net/http: allows read from Response.Body after Close

[rsc]

This program runs correctly in Go 1.5: it exits 0. In Go 1.6 it dies because it detects the ReadAll succeeding despite having called Body.Close.

This was masking some bad code in go get but it's a real problem in its own right: Read after Close should fail.

package main

import (
    "io/ioutil"
    "log"
    "net/http"
)

func main() {
    resp, err := http.DefaultClient.Get("https://bazil.org/fuse/fs/fstestutil?go-get=1")
    if err != nil {
        log.Fatal(err)
    }
    resp.Body.Close()
    data, err := ioutil.ReadAll(resp.Body)
    if len(data) != 0 || err == nil {
        log.Fatalf("ReadAll returned %q, %v", data, err)
    }
}

[gopherbot]

CL https://golang.org/cl/17944 mentions this issue.

[rsc]

For the Github record, that CL mentions the issue but is not a fix for it.

[bradfitz]

Ah! This is only in http2 mode.

[gopherbot]

CL https://golang.org/cl/17937 mentions this issue.

[gopherbot]

CL https://golang.org/cl/17938 mentions this issue.