Fix compatibility with old versions of PostgreSQL dealing with double…

… precision

sql/provsql.sql

@@ -234,7 +234,7 @@ $$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
 
 CREATE OR REPLACE FUNCTION epsilon() RETURNS DOUBLE PRECISION AS
 $$
-  SELECT 0.001
+  SELECT CAST(0.001 AS DOUBLE PRECISION)
 $$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
 
 CREATE OR REPLACE FUNCTION provenance_times(VARIADIC tokens uuid[])
@@ -688,10 +688,10 @@ BEGIN
   ELSE
     RAISE EXCEPTION USING MESSAGE='Cannot compute expected value for aggregation function ' || aggregation_function;
   END IF;
-  IF prov <> gate_one() AND result <> 0. THEN
+  IF prov <> gate_one() AND result <> 0. AND result <> 'Infinity' AND result <> '-Infinity' THEN
     result := result/probability_evaluate(prov, method, arguments);
   END IF;
-  RETURN CAST(result AS DOUBLE PRECISION);
+  RETURN result;
 END
 $$ LANGUAGE plpgsql PARALLEL SAFE;
 

test/sql/expected.sql

@@ -10,7 +10,7 @@ GROUP BY CITY;
 
 SELECT remove_provenance('expected_result');
 
-SELECT city, ROUND(c1::numeric,2) AS c1, ROUND(c2::numeric,2) AS c2, ROUND(s::numeric,2) AS s, ROUND(min::numeric,2) AS min, ROUND(max::numeric,2) AS max
+SELECT city, ROUND(c1::numeric,2) AS c1, ROUND(c2::numeric,2) AS c2, ROUND(s::numeric,2) AS s, min, max
 FROM expected_result
 ORDER BY city;