BUG #4680: Server crashed if using wrong (mismatch) conversion functions

The following bug has been logged online:

Bug reference: 4680
Logged by: Denis Afonin
Email address: vadm(at)itkm(dot)ru
PostgreSQL version: 8.3.6
Operating system: Linux Debian Lenny
Description: Server crashed if using wrong (mismatch) conversion
functions
Details:

I do:

=cut=
postgres(at)sunset:~$ createdb test -E KOI8
postgres(at)sunset:~$ psql test
Welcome to psql 8.3.6, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit

test=# SHOW server_version;
server_version
----------------
8.3.6
(1 row)

test=# CREATE DEFAULT CONVERSION test1 FOR 'LATIN1' TO 'KOI8' FROM
ascii_to_mic;
CREATE CONVERSION
test=# CREATE DEFAULT CONVERSION test2 FOR 'KOI8' TO 'LATIN1' FROM
mic_to_ascii;
CREATE CONVERSION
test=# set client_encoding to 'LATIN1';
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
Соединение с сервером было потеряно.
Попытка переустановить: Безуспешно.
!> \q
=end cut=

In Logs:
=cut=
2009-02-27 10:29:40 UTC LOG: database system was shut down at 2009-02-27
10:29:38 UTC
2009-02-27 10:29:40 UTC LOG: autovacuum launcher started
2009-02-27 10:29:40 UTC LOG: database system is ready to accept
connections
2009-02-27 10:29:50 UTC ERROR: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC STATEMENT: set client_encoding to 'LATIN1';
2009-02-27 10:29:50 UTC ERROR: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC STATEMENT: set client_encoding to 'LATIN1';
2009-02-27 10:29:50 UTC ERROR: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC ERROR: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC ERROR: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: ERRORDATA_STACK_SIZE exceeded
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: ERRORDATA_STACK_SIZE exceeded
<<<<many-many-many-of-above-lines-skipped>>>>>
2009-02-27 10:29:50 UTC PANIC: ERRORDATA_STACK_SIZE exceeded
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: ERRORDATA_STACK_SIZE exceeded
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC PANIC: expected source encoding "MULE_INTERNAL",
but got "KOI8"
2009-02-27 10:29:50 UTC LOG: server process (PID 4958) was terminated by
signal 11: Segmentation fault
2009-02-27 10:29:50 UTC LOG: terminating any other active server processes
2009-02-27 10:29:50 UTC LOG: all server processes terminated;
reinitializing
2009-02-27 10:29:50 UTC LOG: database system was interrupted; last known up
at 2009-02-27 10:29:40 UTC
2009-02-27 10:29:50 UTC LOG: database system was not properly shut down;
automatic recovery in progress
=end cut=