fix: DumpResponse error in HEAD request

[yuweizzz]

fix:

bin/ecapture tls -m text
curl -I --http1.1  https://www.google.com/
......
2024-06-18T10:19:58+08:00 INF UUID:104243_104243_curl_0_1_0.0.0.0, Name:HTTPRequest, Type:1, Length:75
HEAD / HTTP/1.1
Host: www.google.com
Accept: */*
User-Agent: curl/7.88.1



2024/06/18 10:19:58 [http response] DumpResponse error: unexpected EOF
......

[cfc4n]

Can you provide some reasons for the bugs?

[yuweizzz]

We use http.ReadResponse(buf, nil) to get the Response. This function defaults to handling it as a GET Method because no request param is passed. The Response.Body will be a new struct. When we dump the response, the Response.Body.Close() will be called and raise an IO error.

package main

import (
	"bufio"
	"bytes"
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/http/httputil"
)

func main() {
	const body = "abc"
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Date", "Wed, 19 Jul 1972 19:00:00 GMT")
		w.Header().Set("Content-Length", "9999")
		fmt.Fprintln(w, body)
	}))
	defer ts.Close()

	resp, err := http.Head(ts.URL)
	if err != nil {
		fmt.Println(err)
	}
	defer resp.Body.Close()

	dump, err := httputil.DumpResponse(resp, true)
	if err != nil {
		fmt.Println(err)
	}

	rd := bytes.NewReader(dump)
	buf := bufio.NewReader(rd)
	resp, err = http.ReadResponse(buf, nil)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(resp.Body)
	err = resp.Body.Close()
	fmt.Println(err)

       //&{0xc0000b4018 <nil> <nil> false false {0 0} false false false <nil>}
       //unexpected EOF
}

[cfc4n]

LGTM, thanks.