BUG #5950: backend terminating after altering table

The following bug has been logged online:

Bug reference: 5950
Logged by: alex
Email address: perepelica(dot)alex(at)gmail(dot)com
PostgreSQL version: 9.0.3
Operating system: archlinux x86_64
Description: backend terminating after altering table
Details:

Such steps:
1. create table t (
);
2. alter table t add childs t;
3. alter table t add id serial not null primary key;
This messages from psql:

NOTICE: ALTER TABLE will create implicit sequence "t_id_seq" for serial
column "t.id"
NOTICE: ALTER TABLE / ADD PRIMARY KEY will create implicit index "t_pkey"
for table "t"
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

backend - terminated