@@ -24,7 +24,6 @@ import (

 	"github.com/docker/docker/dockerversion"

 	"gotest.tools/assert"

 	is "gotest.tools/assert/cmp"

-	"gotest.tools/skip"

 )

 const (

@@ -286,8 +285,10 @@ func TestLogClosed(t *testing.T) {

 	}

 }

+// TestLogBlocking tests that the Log method blocks appropriately when

+// non-blocking behavior is not enabled.  Blocking is achieved through an

+// internal channel that must be drained for Log to return.

 func TestLogBlocking(t *testing.T) {

-	skip.If(t, runtime.GOOS == "windows", "FIXME: test is flaky on Windows. See #39857")

 	mockClient := newMockClient()

 	stream := &logStream{

 		client:   mockClient,

@@ -301,18 +302,20 @@ func TestLogBlocking(t *testing.T) {

 		err := stream.Log(&logger.Message{})

 		errorCh <- err

 	}()

+	// block until the goroutine above has started

 	<-started

 	select {

 	case err := <-errorCh:

 		t.Fatal("Expected stream.Log to block: ", err)

 	default:

-		break

 	}

+	// assuming it is blocked, we can now try to drain the internal channel and

+	// unblock it

 	select {

-	case <-stream.messages:

-		break

-	default:

+	case <-time.After(10 * time.Millisecond):

+		// if we're unable to drain the channel within 10ms, something seems broken

 		t.Fatal("Expected to be able to read from stream.messages but was unable to")

+	case <-stream.messages:

 	}

 	select {

 	case err := <-errorCh: