
         return FormatStylePlaceholderCursor(self.connection)

django/db/backends/postgresql_psycopg2/base.py

@@ -142,12 +142,12 @@ class DatabaseWrapper(BaseDatabaseWrapper):
                 conn_tz = get_parameter_status('TimeZone')
 
             if conn_tz != tz:
-                self.connection.cursor().execute(
-                    self.ops.set_time_zone_sql(), [tz]
-                )
+                cursor = self.connection.cursor()
+                cursor.execute(self.ops.set_time_zone_sql(), [tz])
+                cursor.close()
                 # Commit after setting the time zone (see #17062)
-                self.connection.commit()
-        self.connection.set_isolation_level(self.isolation_level)
+                if not self.get_autocommit():
+                    self.connection.commit()
 
     def create_cursor(self):
         cursor = self.connection.cursor()

docs/releases/1.7.txt

@@ -899,6 +899,11 @@ Miscellaneous
 
 * GeoDjango dropped support for GEOS < 3.1.
 
+* The ``init_connection_state`` method of database backends now executes in
+  autocommit mode (unless you set :setting:`AUTOCOMMIT <DATABASE-AUTOCOMMIT>`
+  to ``False``). If you maintain a custom database backend, you should check
+  that method.
+
 Features deprecated in 1.7
 ==========================