[reSIProcate] unresponsive DNS query blocks stack thread if USE_IPV6 is not defined (windows)

["Justin Matthews" <jmatthewsr@xxxxxxxxx>]

Hi,

Does anyone know if it's intended behavior for the ares UDP socket to block
if USE_IPV6 is not defined (Windows OS)?  In ares_process.c ,
open_udp_socket() will set the socket non-blocking only if USE_IPV6 is
defined.  If DNS is misconfigured or there is no response for a DNS record
lookup, the resip stack thread will block indefinitely in the recv() call in
read_udp_packets().

Thanks,

-justin