BEGIN;

CREATE TYPE int8alias1;
CREATE FUNCTION int8alias1in(cstring) RETURNS int8alias1
  STRICT IMMUTABLE LANGUAGE internal AS 'int8in';
CREATE FUNCTION int8alias1out(int8alias1) RETURNS cstring
  STRICT IMMUTABLE LANGUAGE internal AS 'int8out';
CREATE TYPE int8alias1 (input = int8alias1in, output = int8alias1out, like = int8);
CREATE CAST (int8 AS int8alias1) WITHOUT FUNCTION;

CREATE FUNCTION int8alias1eq(int8alias1, int8alias1) RETURNS bool
  STRICT IMMUTABLE LANGUAGE internal AS 'int8eq';
CREATE OPERATOR = (
  procedure = int8alias1eq,
  leftarg = int8alias1, rightarg = int8alias1,
  commutator = =, merges
);
CREATE FUNCTION int8alias1lt(int8alias1, int8alias1) RETURNS bool
  STRICT IMMUTABLE LANGUAGE internal AS 'int8lt';
CREATE OPERATOR < (procedure = int8alias1lt,
  leftarg = int8alias1, rightarg = int8alias1);

CREATE FUNCTION int8alias1gt(int8alias1, int8alias1) RETURNS bool
  STRICT IMMUTABLE LANGUAGE internal AS 'int8gt';
CREATE OPERATOR > (procedure = int8alias1gt,
  leftarg = int8alias1, rightarg = int8alias1);

CREATE FUNCTION int8alias1cmp(int8alias1, int8alias1) RETURNS int
  STRICT IMMUTABLE LANGUAGE internal AS 'btint8cmp';

ALTER OPERATOR FAMILY integer_ops USING btree ADD
    OPERATOR 3 = (int8alias1, int8alias1),
--    OPERATOR 1 < (int8alias1, int8alias1),
    OPERATOR 5 > (int8alias1, int8alias1),
    FUNCTION 1 int8alias1cmp(int8alias1, int8alias1);

CREATE TABLE t1 (b int8alias1);
CREATE TABLE t2 (b int8alias1);

SET enable_nestloop = off;
SET enable_hashjoin = off;
SET enable_mergejoin = on;

EXPLAIN (COSTS OFF) SELECT * FROM t1 JOIN t2 ON t1.b = t2.b;

ROLLBACK;

/*
Expected on vanilla PostgreSQL:

ERROR:  missing operator 1(1...) in opfamily 1976

Expected with the patch applied:

             QUERY PLAN
------------------------------------
 Nested Loop
   Disabled: true
   Join Filter: (t1.b = t2.b)
   ->  Seq Scan on t1
   ->  Seq Scan on t2
(5 rows)
*/