BUG #14105: regression for right join - failed to build any 2-way joins

The following bug has been logged on the website:

Bug reference:      14105
Logged by:          Vojtech Rylko
Email address:      vojta.rylko@gmail.com
PostgreSQL version: 9.5.2
Operating system:   Linux version 3.16.0-30-generic
Description:

I have problem with right join which uses coalesce in join condition. With
other type of join or without coalesce query works.

Minimal reproducer:

create table a as (select 1 as id);
select *
from ((
       a as a1
       full join (select 1 as id) as tt
       on (a1.id = tt.id)
      )
      right join (select 1 as id) as tt2
      on (coalesce(tt.id) = tt2.id)
     )
;
ERROR:  XX000: failed to build any 2-way joins
LOCATION:  standard_join_search, allpaths.c:1832


It works on PostgreSQL 9.2.13., returning:
 id | id | id
----+----+----
  1 |  1 |  1
(1 row)

Cheers,
V.