protection: TRASH in delete

fixed a bug that it discovered


include/my_sys.h:
  move TRASH to my_sys.h from sql_list.h
sql/field.h:
  use TRASH macro
sql/item.h:
  TRASH in delete
sql/item_func.h:
  never delete item's manually!
sql/opt_range.cc:
  TRASH in delete
sql/sql_lex.h:
  TRASH in delete
sql/sql_list.h:
  move TRASH to my_sys.h from sql_list.h
sql/sql_parse.cc:
  don't use properties of deleted objects (even when it's safe)
sql/sql_select.cc:
  TRASH in delete
sql/sql_show.cc:
  TRASH in delete
sql/sql_string.h:
  TRASH in delete

1 files changed, 3 insertions, 2 deletions

diff --git a/sql/item.h b/sql/item.h
index 8f6d6581884..2c2978e841c 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -120,8 +120,9 @@ public:
   static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
   static void *operator new(size_t size, MEM_ROOT *mem_root)
   { return (void*) alloc_root(mem_root, (uint) size); }
-  static void operator delete(void *ptr,size_t size) {}
-  static void operator delete(void *ptr,size_t size, MEM_ROOT *mem_root) {}
+  static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); }
+  static void operator delete(void *ptr,size_t size, MEM_ROOT *mem_root)
+  { TRASH(ptr, size); }
 
   enum Type {FIELD_ITEM, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM,
 	     INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM,