make server crash

UPDATE against CSV table may cause server crash or update a table with wrong
values.

CSV can write only a whole row at once. That means it must read all columns,
that it is not going to update, and write them along with updated columns.
But only limited set of columns was read, those that were needed for the
UPDATE query.

With this fix all columns are read in case we're performing an UPDATE.

into  mysql.com:/home/svoj/devel/mysql/BUG26976/mysql-5.1-engines

  Problem: crash on attempt to open a table
  having "#mysql50#" prefix in db or table name.
  Fix: This prefix is reserved for "mysql_upgrade"
  to access 5.0 tables  whose file names are not encoded
  according to "5.1 tablename to filename encoded".
  Don't try open tables whose db name or table name
  has this prefix.

into  mysql.com:/home/svoj/devel/mysql/BUG26976/mysql-5.1-engines

            SHOW CREATE TABLE fails
Addition to the fix: report db name + table name instead of table path.
This solves embedded merge test failure.

            SHOW CREATE TABLE fails

After merge fixes.

into  mysql.com:/home/svoj/devel/mysql/BUG26976/mysql-5.1-engines

into  mysql.com:/home/svoj/devel/mysql/BUG26976/mysql-5.0-engines

into  xiphis.org:/home/antony/work2/mysql-5.1-merge

into  xiphis.org:/home/antony/work2/mysql-5.0-merge

into  xiphis.org:/home/antony/work2/mysql-5.0-engines.merge

into  xiphis.org:/home/antony/work2/mysql-5.1-engines.merge

into  xiphis.org:/home/antony/work2/mysql-4.1-engines.merge

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/41

  Add another exception to the acceptable mysqld errors, for test case for bug 28436

            SHOW CREATE TABLE fails

Underlying table names, that merge engine fails to open were not
reported.

With this fix CHECK TABLE issued against merge table reports all
underlying table names that it fails to open. Other statements
are unaffected, that is underlying table names are not included
into error message.

This fix doesn't solve SHOW CREATE TABLE issue.

  Post-merge fix warning

  Post-merge fix (byte -> uchar)

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/51

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/51

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/50

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/51

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/50

into  chilla.local:/home/mydev/mysql-5.1-axmrg

into  chilla.local:/home/mydev/mysql-5.1-axmrg

into  chilla.local:/home/mydev/mysql-5.0-axmrg

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/51

into  quadxeon.mysql.com:/benchmarks/ext3/TOSAVE/tsmith/bk/maint/jun05/50

into  mysql.com:/home/svoj/devel/mysql/BUG27141/mysql-5.1-engines

Original problem was fixed by Magnus (see BUG25807).

Currently only windows debug build causes assertion failure. This patch assures
that my_tell gets correct file descriptor on any platform by DBUG_ASSERT macro.

into  amd64.(none):/src/bug24400/my41-bug24400

into  amd64.(none):/src/bug24400/my50-bug24400

into  amd64.(none):/src/bug24400/my51-bug24400

into  amd64.(none):/src/bug24400/my51-bug24400

into  amd64.(none):/src/bug24400/my50-bug24400

into  olga.mysql.com:/home/igor/mysql-5.1-opt

into  olga.mysql.com:/home/igor/mysql-5.1-opt-merge