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,
compiledby GCC
 
egcs-2.91.66


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

Mike Mascari