MDEV-5344: LEFT OUTER JOIN table data is lost in ON DUPLICATE KEY UPDATE section

- For INSERT ... SELECT ... ON DUPLICATE KEY UPDATE, table elimination should 
  check which tables are referenced in the ON DUPLICATE KEY UPDATE clause.

mysql-test/r/table_elim.result

@@ -609,4 +609,32 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using where; Using index
 drop view v1;
 DROP TABLE t1,t2,t3;
+#
+# MDEV-5344: LEFT OUTER JOIN table data is lost in ON DUPLICATE KEY UPDATE section
+#
+create table t1 (
+id int(10) unsigned NOT NULL DEFAULT '0',
+v int(10) unsigned DEFAULT '0',
+PRIMARY KEY (id)
+);
+create table t2 (
+id int(10) unsigned NOT NULL DEFAULT '0',
+PRIMARY KEY (id)
+) ;
+create table t3 (
+id int(10) unsigned NOT NULL DEFAULT '0',
+v int(10) unsigned DEFAULT '0',
+PRIMARY KEY (id)
+);
+insert into t1 values (1, 10), (2, 10);
+insert into t2 values (1), (2);
+insert into t3 values (1, 20);
+insert into t1 
+select t2.id, 5 from t2 LEFT OUTER JOIN t3 ON t2.id = t3.id
+on duplicate key update t1.v = t3.v;
+select * from t1;
+id	v
+1	20
+2	NULL
+drop table t1,t2,t3;
 SET optimizer_switch=@save_optimizer_switch;

mysql-test/t/table_elim.test

@@ -543,6 +543,35 @@ EXPLAIN SELECT alias1.* FROM t3 LEFT JOIN v1 as alias1 ON ( t3.a = alias1.b );
 drop view v1;
 DROP TABLE t1,t2,t3;
 
+--echo #
+--echo # MDEV-5344: LEFT OUTER JOIN table data is lost in ON DUPLICATE KEY UPDATE section
+--echo #
+create table t1 (
+	id int(10) unsigned NOT NULL DEFAULT '0',
+	v int(10) unsigned DEFAULT '0',
+	PRIMARY KEY (id)
+);
 
+create table t2 (
+	id int(10) unsigned NOT NULL DEFAULT '0',
+	PRIMARY KEY (id)
+) ;
+
+create table t3 (
+	id int(10) unsigned NOT NULL DEFAULT '0',
+	v int(10) unsigned DEFAULT '0',
+	PRIMARY KEY (id)
+);
+
+insert into t1 values (1, 10), (2, 10);
+insert into t2 values (1), (2);
+insert into t3 values (1, 20);
+
+insert into t1 
+select t2.id, 5 from t2 LEFT OUTER JOIN t3 ON t2.id = t3.id
+on duplicate key update t1.v = t3.v;
+
+select * from t1;
+drop table t1,t2,t3;
 
 SET optimizer_switch=@save_optimizer_switch;

sql/opt_table_elimination.cc

@@ -594,6 +594,21 @@ void eliminate_tables(JOIN *join)
   /* Find the tables that are referred to from WHERE/HAVING */
   used_tables= (join->conds?  join->conds->used_tables() : 0) | 
                (join->having? join->having->used_tables() : 0);
+
+  /*
+    For "INSERT ... SELECT ... ON DUPLICATE KEY UPDATE column = val"
+    we should also take into account tables mentioned in "val".
+  */
+  if (join->thd->lex->sql_command == SQLCOM_INSERT_SELECT &&
+      join->select_lex == &thd->lex->select_lex)
+  {
+    List_iterator<Item> val_it(thd->lex->value_list);
+    while ((item= val_it++))
+    {
+      DBUG_ASSERT(item->fixed);
+      used_tables |= item->used_tables();
+    }
+  }
   
   /* Add tables referred to from the select list */
   List_iterator<Item> it(join->fields_list);