Post-merge fix.

mysql-test/r/olap.result

@@ -667,6 +667,7 @@ x	2	90
 x	3	30
 x	NULL	150
 NULL	NULL	150
+DROP TABLE t1;
 CREATE TABLE t1(id int, type char(1));
 INSERT INTO t1 VALUES
 (1,"A"),(2,"C"),(3,"A"),(4,"A"),(5,"B"),

sql/item_func.h

@@ -728,10 +728,14 @@ class Item_func_rollup_const :public Item_func
 {
 public:
   Item_func_rollup_const(Item *a) :Item_func(a)
-    { name= a->name; }
-  double val() { return args[0]->val(); }
+  {
+    name= a->name;
+    name_length= a->name_length;
+  }
+  double val_real() { return args[0]->val_real(); }
   longlong val_int() { return args[0]->val_int(); }
   String *val_str(String *str) { return args[0]->val_str(str); }
+  my_decimal *val_decimal(my_decimal *dec) { return args[0]->val_decimal(dec); }
   const char *func_name() const { return "rollup_const"; }
   bool const_item() const { return 0; }
   Item_result result_type() const { return args[0]->result_type(); }

sql/sql_select.cc

@@ -14571,7 +14571,7 @@ bool JOIN::rollup_init()
           Item* new_item= new Item_func_rollup_const(item);
           if (!new_item)
             return 1;
-          new_item->fix_fields(thd,0, (Item **) 0);
+          new_item->fix_fields(thd, (Item **) 0);
           thd->change_item_tree(it.ref(), new_item);
           for (ORDER *tmp= group_tmp; tmp; tmp= tmp->next)
           {