BUG #15658: Window Function in a left join using AS or alias for the cloumn name

The following bug has been logged on the website:

Bug reference:      15658
Logged by:          Justin G
Email address:      zzzzz.graf@gmail.com
PostgreSQL version: 11.2
Operating system:   Debian 9
Description:

Hello postgresql developers

I believe I found an obscure bug with the window function 

Postgresql version 11.2 
OS Debian 9 
PG Admin 4.1

Have  2 basic tables with a Parent child relationship, a One to Many
relationship.  The child table also makes reference to a 3rd table which can
have a many to many relationship.  This query returns count(*)  of the 3rd
table’s keys in the child table grouped by Parent Table ID.  

The base SQL statement works:

select calprorules_id cid , count(*) over 
 (PARTITION BY calprorules_calprorange_id, calprorules_calprohd_id  ) as
howmany
from mcal.calprorules

The error occurs when I put the query into a LEFT JOIN:

select counts.count, 
    caldetail.*, calprorules_desired_value, calprorules_stdpreceision,
calprorules_mutpreceision , 
    calprorange_description, calprorange_id, calprorange_from, calprorange_to

    from mcal.caldetail 
    left join mcal.calprorules on calprorules_id = caldetail_calprorules_id
    left join (select calprorules_id as cid , count(*) over 
                (PARTITION BY calprorules_calprorange_id, calprorules_calprohd_id  )  as
howmany
                from mcal.calprorules)  counts 
            on counts.cid = caldetail_calprorules_id
    left join mcal.calprorange on calprorange_id = calprorules_calprorange_id
    where caldetail_calhead_id = 179 
    order by calprorange_description, caldetails_seqence 


Postgresql returns  
ERROR: column "caldetail.caldetail_id" must appear in the GROUP BY clause or
be used in an aggregate function LINE 2: caldetail.*,
calprorules_desired_value, calprorules_stdprec... 
SQL state: 42803 Character: 24

Delete the AS howmany; it works.

I realized after writing this that I should have written the SQL like this,
deleting the LEFT JOIN and moving the window function into the select
statement:

select caldetail.*, calprorules_desired_value, calprorules_stdpreceision,
calprorules_mutpreceision , 
            calprorange_description, calprorange_id, calprorange_from, calprorange_to
, 
            count(*) over (PARTITION BY calprorules_calprorange_id,
calprorules_calprohd_id  ) 
            from mcal.caldetail 
                left join mcal.calprorules on calprorules_id =
caldetail_calprorules_id
                left join mcal.calprorange on calprorange_id =
calprorules_calprorange_id
            where caldetail_calhead_id = 179 
            order by calprorange_description, caldetails_seqence 


Clearly the second SQL statement is better, but i do not believe the window
function should error when put into a join