mysql-test/r/sp.result:
  update result
mysql-test/t/sp.test:
  Add test for Bug #11333 "Stored Procedure: Memory blow up on repeated SELECT ... INTO query"
sql/item.cc:
  we should call destructors for Items before reuse
sql/item.h:
  Add new method and constructor for Item_string.
sql/sp_head.cc:
  String allocation should be done on the system heap for now.