s4: Composite async callback on error conditions

[Matthias Dieter Wallnöfer]

Given the file "libcli/composite/composite.c":
> _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS 
> status)
> {
>         /* you are allowed to pass NT_STATUS_OK to composite_error(), 
> in which
>            case it is equivalent to composite_done() */
>         if (NT_STATUS_IS_OK(status)) {
>                 composite_done(ctx);
>                 return;
>         }
>         if (!ctx->used_wait && !ctx->async.fn) {
>                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), 
> composite_trigger, ctx);
>         }
>         ctx->status = status;
>         ctx->state = COMPOSITE_STATE_ERROR;
>         if (ctx->async.fn != NULL) {
>                 ctx->async.fn(ctx);
>         }
> }
Regardless if an action succeeds (composite_done branch) or fails a 
specified async callback is launched if it has been set. As far as I can 
see this leads to problems: see 
http://build.samba.org/build.cgi/build/50b21d3db7ff575c3bdac41bedc8d77ab74680a9 
(access in talloc destructor).
So my question: should we still be running async callbacks also on 
failure conditions? Or can this particular problem be solved differently?

Cheers,
Matthias