missed table to drop after merge from 4.1 

into  dl145k.mysql.com:/tmp/andrei/MERGE/5.0

into  mysql.com:/space/pekka/ndb/version/my50

into  mysql.com:/usr/home/ram/work/mysql-5.0

into  mysql.com:/home/alik/MySQL/devel/5.0-tree

into  mysql.com:/usr/home/ram/work/mysql-5.0

Bug#18282 "INFORMATION_SCHEMA.TABLES provides inconsistent info about invalid views"
This bug caused crashes or resulted in wrong data being returned
when one tried to obtain information from I_S tables about views
using stored functions.

It was caused by the fact that we were using LEX representing
statement which were doing select from I_S tables as active LEX
when contents of I_S table were built. So state of this LEX both
affected and was affected by open_tables() calls which happened
during this process. This resulted in wrong behavior and in
violations of some of invariants which caused crashes.

This fix tries to solve this problem by properly saving/resetting
and restoring part of LEX which affects and is affected by the
process of opening tables and views in get_all_tables() routine.
To simplify things we separated this part of LEX in a new class
and made LEX its descendant.

into  mysql.com:/space/pekka/ndb/version/my50

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0

monitor interval must be > 2sec.

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0

into  devsrv-b.mysql.com:/users/msvensson/mysql-5.0

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0

into  shellback.(none):/home/msvensson/mysql/mysql-5.0

into  devsrv-b.mysql.com:/users/msvensson/mysql-5.0

into  neptunus.(none):/home/msvensson/mysql/mysql-5.0

into  mysql.com:/usr/home/ram/work/mysql-5.0

refining the test case to exclude problems with koi8r on some platforms.

into  mysql.com:/space/pekka/ndb/version/my50

into  mysql.com:/home/emurphy/iggy/mysql-5.0

into  mysql.com:/home/kgeorge/mysql/5.0/clean

into  mysql.com:/home/kgeorge/mysql/5.0/B18681

into  mysql.com:/home/kgeorge/mysql/5.0/B18681

into  mysql.com:/home/kgeorge/mysql/5.0/B14875

When reading a view definition from a .frm file it was
throwing a SQL error if the DEFINER user is not defined.
Changed it to a warning to match the (documented) case
when a view with undefined DEFINER user is created.

The check for view security was lacking several points :
1. Check with the right set of permissions : for each table ref that
participates in a view there were the right credentials to use in it's
security_ctx member, but these weren't used for checking the credentials.
This makes hard enforcing the SQL SECURITY DEFINER|INVOKER property
consistently.
2. Because of the above the security checking for views was just ruled out
in explicit ways in several places.
3. The security was checked only for the columns of the tables that are
brought into the query from a view. So if there is no column reference
outside of the view definition it was not detecting the lack of access to
the tables in the view in SQL SECURITY INVOKER mode.

The fix below tries to fix the above 3 points.

into  mysql.com:/space/pekka/ndb/version/my50-bug14509

into  mysql.com:/space/pekka/ndb/version/my50-bug14509