Current table is placed into read_tables set of the current join_tab->select
so get_mm_parts function thinks that current table's record is read and
tries to calculate WHERE condition with the fields of the record.
Result of these calculations is unpredictable.
Looks funny - outcome of the SELECT depends on the queries executed before.

Anyway i think we should have testcase on this part of the code.


mysql-test/r/sel000001.result:
  appropriate result added
mysql-test/t/sel000001.test:
  testcase added
sql/sql_select.cc:
  I think we should count current table out of read_tables set