BUG #9148: generate invalid index (create index CONCURRENTLY ... )

The following bug has been logged on the website:

Bug reference: 9148
Logged by: tanhongwei(谭洪伟)
Email address: tiyukeji(at)126(dot)com
PostgreSQL version: 9.1.9
Operating system: Debian GNU/Linux 6.0
Description:

eg :

canceling sql :
CREATE INDEX CONCURRENTLY t_1_index
ON t_1 USING btree
(name);

result:
index t_1_index exist， but size 0

note：
select * from pg_index
where indisvalid <> true
result :
have record.