From 859f599e1ed8a85b6c8909b32fdfa5dc223e929b Mon Sep 17 00:00:00 2001
From: unknown <hf@deer.(none)>
Date: Sat, 6 Dec 2003 23:37:24 +0400
Subject: [PATCH] Fix for #1992 This bug happens when a query, having
 subselects in the fields list, needs temporary table.
 Item_subselect::get_tmp_table_item isn't implemented and just returns *this.
 So the tmp_table_item takes value not from temporary but from original table.

mysql-test/r/subselect.result:
  appropriate test result added
mysql-test/t/subselect.test:
  test case added
sql/item_subselect.cc:
  Item_subselect::get_tmp_table_item implementation
sql/item_subselect.h:
  Item_subselect::get_tmp_table_item declaration
---
 mysql-test/r/subselect.result | 10 ++++++++++
 mysql-test/t/subselect.test   |  5 +++++
 sql/item_subselect.cc         |  6 ++++++
 sql/item_subselect.h          |  1 +
 4 files changed, 22 insertions(+)

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 71755aac52d..9f64281185f 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -1569,3 +1569,13 @@ INSERT INTO t2 VALUES (100, 200, 'C');
 SELECT DISTINCT COLC FROM t1 WHERE COLA = (SELECT COLA FROM t2 WHERE COLB = 200 AND COLC ='C' LIMIT 1);
 COLC
 DROP TABLE t1, t2;
+CREATE TABLE t1 (a int(1));
+INSERT INTO t1 VALUES (1),(1),(1),(1),(1),(2),(3),(4),(5);
+SELECT DISTINCT (SELECT a) FROM t1 LIMIT 100;
+(SELECT a)
+1
+2
+3
+4
+5
+DROP TABLE t1;
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index e53679b444e..2879a4d7177 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -1009,3 +1009,8 @@ INSERT INTO t1 VALUES (1,1,'1A3240'), (1,2,'4W2365');
 INSERT INTO t2 VALUES (100, 200, 'C');
 SELECT DISTINCT COLC FROM t1 WHERE COLA = (SELECT COLA FROM t2 WHERE COLB = 200 AND COLC ='C' LIMIT 1);
 DROP TABLE t1, t2;
+
+CREATE TABLE t1 (a int(1));
+INSERT INTO t1 VALUES (1),(1),(1),(1),(1),(2),(3),(4),(5);
+SELECT DISTINCT (SELECT a) FROM t1 LIMIT 100;
+DROP TABLE t1;
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc
index 7b401b50d4c..123362b917b 100644
--- a/sql/item_subselect.cc
+++ b/sql/item_subselect.cc
@@ -166,6 +166,12 @@ bool Item_subselect::const_item() const
   return const_item_cache;
 }
 
+Item *Item_subselect::get_tmp_table_item(THD *thd)
+{
+  if (!with_sum_func && !const_item())
+    return new Item_field(result_field);
+  return copy_or_same(thd);
+}
 
 void Item_subselect::update_used_tables()
 {
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
index 8444dc7bf66..84f5de5a622 100644
--- a/sql/item_subselect.h
+++ b/sql/item_subselect.h
@@ -89,6 +89,7 @@ public:
   bool const_item() const;
   inline table_map get_used_tables_cache() { return used_tables_cache; }
   inline bool get_const_item_cache() { return const_item_cache; }
+  Item *get_tmp_table_item(THD *thd);
   void update_used_tables();
   void print(String *str);
   bool change_engine(subselect_engine *eng)