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revno: 2617.69.32
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-next-bg46747
timestamp: Wed 2009-08-19 18:12:27 +0400
message:
  Fix for bug #46747 "Crash in MDL_ticket::upgrade_shared_lock_to_exclusive
  on TRIGGER + TEMP table".

  Server crashed when one tried to drop trigger which had its subject
  table shadowed by a temporary table with the same name.

  This problem occured because in such situation DROP TRIGGER has opened
  temporary table instead of base table on which trigger was defined.
  Attempt to upgrade metadata lock on this temporary table led to crash
  (we don't acquire metadata locks for temporary tables).

  This fix ensures that DROP TRIGGER ignores temporary tables when
  trying to open table on which trigger to be dropped is defined.


mysql-test/r/trigger.result:
  Added test case for bug #46747 "Crash in
  MDL_ticket::upgrade_shared_lock_to_exclusive
  on TRIGGER + TEMP table".
mysql-test/t/trigger.test:
  Added test case for bug #46747 "Crash in
  MDL_ticket::upgrade_shared_lock_to_exclusive
  on TRIGGER + TEMP table".
sql/sql_trigger.cc:
  Prevent DROP TRIGGER from opening temporary table which might
  shadow base table on which trigger to be dropped is defined.