fix use of arg in ltn12

[catwell]

arg is not part of Lua 5.1 and hence no longer works in Lua 5.2 or LuaJIT with its default compilation options.

Note that arg is apparently used in other parts of the codebase, but I have only hit this issue in ltn12 so far. If you think this fix is correct I can git a try at hunting use of arg in other places.

[diegonehab]

The alternative would be to use the select function, which may be more efficient. On the other hand, these functions are not performance critical, so I am merging the request.

[catwell]

Awesome, thank you!

[sbernard31]

Hi,
Remove all the reference to arg would be nice.

Will luasocket 2.1 will be compatible with Lua 5.1 ? Or will luasocket 2.1 be only for Lua 5.2 and luasocket 2.0 is only for Lua 5.1 ?
In the second case, it could be nice to backport those fixes on luasocket 2.0 maintenance branch.
Because, arg is deprecated in Lua 5.1 and not present in LuaJIT 2.0 (which is a Lua 5.1 VM)

[catwell]

@sbernard31 This is precisely what this commit fixes.

EDIT: Oh, sorry, maybe I misread you. I think that, even if v2.0 doesn't support Lua 5.2, v2.1 will be usable on all versions (5.1, 5.2 and LuaJIT), right @diegonehab ?

[sbernard31]

When I say

Remove all the reference to arg would be nice.

I mean remove all the references of arg in the whole codebase, not only in the ltn12 file.

You said :

Note that arg is apparently used in other parts of the codebase, but I have only hit this issue in ltn12 so far. If you think this fix is correct I can git a try at hunting use of arg in other places.

So I understood that this problem occur in other files, that's right ?

For the second point, if you are right, it's a good news :).

[catwell]

OK, see above :)