fixed error handling bug

mysql-test/r/subselect.result:
  test for error handling bug
mysql-test/t/subselect.test:
  test for error handling bug

mysql-test/r/subselect.result

 select (select 2);
 (select 2)
 2
-drop table if exists t1,t2,t3,t4,t5,attend,clinic;
+drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
 create table t1 (a int);
 create table t2 (a int, b int);
 create table t3 (a int);
@@ -147,4 +147,16 @@ W	1
 SELECT * FROM t3 WHERE b = (SELECT MIN(b) FROM t3);
 a	b
 W	a
-drop table t1,t2,t3,t4,t5,attend,clinic;
+drop table if exists inscrit;
+CREATE TABLE `inscrit` (
+`pseudo` varchar(35) character set latin1 NOT NULL default '',
+`email` varchar(60) character set latin1 NOT NULL default '',
+PRIMARY KEY  (`pseudo`),
+UNIQUE KEY `email` (`email`)
+) TYPE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC;
+INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
+INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
+INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
+SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
+Subselect returns more than 1 record
+drop table if exists inscrit;

mysql-test/t/subselect.test

 
 select (select 2);
-drop table if exists t1,t2,t3,t4,t5,attend,clinic;
+drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit;
 create table t1 (a int);
 create table t2 (a int, b int);
 create table t3 (a int);
@@ -66,4 +66,19 @@ SELECT * FROM t1 WHERE b = (SELECT MIN(b) FROM t1);
 SELECT * FROM t2 WHERE b = (SELECT MIN(b) FROM t2);
 SELECT * FROM t3 WHERE b = (SELECT MIN(b) FROM t3);
 
-drop table t1,t2,t3,t4,t5,attend,clinic;
+drop table if exists inscrit;
+
+CREATE TABLE `inscrit` (
+  `pseudo` varchar(35) character set latin1 NOT NULL default '',
+  `email` varchar(60) character set latin1 NOT NULL default '',
+  PRIMARY KEY  (`pseudo`),
+  UNIQUE KEY `email` (`email`)
+) TYPE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC;
+
+INSERT INTO inscrit (pseudo,email) VALUES ('joce','test');
+INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1');
+INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1');
+-- error 1240
+SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%');
+
+drop table if exists inscrit;
\ No newline at end of file

sql/item_subselect.cc

@@ -119,21 +119,30 @@ Item::Type Item_subselect::type() const
 double Item_singleval_subselect::val () 
 {
   if (engine->exec())
+  {
+    assign_null();
     return 0;
+  }
   return real_value;
 }
 
 longlong Item_singleval_subselect::val_int () 
 {
   if (engine->exec())
+  {
+    assign_null();
     return 0;
+  }
   return int_value;
 }
 
 String *Item_singleval_subselect::val_str (String *str) 
 {
   if (engine->exec() || null_value)
+  {
+    assign_null();
     return 0;
+  }
   return &str_value;
 }
 
@@ -157,21 +166,30 @@ void Item_exists_subselect::fix_length_and_dec()
 double Item_exists_subselect::val () 
 {
   if (engine->exec())
+  {
+    assign_null();
     return 0;
+  }
   return (double) value;
 }
 
 longlong Item_exists_subselect::val_int () 
 {
   if (engine->exec())
+  {
+    assign_null();
     return 0;
+  }
   return value;
 }
 
 String *Item_exists_subselect::val_str(String *str)
 {
   if (engine->exec())
+  {
+    assign_null();
     return 0;
+  }
   str->set(value);
   return str;
 }