From 18904e9adbb4757f81cd7b2f00452d78df70be99 Mon Sep 17 00:00:00 2001
From: Darien Raymond <admin@v2ray.com>
Date: Tue, 18 Apr 2017 13:39:34 +0200
Subject: [PATCH] only keep connection alive when content length is known

---
 proxy/http/server.go | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/proxy/http/server.go b/proxy/http/server.go
index 9ee768d75..628753c84 100644
--- a/proxy/http/server.go
+++ b/proxy/http/server.go
@@ -236,10 +236,12 @@ func (s *Server) handlePlainHTTP(ctx context.Context, request *http.Request, rea
 		response, err := http.ReadResponse(responseReader, request)
 		if err == nil {
 			StripHopByHopHeaders(response.Header)
-			response.Header.Set("Proxy-Connection", "keep-alive")
-			response.Header.Set("Connection", "keep-alive")
-			response.Header.Set("Keep-Alive", "timeout=4")
-			response.Close = false
+			if response.ContentLength >= 0 {
+				response.Header.Set("Proxy-Connection", "keep-alive")
+				response.Header.Set("Connection", "keep-alive")
+				response.Header.Set("Keep-Alive", "timeout=4")
+				response.Close = false
+			}
 		} else {
 			log.Trace(newError("failed to read response from ", request.Host).Base(err).AtWarning())
 			response = &http.Response{