commit f1c82168ea3909ad94e7814cee86fefcbf207b52 Author: David Fifield <david@bamsoftware.com> Date: Wed Jul 26 11:49:40 2017 -0700 Add a comment about why we leave body == nil for empty buffers. --- meek-client/meek-client.go | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/meek-client/meek-client.go b/meek-client/meek-client.go index d378b8b..c2ceaf9 100644 --- a/meek-client/meek-client.go +++ b/meek-client/meek-client.go @@ -118,6 +118,15 @@ type RequestInfo struct { func roundTripWithHTTP(buf []byte, info *RequestInfo) (*http.Response, error) { var body io.Reader if len(buf) > 0 { + // Leave body == nil when buf is empty. A nil body is an + // explicit signal that the body is empty. An empty + // *bytes.Reader or the magic value http.NoBody are supposed to + // be equivalent ways to signal an empty body, but in Go 1.8 the + // HTTP/2 code only understands nil. Not leaving body == nil + // causes the Content-Length header to be omitted from HTTP/2 + // requests, which in some cases can cause the server to return + // a 411 "Length Required" error. See + // https://bugs.torproject.org/22865. body = bytes.NewReader(buf) } req, err := http.NewRequest("POST", info.URL.String(), body)