Bug in psql (on_error_rollback)

There is a bug in psql for the new ON_ERROR_ROLLBACK feature. In AUTOCOMMIT
off mode it does not work correctly for the first statement.

This is how it works usually:
====================================
postgres=# \set AUTOCOMMIT off
postgres=# \set ON_ERROR_ROLLBACK interactive
postgres=# SELECT 1;
 ?column?
----------
        1
(1 row)

postgres=# SELECT a;
ERROR:  column "a" does not exist
postgres=# SELECT 1;
 ?column?
----------
        1
(1 row)

postgres=# BEGIN;
WARNING:  there is already a transaction in progress
BEGIN
postgres=# ROLLBACK;
ROLLBACK
====================================

For the first statement in a transaction after the implicit BEGIN it does
not work:
====================================
postgres=# ROLLBACK;
ROLLBACK
postgres=#
postgres=# SELECT a;
ERROR:  column "a" does not exist
postgres=# SELECT 1;
ERROR:  current transaction is aborted, commands ignored until end of
transaction block
====================================

With the attaced patch it works correctly even for the first statement.
====================================
postgres=# \set AUTOCOMMIT off
postgres=# \set ON_ERROR_ROLLBACK interactive
postgres=# SELECT a;
ERROR:  column "a" does not exist
postgres=# SELECT 1;
 ?column?
----------
        1
(1 row)

postgres=# BEGIN;
WARNING:  there is already a transaction in progress
BEGIN
postgres=# ABORT;
ROLLBACK
====================================

Please check the patch and apply to CVS tip.
I think it would be good to add regression tests for AUTOCOMMIT and
ON_ERROR_ROLLBACK and possibly others. There are currently no regression
tests specifically for psql features, but since the regression tests are
executed via psql, there would be no problem in creating a set of such
tests, right?. I could write some.

Best Regards,
Michael Paesold