Strang behaviour SELECT ... LIMIT n FOR UPDATE

Hi,

I'm facing a strange behaviour with a statement SELECT ... LIMIT n FOR
UPDATE in PostgreSQL 8.1. The number of rows returned is actually (n -
1). I'm trying to find whether this is an identified issue with
PostgreSQL 8.1 that might have been fixed in a later version such as
8.2; I don't have any problem in moving to a later version if needed.

agoratokens=> SELECT * FROM "Tokens" INNER JOIN "Tokentypes" ON
"Tokens"."type"="Tokentypes"."type" WHERE "Tokentypes"."tokenName"
='clanName' AND "Tokens"."isLocked" = false limit 2 FOR UPDATE;

id | type | value | isLocked | timestamp
| type | tokenName

-----+------+--------------------------+----------+---------------------
-------+------+-----------

104 | 2 | RegressionTestClanName13 | f | 2007-11-27
20:40:25.208074 | 2 | clanName

(1 row)

agoratokens=> SELECT * FROM "Tokens" INNER JOIN "Tokentypes" ON
"Tokens"."type"="Tokentypes"."type" WHERE "Tokentypes"."tokenName"
='clanName' AND "Tokens"."isLocked" = false limit 3 FOR UPDATE;

id | type | value | isLocked | timestamp
| type | tokenName

-----+------+--------------------------+----------+---------------------
-------+------+-----------

104 | 2 | RegressionTestClanName13 | f | 2007-11-27
20:40:25.208074 | 2 | clanName

118 | 2 | RegressionTestClanName28 | f | 2007-11-21
21:10:29.872352 | 2 | clanName

(2 rows)

If I remove the FOR UPDATE clause, the SELECT ... LIMIT n statement
returns n rows as expected:

agoratokens=> SELECT * FROM "Tokens" INNER JOIN "Tokentypes" ON
"Tokens"."type"="Tokentypes"."type" WHERE "Tokentypes"."tokenName"
='clanName' AND "Tokens"."isLocked" = false limit 3;

id | type | value | isLocked | timestamp
| type | tokenName

-----+------+--------------------------+----------+---------------------
-------+------+-----------

104 | 2 | RegressionTestClanName13 | f | 2007-11-27
20:40:25.208074 | 2 | clanName

40 | 2 | RegressionTestClanName9 | f | 2007-10-15
11:27:31.897 | 2 | clanName

118 | 2 | RegressionTestClanName28 | f | 2007-11-21
21:10:29.872352 | 2 | clanName

(3 rows)

--
Daniel