Re: Xavate crash and coxpcall missing 'arg' variable

[Romulo Bahiense <romulo@...>]

> remove the changes you did and post the whole error message; 

D:\lib\Xavante\xavante-1.1b\bin>lua
Lua 5.0.2  Copyright (C) 1994-2004 Tecgraf, PUC-Rio
> require 'start'
D:\b\bin\coxpcall.lua:19: bad argument #1 to `unpack' (table expected, 
got nil)
stack traceback:
        [C]: in function `unpack'
        D:\b\bin\coxpcall.lua:19: in function `coxpcall'
        (tail call): ?
        xavante/server.lua:65: in function `start'
        start.lua:35: in main chunk
        [C]: in function `require'
        stdin:1: in main chunk
        [C]: ?


start.lua -> t_xavante_start.lua


As attachment, unmodified coxpcall.lua .


> i'll try to determine the real troubling line.
	I don't know if you looked at the commented source I sent in the first 
post, but the problem is that coxpcall is attempting to read/write to 
'arg', and there is no 'arg' in coxpcall. Also, I don't know where to 
take it because, in theory, xpcall don't have extra arguments; just two.

Thanks,
Romulo.

-------------------------------------------------------------------------------
-- Coroutine safe xpcall and pcall versions
--
-- Encapsulates the protected calls with a coroutine based loop, so errors can
-- be dealed without the usual Lua 5.0 pcall/xpcall issues with coroutines
-- yielding inside the call to pcall or xpcall.
--
-- Authors: Roberto Ierusalimschy and Andre Carregal 
--
-- Copyright 2005 - Kepler Project (www.keplerproject.org)
-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
-- Implements xpcall with coroutines
-------------------------------------------------------------------------------
function coxpcall(f, err)
  local co = coroutine.create(f)
  while true do
    local results = {coroutine.resume(co , unpack(arg) )}
    local status = results[1]
    table.remove (results, 1) -- remove status of coroutine.resume
    if not status then
      return false, err(unpack(results))
    end
    if coroutine.status(co) == "suspended" then
      arg = {coroutine.yield(unpack(results))}
    else
      return true, unpack(results)
    end
  end
end

-------------------------------------------------------------------------------
-- Implements pcall with coroutines
-------------------------------------------------------------------------------
function copcall(f, ...)
  return coxpcall(function() return f(unpack(arg)) end, error) 
end