static int stbi__parse_uncompressed_block(stbi__zbuf *a)
{
   stbi_uc header[4];
   int len,nlen,k;
   if (a->num_bits & 7)
      stbi__zreceive(a, a->num_bits & 7); // discard
   // drain the bit-packed data into header
   k = 0;
   while (a->num_bits > 0) {
      header[k++] = (stbi_uc) (a->code_buffer & 255); // suppress MSVC run-time check
      a->code_buffer >>= 8;
      a->num_bits -= 8;
   }
   if (a->num_bits < 0) return stbi__err("zlib corrupt","Corrupt PNG");
   // now fill header the normal way
   while (k < 4)
      header[k++] = stbi__zget8(a);
   len  = header[1] * 256 + header[0];
   nlen = header[3] * 256 + header[2];
   if (nlen != (len ^ 0xffff)) return stbi__err("zlib corrupt","Corrupt PNG");
   if (a->zbuffer + len > a->zbuffer_end) return stbi__err("read past buffer","Corrupt PNG");
   if (a->zout + len > a->zout_end)
      if (!stbi__zexpand(a, a->zout, len)) return 0;
   memcpy(a->zout, a->zbuffer, len);
   a->zbuffer += len;
   a->zout += len;
   return 1;
}
Unknown