BUG #14718: unable to update table with identity column GENERATED ALWAYS

The following bug has been logged on the website:

Bug reference: 14718
Logged by: zam6ak
Email address: zam6ak(at)gmail(dot)com
PostgreSQL version: 10beta1
Operating system: Windows Server 2012 R2
Description:

I have downloaded a PG10 distro for Windows from BigSQL.

if I try to update table that uses identity column generated always, the
update fails...

If I switch to "generated by default" it works...

-- create tbl1
create table tbl1 (
id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY, -- fails
--id bigint GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY, -- works
name text NOT NULL
);
-- add some values
insert into tbl1 (name) values ('Tommy');
-- verify
select * from tbl1; -- 1;"Tommy"

-- now try to update
update tbl1 set name = 'Bobby' where id = 1;

ERROR: column "id" can only be updated to DEFAULT
DETAIL: Column "id" is an identity column defined as GENERATED ALWAYS.

********** Error **********

ERROR: column "id" can only be updated to DEFAULT
SQL state: 428C9
Detail: Column "id" is an identity column defined as GENERATED ALWAYS.