Row comparison now does compare field collations, e.g.

  ROW('a','b','c) = ROW('A' collate latin1_bin,'b','c') returns 0
When a number is compared to a string, character sets and 
collations are not aggregated. e.g. this returned error in 4.1.0:

SELECT 1=_latin2'1';
because character sets was aggregated, and 1 was considered as
a string of latin1 charset during this aggregation.

1 files changed, 3 insertions, 4 deletions

diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 1d93c9b6892..8309cd25a72 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -35,6 +35,8 @@ class Arg_comparator: public Sql_alloc
   Arg_comparator *comparators;   // used only for compare_row()
 
 public:
+  DTCollation cmp_collation;
+
   Arg_comparator() {};
   Arg_comparator(Item **a1, Item **a2): a(a1), b(a2) {};
 
@@ -112,13 +114,10 @@ class Item_bool_func2 :public Item_int_func
 protected:
   Arg_comparator cmp;
   String tmp_value1,tmp_value2;
-  DTCollation cmp_collation;
 
 public:
   Item_bool_func2(Item *a,Item *b):
-    Item_int_func(a,b), cmp(tmp_arg, tmp_arg+1)
-    { cmp_collation.set(0,DERIVATION_NONE);}
-  bool fix_fields(THD *thd, TABLE_LIST *tlist, Item ** ref);
+    Item_int_func(a,b), cmp(tmp_arg, tmp_arg+1) {}
   void fix_length_and_dec();
   void set_cmp_func()
   {