From ae40c7207760ea6c829a6bdbbabc1e19941f1240 Mon Sep 17 00:00:00 2001
From: Igor Babaev <igor@askmonty.org>
Date: Wed, 13 Nov 2013 14:43:09 -0800
Subject: [PATCH] Fixed bug mdev-5091. The function
 SELECT_LEX::update_used_tables should process all ORDER BY lists in any
 subselect of a union.

---
 mysql-test/r/union.result | 15 +++++++++++++++
 mysql-test/t/union.test   | 19 +++++++++++++++++++
 sql/sql_lex.cc            |  2 +-
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index 13941d3f84d..05dab9e2874 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -1724,3 +1724,18 @@ foo
 1
 deallocate prepare stmt1;
 End of 5.1 tests
+#
+# mdev-5091: Asseirtion failure for UNION with ORDER BY 
+#            in one of selects
+#
+CREATE TABLE t1 (i int, c char(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES (6,'b');
+CREATE VIEW v1 AS SELECT * FROM t1;
+( SELECT i FROM v1 GROUP BY i ORDER BY CONCAT( c, c ) LIMIT 1 )
+UNION 
+( SELECT i FROM t1 );
+i
+6
+DROP VIEW v1;
+DROP TABLE t1;
+End of 5.3 tests
diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test
index fefd67fd2f7..bb0e5610a26 100644
--- a/mysql-test/t/union.test
+++ b/mysql-test/t/union.test
@@ -1210,3 +1210,22 @@ execute stmt1;
 deallocate prepare stmt1;
 
 --echo End of 5.1 tests
+--echo #
+--echo # mdev-5091: Asseirtion failure for UNION with ORDER BY 
+--echo #            in one of selects
+--echo #
+ 
+ CREATE TABLE t1 (i int, c char(1)) ENGINE=MyISAM;
+ INSERT INTO t1 VALUES (6,'b');
+
+ CREATE VIEW v1 AS SELECT * FROM t1;
+
+ ( SELECT i FROM v1 GROUP BY i ORDER BY CONCAT( c, c ) LIMIT 1 )
+ UNION 
+ ( SELECT i FROM t1 );
+
+ DROP VIEW v1;
+ DROP TABLE t1;
+
+ --echo End of 5.3 tests
+
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 6f34dd23f36..e8c795e9c54 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -3534,7 +3534,7 @@ void SELECT_LEX::update_used_tables()
   }
   for (ORDER *order= group_list.first; order; order= order->next)
     (*order->item)->update_used_tables();
-  if (!master_unit()->is_union())
+  if (master_unit()->global_parameters != this)
   {
     for (ORDER *order= order_list.first; order; order= order->next)
       (*order->item)->update_used_tables();