#1 immutable functions are not created as immutable

[martin sarsale]

For example:

CREATE OR REPLACE FUNCTION rankeable(int8, int8)
RETURNS bool AS
'
select case
when $1 > 0 or $2 > 0 then
true
else
false
end;'
LANGUAGE 'sql' IMMUTABLE;

is not created as "immutable" on the output diff

thanks in advance