fa81d7a11a
User @bes-internal reported a Perl module crasher on GitHub. This was due to a Perl application sending back two responses, for each response we would call down into XS_NGINX__Unit__Sandbox_cb(), the first time pctx->req would point to a valid nxt_unit_request_info_t, the second time pctx->req would be NULL. Add an invalid responses check which covers this case. Closes: <https://github.com/nginx/unit/issues/841> Reviewed-by: Alejandro Colomar <alx@nginx.com> Signed-off-by: Andrew Clayton <a.clayton@nginx.com>