Hang with IPv6 resolution but no uplink

[martinpelikan]

Hangups seems to stall when accounts.google.com resolves to an IPv6 address but no IPv6 uplink is available. The circumstances for this are probably rare, but Hangups simply stalls trying to connect to the IPv6 address.

I propose that Hangups either has a fallback mechanism to IPv4 after a timeout period, or takes an argument which forces IPv4 / IPv6, in a similar manner to ping, dig, etc...

[tdryer]

The Happy Eyeballs algorithm might be the fix for this. It might be better solved at the HTTP client level, but I'm curious how/if other applications deal with this.