* PAYLOAD_TYPE_PATH: reserving upper 4 bits if 'extra_type' field, for future use

src/Mesh.cpp

@@ -135,7 +135,7 @@ DispatcherAction Mesh::onRecvPacket(Packet* pkt) {
                 int k = 0;
                 uint8_t path_len = data[k++];
                 uint8_t* path = &data[k]; k += path_len;
-                uint8_t extra_type = data[k++];
+                uint8_t extra_type = data[k++] & 0x0F;   // upper 4 bits reserved for future use
                 uint8_t* extra = &data[k];
                 uint8_t extra_len = len - k;   // remainder of packet (may be padded with zeroes!)
                 if (onPeerPathRecv(pkt, j, secret, path, path_len, extra_type, extra, extra_len)) {