Set TCP_NODELAY option on the TCPSocket

* Fixes slowness issues on Linux

lib/capybara/webkit/connection.rb

@@ -112,6 +112,9 @@ module Capybara::Webkit
 
     def attempt_connect
       @socket = @socket_class.open("127.0.0.1", @port)
+      if @socket.kind_of?(TCPSocket) and defined?(Socket::TCP_NODELAY)
+        @socket.setsockopt(:IPPROTO_TCP, :TCP_NODELAY, 1)
+      end
     rescue Errno::ECONNREFUSED
     end
   end

spec/connection_spec.rb

@@ -34,6 +34,16 @@ describe Capybara::Webkit::Connection do
     connection.port.should be_between 0x400, 0xffff
   end
 
+  it 'sets appropriate options on its socket' do
+    if defined?(Socket::TCP_NODELAY)
+      args = [:IPPROTO_TCP, :TCP_NODELAY, 1]
+      TCPSocket.any_instance.should_receive(:setsockopt).with(*args)
+    else
+      TCPSocket.any_instance.should_not_receive(:setsockopt)
+    end
+    Capybara::Webkit::Connection.new
+  end
+
   it "chooses a new port number for a new connection" do
     new_connection = Capybara::Webkit::Connection.new
     new_connection.port.should_not == connection.port