Fixed random test failure

mysql-test/include/index_merge2.inc:
  InnoDB did report 9 or 7 rows in explain

mysql-test/include/index_merge2.inc

@@ -343,6 +343,7 @@ alter table t1 add index i3(key3);
 update t1 set key2=key1,key3=key1;
 
 # to test the bug, the following must use "sort_union":
+--replace_column 9 REF
 explain select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 drop table t1;

mysql-test/r/index_merge_innodb.result

@@ -313,7 +313,7 @@ alter table t1 add index i3(key3);
 update t1 set key2=key1,key3=key1;
 explain select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index_merge	i2,i3	i3,i2	4,4	NULL	9	Using sort_union(i3,i2); Using where
+1	SIMPLE	t1	index_merge	i2,i3	i3,i2	4,4	NULL	REF	Using sort_union(i3,i2); Using where
 select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 key1	key2	key3
 31	31	31

mysql-test/r/index_merge_myisam.result

@@ -1146,7 +1146,7 @@ alter table t1 add index i3(key3);
 update t1 set key2=key1,key3=key1;
 explain select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index_merge	i2,i3	i3,i2	4,4	NULL	11	Using sort_union(i3,i2); Using where
+1	SIMPLE	t1	index_merge	i2,i3	i3,i2	4,4	NULL	REF	Using sort_union(i3,i2); Using where
 select * from t1 where (key3 > 30 and key3<35) or (key2 >32 and key2 < 40);
 key1	key2	key3
 31	31	31