here is a bug, if we make a http request with more than 64 http headers, then varnish will issue a 413 error, and this will go on to call vcl_error, however, vcl_error may already be hooked by lib-parsereq, thus the hooked error function will be called. The hooked error function will try to initialise the module and do http_SetHeader. Here is the problem, the call to http_SetHeader will fail because there are already 64 headers, so parsereq-mod will keep trying to reinitialise itself and exhaust the stack, finally core dumped.
