Fixed bug mdev-9028.

This patch is actually a complement for the fix of bug mdev-6892.
The procedure create_tmp_table() now must take into account
Item_direct_refs that wrap up constant fields of derived tables/views
that are used as inner tables in outer join operations.

1 files changed, 23 insertions, 0 deletions

diff --git a/mysql-test/t/derived.test b/mysql-test/t/derived.test
index e8a6ac34392..f8ba87ac1f5 100644
--- a/mysql-test/t/derived.test
+++ b/mysql-test/t/derived.test
@@ -842,4 +842,27 @@ SELECT Customer, Success, SUM(OrderSize)
 DROP TABLE example1463;
 set sql_mode= @save_sql_mode;
 
+--echo #
+--echo # MDEV-9028: SELECT DISTINCT constant column of  derived  table
+--echo #            used as the second operand of LEFT JOIN
+--echo #
+
+create table t1 (id int, data varchar(255));
+insert into t1 values (1,'yes'),(2,'yes');
+
+select distinct t1.id, tt.id, tt.data
+  from t1
+       left join
+       (select t1.id, 'yes' as data from t1) as tt
+       on t1.id = tt.id;
+
+select distinct t1.id, tt.id, tt.data
+  from t1
+       left join
+       (select t1.id, 'yes' as data from t1 where id > 1) as tt
+       on t1.id = tt.id;
+
+drop table t1;
+
+
 --echo # end of 5.5