Environment

• JRuby version (jruby -v) and command line (flags, JRUBY_OPTS, etc):

jruby 9.2.7.0 (2.5.3) 2019-04-09 8a269e3 Java HotSpot(TM) 64-Bit Server VM 25.172-b11 on 1.8.0_172-b11 +jit [darwin-x86_64]

• Operating system and platform (e.g. uname -a)

Darwin MacBoosha.local 18.2.0 Darwin Kernel Version 18.2.0: Thu Dec 20 20:46:53 PST 2018; root:xnu-4903.241.1~1/RELEASE_X86_64 x86_64

Expected Behavior

I'm trying to check if the port 9250 is open and as a part of this exercise I execute the following code:

require 'socket'

sock = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM)
addr = Socket.pack_sockaddr_in(9250, '127.0.0.1')

begin
  sock.connect_nonblock(addr)
rescue Errno::EINPROGRESS
  IO.select(nil, [sock], nil, 1) # select socket for writing
  sock.getsockopt(Socket::SOL_SOCKET, Socket::SO_ERROR) # read any errors from last connection
  retry
rescue Errno::ECONNREFUSED, Errno::EINVAL
  puts 'Open!'
end

sock.close

Running this code on MRI (ruby 2.5.5p157 (2019-03-15 revision 67260) [x86_64-darwin18]) raises no error:

$ ruby socket.rb
Open!

Actual Behavior

Running the code on JRuby raises Errno::EBADF when it's trying to close socket:

$ ruby socket.rb
Open!
Errno::EBADF: Bad file descriptor - No message available
   close at org/jruby/ext/socket/RubySocket.java:694
  <main> at socket.rb:16