net/http: 301 redirect loses POST data

[johndaniels]

What I did:

Because of a coding error, I was trying to make a POST request to a go webserver with the path "//create", instead of "/create"

Expected Behavior:

The server should give me a 404 or 400 error, or pass the request along normally. I'm not convinced that "//foo" is a valid path, but if it isn't the server should return an error rather then mangling the request passed to the handler.

Actual Behavior:

The Go server decided to claim that the request was a GET request with no content. Attached is a go server that exhibits this bug along with python code to make the strange request.

Python request script

import requests
data = {'a': 1}
requests.post("http://localhost:8081//foo", data=data)

Go Server

package main

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

func handler(w http.ResponseWriter, r *http.Request) {
    data, _ := httputil.DumpRequest(r, true)
    log.Println(string(data))
}

func main() {
    http.HandleFunc("/foo", handler)
    http.ListenAndServe("127.0.0.1:8081", nil)
}

The output I get from the go script is the following

2015/09/02 13:32:45 GET /foo HTTP/1.1
Host: localhost:8081
Accept: */*
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Type: application/x-www-form-urlencoded
User-Agent: python-requests/2.7.0 CPython/2.7.6 Windows/8

I'm using go 1.4.2 windows/amd64

[minux]

If you look closely, this is what happened:

python requests send this:
POST //foo HTTP/1.1
Host: localhost:8081
Content-Length: 0
User-Agent: python-requests/2.7.0 CPython/2.7.10 Linux/2.6
Connection: keep-alive
Accept: /
Accept-Encoding: gzip, deflate

Go response with 301:
HTTP/1.1 301 Moved Permanently
Location: /foo
Date: Wed, 02 Sep 2015 18:07:41 GMT
Content-Length: 0
Content-Type: text/plain; charset=utf-8

requests resend the request as a GET:
GET /foo HTTP/1.1
Host: localhost:8081
Connection: keep-alive
Accept-Encoding: gzip, deflate
Accept: /
User-Agent: python-requests/2.7.0 CPython/2.7.10 Linux/2.6

And this is what the Go handler gets, and it responses with:
HTTP/1.1 200 OK
Date: Wed, 02 Sep 2015 18:07:41 GMT
Content-Length: 0
Content-Type: text/plain; charset=utf-8

I think this is working as intended.

/cc @bradfitz

[johndaniels]

I guess that's fine then.