[tor-commits] [meek/master] Explicitly set Content-Length to zero when there is no data to send.

[dcf at torproject.org]

commit 0ea861efe5873b517fbd08c4bc48027e4db16a95
Author: Ivan Markin <twim at riseup.net>
Date:   Sun Jul 9 19:56:56 2017 +0000

    Explicitly set Content-Length to zero when there is no data to send.
    
    Since Go 1.8 http.Transport does not set Content-Length header
    if body contains no bytes.
    https://golang.org/doc/go1.8#net_http
    https://go-review.googlesource.com/c/31445/
    
    However some of domain fronts do inspect Content-Length header
    and return 411 error when it is not set. This breaks connection
    entierly since these packets do not travel beyond a frontend
    to a meek server.
    
    Closes #22865.
---
 meek-client/meek-client.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/meek-client/meek-client.go b/meek-client/meek-client.go
index 9a818d0..d378b8b 100644
--- a/meek-client/meek-client.go
+++ b/meek-client/meek-client.go
@@ -116,7 +116,11 @@ type RequestInfo struct {
 // Do an HTTP roundtrip using the payload data in buf and the request metadata
 // in info.
 func roundTripWithHTTP(buf []byte, info *RequestInfo) (*http.Response, error) {
-	req, err := http.NewRequest("POST", info.URL.String(), bytes.NewReader(buf))
+	var body io.Reader
+	if len(buf) > 0 {
+		body = bytes.NewReader(buf)
+	}
+	req, err := http.NewRequest("POST", info.URL.String(), body)
 	if err != nil {
 		return nil, err
 	}