BUG #18123: The execution plan for the left join is incorrect, returning incorrect rows of data.

The following bug has been logged on the website:

Bug reference:      18123
Logged by:          The execution plan for the left join is incorrect, returning incorrect rows
of data.
Email address:      dafoer_x@163.com
PostgreSQL version: 14.0
Operating system:   centos_x86
Description:

create table tb11(a int, b int);
insert into tb11 values(1,1);
select count(1) from tb11 a1 where a1.a =1;
select count(1) from tb11 a1 left join tb11 a2 on a1.a=a2.a where a1.a=1 and
a2.a=3;

postgres=# select count(1) from tb11 a1 where a1.a =1;
 count 
-------
     1
(1 row)

postgres=# select count(1) from tb11 a1 left join tb11 a2 on a1.a=a2.a where
a1.a=1 and a2.a=3;
 count 
-------
     0
(1 row)

postgres=# explain select count(1) from tb11 a1 left join tb11 a2 on
a1.a=a2.a where a1.a=1 and a2.a=3;
                   QUERY PLAN                   
------------------------------------------------
 Aggregate  (cost=0.00..0.01 rows=1 width=8)
   ->  Result  (cost=0.00..0.00 rows=0 width=0)
         One-Time Filter: false
(3 rows)


In the left join scenario, the conclusion of 'result = false' cannot be
obtained.
Could you please help analyze this issue? 

Thank you.
dafoer