http://bugs.winehq.org/show_bug.cgi?id=11256
--- Comment #3 from rasz citizenr@gmail.com 2008-01-23 12:14:39 --- http://msdn2.microsoft.com/en-us/library/ms742214(VS.85).aspx
"For AF_INET6 to succeed, IPv6 must be installed."
this is MSDN, this is how windows handles WSAStringToAddressA, Wine has a BUG, its not handling it the same way as Windows, What is invalid about this bug? Are you saying its ok as long as no app is failing? Wine fails to implement this function properly, uTorrent will be the first widespread ipv6 app and will break becouse of it (or as always will have to implement wine specific hack).
WSAStringToAddressA for AF_INET6 should check if ipv6 is available in the system before doing anything further. The easiest way to check for ipv6 I could find is to try and setup dummy INET6 socket.