3d04f5db20
Fixes BZ #15339. NSS_STATUS_UNAVAIL may mean that a necessary input resource is not available. This could occur in a number of cases including when the network is down, system runs out of file descriptors, etc. The correct differentiator in such a case is the h_errno, which gives the nature of failure. In case of failures other than a simple 'not found', we set h_errno as NETDB_INTERNAL and let errno be the identifier for the exact error.