A few days ago I reported on a problem with savepoints, but all
that it appeared to be was an extemporaneous warning message.
Well, I just found out that InnoDB can actually lose the
savepoints! The overall transaction can still be rolled back
successfully, but the savepoints themselves are completely gone.
This only occurs after the warning: "Got error 153 from storage
engine" happens twice in one transaction (if it only happens
once, the savepoints still work) which requires that alternating
savepoints be set 6 times. See the full report here: http://bugs.mysql.com/bug.php?id=38187.