cleanup: remove Item_default_value::cached_field

sql/item.cc

@@ -1055,8 +1055,7 @@ bool Item_field::check_field_expression_processor(void *arg)
           (!field->vcol_info && !org_field->vcol_info)) &&
          field->field_index >= org_field->field_index))
     {
-      my_error(ER_EXPRESSION_REFERS_TO_UNINIT_FIELD,
-               MYF(0),
+      my_error(ER_EXPRESSION_REFERS_TO_UNINIT_FIELD, MYF(0),
                org_field->field_name, field->field_name);
       return 1;
     }
@@ -9024,7 +9023,6 @@ bool Item_default_value::fix_fields(THD *thd, Item **items)
   }
   if (!(def_field= (Field*) thd->alloc(field_arg->field->size_of())))
     goto error;
-  cached_field= def_field;
   memcpy((void *)def_field, (void *)field_arg->field,
          field_arg->field->size_of());
   def_field->reset_fields();
@@ -9063,8 +9061,7 @@ bool Item_default_value::enchant_default_with_arg_processor(void *proc_arg)
 
 void Item_default_value::cleanup()
 {
-  delete cached_field;                        // Free cached blob data
-  cached_field= 0;
+  delete field;                        // Free cached blob data
   Item_field::cleanup();
 }
 

sql/item.h

@@ -5455,18 +5455,17 @@ class Item_default_value : public Item_field
   Item_default_value(THD *thd, Name_resolution_context *context_arg, Item *a)
           :Item_field(thd, context_arg, (const char *)NULL, (const char *)NULL,
                       (const char *)NULL),
-           arg(a), cached_field(NULL) {}
+           arg(a) {}
 public:
   Item *arg;
-  Field *cached_field;
   Item_default_value(THD *thd, Name_resolution_context *context_arg)
     :Item_field(thd, context_arg, (const char *)NULL, (const char *)NULL,
                (const char *)NULL),
-    arg(NULL), cached_field(NULL) {}
+    arg(NULL) {}
   Item_default_value(THD *thd, Name_resolution_context *context_arg, Field *a)
     :Item_field(thd, context_arg, (const char *)NULL, (const char *)NULL,
                 (const char *)NULL),
-    arg(NULL),cached_field(NULL) {}
+    arg(NULL) {}
   enum Type type() const { return DEFAULT_VALUE_ITEM; }
   bool vcol_assignment_allowed_value() const { return true; }
   bool eq(const Item *item, bool binary_cmp) const;
@@ -5498,7 +5497,7 @@ class Item_default_value : public Item_field
     return false;
   }
   table_map used_tables() const;
-  virtual void update_used_tables()
+  void update_used_tables()
   {
     if (field && field->default_value)
       field->default_value->expr->update_used_tables();