Change-Id: I08ffdc1eda8921745e0459ca375e154ac3cf8b9d
:tickets: 13144
Fixed a critical issue in :class:`.Engine` where connections created in
- conjunction with the :meth:`.ConnectionEvents.do_connect` event listeners
+ conjunction with the :meth:`.DialectEvents.do_connect` event listeners
would receive shared, mutable collections for the connection arguments,
leading to a variety of potential issues including unlimited growth of the
argument list as well as elements within the parameter dictionary being