Use NGTCP2_FRAME_FORMAT_ERROR in case of NGTCP2_ERR_ACK_FRAME
Right now, we don't have complete ACK frame type in
NGTCP2_ERR_ACK_FRAME because it includes variable flags, and cannot
use specific error code range (0x800001xx).
@@ -30,6 +30,8 @@ uint32_t infer_quic_error_code(int liberr) {
switch (liberr) {
case 0:
return NGTCP2_NO_ERROR;
+ case NGTCP2_ERR_ACK_FRAME:
+ return NGTCP2_FRAME_FORMAT_ERROR;
case NGTCP2_ERR_FLOW_CONTROL:
return NGTCP2_FLOW_CONTROL_ERROR;
case NGTCP2_ERR_STREAM_ID:
