Merge of r4530, r4531: null character fixes. *) Fixed incorrect ngx_cpystrn() usage in ngx_http_*_process_header(). This resulted in a disclosure of previously freed memory if upstream server returned specially crafted response, potentially exposing sensitive information. Reported by Matthew Daley. *) Headers with null character are now rejected. Headers with NUL character aren't allowed by HTTP standard and may cause various security problems. They are now unconditionally rejected.