into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/Merge/5.0-bug19136

into  mysql.com:/usr_rh9/home/elkin.rh9/MySQL/FIXES/4.1-bug19136_unass_user_var

into mysql.com:/home/psergey/mysql-4.1-bug16798

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.0-merge

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  mysql.com:/home/mydev/mysql-4.1-bug10405

into  mysql.com:/home/mydev/mysql-5.0-bug10405

into mysql.com:/home/psergey/mysql-4.1-bug16798

The bug was as follows: When merge_key_fields() encounters "t.key=X OR t.key=Y" it will 
try to join them into ref_or_null access via "t.key=X OR NULL". In order to make this 
inference it checks if Y<=>NULL, ignoring the fact that value of Y may be not yet known.

The fix is that the check if Y<=>NULL is made only if value of Y is known (i.e. it is a
constant).
TODO: When merging to 5.0, replace used_tables() with const_item() everywhere in merge_key_fields().

after merge.

Concurrent read and update of privilege structures (like simultaneous
run of SHOW GRANTS and ADD USER) could result in server crash.

Ensure that proper locking of ACL structures is done.

No test case is provided because this bug can't be reproduced
deterministically.

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.0-merge

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.0-real

into  hundin.mysql.fi:/home/jani/mysql-5.0merge_4_1_2nd

into  hundin.mysql.fi:/home/jani/mysql-5.0merge_4_1_2nd

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

The reason of the bug is in that `get_var_with_binlog' performs missed
assingment of
the variables as side-effect. Doing that it eventually calls
`free_underlaid_joins' to pass as an argument `thd->lex->select_lex' of the lex
which belongs to the user query, not 
to one which is emulated i.e SET @var1:=NULL.


`get_var_with_binlog' is refined to supply a temporary lex to sql_set_variables's stack.

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16372

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16372

into  mysql.com:/home/tomash/src/mysql_ab/mysql-4.1-bug16501

into  mysql.com:/home/my/mysql-5.0

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-5.0

  Delete: Docs/changelog-5.0.xml

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

  Delete: Docs/changelog-4.1.xml

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

  Delete: Docs/changelog-4.0.xml

into  mysql.com:/home/my/mysql-5.0

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-4.1

mysql-test-run now fails in case of warnings

into  hundin.mysql.fi:/home/jani/mysql-5.0merge_4_1

TIME_FORMAT using "%l:%i" returns 36:00 with 24:00:00 in TIME column

into  mysql.com:/home/my/mysql-5.0

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-5.0

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-4.1