lua:socket settimeout does not work

[Alex Athanasopoulos]

Ubuntu Version: Ubuntu 14.04.2 LTS
package lua-socket:i386 3.0~rc1-3

On Ubuntu 14.04, lua socket settimeout does not work as expected. On a tcp socket, it causes the next receive to close the connection immediately.
It works correctly on Ubuntu 12.04 and debian 7.

To reproduce:
install packages lua5.1 and lua-socket
Take the echo server example from the introduction to luasocket:
http://w3.impa.br/~diego/software/luasocket/introduction.html
Put it in a file echo.lua and run it with "lua echo.lua"
From another window, use telnet localhost {port} to connect to the echo server
Result: Immediately after connecting, the server closes the connection.
Expected Result: The server should wait 10 seconds for input, then close the connection.

package version that works correctly in debian 7: lua-socket:i386 2.0.2-8

-------------
A copy of the example (echo.lua):

-- load namespace
local socket = require("socket")
-- create a TCP socket and bind it to the local host, at any port
local server = assert(socket.bind("*", 0))
-- find out which port the OS chose for us
local ip, port = server:getsockname()
-- print a message informing what's up
print("Please telnet to localhost on port " .. port)
print("After connecting, you have 10s to enter a line to be echoed")
-- loop forever waiting for clients
while 1 do
  -- wait for a connection from any client
  local client = server:accept()
  -- make sure we don't block waiting for this client's line
  client:settimeout(10)
  -- receive the line
  local line, err = client:receive()
  -- if there was no error, send it back to the client
  if not err then client:send(line .. "\n") end
  -- done with client, close the object
  client:close()
end

[Alex Athanasopoulos (filopodaros)]

It works correctly in Ubuntu 12.04, using packages:
liblua5.1-socket2 2.0.2-6
lua5.1

[Alex Athanasopoulos (filopodaros)]

It is also broken with lua5.2 (on ubuntu 14.04).

[AnWilco (anwilco)]

I'm experiencing this and I've tracked it down to an old bug in luasocket (in src/buffer.c) that was first introduced on 7th July 2011 and then fixed on 9th Sept 2013.

Hope this helps

[Alex Athanasopoulos (filopodaros)]

This works correctly on Ubuntu 16.04 with lua5.3 or lua5.2 + lua-socket
With lua5.3 I had to run with "lua5.3" instead of "lua"
It no longer affects me, since Ubuntu 16.04 is the latest LTS.