BUG#20769: Dangling pointer in ctype_recoding test case.

In some functions dealing with strings and character sets, the wrong
pointers were saved for restoration in THD::rollback_item_tree_changes().
This could potentially cause random corruption or crashes.

Fixed by passing the original Item ** locations, not local stack copies.

Also remove unnecessary use of default arguments.


sql/item.cc:
  Function agg_item_charsets() now handles non-consequtive Item *'s.
sql/item.h:
  Remove use of default argument.
sql/item_cmpfunc.cc:
  Remove use of default argument.
sql/item_func.cc:
  Remove use of default argument.
sql/item_func.h:
  Function agg_item_charsets() now handles non-consequtive Item *'s.
sql/item_strfunc.cc:
  Pass original Item **'s to agg_arg_charsets(), not local copies, to ensure
  proper restoration in THD::rollback_item_tree_changes().
sql/item_sum.cc:
  Remove use of default argument.

1 files changed, 5 insertions, 5 deletions

diff --git a/sql/item_func.h b/sql/item_func.h
index 1d8a1bd5e22..2ca4be9f3f2 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -166,21 +166,21 @@ public:
   my_decimal *val_decimal(my_decimal *);
 
   bool agg_arg_collations(DTCollation &c, Item **items, uint nitems,
-                          uint flags= 0)
+                          uint flags)
   {
-    return agg_item_collations(c, func_name(), items, nitems, flags);
+    return agg_item_collations(c, func_name(), items, nitems, flags, 1);
   }
   bool agg_arg_collations_for_comparison(DTCollation &c,
                                          Item **items, uint nitems,
-                                         uint flags= 0)
+                                         uint flags)
   {
     return agg_item_collations_for_comparison(c, func_name(),
                                               items, nitems, flags);
   }
   bool agg_arg_charsets(DTCollation &c, Item **items, uint nitems,
-                        uint flags= 0)
+                        uint flags, int item_sep)
   {
-    return agg_item_charsets(c, func_name(), items, nitems, flags);
+    return agg_item_charsets(c, func_name(), items, nitems, flags, item_sep);
   }
   bool walk(Item_processor processor, byte *arg);
   Item *transform(Item_transformer transformer, byte *arg);