net/http: HTTP request hangs when dumping non-nil body using httputil.DumpRequestOut

[SebastiaanKlippert]

What version of Go are you using (go version)?

go1.8beta2

What operating system and processor architecture are you using (go env)?

windows/amd64

What did you do?

When running below sample program the program hangs on http.DefaultClient.Do(req)

package main

import (
	"net/http"
	"log"
	"net/http/httputil"
)

func main(){

	req, err := http.NewRequest("GET", "https://start.exactonline.nl/api/v1/current/Me", http.NoBody)
	if err != nil {
		log.Fatal(err)
	}

	rdata, err := httputil.DumpRequestOut(req, true)
	if err != nil {
		log.Fatal(err)
	}

	log.Println(string(rdata))

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()

	log.Println(resp.Status)
}

What did you expect to see?

401 Unauthorized

What did you see instead?

Nothing (hangs for minutes)

Other info

I expect this also has something to do with the server side because when using a different URL everything is OK.

But since this code runs fine on Go 1.7.3 and earlier I expect it is a bug in 1.8.
Note: In the go1.7 code we use a new(bytes.Buffer) instead of http.NoBody in a function that does GET, PUT and POST requests, so only in the GET requests will have an empty buffer.

• The program works when compiling in versions < 1.8beta1
• The program works when setting the body to nil
• The program also works if you do not dump the request

Possibly related to #18117 ?

[rakyll]

/cc @bradfitz

[bradfitz]

I verified that this was already fixed by 6e36811 which makes me feel better about that fix.

I'll send out a second minor fix to httputil to recognize NoBody specially.

[gopherbot]

CL https://golang.org/cl/34814 mentions this issue.

[kevinburke]

so that's why my DEBUG_HTTP_TRAFFIC flag has been dumping chunked requests! thanks for the patch! https://github.com/kevinburke/rest/blob/master/client.go#L110-L134