"Which proxy does this support?" has a narrower answer than the docs
gave. `golang.org/x/net/proxy.FromURL` resolves `socks5` and `socks5h`
and nothing else, yet the README and `Proxy`'s doc comment both offered
"socks5, socks4 and socks4a". A `socks4://` URI fails every dial with
`proxy: unknown scheme: socks4`, which is what taking the docs at their
word looks like from the caller's side.
Corrected both, and pointed at `proxy.RegisterDialerType` -- the way
x/net/proxy expects a caller to add a scheme it does not carry.
That escape hatch had a second problem waiting. `establishProxyConnection`
asserted the dialer to `proxy.ContextDialer` unconditionally, but a
registered dialer need only implement `Dial`, and the assertion panicked
on those:
interface conversion: T is not proxy.ContextDialer: missing method
DialContext
It now falls back to dialing on a goroutine and abandoning the attempt
when the context expires, which is what x/net/proxy itself does for the
same case.
Closes: #95
dualfroz
upstream