Code cleanup:

- added unsigned_flag= 1; to Item_uint constructors
- removed Item_uint::fix_fields()
- added a comment about fix_fields() call


sql/item.h:
  added unsigned_flag= 1; to Item_uint constructors
  removed Item_uint::fix_fields()
sql/item_func.cc:
  added a comment about fix_fields() call.

sql/item.h

@@ -429,19 +429,13 @@ class Item_uint :public Item_int
 public:
   Item_uint(const char *str_arg, uint length) :
     Item_int(str_arg, (longlong) strtoull(str_arg,(char**) 0,10), length) 
-    { fixed= 0; }
+    { unsigned_flag= 1; }
   Item_uint(uint32 i) :Item_int((longlong) i, 10) 
-    { fixed= 0; }
+    { unsigned_flag= 1; }
   double val() { return ulonglong2double((ulonglong)value); }
   String *val_str(String*);
   Item *new_item() { return new Item_uint(name,max_length); }
   int save_in_field(Field *field, bool no_conversions);
-  bool fix_fields(THD *thd, struct st_table_list *list, Item **item)
-  {
-    bool res= Item::fix_fields(thd, list, item);
-    unsigned_flag= 1;
-    return res;
-  }
   void print(String *str);
 };
 

sql/item_func.cc

@@ -205,6 +205,7 @@ Item_func::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
     {
       Item *item;
       /* We can't yet set item to *arg as fix_fields may change *arg */
+      /* We shouldn't call fix_fields() twice, so check 'fixed' field first */
       if ((!(*arg)->fixed && (*arg)->fix_fields(thd, tables, arg)) ||
 	  (*arg)->check_cols(allowed_arg_cols))
 	return 1;				/* purecov: inspected */