into  mysql.com:/home/hf/work/16813/my51-16813

into  mysql.com:/home/hf/work/16813/my51-16813

into  mysql.com:/home/hf/work/21888/my51-21888

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  bk-internal.mysql.com:/data0/bk/mysql-5.1-arch

into  mysql.com:/home/psergey/mysql-5.1-bug14940-r10a

into  mysql.com:/home/hf/work/21888/my51-21888

into  mysql.com:/home/hf/work/21888/my50-21888

RTree keys are really different from BTree and need specific
paramters to be set by optimizer to work.
Sometimes optimizer doesn't set those properly.
Here we decided just to add code to check that the parameters
are correct. Hope to fix optimizer sometimes.

- Re-worked the prev_record_reads() function to return the lower bound of
  number of different table access scans that will be performed.

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  mysql.com:/home/hf/work/16813/my51-16813

We use the condition from CHECK OPTION twice handling UPDATE command.
First we construnct 'update_cond' AND 'option_cond'
condition to select records to be updated, then we check the
'option_cond' for the updated row.
The problem is that first 'AND' condition is optimized during the 'select'
which can break 'option_cond' structure, so it will be unusable for
the sectond use - to check the updated row.
Possible soultion is either use copy of the condition in the first
use or to make optimization less traumatic for the operands.
I picked the first one. 

  After merge fix

into  moonbone.local:/work/5505-bug-5.0-opt-mysql

On an INSERT into an updatable but non-insertable view an error message was
issued stating the view being not updatable. This can lead to a confusion of a
user.

A new error message is introduced. Is is showed when a user tries to insert
into a non-insertable view.

into  zim.(none):/home/brian/mysql/merge-5.1

into  zim.(none):/home/brian/mysql/merge-5.1

into  mysql.com:/home/gluh/MySQL/Merge/5.1

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  moonbone.local:/work/18360-bug-5.1-opt-mysql

into  dl145h.mysql.com:/users/gbichot/mysql-5.1-arch

and so the engine calls current_thd to derive transaction information;
instead we now pass THD to those functions, it looks more logical
(it makes the implicit current_thd parameter more visible).
Approved by Brian and Monty.

into  mysql.com:/home/gluh/MySQL/Merge/5.1

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.1-opt

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.0-opt

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.0-opt

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-4.1-opt

into  mysql.com:/home/cps/mysql/trees/5.1-runtime-new

at the moment, so we can safely do that). Update an error
mesage to make it translateable.

into  mysql.com:/home/gluh/MySQL/Merge/5.0