Bug #33629: last_day function can return null, but has 'not null' flag set for result

LAST_DAY and MAKEDATE functions are documented as
returning NULL value, but actually they was implemented
as returning NOT NULL typed values.

That caused a confusing error "ERROR 1048 (23000): Column
'...' cannot be null" on queries like: 

  SELECT 1 FROM (SELECT LAST_DAY('0')) a;


mysql-test/r/func_sapdb.result:
    Updated test case for bug #33629.
mysql-test/r/func_time.result:
    Updated test case for bug #33629.
mysql-test/r/type_date.result:
    Added test case for bug #33629.
mysql-test/t/type_date.test:
    Added test case for bug #33629.
sql/item_timefunc.h:
    Bug #33629: last_day function can return null, but has 'not null' flag set for result
    
    1. The Item_func_makedate::fix_length_and_dec method
       has been modified to declare MAKEDATE() as a function
       returning nullable value.
    2. The Item_func_last_day::fix_length_and_dec method
       has been overloaded for the same purpose.

indexed column in mysql.plugin table should use case-insensitive collation
for index lookups to work

(backport from 6.0)

sql/sql_plugin.cc:
  generate the key correctly using key_copy.
  field->store() stores the value in record format, not key format.

Original revision in 6.0:
------------------------------------------------------------
revno: 2599.108.1
committer: Alexander Nozdrin <alik@sun.com>
branch nick: 6.0-rpl-bug40128
timestamp: Wed 2009-01-21 15:33:42 +0300
message:
  Fix for Bug#40128: drop-no_root fails under windows in 6.0-rpl.
  
  The problem was that directories with no permission (000) files
  are deleted differently on UNIX and on Windows.
  
  On UNIX, 000-permission file is deleted perfectly, but other files
  are left in the directory.
  
  On Windows, 000-permission file is not deleted, but other files
  are deleted.
  
  Also, the fix needed a change in mysqltest.c: 'chmod' directive
  should return a positive error code (in order to be handled).
  It's decided to return a constant '1' for all error codes
  just to be OS-independent.
------------------------------------------------------------

Original revision in mysql-6.0-codebase is:

revno: 2617.31.14
committer: Konstantin Osipov <kostja@sun.com>
branch nick: mysql-6.0-runtime
timestamp: Sat 2009-03-28 11:42:55 +0300
message:
  Bug#35297 SHOW CREATE EVENT does not show the DEFINER:
  update test result after a merge from now.

Original revision is from mysql-6.0-codebase:

revno: 2617.23.13
committer: Alexander Nozdrin <alik@sun.com>
branch nick: 6.0-rt-bug34828
timestamp: Tue 2009-02-24 14:25:46 +0300
message:
  A patch for Bug#34828: OF is taken as OFF and a value of 0
  is set for variable SQL_notes.
  
  The problem was that partial match was allowed for keywords.
  
  A fix is to disable partial match and require full match.

Original revision is from mysql-6.0-codebase:

revno: 2630.3.1
committer: Alexander Nozdrin <alik@mysql.com>
branch nick: 6.0-rt-bug26704
timestamp: Thu 2008-05-29 21:04:06 +0400
message:
  A fix for Bug#26704: Failing DROP DATABASE brings
  mysql-client out of sync.

  The problem was that we changed current database w/o caring
  whether it was dropped successfully or not.

  The fix is not to change current database if we failed to drop it.

Backport of the fix for BUG#33730 "Full table scan instead selected partitions for query more than 10 partitions"
from 6.0, made in sergefp@mysql.com-20090205190644-q8632sniogedhtsu

(from revision konstantin@mysql.com-20080627154042-923m6lzk7z77lrgj ). This moves the slow part
(10 seconds over 13) into a separate big test.

2. Mark ndb, rpl_ndb test suites experimental.