BUG #4564: multi threaded queries corrupt client when server debugging levels are hi

The following bug has been logged online:

Bug reference:      4564
Logged by:          Diez Roggisch
Email address:      diez.roggisch@ableton.com
PostgreSQL version: 8.3
Operating system:   Debian Lenny
Description:        multi threaded queries corrupt client when server
debugging levels are hi
Details:

We yesterday hunted down a bug that made our
python/psycopg2/libpq.so.5-based apache processes segfault at random.

In the end, we could reproduce the error with this script

http://www.initd.org/svn/psycopg/psycopg2/trunk/examples/threads.py

locally on the machine, regardless of tcp or socket being used.

It occured after turning all logging facilities like log_min_error_statement
to the highest level possible.

The problem can't be reproduced on my developer machine (ubuntu hardy)