Changed version to 4.1.20

  Backport of changes in 5.0 (bug#18294)

into mysql.com:/Users/kent/mysql/bk/mysql-4.1-new

Now test for NULLness the pointers returned from objects created from the
default value. Pushing patch on behalf of cmiller.

into mysql.com:/Users/kent/mysql/bk/mysql-4.1-new

into  devsrv-b.mysql.com:/users/msvensson/mysql-4.1

into  devsrv-b.mysql.com:/users/msvensson/mysql-4.1

In the code that converts IN predicates to EXISTS predicates it is changing
the select list elements to constant 1. Example :
SELECT ... FROM ...  WHERE a IN (SELECT c FROM ...)
is transformed to :
SELECT ... FROM ... WHERE EXISTS (SELECT 1 FROM ...  HAVING a = c)
However there can be no FROM clause in the IN subquery and it may not be
a simple select : SELECT ... FROM ... WHERE a IN (SELECT f(..) AS
c UNION SELECT ...) This query is transformed to : SELECT ... FROM ...
WHERE EXISTS (SELECT 1 FROM (SELECT f(..) AS c UNION SELECT ...)
x HAVING a = c) In the above query c in the HAVING clause is made to be
an Item_null_helper (a subclass of Item_ref) pointing to the real
Item_field (which is not referenced anywhere else in the query anymore).
This is done because Item_ref_null_helper collects information whether
there are NULL values in the result.  This is OK for directly executed
statements, because the Item_field pointed by the Item_null_helper is
already fixed when the transformation is done.  But when executed as
a prepared statement all the Item instances are "un-fixed" before the
recompilation of the prepared statement. So when the Item_null_helper
gets fixed it discovers that the Item_field it points to is not fixed
and issues an error.  The remedy is to keep the original select list
references when there are no tables in the FROM clause. So the above
becomes : SELECT ... FROM ...  WHERE EXISTS (SELECT c FROM (SELECT f(..)
AS c UNION SELECT ...) x HAVING a = c) In this way c is referenced
directly in the select list as well as by reference in the HAVING
clause. So it gets correctly fixed even with prepared statements.  And
since the Item_null_helper subclass of Item_ref_null_helper is not used
anywhere else it's taken out.

  System variable was added out of lexical order.

into mysql.com:/Users/kent/mysql/bk/mysql-4.1-new

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1

into sergbook.mysql.com:/usr/home/serg/Abk/mysql-4.1

into mysql.com:/Users/kent/mysql/bk/mysql-4.1-new

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1

into  perch.ndb.mysql.com:/home/jonas/src/mysql-4.1

into  mysql.com:/home/alexi/innodb/mysql-4.1-innodb

into  mysql.com:/home/alexi/innodb/mysql-4.1-innodb

 Use files innodb_mysql.[test|result] instead.

(based on the fact that packet is ALWAYS \0 terminated, see my_net_read)

(reported by Stefano Di Paola)

  Handle early abort of scan, so that resources are correctly freed

into  neptunus.(none):/home/msvensson/mysql/mysql-4.1

into  mysql.com:/data0/knielsen/mysql-4.1-mtr-fix

into  production.mysql.com:/usersnfs/rkalimullin/4.1.b17896

into  polar.kitebird.com:/src/extern/MySQL/bk/mysql-4.1

  myisam_ftdump options: --help first, then rest in
  lexical order.

accounting non-ai32 in tmpkeyval. This changeset is supposed to be specifically for 4.1.
Another changeset is going to push into 5. 

  Backporting a changeset made for 5.0. Comments from there:

  The fix refines the algorithm of generating DROPs for binlog.
  Temp tables with common pseudo_thread_id are clustered into one query.
  Consequently one replication event per pseudo_thread_id is generated.

into  mysql.com:/home/alexi/innodb/mysql-4.1

into  rurik.mysql.com:/home/igor/mysql-4.1

into  production.mysql.com:/usersnfs/rkalimullin/4.1.b18643

- after review fixes

into  rurik.mysql.com:/home/igor/dev/mysql-4.1-0

The bug caused wrong result sets for union constructs of the form
(SELECT ... ORDER BY order_list1 [LIMIT n]) ORDER BY order_list2.
For such queries order lists were concatenated and limit clause was
completely neglected. 

 Fix BUG#16814: "SHOW INNODB STATUS format error in LATEST FOREIGN KEY ERROR section"
     Add a missing newline to the LAST FOREIGN KEY ERROR section in SHOW INNODB STATUS
     output.
 Fix BUG#18934: "InnoDB crashes when table uses column names like DB_ROW_ID".
     Refuse tables that use reserved column names.