Fix join alias resolution

[serprex]

Fixes #2642

FROM (query) alias ignored renaming
In nested subqueries the select list would rename, while the join alias would not respect that

DESCRIPTION: fix error caused by joins with shadowed aliases

[codecov]

Codecov Report

Merging #2733 into master will increase coverage by 0.86%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2733      +/-   ##
==========================================
+ Coverage   91.28%   92.14%   +0.86%     
==========================================
  Files         127      127              
  Lines       30492    30470      -22     
==========================================
+ Hits        27835    28078     +243     
+ Misses       2657     2392     -265

[serprex]

I've confirmed this is an upstream bug

postgres=# create table events_table (id integer primary key, user_id integer);
CREATE TABLE
postgres=# create table users_table_ref (id integer primary key, value_2 integer);
CREATE TABLE
postgres=# create view asdf as SELECT r
FROM
  (SELECT  user_id_deep, random() as r -- prevent pulling up the subquery
   FROM (events_table
         INNER JOIN
         users_table_ref ON (events_table.user_id = users_table_ref.value_2)) AS join_alias(user_id_dee
p)) AS bar,
     (events_table
      INNER JOIN
     users_table_ref ON (events_table.user_id = users_table_ref.value_2)) AS join_alias(user_id_deep)
WHERE (bar.user_id_deep = join_alias.user_id_deep);
CREATE VIEW
postgres=# \d+ asdf
                                 View "public.asdf"
 Column |       Type       | Collation | Nullable | Default | Storage | Description 
--------+------------------+-----------+----------+---------+---------+-------------
 r      | double precision |           |          |         | plain   | View definition:
 SELECT bar.r
   FROM ( SELECT join_alias_1.user_id_deep,
            random() AS r
           FROM (events_table events_table_1
             JOIN users_table_ref users_table_ref_1 ON events_table_1.user_id = users_table_ref_1.value_2) join_alias(user_id_deep, user_id, id, value_2)) bar,
    (events_table
     JOIN users_table_ref ON events_table.user_id = users_table_ref.value_2) join_alias(user_id_deep, user_id, id, value_2)
  WHERE bar.user_id_deep = join_alias.user_id_deep;

& confirmed that my one liner fix fixes this

[serprex]

Upstream: https://www.postgresql.org/message-id/CY4PR2101MB080246F2955FF58A6ED1FEAC98140%40CY4PR2101MB0802.namprd21.prod.outlook.com

[marcocitus]

Maybe wait 1-2 days before merging to see if pgsql-hackers responds with an alternative suggestion, but otherwise seems fine.

[serprex]

Postgres has committed this fix to their ruleutils

Updating branch to match Tom's commit

[onderkalaci]

Postgres has committed this fix to their ruleutils
Updating branch to match Tom's commit

Great!