Weird function behavior from Sept 11 snapshot

Under both 6.5 and 7.0:
----------------------
stocks=# create table test (key int4);
CREATE
stocks=# create function crap(int4) returns int4 as
'select sum(key) from test' language 'sql';
CREATE
stocks=# select version();

version
---------------------------------------------------------------------
PostgreSQL 7.0.0 on i686-pc-linux-gnu, compiled by gcc
egcs-2.91.66

Under the snapshot from yesterday:
---------------------------------

template1=# create table test (key int4);
CREATE
template1=# create function crap(int4) returns int4
as 'select sum(key) from test' language 'sql';
ERROR: return type mismatch in function: declared to return
int4, returns numeric
template1=# select version();

version
------------------------------------------------------------------------
PostgreSQL 7.1devel on i586-pc-linux-gnu, compiled by GCC
egcs-2.91.66

Is this correct behavior? All of the regression tests pass on the
snapshot version, BTW.

Mike Mascari