net/http: fix cancelation of requests with a readTrackingBody wrapper

Use the original *Request in the reqCanceler map, not the transient
wrapper created to handle body rewinding.

Change the key of reqCanceler to a struct{*Request}, to make it more
difficult to accidentally use the wrong request as the key.

Fixes #40453.

Change-Id: I4e61ee9ff2c794fb4c920a3a66c9a0458693d757
Reviewed-on: https://go-review.googlesource.com/c/go/+/245357
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index 31a41f5351..0a47687d9a 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -2364,6 +2364,50 @@ func TestTransportCancelRequest(t *testing.T) {
 	}
 }
 
+func testTransportCancelRequestInDo(t *testing.T, body io.Reader) {
+	setParallel(t)
+	defer afterTest(t)
+	if testing.Short() {
+		t.Skip("skipping test in -short mode")
+	}
+	unblockc := make(chan bool)
+	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {
+		<-unblockc
+	}))
+	defer ts.Close()
+	defer close(unblockc)
+
+	c := ts.Client()
+	tr := c.Transport.(*Transport)
+
+	donec := make(chan bool)
+	req, _ := NewRequest("GET", ts.URL, body)
+	go func() {
+		defer close(donec)
+		c.Do(req)
+	}()
+	start := time.Now()
+	timeout := 10 * time.Second
+	for time.Since(start) < timeout {
+		time.Sleep(100 * time.Millisecond)
+		tr.CancelRequest(req)
+		select {
+		case <-donec:
+			return
+		default:
+		}
+	}
+	t.Errorf("Do of canceled request has not returned after %v", timeout)
+}
+
+func TestTransportCancelRequestInDo(t *testing.T) {
+	testTransportCancelRequestInDo(t, nil)
+}
+
+func TestTransportCancelRequestWithBodyInDo(t *testing.T) {
+	testTransportCancelRequestInDo(t, bytes.NewBuffer([]byte{0}))
+}
+
 func TestTransportCancelRequestInDial(t *testing.T) {
 	defer afterTest(t)
 	if testing.Short() {