[session] call rollback in Connection.__exit__
If we just free the cnxset and clear the Connection, we're missing the
pending operation's rollback_event callbacks, which may be needed for
cleanup.
Latest changes
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* table of `all latest changes`_
Links below is providing useful RQL query example.
.. _all latest changes: view?rql=Any+M%2CX+WHERE+X+modification_date+M+ORDERBY+M+DESC+LIMIT+30