The problem is in the Item_func_isnull::update_used_tables() function,
bracket is at the wrong place. Because of that isnull item erroneously
is treated as const item. The fix is to set brackets in the right place.


mysql-test/r/func_isnull.result:
  test case
mysql-test/t/func_isnull.test:
  test case
sql/item_cmpfunc.h:
  set brackets in the right place.

    For application compatibility reasons  MySQL converts "<autoincrement_column> IS NULL"
    predicates to "<autoincrement_column> = LAST_INSERT_ID()" in the first SELECT following an
    INSERT regardless of whether they're top level predicates or not. This causes wrong and
    obscure results when these predicates are combined with others on the same columns. Fixed
    by only doing the transformation on a single top-level predicate if a special SQL mode is
    turned on (sql_auto_is_null).
    Also made sql_auto_is_null off by default.

per-file comments:
  mysql-test/r/func_isnull.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
    test result updated

  mysql-test/t/func_isnull.test
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
    test case added

  sql/mysqld.cc
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
    sql_auto_is_null now is OFF by default.

  sql/sql_select.cc
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
    remove_eq_conds() split in two parts - one only checks the upper condition,
    the req_remove_eq_conds() recursively checks all the condition tree.

  mysql-test/extra/rpl_tests/rpl_insert_id.test
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        test fixed (set the sql_auto_is_null variable)

  mysql-test/r/mysqlbinlog.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/r/mysqlbinlog2.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/r/odbc.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/r/query_cache.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/r/user_var-binlog.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/suite/binlog/r/binlog_row_ctype_ucs.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/suite/binlog/r/binlog_stm_ctype_ucs.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/suite/rpl/r/rpl_insert_id.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/suite/rpl/r/rpl_row_mysqlbinlog.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/suite/rpl/r/rpl_sp.result
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        result updated

  mysql-test/t/odbc.test
Bug#41371      Select returns 1 row with condition "col is not null and col is null"
        test fixed (set the sql_auto_is_null variable)

Docs/manual.texi:
  Small changes regarind user resources
client/mysqlbinlog.cc:
  Applied patch to support --database
mysql-test/r/func_isnull.result:
  New test results
mysql-test/r/join.result:
  New test results
mysql-test/r/show_check.result:
  New test results
mysql-test/r/type_datetime.result:
  New test results
mysql-test/r/type_decimal.result:
  New test results
mysql-test/r/type_float.result:
  New test results
mysys/my_gethostbyname.c:
  Fixed type on last push
mysys/my_pthread.c:
  Fixed type on last push
sql/sql_select.cc:
  Fixed bug in LIMIT handling

Docs/manual.texi:
  Changlelog