causes incorrect duplicate entries

Keys for BTREE indexes on ENUM and SET columns of MEMORY tables
with character set UTF8 were computed incorrectly. Many
different column values got the same key value.

Apart of possible performance problems, it made unique indexes
of this type unusable because it rejected many different
values as duplicates.

The problem was that multibyte character detection was tried
on the internal numeric column value. Many values were not
identified as characters. Their key value became blank filled.

Thanks to Alexander Barkov and Ramil Kalimullin for the patch,
which sets the character set of ENUM and SET key segments to
the pseudo binary character set.

            my_seek: Assertion `fd != -1' failed"

In difficult optimize/repair situations the server could crash.
Under some circumstances the server retries an optimize/repair
with more elaborate options. But it did not check if the first
attempt failed so badly that a second one must not be tried.

This could happen when a new data file has been created
but it was not possible to open it. In this case the
repair leaves behind a table with closed data file.
This must not be used for another repair attempt.

We do now detect the closed data file and do not try
another repair attempt in this situation.

No test case. The required table corruption can not be
repeated easily. There is a test program attached to
bug 25433.

Using INSERT DELAYED on MERGE tables could lead to table
corruptions.

The manual lists a couple of storage engines, which can be
used with INSERT DELAYED. MERGE is not in this list.

The attempt to try it anyway has not been rejected yet.
This bug was not detected earlier as it can work under
special circumstances. Most notable is low concurrency.

To be safe, this patch rejects any attempt to use INSERT
DELAYED on MERGE tables.

into  bk-internal.mysql.com:/data0/bk/mysql-4.1-opt

into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-4.1-maint

into  mysql.com:/home/hf/work/25492/my41-25492

into  mysql.com:/home/tnurnberg/24660/41-24660

ENUMs weren't allowed to have character 0xff, a perfectly good character in some locales.
This was circumvented by mapping 0xff in ENUMs to ',', thereby prevent actual commas from
being used. Now if 0xff makes an appearance, we find a character not used in the enum and
use that as a separator. If no such character exists, we throw an error.

Any solution would have broken some sort of existing behaviour. This solution should
serve both fractions (those with 0xff and those with ',' in their enums), but
WILL REQUIRE A DUMP/RESTORE CYCLE FROM THOSE WITH 0xff IN THEIR ENUMS. :-/
That is, mysqldump with their current server, and restore when upgrading to one with
this patch.

into  siva.hindu.god:/home/tsmith/m/bk/maint/41

into  mysql.com:/home/gluh/MySQL/Merge/4.1-opt

into  poseidon.mysql.com:/home/tomas/mysql-4.1-ndb

into  pilot.mysql.com:/home/msvensson/mysql/mysql-4.1-maint

 - strerror might return NULL on some platforms

into  pilot.mysql.com:/home/msvensson/mysql/mysql-4.1-maint

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

into  pilot.mysql.com:/home/msvensson/mysql/mysql-4.1-maint

into  pilot.mysql.com:/home/msvensson/mysql/mysql-4.1-maint

 - Backport fix from 5.0

into  mysql.com:/usr/home/ram/work/bug23938/my41-bug23938

into  mysql.com:/usr/home/ram/work/bug10798/my41-bug10798

into  chilla.local:/home/mydev/mysql-4.1-axmrg

added valgrind.supp to EXTRA_SCRIPTS(for pushbuild)

into  mysql.com:/home/ram/work/b26012/b26012.4.1

As we have Field_double::not_fixed we must have Field_double::size_of().

into  dev3-63.(none):/home/zhl/mysql/tree-merge/4.1/mysql-4.1-ndb

into  chilla.local:/home/mydev/mysql-4.1-axmrg

Notes:
This patch doesn't fix all issues in the tree and we need jani's fix for that
This patch shoud not be merged into 5.0

into  chilla.local:/home/mydev/mysql-4.1-axmrg

into  chilla.local:/home/mydev/mysql-4.1-axmrg

into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-4.1-maint

into  zippy.cornsilk.net:/home/cmiller/work/mysql/mysql-4.1-maint

into  qualinost.(none):/home/mtaylor/src/mysql-4.1-maint

into  mysql.com:/home/svoj/devel/mysql/WL3567/mysql-4.1-engines

When a merge table is opened compare column and key definition of
underlying tables against column and key definition of merge table.

If any of underlying tables have different column/key definition
refuse to open merge table.

into  mysql.com:/home/ram/work/b19690/b19690.4.1