[release-branch.go1.17] net/http: do not cancel request context on response body...

When sending a Request with a non-context deadline, we create a
context with a timeout. This context is canceled when closing the
response body, and also if a read from the response body returns
an error (including io.EOF).

Cancelling the context in Response.Body.Read interferes with the
HTTP/2 client cleaning up after a request is completed, and is
unnecessary: The user should always close the body, the impact
from not canceling the context is minor (the context timer leaks
until it fires).

Fixes #49559.
For #49366.

Change-Id: Ieaed866116916261d9079f71d8fea7a7b303b8fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/361919
Trust: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
(cherry picked from commit 76fbd6167364fb98e3ebe946cfc16b5b84d4240e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/368085
Reviewed-by: Michael Knyszek <mknyszek@google.com>

diff --git a/src/net/http/client.go b/src/net/http/client.go
index 4d380c65db983672ea22974c1be303c2f8065c41..22db96b2674c9037fd8620b38ea6c1f03ef85c87 100644 (file)
--- a/src/net/http/client.go
+++ b/src/net/http/client.go
@@ -965,7 +965,6 @@ func (b *cancelTimerBody) Read(p []byte) (n int, err error) {
        if err == nil {
                return n, nil
        }
-       b.stop()
        if err == io.EOF {
                return n, err
        }

diff --git a/src/net/http/client_test.go b/src/net/http/client_test.go
index 01d605c35194f88e954c2b348458f5e7aae9c478..9788c7a9c389843d606e48839eb825472fcb0f6e 100644 (file)
--- a/src/net/http/client_test.go
+++ b/src/net/http/client_test.go
@@ -1353,6 +1353,33 @@ func TestClientTimeoutCancel(t *testing.T) {
        }
 }
 
+func TestClientTimeoutDoesNotExpire_h1(t *testing.T) { testClientTimeoutDoesNotExpire(t, h1Mode) }
+func TestClientTimeoutDoesNotExpire_h2(t *testing.T) { testClientTimeoutDoesNotExpire(t, h2Mode) }
+
+// Issue 49366: if Client.Timeout is set but not hit, no error should be returned.
+func testClientTimeoutDoesNotExpire(t *testing.T, h2 bool) {
+       setParallel(t)
+       defer afterTest(t)
+
+       cst := newClientServerTest(t, h2, HandlerFunc(func(w ResponseWriter, r *Request) {
+               w.Write([]byte("body"))
+       }))
+       defer cst.close()
+
+       cst.c.Timeout = 1 * time.Hour
+       req, _ := NewRequest("GET", cst.ts.URL, nil)
+       res, err := cst.c.Do(req)
+       if err != nil {
+               t.Fatal(err)
+       }
+       if _, err = io.Copy(io.Discard, res.Body); err != nil {
+               t.Fatalf("io.Copy(io.Discard, res.Body) = %v, want nil", err)
+       }
+       if err = res.Body.Close(); err != nil {
+               t.Fatalf("res.Body.Close() = %v, want nil", err)
+       }
+}
+
 func TestClientRedirectEatsBody_h1(t *testing.T) { testClientRedirectEatsBody(t, h1Mode) }
 func TestClientRedirectEatsBody_h2(t *testing.T) { testClientRedirectEatsBody(t, h2Mode) }
 func testClientRedirectEatsBody(t *testing.T, h2 bool) {