mkboot segfault

I meet segment fault when I use mkboot to map GPT partition for raspi sd card, and I found it happen in bootboot/aarch64-rpi/mkboot.c:89

        memcpy(&data+0x1EE, &data+0x1DE, 16);
        memcpy(&data+0x1DE, &data+0x1CE, 16);
        memcpy(&data+0x1CE, &data+0x1BE, 16);

So I modify them to:

        memcpy(&data[0x1EE], &data[0x1DE], 16);
        memcpy(&data[0x1DE], &data[0x1CE], 16);
        memcpy(&data[0x1CE], &data[0x1BE], 16);

Then it succeed and raspi can boot from sd card. Is it a bug?