Comment 5 for bug 234543

127.0.* addresses are reserved for loopbacks. The name for the loopback address is usually localhost and sometimes localdomain is also used with another loopback address.

It is highly unusual to use the hostname for a loopback address. The issues with the xserver (and maybe also other applications) should IMHO not be fixed with a bandage like locally resolving the hostname to the loopback address.