Fixed #21235 -- Disabled savepoints for old versions of SQLite.

            BaseDatabaseWrapper.close(self)

    def _savepoint_allowed(self):

        # Two conditions are required here:

        # - A sufficiently recent version of SQLite to support savepoints,

        # - Being in a transaction, which can only happen inside 'atomic'.

        # When 'isolation_level' is not None, sqlite3 commits before each

        # savepoint; it's a bug. When it is None, savepoints don't make sense

        # because autocommit is enabled. The only exception is inside atomic

        # blocks. To work around that bug, on SQLite, atomic starts a

        # because autocommit is enabled. The only exception is inside 'atomic'

        # blocks. To work around that bug, on SQLite, 'atomic' starts a

        # transaction explicitly rather than simply disable autocommit.

        return self.in_atomic_block

        return self.features.uses_savepoints and self.in_atomic_block

    def _set_autocommit(self, autocommit):

        if autocommit: