logtrigger issue in PostgreSQL HEAD

Something has evidently changed of late (not quite sure when) which
causes the Slony-I log triggers to break when working against PostreSQL
HEAD.

A more-or-less simplest case is demonstrated thus:

chris@dba2:/mnt/PostgreSQL/dbs> psql slonyregress1
Line style is ascii.
psql (8.5devel)
Type "help" for help.

slonyregress1=# \d table1
Table "public.table1"
Column | Type | Modifiers
--------+---------+-----------------------------------------------------
id | integer | not null default nextval('table1_id_seq'::regclass)
data | text |
Indexes:
"table1_pkey" PRIMARY KEY, btree (id)
Referenced by:
TABLE "table2" CONSTRAINT "table2_table1_id_fkey" FOREIGN KEY (table1_id) REFERENCES table1(id) ON UPDATE CASCADE ON DELETE CASCADE
Triggers:
_slony_regress1_logtrigger_1 AFTER INSERT OR DELETE OR UPDATE ON table1 FOR EACH ROW EXECUTE PROCEDURE _slony_regress1.logtrigger('_slony_regress1', '1', 'kv')

slonyregress1=# delete from table1 where id = 1;
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.
!> \q

There are no notable compiler complaints about
src/backend/slony_funcs.c, so the mismatch must be at a subtler level
than that of an up-front API change for something.

I suppose a next step might be to kick off gdb against the backend when
processing this.
--
output = ("cbbrowne" "@" "ca.afilias.info")
Christopher Browne
"Bother," said Pooh, "Eeyore, ready two photon torpedoes and lock
phasers on the Heffalump, Piglet, meet me in transporter room three"