Re: gperl_callback_invoke userdata copy

[Torsten Schoenfeld <kaffeetisch gmx de>]

Kevin Ryde wrote:

> > Do we want to support assigning to $_[-1]?
>
> It could be in the docs if it's meant to work.  I can't see any
> disadvantage, it gets you a free bit of "state data" if you want to use
> it that way.
>
> I see GClosure for signals is this way -- refcnt inc and mortalize --
> and assigning alters the stored data.  I guess GPerlCallback can be the
> same.  The net change then to it is just a refcount fix which was
> tickled by a callback disconnecting/destroying itself.

Yeah.  Makes sense.

The patch looks good to me, except for this bit:

+                       SvREFCNT_inc_simple_void_NN (data);
+                       XPUSHs (sv_2mortal (data));

Why not this instead?

                        XPUSHs (sv_2mortal (SvREFCNT_inc (data)));

Or, if you really wanted to avoid the duplicate NULL check, SvREFCNT_inc_NN
instead of SvREFCNT_inc.  But I don't think the win justifies using an obscure
SvREFCNT_inc variant.

-Torsten