}
		if fn := cs.get1xxTraceFunc(); fn != nil {
			if err := fn(statusCode, textproto.MIMEHeader(header)); err != nil {
				return nil, err
			}
		}
		if statusCode == 100 {
			http2traceGot100Continue(cs.trace)
			select {
			case cs.on100 <- struct{}{}:
			default:
			}
		}
		cs.pastHeaders = false // do it all again
		return nil, nil
	}

	res.ContentLength = -1