3 files changed, 81 insertions, 0 deletions

diff --git a/mysql-test/r/trigger.result b/mysql-test/r/trigger.result
index 9f34f60eb1a..3d40a2d05df 100644
--- a/mysql-test/r/trigger.result
+++ b/mysql-test/r/trigger.result
@@ -1278,4 +1278,36 @@ a	b
 2	b
 3	c
 drop table t1;
+CREATE TABLE t1 (
+id int NOT NULL DEFAULT '0',
+a  varchar(10) NOT NULL,
+b  varchar(10),
+c  varchar(10),
+d  timestamp NOT NULL,
+PRIMARY KEY (id, a)
+);
+CREATE TABLE t2 (
+fubar_id         int unsigned NOT NULL DEFAULT '0',
+last_change_time datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+PRIMARY KEY  (fubar_id)
+);
+CREATE TRIGGER fubar_change
+AFTER UPDATE ON t1
+FOR EACH ROW
+BEGIN
+INSERT INTO t2 (fubar_id, last_change_time)
+SELECT DISTINCT NEW.id AS fubar_id, NOW() AS last_change_time
+FROM t1 WHERE (id = NEW.id) AND (OLD.c != NEW.c)
+ON DUPLICATE KEY UPDATE
+last_change_time =
+IF((fubar_id = NEW.id)AND(OLD.c != NEW.c),NOW(),last_change_time);
+END
+|
+INSERT INTO t1 (id,a, b,c,d) VALUES
+(1,'a','b','c',now()),(2,'a','b','c',now());
+UPDATE t1 SET c='Bang!' WHERE id=1;
+SELECT fubar_id FROM t2;
+fubar_id
+1
+DROP TABLE t1,t2;
 End of 5.0 tests
diff --git a/mysql-test/t/trigger.test b/mysql-test/t/trigger.test
index ae01a4b2c3d..ea569f4ce09 100644
--- a/mysql-test/t/trigger.test
+++ b/mysql-test/t/trigger.test
@@ -1548,4 +1548,50 @@ select * from t1;
 
 drop table t1;
 
+#
+# Bug#25398: crash when a trigger contains a SELECT with 
+#            trigger fields in the select list under DISTINCT
+#
+
+CREATE TABLE t1 (
+  id int NOT NULL DEFAULT '0',
+  a  varchar(10) NOT NULL,
+  b  varchar(10),
+  c  varchar(10),
+  d  timestamp NOT NULL,
+  PRIMARY KEY (id, a)
+);
+
+CREATE TABLE t2 (
+  fubar_id         int unsigned NOT NULL DEFAULT '0',
+  last_change_time datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
+  PRIMARY KEY  (fubar_id)
+);
+
+DELIMITER |;
+
+CREATE TRIGGER fubar_change
+  AFTER UPDATE ON t1
+    FOR EACH ROW
+      BEGIN
+        INSERT INTO t2 (fubar_id, last_change_time)
+          SELECT DISTINCT NEW.id AS fubar_id, NOW() AS last_change_time
+            FROM t1 WHERE (id = NEW.id) AND (OLD.c != NEW.c)
+        ON DUPLICATE KEY UPDATE
+          last_change_time =
+            IF((fubar_id = NEW.id)AND(OLD.c != NEW.c),NOW(),last_change_time);
+      END
+|
+
+DELIMITER ;|
+
+INSERT INTO t1 (id,a, b,c,d) VALUES
+ (1,'a','b','c',now()),(2,'a','b','c',now());
+
+UPDATE t1 SET c='Bang!' WHERE id=1;
+
+SELECT fubar_id FROM t2;
+
+DROP TABLE t1,t2;
+
 --echo End of 5.0 tests
diff --git a/sql/item.h b/sql/item.h
index 6065e385a6c..62d6127f10b 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -2269,6 +2269,9 @@ public:
   bool fix_fields(THD *, Item **);
   void print(String *str);
   table_map used_tables() const { return (table_map)0L; }
+  Field *get_tmp_table_field() { return 0; }
+  Item *copy_or_same(THD *thd) { return this; }
+  Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); }
   void cleanup();
 
 private: