(meek_lite) Explicitly set Content-Length to zero when there is no data to send.

https://gitweb.torproject.org/pluggable-transports/meek.git/commit/?h=0.28&id=0ea861efe5873b517fbd08c4bc48027e4db16a95

ChangeLog

@@ -1,5 +1,7 @@
 Changes in version 0.0.8 - UNRELEASED:
  - Bug 24793: Send the correct authorization HTTP header for basic auth.
+ - (meek_lite) Explicitly set Content-Length to zero when there is no data
+   to send.
 
 Changes in version 0.0.7 - 2016-11-15:
  - Support configuring the obfs4 IAT parameter as the sole

transports/meeklite/meek.go

@@ -231,7 +231,11 @@ func (c *meekConn) roundTrip(sndBuf []byte) (recvBuf []byte, err error) {
 		if c.args.front != "" {
 			url.Host = c.args.front
 		}
-		req, err = http.NewRequest("POST", url.String(), bytes.NewReader(sndBuf))
+		var body io.Reader
+		if len(sndBuf) > 0 {
+			body = bytes.NewReader(sndBuf)
+		}
+		req, err = http.NewRequest("POST", url.String(), body)
 		if err != nil {
 			return nil, err
 		}