WEBrick::HTTPProxyServer hangs when process exits

[route]

I have a proxy server running in a thread:

@server = WEBrick::HTTPProxyServer.new(ServerType: Thread, BindAddress: host, Port: port)

when process exists I call @server.shutdown but it hangs forever so that I have to send Ctrl+C. While debugging this issue I figured that def do_CONNECT(req, res) which binds a socket os = TCPSocket.new(host, port) sometimes in ensure block has os set to nil. Which leads me to a question if https://github.com/ruby/ruby/blob/55c771c302f94f1d1d95bf41b42459b4d2d1c337/ext/socket/ipsocket.c#L187 socket can be nil if we take into account inetsock_cleanup(VALUE v) which returns return Qnil;

I fixed the issue by adding raise HTTPStatus::EOFError unless os in ensure block so that we don't interact with the rest of descriptors. Other note is that none of the rescue blocks were called in do_CONNECT.

Update: I still assume that TCPSocket.new returns a socket or raises an error, but in my case I have no idea how I end up with nil as a socket even though we call thgroup.list.each{|th| th.join if th[:WEBrickThread] } in shutdown. Maybe because ruby starts to terminate all threads because main thread exits?

[ioquatix]

This is probably another instance of #102.