A lot of comments about flooding if the toilet breaks, which is great, but OP, I'm begging you to replace that toilet if it is cracked. Sharp porcelain will cut through your body like butter and people have been seriously injured (or worse) by being on one of those when it breaks. Image search will show you some horrifying accidents if you ever want to see what a broken toilet can do to you, but I don't recommend it unless you have a strong stomach.