Fixed LP bug #609121

Post-review fix - avoid re-evaluation of the having clause
when it evaluates to true.

sql/sql_select.cc

@@ -12651,12 +12651,15 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
       DBUG_ASSERT(join->examined_rows <= 1);
     }
     else if (join->send_row_on_empty_set())
+    {
+      if (!join->having || join->having->val_int())
       {
         List<Item> *columns_list= (procedure ? &join->procedure_fields_list :
                                    fields);
         rc= join->result->send_data(*columns_list);
       }
     }
+  }
   else
   {
     DBUG_ASSERT(join->tables);

sql/sql_select.h

@@ -1722,8 +1722,7 @@ public:
   bool send_row_on_empty_set()
   {
     return (do_send_rows && tmp_table_param.sum_func_count != 0 &&
-	    !group_list && having_value != Item::COND_FALSE &&
-            (!having || having->val_int()));
+	    !group_list && having_value != Item::COND_FALSE);
   }
   bool change_result(select_result *result);
   bool is_top_level_join() const