src_y = 1 - block_h;
}
if (src_x >= w) {
- src += (w - 1 - src_x) * sizeof(pixel);
+ // The subtracted expression has an unsigned type and must thus not be negative
+ src -= (1 + src_x - w) * sizeof(pixel);
src_x = w - 1;
} else if (src_x <= -block_w) {
src += (1 - block_w - src_x) * sizeof(pixel);