bug in function Sha1Digest_fromStr

[windyuuy]

assert(src); // also, src must be at least 40 bytes
for (i = 0; i < 20 && src[i]; i++)
{
    // \todo just use atoi or something
    int c0 = tolower(*src++);
    int c1 = tolower(*src++);

    c0 = '0' <= c0 && c0 <= '9' ? c0 - '0' : ('a' <= c0 && c0 <= 'f' ? 0xa + c0 - 'a' : -1);
    c1 = '0' <= c1 && c1 <= '9' ? c1 - '0' : ('a' <= c1 && c1 <= 'f' ? 0xa + c1 - 'a' : -1);
    ((uint8_t*)d.digest)[i] = (uint8_t)((c0 << 4) | c1);
}

there "src[i]" seems conflict with "*sc++"