BUG #13860: Duplicated primary key

The following bug has been logged on the website:

Bug reference:      13860
Logged by:          baso10
Email address:      baso10dev@gmail.com
PostgreSQL version: 9.4.5
Operating system:   Debian 4.9.2-10 64-bit
Description:

Table has duplicated values in primary key column.

I have a table A.
I have created table B that inherits table A.

After playing around I noticed there are duplicate keys in table A.

Thanks