golang-13667-investigation

13667-client.go

package main

import (
    "fmt"
    "net"
    "net/http"
)

func main() {
    dialer := &net.Dialer{}
    transport := &http.Transport{
        Dial: dialer.Dial,
    }

    request, _ := http.NewRequest("GET", "http://127.0.0.1:19870/", nil)
    _, err := transport.RoundTrip(request)
    fmt.Println(err)
}

13667-server.go

package main

import "net"

func main() {
    ln, _ := net.Listen("tcp", ":19870")
    conn, _ := ln.Accept()
    conn.Close()
}

13667.sh

#!/bin/bash
go run 13667-server.go &
go run 13667-client.go

go-src.diff

diff --git a/src/net/http/request.go b/src/net/http/request.go
index d1793c7..9e1d96e 100644
--- a/src/net/http/request.go
+++ b/src/net/http/request.go
@@ -1051,6 +1051,7 @@ func (r *Request) wantsClose() bool {
 }
 
 func (r *Request) closeBody() {
+	fmt.Println("body==nil?", r.Body, r.Body==nil)
 	if r.Body != nil {
 		r.Body.Close()
 	}
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index e610f97..1a31d1d 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -225,6 +225,7 @@ func (tr *transportRequest) extraHeaders() Header {
 // For higher-level HTTP client support (such as handling of cookies
 // and redirects), see Get, Post, and the Client type.
 func (t *Transport) RoundTrip(req *Request) (*Response, error) {
+	log.Println("done here", req)
 	t.nextProtoOnce.Do(t.onceSetNextProtoDefaults)
 	if req.URL == nil {
 		req.closeBody()
@@ -239,6 +240,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 	altRT := t.altProto[req.URL.Scheme]
 	t.altMu.RUnlock()
 	if altRT != nil {
+		log.Println("altRT is non-nil")
 		if resp, err := altRT.RoundTrip(req); err != ErrSkipAltProtocol {
 			return resp, err
 		}
@@ -259,7 +261,9 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 		// treq gets modified by roundTrip, so we need to recreate for each retry.
 		treq := &transportRequest{Request: req}
 		cm, err := t.connectMethodForRequest(treq)
+		log.Println("cm, err", cm, err, err == nil)
 		if err != nil {
+			log.Println("closing here, err", err)
 			req.closeBody()
 			return nil, err
 		}
@@ -269,6 +273,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 		// pre-CONNECTed to https server.  In any case, we'll be ready
 		// to send it requests.
 		pconn, err := t.getConn(req, cm)
+		log.Println("pconn, err", pconn, err, err == nil)
 		if err != nil {
 			t.setReqCanceler(req, nil)
 			req.closeBody()
@@ -299,6 +304,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 // The return value is err or the unwrapped error inside a
 // beforeRespHeaderError.
 func checkTransportResend(err error, req *Request, pconn *persistConn) error {
+	log.Println("checkTransportResend", err, err == io.EOF)
 	brhErr, ok := err.(beforeRespHeaderError)
 	if !ok {
 		return err
@@ -1071,6 +1077,7 @@ func (pc *persistConn) readLoop() {
 		resp.Body.(*bodyEOFSignal).fn = func(err error) error {
 			isEOF := err == io.EOF
 			waitForBodyRead <- isEOF
+			log.Println("err encountered here", err)
 			if isEOF {
 				<-eofc // see comment above eofc declaration
 			} else if err != nil && pc.isCanceled() {
@@ -1515,6 +1522,7 @@ func (es *bodyEOFSignal) Close() error {
 		return nil
 	}
 	es.closed = true
+	log.Println("err encountered here", es.rerr)
 	if es.earlyCloseFn != nil && es.rerr != io.EOF {
 		return es.earlyCloseFn()
 	}

printout.md

$ git log | head -n 1
commit 90a68935733ef37d41cb520ffeb56f196a356811

$ ./13667.sh 
2015/12/17 18:50:12 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:50:12 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:50:12 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
EOF
$ ./13667.sh 
2015/12/17 18:50:41 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:50:41 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:50:41 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
EOF


$ ./13667.sh 
2015/12/17 18:52:11 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:52:11 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:52:11 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
2015/12/17 18:52:11 checkTransportResend net/http: transport closed before response was received false
net/http: transport closed before response was received

$ ./13667.sh 
2015/12/17 18:52:18 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:52:18 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:52:18 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
2015/12/17 18:52:18 checkTransportResend net/http: transport closed before response was received false
net/http: transport closed before response was received
$ 

$ ./13667.sh 
2015/12/17 18:52:39 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:52:39 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:52:39 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
2015/12/17 18:52:39 checkTransportResend EOF false
2015/12/17 18:52:39 checkTransportResend EOF false
EOF
$ ./13667.sh 
2015/12/17 18:52:52 done here &{GET http://127.0.0.1:19870/ HTTP/1.1 1 1 map[] <nil> 0 [] false 127.0.0.1:19870 map[] map[] <nil> map[]   <nil> <nil>}
2015/12/17 18:52:52 cm, err {<nil> http 127.0.0.1:19870} <nil> true
2015/12/17 18:52:52 pconn, err &{<nil> 0xc8200bc210 { http 127.0.0.1:19870} 0xc820028028 <nil> 0xc82005e660 false 0xc820010500 0xc82005e4e0 0xc82005e540 0xc82005e5a0 false 0xc82005e600 {0 0} 0 false false false false <nil>} <nil> true
2015/12/17 18:52:52 checkTransportResend EOF false
2015/12/17 18:52:52 checkTransportResend EOF false
EOF