pgsql-bugs@postgresql.org writes:
> The bug is repeatable so if anyone wants more information please request.
Hmm. There's a known bug in plpy.execute concerning handling of NULLs,
but offhand this doesn't look like it ever passes NULLs to execute() ---
is that correct? Otherwise, we'll need a stack trace from the crashed
backend, or enough data to reproduce the problem locally. (The trigger
definition alone isn't very useful; I'm not interested in guessing at
the table you have it on... a pg_dump script to create everything needed
to duplicate the problem would be useful.)
regards, tom lane