union.result:

   A test case for the bug  that allowed table names to be used in ORDER BY columns (But #3064)
union.test:
  A test case for the bug  that allowed table names to be used in ORDER BY columns (But #3064)
sql_union.cc:
  A fix for a bug that allowed table names to be used in ORDER BY columns (But #3064)


sql/sql_union.cc:
  A fix for a bug that allowed table names to be used in ORDER BY columns (But #3064)
mysql-test/t/union.test:
  A test case for the bug  that allowed table names to be used in ORDER BY columns (But #3064)
mysql-test/r/union.result:
   A test case for the bug  that allowed table names to be used in ORDER BY columns (But #3064)

mysql-test/r/union.result

@@ -422,6 +422,8 @@ Wrong usage/placement of 'SQL_CALC_FOUND_ROWS'
 create temporary table t1 select a from t1 union select a from t2;
 create table t1 select a from t1 union select a from t2;
 INSERT TABLE 't1' isn't allowed in FROM table list
+select a from t1 union select a from t2 order by t2.a;
+Unknown column 't2.a' in 'ORDER BY'
 drop table t1,t2;
 select length(version()) > 1 as `*` UNION select 2;
 *

mysql-test/t/union.test

@@ -226,6 +226,8 @@ SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY a desc LIMIT 1;
 create temporary table t1 select a from t1 union select a from t2;
 --error 1093
 create table t1 select a from t1 union select a from t2;
+--error 1054
+select a from t1 union select a from t2 order by t2.a;
 drop table t1,t2;
 
 #

sql/sql_union.cc

@@ -100,6 +100,7 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
   else
   {
     Item *item;
+    ORDER *orr;
     List_iterator<Item> it(lex->select_lex.item_list);
     TABLE_LIST *first_table= (TABLE_LIST*) lex->select_lex.table_list.first;
 
@@ -110,6 +111,15 @@ int mysql_union(THD *thd, LEX *lex,select_result *result)
     if (setup_tables(first_table) ||
 	setup_fields(thd,first_table,item_list,0,0,1))
       DBUG_RETURN(-1);
+    for (orr=order;orr;orr=orr->next)
+    {
+      item=*orr->item;
+      if (((item->type() == Item::FIELD_ITEM) && ((class Item_field*)item)->table_name))
+      {
+	my_error(ER_BAD_FIELD_ERROR,MYF(0),item->full_name(),"ORDER BY");
+	DBUG_RETURN(-1);
+      }
+    }
   }
 
   bzero((char*) &tmp_table_param,sizeof(tmp_table_param));