The following bug has been logged on the website:
Bug reference: 7832
Logged by: George Shuklin
Email address: shuklin(at)selectel(dot)ru
PostgreSQL version: 9.1.0
Operating system: GNU/Debian Linux Wheezy
Description:
Normal summation:
SELECT cidr'0::1/128'+1;
?column?
----------
::2
SELECT cidr'0::1/128'+65535;
?column?
-----------
::0.1.0.0
(strange dots in the middle of the ipv6 address).