[Joker_vD]

I propose we rewrite everything in my yet-unnamed new low-level language:

    loop
        while l >= bsize - blen;
        bsiz, ovf := bsiz * 2;
        if ovf <> 0 then
            mrb_raise(mrb, E_ARGUMENT_ERROR, ("too big specifier\x00"));
        end
    end

[ryao]

Just stop using signed integers to hold sizes. malloc itself takes size_t, which is unsigned.