Log Message:
Changes 8.2.18:

* Use a separate interpreter for each calling SQL userid in PL/Perl and PL/Tcl
* Prevent possible crashes in pg_get_expr() by disallowing it from being called
  with an argument that is not one of the system catalog columns it's intended
  to be used with
* Fix Windows shared-memory allocation code
* Treat exit code 128 (ERROR_WAIT_NO_CHILDREN) as non-fatal on Windows
* Fix possible duplicate scans of UNION ALL member relations
* Fix "cannot handle unplanned sub-select" error
* Reduce PANIC to ERROR in some occasionally-reported btree failure cases, and
  provide additional detail in the resulting error messages
* Prevent show_session_authorization() from crashing within autovacuum
  processes
* Defend against functions returning setof record where not all the returned
  rows are actually of the same rowtype
* Fix possible failure when hashing a pass-by-reference function result
* Take care to fsync the contents of lockfiles (both "postmaster.pid" \ 
and the
  socket lockfile) while writing them
* Avoid recursion while assigning XIDs to heavily-nested subtransactions
* Fix log_line_prefix's %i escape, which could produce junk early in backend
  startup
* Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE" when
  archiving is enabled
* Allow "CREATE DATABASE" and "ALTER DATABASE ... SET \ 
TABLESPACE" to be
  interrupted by query-cancel
* In PL/Python, defend against null pointer results from PyCObject_AsVoidPtr
  and PyCObject_FromVoidPtr
* Improve "contrib/dblink"'s handling of tables containing dropped columns
* Fix connection leak after "duplicate connection name" errors in
  "contrib/dblink"
* Fix "contrib/dblink" to handle connection names longer than 62 bytes
  correctly