feat: use go1.20.4 (#40)

See ooni/probe#2417 and ooni/probe#2478.

.github/workflows/go.yml

@@ -11,12 +11,12 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Set up Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v4
       with:
-        go-version: 1.19
+        go-version: ">=1.20.4"
 
     - name: Build
       run: go build -v ./...

UPSTREAM

@@ -1 +1 @@
-go1.19.6
+go1.20.4

cgi/child.go

@@ -83,10 +83,12 @@ func RequestFromMap(params map[string]string) (*http.Request, error) {
 
 	// Copy "HTTP_FOO_BAR" variables to "Foo-Bar" Headers
 	for k, v := range params {
-		if !strings.HasPrefix(k, "HTTP_") || k == "HTTP_HOST" {
+		if k == "HTTP_HOST" {
 			continue
 		}
-		r.Header.Add(strings.ReplaceAll(k[5:], "_", "-"), v)
+		if after, found := strings.CutPrefix(k, "HTTP_"); found {
+			r.Header.Add(strings.ReplaceAll(after, "_", "-"), v)
+		}
 	}
 
 	uriStr := params["REQUEST_URI"]

cgi/host.go

@@ -138,7 +138,6 @@ func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 
 	env := []string{
 		"SERVER_SOFTWARE=go",
-		"SERVER_NAME=" + req.Host,
 		"SERVER_PROTOCOL=HTTP/1.1",
 		"HTTP_HOST=" + req.Host,
 		"GATEWAY_INTERFACE=CGI/1.1",
@@ -158,6 +157,12 @@ func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		env = append(env, "REMOTE_ADDR="+req.RemoteAddr, "REMOTE_HOST="+req.RemoteAddr)
 	}
 
+	if hostDomain, _, err := net.SplitHostPort(req.Host); err == nil {
+		env = append(env, "SERVER_NAME="+hostDomain)
+	} else {
+		env = append(env, "SERVER_NAME="+req.Host)
+	}
+
 	if req.TLS != nil {
 		env = append(env, "HTTPS=on")
 	}

cgi/host_test.go

@@ -8,7 +8,6 @@ package cgi
 
 import (
 	"bufio"
-	"bytes"
 	"fmt"
 	"io"
 	"net"
@@ -115,7 +114,7 @@ func TestCGIBasicGet(t *testing.T) {
 		"param-a":               "b",
 		"param-foo":             "bar",
 		"env-GATEWAY_INTERFACE": "CGI/1.1",
-		"env-HTTP_HOST":         "example.com",
+		"env-HTTP_HOST":         "example.com:80",
 		"env-PATH_INFO":         "",
 		"env-QUERY_STRING":      "foo=bar&a=b",
 		"env-REMOTE_ADDR":       "1.2.3.4",
@@ -129,7 +128,7 @@ func TestCGIBasicGet(t *testing.T) {
 		"env-SERVER_PORT":       "80",
 		"env-SERVER_SOFTWARE":   "go",
 	}
-	replay := runCgiTest(t, h, "GET /test.cgi?foo=bar&a=b HTTP/1.0\nHost: example.com\n\n", expectedMap)
+	replay := runCgiTest(t, h, "GET /test.cgi?foo=bar&a=b HTTP/1.0\nHost: example.com:80\n\n", expectedMap)
 
 	if expected, got := "text/html", replay.Header().Get("Content-Type"); got != expected {
 		t.Errorf("got a Content-Type of %q; expected %q", got, expected)
@@ -541,7 +540,7 @@ func TestEnvOverride(t *testing.T) {
 
 func TestHandlerStderr(t *testing.T) {
 	check(t)
-	var stderr bytes.Buffer
+	var stderr strings.Builder
 	h := &Handler{
 		Path:   "testdata/test.cgi",
 		Root:   "/test.cgi",

client.go

@@ -22,6 +22,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/ooni/oohttp/internal/ascii"
@@ -362,7 +363,7 @@ func setRequestCancel(req *Request, rt RoundTripper, deadline time.Time) (stopTi
 	initialReqCancel := req.Cancel // the user's original Request.Cancel, if any
 
 	var cancelCtx func()
-	if oldCtx := req.Context(); timeBeforeContextDeadline(deadline, oldCtx) {
+	if timeBeforeContextDeadline(deadline, oldCtx) {
 		req.ctx, cancelCtx = context.WithDeadline(oldCtx, deadline)
 	}
 
@@ -392,22 +393,22 @@ func setRequestCancel(req *Request, rt RoundTripper, deadline time.Time) (stopTi
 	}
 
 	timer := time.NewTimer(time.Until(deadline))
-	var timedOut atomicBool
+	var timedOut atomic.Bool
 
 	go func() {
 		select {
 		case <-initialReqCancel:
 			doCancel()
 			timer.Stop()
 		case <-timer.C:
-			timedOut.setTrue()
+			timedOut.Store(true)
 			doCancel()
 		case <-stopTimerCh:
 			timer.Stop()
 		}
 	}()
 
-	return stopTimer, timedOut.isSet
+	return stopTimer, timedOut.Load
 }
 
 // See 2 (end of page 4) https://www.ietf.org/rfc/rfc2617.txt
@@ -499,7 +500,7 @@ func (c *Client) checkRedirect(req *Request, via []*Request) error {
 }
 
 // redirectBehavior describes what should happen when the
-// client encounters a 3xx status code from the server
+// client encounters a 3xx status code from the server.
 func redirectBehavior(reqMethod string, resp *Response, ireq *Request) (redirectMethod string, shouldRedirect, includeBody bool) {
 	switch resp.StatusCode {
 	case 301, 302, 303: