The problem with your patch is that it changes the (effective) meaning of the 'name' parameter.  Before the patch, name can be an IP address.  After the patch, that will fail on Fedora.  (It also fails on my Gentoo system).

It is interesting to note, as well, that the documentation for gethostbyaddr says that it is obsolete and getaddrinfo should be used instead.

Could we use the getaddrinfo call if we don't get an FQDN back from gethostbyaddr?  It doesn't look like that would completely solve your problem, though, given your example output.  Have you figured out why that is happening? 

Alternatively, perhaps we could fall back to gethostbyaddr if we don't get an fqdn from the getaddrinfo call.  

However, given that the documentation actually specifies the algorithm used by getfqdn, I'm not sure if we can make either change in a bugfix version.