subselect.result:

  Added test case for bug #11867.
  Fixed results for two existing test cases.
subselect.test:
  Added test case for bug #11867.
item_subselect.cc:
  Fixed bug #11867.
  Added missing code in Item_in_subselect::row_value_transformer
  that caused problems for queries with
  ROW(elems) IN (SELECT DISTINCT cols FROM ...).

mysql-test/r/subselect.result

@@ -932,7 +932,7 @@ ROW(1, 1, 'a') IN (select a,b,c from t1)
 1
 select ROW(1, 2, 'a') IN (select a,b,c from t1);
 ROW(1, 2, 'a') IN (select a,b,c from t1)
-NULL
+0
 select ROW(1, 1, 'a') IN (select b,a,c from t1);
 ROW(1, 1, 'a') IN (select b,a,c from t1)
 1
@@ -950,7 +950,7 @@ ROW(1, 1, 'a') IN (select a,b,c from t1 where c='b' or c='a')
 1
 select ROW(1, 2, 'a') IN (select a,b,c from t1 where c='b' or c='a');
 ROW(1, 2, 'a') IN (select a,b,c from t1 where c='b' or c='a')
-NULL
+0
 select ROW(1, 1, 'a') IN (select b,a,c from t1 where c='b' or c='a');
 ROW(1, 1, 'a') IN (select b,a,c from t1 where c='b' or c='a')
 1
@@ -2727,3 +2727,18 @@ select * from (select max(fld) from t1) as foo;
 max(fld)
 1
 drop table t1;
+CREATE TABLE t1 (one int, two int, flag char(1));
+CREATE TABLE t2 (one int, two int, flag char(1));
+INSERT INTO t1 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
+INSERT INTO t2 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
+SELECT * FROM t1
+WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t2 WHERE flag = 'N');
+one	two	flag
+5	6	N
+7	8	N
+SELECT * FROM t1
+WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t1 WHERE flag = 'N');
+one	two	flag
+5	6	N
+7	8	N
+DROP TABLE t1,t2;

mysql-test/t/subselect.test

@@ -1754,5 +1754,20 @@ insert into t1 values ('1');
 select * from (select max(fld) from t1) as foo;
 drop table t1;
 
+#
+# Bug #11867: queries with ROW(,elems>) IN (SELECT DISTINCT <cols> FROM ...)
+#
+
+CREATE TABLE t1 (one int, two int, flag char(1));
+CREATE TABLE t2 (one int, two int, flag char(1));
+INSERT INTO t1 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
+INSERT INTO t2 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
+
+SELECT * FROM t1
+  WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t2 WHERE flag = 'N');
+SELECT * FROM t1
+  WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t1 WHERE flag = 'N');
+
+DROP TABLE t1,t2;
 
 # End of 4.1 tests

sql/item_subselect.cc

@@ -951,14 +951,19 @@ Item_in_subselect::row_value_transformer(JOIN *join)
     List_iterator_fast<Item> li(select_lex->item_list);
     for (uint i= 0; i < n; i++)
     {
+      Item *func;
       DBUG_ASSERT(left_expr->fixed && select_lex->ref_pointer_array[i]->fixed);
       if (select_lex->ref_pointer_array[i]->
           check_cols(left_expr->el(i)->cols()))
         DBUG_RETURN(RES_ERROR);
-      Item *func= new Item_ref_null_helper(this,
+      if (join->having || select_lex->with_sum_func ||
+          select_lex->group_list.elements)
+        func= new Item_ref_null_helper(this,
 				       select_lex->ref_pointer_array+i,
 				       (char *) "<no matter>",
 				       (char *) "<list ref>");
+      else
+        func= li++;
       func=
 	eq_creator.create(new Item_direct_ref((*optimizer->get_cache())->
 					      addr(i),