Re: Interesting stack overflow in Lua 5.3

[Sean Conner <sean@...>]

It was thus said that the Great Roberto Ierusalimschy once stated:
> > The following function, when invoked, causes a C stack overflow
> > in Lua 5.3.
> > 
> > local subsystem_mt = {__index =
> >    function(spec,auction)
> >       for key,bid in ipairs(spec) do
> >          print("Checking '"..auction.."' against '"..key.."'")
> >       end
> >    end}
> 
> I may be missing something, but "The following function" does not seem
> to be a function. It looks like a table... (Therefore, I do not know
> how to invoke it to cause something.)

  All I did was take that code, then add

x = setmetatable({},subsystem_mt)
print(x.one)

Under Lua 5.1, I got:

nil

Under Lua 5.3, I got:

lua-53: y.lua:5: C stack overflow
stack traceback:
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	...
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in function <y.lua:4>
	[C]: in for iterator 'for iterator'
	y.lua:5: in metamethod '__index'
	y.lua:11: in main chunk
	[C]: in ?

  -spc (seems pretty straightforward to me ... )