Re: userdata access after __gc?

[Roberto Ierusalimschy <roberto@...>]

> While that holds in this case, I can modify my test program to trigger
> the call on the gc'd object even when the userdata is not exposed to Lua
> (see attached).  My example differs from the PIL example only in the
> order of object creation.

If you can crash the PiL example please let me know.


> Also, in the other example from the book, it appears that lxp_parse()
> accesses xpu->parser without a guard, which comes from a userdata that
> is exposed to Lua.  Actually in this case it appears you could trigger
> a crash just by calling close() explicitly and then parse()?  Maybe I
> am missing something here.  http://www.lua.org/pil/29.2.html

That is a real bug (although not directly related to finalizers)!
Thanks for the report.

-- Roberto