BUG #1802: index is not a btree

The following bug has been logged online:

Bug reference: 1802
Logged by: Jenny Wang
Email address: y6108(at)vip(dot)sina(dot)com
PostgreSQL version: 7.3.10
Operating system: RedHat 8
Description: index is not a btree
Details:

1 $ cd <prefix>
$ cd bin

2 $ ./postmaster -D data &
$ ./psql TEST
TEST=#create table a(col1 int primary key);

3 $ kill -9 <postmaster pid>

4 $ ./postmaster -D data &
$ ./psql TEST
TEST=#insert into a values(1);

ERROR: Index a_pkey is not a btree

the file of a_pkey has size 8k, and is all zero.