BUG #2303: UPDATE from manual is incorrect

The following bug has been logged online:

Bug reference:      2303
Logged by:          Massimo Fidanza
Email address:      malix0@gmail.com
PostgreSQL version: 8.1
Operating system:   Linux
Description:        UPDATE from manual is incorrect
Details:

Hi all, I have an update similar to the one included in Postgresql
documentation in Postgresql 8.1 -> VI. Reference -> I. SQL Commands ->
UPDATE

The query is the last but one

UPDATE employees SET last_closed_deal = deal.id
    FROM accounts JOIN deals ON (account.id = deal.account_id)
    WHERE deal.employee_id = employees.id
    AND deal.name = 'Rocket Powered Skates'
    AND accounts.name = 'Acme Corporation'
    ORDER BY deal.signed_date DESC LIMIT 1;

this query is not correct and doesn't work with postgresql 8.1.


My query that doesn't work is the first and I modify it in second form that
is the correct one.

------------- FIRST QUERY (NOT WORKING) ---------------
update
    tblstock
set
    npezzi = sum(sr.npezzi)
    ,npezzirimanenti = sum(sr.npezzi)
    ,modelloid = sr.modelloid
    ,objid = sr2.objid
    ,tipostockid = 3
from
    tblstockrighe sr join tblstockrighe sr2
            on sr.modelloid = sr2.modelloid and sr2.id = 110
where
    sr.stockid = tblstock.id
    and sr.stockid = 270
group by
    sr.stockid
    ,sr.modelloid
    ,sr2.objid



------------- SECOND QUERY (WORK) ----------------
update
    tblstock
set
    npezzi = sr.npezzi
    ,npezzirimanenti = sr.npezzi
    ,modelloid = sr.modelloid
    ,objid = sr.objid
    ,tipostockid = 3
from
    (select
        sr.stockid
        ,sum(sr.npezzi) as npezzi
        ,sr.modelloid
        ,sr2.objid
    from
        tblstockrighe sr join tblstockrighe sr2
            on sr.modelloid = sr2.modelloid and sr2.id = 110
    where
        sr.stockid = 270
    group by
        sr.stockid
        ,sr.modelloid
        ,sr2.objid
    ) sr
where
    sr.stockid = tblstock.id