[patches] [bug] when /etc/hosts doesn't exist, apt fails to resolve hostnames using libc6 2.10.1

[Matthias Klose <doko@xxxxxxxxxx>]

[not a patch, but there's no way to subscribe to the bug tracker, and no general 
ML; was told to use this list]

forwarded from
  https://launchpad.net/bugs/408901
  http://bugs.debian.org/539950

E.g. apt-get's call to getaddrinfo() returns with EAI_SYSTEM when /etc/hosts is 
missing and EAI_NONAME if /etc/hosts is empty. This is different from 2.9, where 
EAI_NONAME is returned in both cases, resulting in the regression in apt-get. 
`sudo whoami' prints an additional error message but works as expected otherwise.