Merge of r4919: fixed segfault on PUT in dav module. Dav: fixed segfault on PUT if body was already read (ticket #238). If request body reading happens with different options it's possible that there will be no r->request_body->temp_file available (or even no r->request_body available if body was discarded). Return internal server error in this case instead of committing suicide by dereferencing a null pointer.