ELT passes the first argument in args[0] instead of having a separate Item.

mysql-test/r/func_str.result

@@ -297,9 +297,9 @@ select FIELD('b','A' COLLATE latin1_bin,'B');
 FIELD('b','A' COLLATE latin1_bin,'B')
 0
 select FIELD(_latin2'b','A','B');
-Illegal mix of collations (latin2_general_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE) for operation 'field'
+ERROR HY000: Illegal mix of collations (latin2_general_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE) for operation 'field'
 select FIELD('b',_latin2'A','B');
-Illegal mix of collations (latin1_swedish_ci,COERCIBLE), (latin2_general_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE) for operation 'field'
+ERROR HY000: Illegal mix of collations (latin1_swedish_ci,COERCIBLE), (latin2_general_ci,COERCIBLE), (latin1_swedish_ci,COERCIBLE) for operation 'field'
 select FIELD('b',_latin2'A','B',1);
 FIELD('b',_latin2'A','B',1)
 1

mysql-test/t/func_str.test

@@ -167,9 +167,9 @@ select FIELD('b','A','B');
 select FIELD('B','A','B');
 select FIELD('b' COLLATE latin1_bin,'A','B');
 select FIELD('b','A' COLLATE latin1_bin,'B');
---error 1265
+--error 1268
 select FIELD(_latin2'b','A','B');
---error 1265
+--error 1268
 select FIELD('b',_latin2'A','B');
 select FIELD('b',_latin2'A','B',1);
 

sql/item_strfunc.cc

@@ -1660,81 +1660,53 @@ void Item_func_elt::fix_length_and_dec()
   max_length=0;
   decimals=0;
   
-  if (agg_arg_collations(collation, args, arg_count))
+  if (agg_arg_collations(collation, args+1, arg_count-1))
     return;
 
-  for (uint i=0 ; i < arg_count ; i++)
+  for (uint i=1 ; i < arg_count ; i++)
   {
     set_if_bigger(max_length,args[i]->max_length);
     set_if_bigger(decimals,args[i]->decimals);
   }
   maybe_null=1;					// NULL if wrong first arg
-  with_sum_func= with_sum_func || item->with_sum_func;
-  used_tables_cache|=item->used_tables();
-  const_item_cache&=item->const_item();
-}
-
-
-void Item_func_elt::split_sum_func(Item **ref_pointer_array,
-				   List<Item> &fields)
-{
-  if (item->with_sum_func && item->type() != SUM_FUNC_ITEM)
-    item->split_sum_func(ref_pointer_array, fields);
-  else if (item->used_tables() || item->type() == SUM_FUNC_ITEM)
-  {
-    uint el= fields.elements;
-    fields.push_front(item);
-    ref_pointer_array[el]= item;
-    item= new Item_ref(ref_pointer_array + el, 0, item->name);
-  }
-  Item_str_func::split_sum_func(ref_pointer_array, fields);
-}
-
-
-void Item_func_elt::update_used_tables()
-{
-  Item_func::update_used_tables();
-  item->update_used_tables();
-  used_tables_cache|=item->used_tables();
-  const_item_cache&=item->const_item();
 }
 
 
 double Item_func_elt::val()
 {
   uint tmp;
-  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
+  if ((tmp=(uint) args[0]->val_int()) == 0 || tmp >= arg_count)
   {
     null_value=1;
     return 0.0;
   }
   null_value=0;
-  return args[tmp-1]->val();
+  return args[tmp]->val();
 }
 
 longlong Item_func_elt::val_int()
 {
   uint tmp;
-  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
+  if ((tmp=(uint) args[0]->val_int()) == 0 || tmp >= arg_count)
   {
     null_value=1;
     return 0;
   }
   null_value=0;
-  return args[tmp-1]->val_int();
+  return args[tmp]->val_int();
 }
 
 String *Item_func_elt::val_str(String *str)
 {
   uint tmp;
   String *res;
-  if ((tmp=(uint) item->val_int()) == 0 || tmp > arg_count)
+  if ((tmp=(uint) args[0]->val_int()) == 0 || tmp >= arg_count)
   {
     null_value=1;
     return NULL;
   }
   null_value=0;
-  res= args[tmp-1]->val_str(str);
+  res= args[tmp]->val_str(str);
   res->set_charset(charset());
   return res;
 }

sql/item_strfunc.h

@@ -372,29 +372,13 @@ public:
 
 class Item_func_elt :public Item_str_func
 {
-  Item *item;
-
 public:
-  Item_func_elt(Item *a,List<Item> &list) :Item_str_func(list),item(a) {}
-  ~Item_func_elt() { delete item; }
+  Item_func_elt(List<Item> &list) :Item_str_func(list) {}
   double val();
   longlong val_int();
   String *val_str(String *str);
-  bool fix_fields(THD *thd, TABLE_LIST *tlist, Item **ref)
-  {
-    return (item->fix_fields(thd, tlist, &item) ||
-	    item->check_cols(1) ||
-	    Item_func::fix_fields(thd, tlist, ref));
-  }
-  void split_sum_func(Item **ref_pointer_array, List<Item> &fields);
   void fix_length_and_dec();
-  void update_used_tables();
   const char *func_name() const { return "elt"; }
-  void set_outer_resolving()
-  {
-    item->set_outer_resolving();
-    Item_str_func::set_outer_resolving();
-  }
 };
 
 

sql/sql_yacc.yy

@@ -2389,7 +2389,7 @@ simple_expr:
 	| DAY_SYM '(' expr ')'
 	  { $$= new Item_func_dayofmonth($3); }
 	| ELT_FUNC '(' expr ',' expr_list ')'
-	  { $$= new Item_func_elt($3, *$5); }
+	  { $5->push_front($3); $$= new Item_func_elt(*$5); }
 	| MAKE_SET_SYM '(' expr ',' expr_list ')'
 	  { $$= new Item_func_make_set($3, *$5); }
 	| ENCRYPT '(' expr ')'