BUG #15692: infinity loop

The following bug has been logged on the website:

Bug reference:      15692
Logged by:          Alisher Aliev
Email address:      allyanaliev@gmail.com
PostgreSQL version: Unsupported/Unknown
Operating system:   CentOS Linux 7
Description:

create table numer (n numeric);
insert into numer values (1);
insert into numer values (2);
insert into numer values (3);
select * from numer;
update numer set n = n * 10;
update numer set n = n * 7777777777777777777777777;
update numer set n = n ^ 1000;
update numer set n = n ^ 1000;

At last command PostgreSQL comming inside infinity loop.