Possible bug in PostgreSQL 8.3beta4 (postgres process segfaults)

While developing a Python program I encountered a situation that makes
on of the PostgreSQL 8.3b4's processes crash badly with a segfault.
Let me explain.

After enabling "debug5" as log level I was able to locate and
reproduce the exact sequence of SQL queries made against my test
database
and crash postgres again using only "psql". See for yourself:


foodb=# \o out.txt
foodb=# SELECT * FROM foobaz.instrument WHERE code = 'TEST0118';
LOG:  duration: 3.683 ms  statement: SELECT * FROM foobaz.instrument
WHERE code = 'TEST0118';
foodb=# SELECT xpath('//sp:description/text()', content,
ARRAY[ARRAY['sp', 'http://www.foobaz.com/']])
foodb-#        FROM foobaz.instrument WHERE code = 'TEST0018';
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

The pgsql log file contains these error logs (the pid 753 is a
postgres child process):

"""""""""
[loluyede:foodb:2007-12-11 14:38:20.992 CET]LOG:  00000: duration:
0.090 ms  statement: BEGIN; SET TRANSACTION ISOLATION LEVEL READ
COMMITTED
[loluyede:foodb:2007-12-11 14:38:20.992 CET]LOCATION:
exec_simple_query, postgres.c:1040
[::2007-12-11 14:38:20.993 CET]LOG:  00000: server process (PID 753)
was terminated by signal 11: Segmentation fault
[::2007-12-11 14:38:20.993 CET]LOCATION:  LogChildExit, postmaster.c:2510
[::2007-12-11 14:38:20.993 CET]LOG:  00000: terminating any other
active server processes
[::2007-12-11 14:38:20.993 CET]LOCATION:  HandleChildCrash, postmaster.c:2355
[::2007-12-11 14:38:20.997 CET]LOG:  00000: all server processes
terminated; reinitializing
[::2007-12-11 14:38:20.997 CET]LOCATION:  PostmasterStateMachine,
postmaster.c:2663
[::2007-12-11 14:38:21.000 CET]LOG:  00000: database system was
interrupted; last known up at 2007-12-11 14:38:02 CET
[::2007-12-11 14:38:21.000 CET]LOCATION:  StartupXLOG, xlog.c:4789
[::2007-12-11 14:38:21.000 CET]DEBUG:  00000: checkpoint record is at 0/2AB634A0
""""""""

The out.txt file contains the output of the "SELECT *" statement

   code   |    kind    |         last_modified         |
created            | modified_by | created_by |
       content

----------+------------+-------------------------------+------------------------------+-------------+------------+----------------------------------------------------------------------
 TEST0118 | bazfoo | 2007-12-12 08:17:01.846919+01 | 2007-12-12
08:17:00.32337+01 | anonymous   | anonymous  | <xml ... >
(1 row)

The "instrument" table has the following schema:

"""
CREATE TABLE foobaz.instrument
(
-- Inherited:   code character varying(32) NOT NULL,
-- Inherited:   kind character varying(32) NOT NULL DEFAULT
'bazfoo'::character varying,
  last_modified timestamp with time zone NOT NULL,
  created timestamp with time zone NOT NULL DEFAULT
('now'::text)::timestamp(3) with time zone,
  modified_by character varying(64),
  created_by character varying(64) NOT NULL DEFAULT
'anonymous'::character varying,
  content xml NOT NULL,
  CONSTRAINT instrument_pkey PRIMARY KEY (code),
  CONSTRAINT instrument_kind_check CHECK (kind::text = 'bazfoo'::text)
)
INHERITS (foobaz.instrument_base)
WITH (OIDS=FALSE);
"""

Its "parent" table is instrument_base and has the following schema:

"""
CREATE TABLE foobaz.instrument_base
(
  code character varying(32) NOT NULL,
  kind character varying(32) NOT NULL,
  CONSTRAINT instrument_base_pkey PRIMARY KEY (code)
)
WITH (OIDS=FALSE);
"""

PostgreSQL is again 8.3beta 4 on Ubuntu Linux 7.10.
It's compiled with the following flags:
./configure --with-python --with-openssl --with-pam --with-libxml
--with-libxslt --enable-thread-safety --enable-debug

libxml is 2.6.30, libxslt is 1.1.21

I think that is all.

Is it a bug or am I doing something wrong?

--
Lawrence, oluyede.org - neropercaso.it
"It is difficult to get a man to understand
something when his salary depends on not
understanding it" - Upton Sinclair