http: Support HTTP/1.0 Keep-Alive

src/pkg/http/transfer.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package http
 
 import (
         "bufio"
         "io"
         "os"
@@ skipping 334 matching lines @@
         if strings.Index(strings.ToLower(header["Content-Type"]), "multipart/byteranges") >= 0 {
                 return -1, ErrNotSupported
         }
 
         // Body-EOF logic based on other methods (like closing, or chunked coding)
         return -1, nil
 }
 
 // Determine whether to hang up after sending a request and body, or
 // receiving a response and body
+// 'header' is the request headers
 func shouldClose(major, minor int, header map[string]string) bool {
-        if major < 1 || (major == 1 && minor < 1) {
+        if major < 1 {
                 return true
+        } else if major == 1 && minor == 0 {
+                v, present := header["Connection"]
+                if !present {
+                        return true
+                }
+                v = strings.ToLower(v)
+                if strings.Index(v, "keep-alive") == -1 {
+                        return true
+                }
+                return false
         } else if v, present := header["Connection"]; present {
                 // TODO: Should split on commas, toss surrounding white space,
                 // and check each field.
                 if v == "close" {
                         header["Connection"] = "", false
                         return true
                 }
         }
         return false
 }
@@ skipping 55 matching lines @@
                 return err
         }
         if b.hdr == nil { // not reading trailer
                 return nil
         }
 
         // TODO(petar): Put trailer reader code here
 
         return nil
 }