Fixed wrong logging of Access denied error (Bug #398)


include/my_global.h:
  Fix for QNX
mysql-test/r/union.result:
  new test case
mysql-test/t/union.test:
  Test of bug in union and left join
mysys/my_seek.c:
  Safety fix to find out when pos gets a wrong value
sql/field.h:
  Fix for UNION and LEFT JOIN
sql/mysql_priv.h:
  Fix for UNION and LEFT JOIN
sql/sql_base.cc:
  Fix for UNION and LEFT JOIN
sql/sql_insert.cc:
  Fix for UNION and LEFT JOIN
sql/sql_parse.cc:
  Fixed wrong logging of Access denied error
sql/sql_union.cc:
  Fix for UNION and LEFT JOIN
sql/sql_update.cc:
  Fix for UNION and LEFT JOIN