Re: require ignores setglobals()

["Wim Couwenberg" <w.couwenberg@...>]

Hi,

Gunnar Zötl:
> this means that the global table I set before executing code is not
> inherited by the require()d file. Instead, everything defined in the
> external file goes to the initial global table. However, assignments
> within the called functions go to my global table.
>
> Is this behavious intentional?

Well, at least it is consistent [;-)].  If I understand correctly, this is
the case:  The "require" function already _has_ a globals table and so it
will use that one, which just happens not to be your sandbox sb!  However,
as require is a C function (in Lua 5) it is not possible to change its
globals table.  So functions "imported" into your sandbox can provide
backdoors to a "protected" globals table... [:-(]

(Btw, I changed your script to require "incl" instead of "incl.lua".)

To show the effect, introduce a fake require Lua function at the top of your
script:

function require()
    a = 1
end

Now run the script...  Nothing has changed!  Now insert the following line
just before you set the sandbox sb as globals table to "code":

setglobals(require, sb)

and run the script again.  You see??

Bottom line: globals tables are only inherited at function _definition_, not
at function _call_ (unless of course explicitly changed by a setglobals
call.)

Bye,
Wim