x/net/http2: Transport hangs forever if using a pipe that has not been written to yet as req.Body #17480
Description
### What version of Go are you using (go version)?
Go 1.7.1
### What operating system and processor architecture are you using (go env)?
set GOARCH=amd64
set GOBIN=
set GOEXE=.exe
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows
set GOPATH=D:\src\psg\server;D:\src\psg\server\vendor
set GORACE=
set GOROOT=C:\apps\Go
set GOTOOLDIR=C:\apps\Go\pkg\tool\windows_amd64
set CC=gcc
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=C:\Users\lunad\AppData\Local\Temp\go-build906126950=/tmp/go-build -gno-record-gcc-switches
set CXX=g++
set CGO_ENABLED=1
### What did you do?
If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.
I ran the following program:
package main
import (
"crypto/rand"
"io"
"log"
"net/http"
"runtime/debug"
"time"
"golang.org/x/net/http2"
)
func main() {
// set a 10 second timer for success
go func() {
timer := time.NewTimer(10 * time.Second)
<-timer.C
debug.SetTraceback("all")
panic("10 second test period expired")
}()
transport := &http2.Transport{}
c := &http.Client{Transport: transport}
// Get a set of pipes, we'll use these to send data to the server
pipeReader, pipeWriter := io.Pipe()
// Initialize the request
req, err := http.NewRequest("PUT", "https://http2.golang.org/bidirectional-stream", pipeReader)
if err != nil {
pipeWriter.Close()
log.Fatalf("Error while initializing http request: %v", err)
}
// Set the body of the request to the reader end of our pipe, and initiate the request.
req.Body = pipeReader
resp, err := c.Do(req)
if err != nil {
pipeWriter.Close()
log.Fatalf("Error during http call: %v", err)
}
// Check that we actually got a 200 OK, if not: error out
if resp.StatusCode != http.StatusOK {
resp.Body.Close()
pipeWriter.Close()
log.Fatalf("http call got non-200 status code %d", resp.StatusCode)
}
// Use a 10 byte buffer
buffer := make([]byte, 10)
// Read some data
dataLen, err := resp.Body.Read(buffer)
if err != nil {
log.Fatalf("Error while reading data: %v", err)
}
log.Printf("Got data: %+v", buffer[:dataLen])
// Reply
if _, err := rand.Read(buffer); err != nil {
log.Fatalf("Error while reading random data: %v", err)
}
if _, err := pipeWriter.Write(buffer); err != nil {
log.Fatalf("Error while writing data: %v", err)
}
}
### What did you expect to see?
I expected to see a bidirectional http-2 stream, with the server talking first, and the client then replying to the server.
### What did you see instead?
The program hangs within http2/transport.go, in the bodyAndLength function, due to that function doing a Read(), which ofcourse hangs.