BUG #1740: Deferred foreign key constraint isn't deferred

The following bug has been logged online:

Bug reference: 1740
Logged by: Daniel Cristian Cruz
Email address: dccruz(at)mega(dot)com(dot)br
PostgreSQL version: 8.0.3
Operating system: Windows XP Professional
Description: Deferred foreign key constraint isn't deferred
Details:

Below there is a script which raises the bug:

CREATE TABLE mat_comissao_itens (
mat_nfs_diretorio character varying(6),
mat_nfs_in_codigo integer,
mat_nsi_in_ordem integer
);
CREATE TABLE mat_nf_saida_itens (
mat_nfs_diretorio character varying(6) NOT NULL,
mat_nfs_in_codigo integer NOT NULL,
mat_nsi_in_ordem integer,
PRIMARY KEY (mat_nfs_diretorio, mat_nfs_in_codigo, mat_nsi_in_ordem)
);
COPY mat_comissao_itens (mat_nfs_diretorio, mat_nfs_in_codigo,
mat_nsi_in_ordem) FROM stdin;
001001 339 1
001001 339 1
001001 339 1
001001 339 2
001001 339 2
001001 339 2
\.
COPY mat_nf_saida_itens (mat_nfs_diretorio, mat_nfs_in_codigo,
mat_nsi_in_ordem) FROM stdin;
001001 339 1
001001 339 2
\.
ALTER TABLE ONLY mat_comissao_itens
ADD CONSTRAINT mat_nf_saida_itens_pa_mat_comissao_itens FOREIGN KEY
(mat_nfs_diretorio, mat_nfs_in_codigo, mat_nsi_in_ordem) REFERENCES
mat_nf_saida_itens(mat_nfs_diretorio, mat_nfs_in_codigo, mat_nsi_in_ordem)
ON UPDATE RESTRICT ON DELETE RESTRICT DEFERRABLE INITIALLY DEFERRED;

BEGIN;
DELETE FROM mat_nf_saida_itens WHERE mat_nsi_in_ordem = 2;
UPDATE mat_comissao_itens SET mat_nsi_in_ordem = 1 WHERE mat_nsi_in_ordem =
2;
COMMIT;

And here is the output:

CREATE TABLE
psql:rafa2.backup:11: NOTICE: CREATE TABLE / PRIMARY KEY will create
implicit index "mat_nf_saida_itens_pkey" for table "mat_nf_saida_itens"
CREATE TABLE
ALTER TABLE
BEGIN
psql:rafa2.backup:28: ERROR: update or delete on "mat_nf_saida_itens"
violates foreign key constraint "mat_nf_saida_itens_pa_mat_comissao_itens"
on "mat_comissao_itens"
DETAIL: Key
(mat_nfs_diretorio,mat_nfs_in_codigo,mat_nsi_in_ordem)=(001001,339,2) is
still referenced from table "mat_comissao_itens".
psql:rafa2.backup:29: ERROR: current transaction is aborted, commands
ignored until end of transaction block
ROLLBACK