id (CVE-2006-0553).  Also fix related bug in SET SESSION AUTHORIZATION that
allows unprivileged users to crash the server, if it has been compiled with
Asserts enabled.  The escalation-of-privilege risk exists only in 8.1.0-8.1.2.
However, the Assert-crash risk exists in all releases back to 7.3.
Thanks to Akio Ishida for reporting this problem.