Only reproducable in 5.1-wl2325, although the missing code is missing from 4.0 and up.


sql/slave.cc:
  Clean up after slave sql thread when exiting.
  
  Wasn't calling close_thread_tables().
  
  This was causing a crashing bug in the 5.1-wl2325 tree. It is conceivable that this
  could cause a problem in earlier versions, but we have not been able to reproduce.