A fix for a bug reported by Per Erik Martin, partaining to

usage of expressions whose result are to be saved into user vars.

sql/item.cc

@@ -1192,7 +1192,16 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
     }
   }
 
-  if (((*ref)->with_sum_func && 
+/*
+ * The following conditional is changed as to correctly identify 
+ * incorrect references in group functions or forward references 
+ * with sub-select's / derived tables, while it prevents this 
+ * check when Item_ref is created in an expression involving 
+ * summing function, which is to be placed in the user variable.
+ *
+ */
+ 
+  if (((*ref)->with_sum_func && name &&
        (depended_from || 
 	!(thd->lex.current_select->linkage != GLOBAL_OPTIONS_TYPE &&
 	  thd->lex.current_select->select_lex()->having_fix_field))) ||