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    Fix for BUG#20188 "REPLACE or ON DUPLICATE KEY UPDATE in · 4e9d7d6c
    unknown authored
    auto_increment breaks binlog":
    if slave's table had a higher auto_increment counter than master's (even
    though all rows of the two tables were identical), then in some cases,
    REPLACE and INSERT ON DUPLICATE KEY UPDATE failed to replicate
    statement-based (it inserted different values on slave from on master).
    write_record() contained a "thd->next_insert_id=0" to force an adjustment
    of thd->next_insert_id after the update or replacement. But it is this
    assigment introduced indeterminism of the statement on the slave, thus
    the bug. For ON DUPLICATE, we replace that assignment by a call to
    handler::adjust_next_insert_id_after_explicit_value() which is deterministic
    (does not depend on slave table's autoinc counter). For REPLACE, this
    assignment can simply be removed (as REPLACE can't insert a number larger
    than thd->next_insert_id).
    We also move a too early restore_auto_increment() down to when we really know
    that we can restore the value.
    
    
    mysql-test/r/rpl_insert_id.result:
      result update, without the bugfix, slave's "3 350" were "4 350".
    mysql-test/t/rpl_insert_id.test:
      test for BUG#20188 "REPLACE or ON DUPLICATE KEY UPDATE in
      auto_increment breaks binlog".
      There is, in this order:
      - a test of the bug for the case of REPLACE
      - a test of basic ON DUPLICATE KEY UPDATE functionality which was not
      tested before
      - a test of the bug for the case of ON DUPLICATE KEY UPDATE
    sql/handler.cc:
      the adjustment of next_insert_id if inserting a big explicit value, is
      moved to a separate method to be used elsewhere.
    sql/handler.h:
      see handler.cc
    sql/sql_insert.cc:
      restore_auto_increment() means "I know I won't use this autogenerated
      autoincrement value, you are free to reuse it for next row". But we were
      calling restore_auto_increment() in the case of REPLACE: if write_row() fails
      inserting the row, we don't know that we won't use the value, as we are going to
      try again by doing internally an UPDATE of the existing row, or a DELETE
      of the existing row and then an INSERT. So I move restore_auto_increment()
      further down, when we know for sure we failed all possibilities for the row.
      Additionally, in case of REPLACE, we don't need to reset THD::next_insert_id:
      the value of thd->next_insert_id will be suitable for the next row.
      In case of ON DUPLICATE KEY UPDATE, resetting thd->next_insert_id is also
      wrong (breaks statement-based binlog), but cannot simply be removed, as
      thd->next_insert_id must be adjusted if the explicit value exceeds it.
      We now do the adjustment by calling
      handler::adjust_next_insert_id_after_explicit_value() (which, contrary to
      thd->next_insert_id=0, does not depend on the slave table's autoinc counter,
      and so is deterministic).
    4e9d7d6c
rpl_insert_id.test 5.47 KB