Logic Error: LEFT JOIN ON FALSE causes incorrect NULL comparison result in PolarDB

Description:
When executing a query involving a LEFT JOIN with a constant FALSE condition, PolarDB returns 1 row, while PostgreSQL and others correctly return 0. The difference occurs when filtering on columns that become NULL due to the join, where comparison predicates involving NULL appear to be evaluated inconsistently in PolarDB.

How to repeat:

-- Schema
CREATE TABLE users (
    id           INT,
    username     VARCHAR(100),
    email        VARCHAR(255),
    age          INT,
    status       VARCHAR(20),
    created_at   TIMESTAMP NULL,
    score        DOUBLE
);

CREATE TABLE posts (
    id          INT,
    user_id     INT,
    title       VARCHAR(255),
    content     VARCHAR(1000),
    views       INT,
    likes       INT,
    created_at  TIMESTAMP NULL,
    rating      DOUBLE
);

INSERT INTO users VALUES
(1, 'alice', 'alice@test.com', 20, 'active',  '2022-01-01 10:00:00', 88.5),
(2, 'bob',   'bob@test.com',   30, 'active',  '2022-01-02 11:00:00', 92.3),
(3, 'carol', NULL,             NULL, 'banned','2022-01-03 12:00:00', NULL),
(4, 'dave',  'dave@test.com',  45, 'active',  '2022-01-04 13:00:00', 65.2),
(5, NULL,    'null@test.com',  18, 'inactive','2022-01-05 14:00:00', 70.0);

INSERT INTO posts VALUES
(1, 1, 'Hello World', 'First post', 100, 10, '2022-01-10 10:00:00', 4.5),
(2, 1, 'Another Post', NULL,        150, 20, '2022-01-11 11:00:00', 3.0),
(3, 2, 'Bob Post',     'Content',   NULL,  5, '2022-01-12 12:00:00', NULL),
(4, 3, NULL,           'Empty',     50,   2, '2022-01-13 13:00:00', 5.0),
(5, 4, 'Last Post',    'Last',      300,  30,'2022-01-14 14:00:00', 4.9);

-- Trigger sql
WITH jennifer_2 AS (
    SELECT
        ref_0.likes AS c0,
        subq_3.c1 AS c1,
        ref_0.rating AS c2
    FROM posts ref_0
    LEFT JOIN (
        SELECT
            ref_1.created_at AS c0,
            76 AS c1
        FROM users ref_1
        WHERE true
    ) subq_3
        ON (false)
    WHERE true
)

SELECT COUNT(*)
FROM jennifer_2 ref_2
WHERE (ref_2.c1 > ref_2.c0) AND (ref_2.c2 IS NULL);

-- Result: {1} wrong!

version info:

MySQL [test]> select version();
+----------------------------------+
| version()                        |
+----------------------------------+
| 8.0.32-X-Cluster-8.4.19-20250825 |
+----------------------------------+
1 row in set (0.00 sec)

MySQL [test]> select polardb_version();
+----------------------------------------------------------+
| polardb_version()                                        |
+----------------------------------------------------------+
| PolarDB V2.0_2.4.2_8.4.19-20250825 (Distributed Edition) |
+----------------------------------------------------------+
1 row in set (0.00 sec)

Start by running the supplied LEFT JOIN query against PolarDB and PostgreSQL using the listed version information, then compare the NULL-filtering results. Trace the query through the SQL execution path to identify why the constant FALSE join produces a row; done means PolarDB returns 0 like PostgreSQL.