add test assertion for closedRemote condition

stream.go

@@ -69,6 +69,25 @@ func (s *Stream) preloadData() {
 }
 
 func (s *Stream) waitForData() error {
+
+	// XXX test code
+	if s.closedRemote {
+		select {
+		case <-s.reset:
+			return streammux.ErrReset
+		case read, ok := <-s.dataIn:
+			if !ok {
+				return io.EOF
+			}
+			s.extra = read
+			s.exbuf = read
+			return nil
+		default:
+			panic("closed remote without a closed channel")
+		}
+	}
+	// XXX
+
 	select {
 	case <-s.reset:
 		// This is the only place where it's safe to return these.