theforeman/foreman — pull request #1537 by pccowboy (2014-06-24 21:25:45+00:00)
Title: Fix instance where a domain id is indicated, but no hostname is given.  ...

...The model was asking the proxy to try and create a record that looks like ".domain.com", and if you were trying to create a second host with the same characteristics (blank hostname, domain name non-nil) on its interface, the proxy would properly fail with a "Entity already exists" error.