Signed/unsigned conversion bug on CHUNKed POST.
vulners.com/securityvulns/securityvulns:doc:3089
vulners.com/securityvulns/securityvulns:doc:3090
vulners.com/securityvulns/securityvulns:doc:3091
vulners.com/securityvulns/securityvulns:doc:3092