if cs.sentHeaders {
			if se, ok := err.(http2StreamError); ok {
				if se.Cause != http2errFromPeer {
					cc.writeStreamReset(cs.ID, se.Code, err)
				}
			} else {
				cc.writeStreamReset(cs.ID, http2ErrCodeCancel, err)
			}
		}
		cs.bufPipe.CloseWithError(err) // no-op if already closed
	} else {
		if cs.sentHeaders && !cs.sentEndStream {