+++ This bug was initially created as a clone of Bug #456413 +++

Description of problem:
Satellite 3.6? - 5.x

When trying to install a RHN Proxy on a system that has a FQDN that is built up
as hostname.root, for example "proxy.com", the Satellite refuses to configure
the new Proxy, and returns "proxy.com does not appear to be a valid hostname",
even though it resolves fine. 

According to the Satellite, the following would be an invalid host name:

$ host redhat.com
redhat.com has address 209.132.177.50

The Satellite expects a FQDN to have at least three parts, which makes no sense,
since it is perfectly valid to use hostname.root. The Satellite software
should allow FQDN with at least two parts.

Version-Release number of selected component (if applicable):
3.6? - 5.x

How reproducible:
Always

Steps to Reproduce:
1. Install a RHN Satellite Server
2. Install a RHN Proxy Server
3. Try to "Configure RHN Proxy Server" from the RHN Satellite webGUI, and press
"Continue".
  
Actual results:

Invalid RHN Proxy Hostname: proxy.com does not appear to be a valid hostname.
Invalid RHN Parent Server: satellite.com does not appear to be a valid hostname.

Expected results:
The RHN Satellite Server recognises the valid hostnames and configures the RHN
Proxy Server

Additional info:
This also goes for the Satellite installer, where we have to use --skip-fqdn
with perfectly resolveable hosts.

-- Additional comment from pkrul on 2008-07-23 09:00 EST --
Created an attachment (id=312479)
Patch to fix FQDN subroutines in rhn-base 5.x (source from spacewalk-git-20080702)