Completely recoded the bugfix for 4.1.
This is just a merge changeset.

Version for 4.1. Committed for merge.
If the result table is one of the select tables in INSERT SELECT,
we must not disable the result tables indexes before selecting.
mysql_execute_command() detects the match for other reasons and
adds the flag OPTION_BUFFER_RESULT to the 'select_options'. 
In this case the result is put into a temporary table first. 
Hence, we can defer the preparation of the insert
table until the result is to be used.

Version for 4.0. Committed for merge.
If the result table is one of the select tables in INSERT SELECT,
we must not disable the result tables indexes before selecting.
mysql_execute_command() detects the match for other reasons and
adds the flag OPTION_BUFFER_RESULT to the 'select_options'. 
In this case the result is put into a temporary table first. 
Hence, we can defer the preparation of the insert
table until the result is to be used.

not default_charset_into. It fixes the
problem that in some cases numbers where
treated as CHAR(N), not as BINARY(N), e.g.
wrong 'charsetnr' when sent to the client side.
2. IFNULL didn't aggregate argument charsets
and collations, so IFNULL(1,'a') produced
a CHAR(N). Now produces a BINARY(N).
3. SELECT PROCEDURE ANALIZE now returns
BINARY columns, which is much better than it worked
previously: CHAR with the default character set.
But in the future it's worth to fix the fields
'Field_name' and 'Optimal_fieldtype' to use UTF8,
and 'Min_value' and 'Max_value' to inherit their charsets
from the original items. But it is not important,
and BINARY(N) is OK for now.
4. Tests were fixed accordingly. No new tests were
made, as the old onces cover everything.

into mysql.com:/home/mysql_src/mysql-4.1-clean

into mysql.com:/space/my/mysql-4.0

into mysql.com:/space/my/mysql-4.1

into mysql.com:/home/mysql_src/mysql-4.1-clean

We should not overwrite res if it is returned from a const item.

into sanja.is.com.ua:/home/bell/mysql/bk/work-valgrind-4.1

Working around hang of master < 3.23.50 on SELECT @@unknown_var
(to enable 3.23.49->4.1.10 replication)

into bob.(none):/home/reggie/bk/mysql-4.1

sql_lex.cc:
  Set query to not cacheable if we are using multistatements and there are multiple statements in this query

into mysql.com:/space/my/mysql-4.1

into kite-hub.kitebird.com:/src/extern/MySQL/bk/mysql-4.1

into mysql.com:/space/my/mysql-4.1

into mysql.com:/space/my/mysql-4.1-build

into kite-hub.kitebird.com:/src/extern/MySQL/bk/mysql-4.1

  Mac OS X PKGs with Do-pkg

into mysql.com:/home/timka/mysql/src/4.1-bug-7331

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

into mysql.com:/home/timka/mysql/src/4.1-bug-7331

  bug#7839 ncorrect collation for char(ascii('a'))

  Move out-of-order option.

  bug#7891: mysql_character_set_name() returns collation

into mysql.com:/home/mysql_src/mysql-4.1-clean

  Bug#7721

into serg.mylan:/usr/home/serg/Abk/mysql-4.1

into mysql.com:/home/mysql_src/mysql-4.1-clean

Fixed bug by adding code that displays the contents of mysql.host when \p is added as part of the prompt.

mysql.cc:
  Added code to display mysql.host as prompt when using shared memory