Rail Bug (Repost)

This bug is reposted due to the unsucessful of reopening of the rail bug, which was resolved by an unrespectful Mojanger with the reason of 'invalid'. I seriously hope that everyone can pay attention to this bug, but also the respect to bug reporters.
Anyway, let's understand what is this bug.
Rail bug 1: When you retract a rail upwards by a sticky piston, instead of not retracted or breaks after retracted, the rail will be retracted and the rail still exist, even there is not blocks under the rail.
Rail bug 2: Extension of Rail bug 1, when you add a minecart on top of the rail, and retract it upwards using a sticky piston, the rail will retract upwards, and the minecart also, even there is no blocks under the rail (and the minecart).
Rail bug 3: Retract the rail upwards first as the steps of Rail bug 1. Then, extend the sticky piston again, the rail exist, but it also drops a rail item*.
Rail bug 4: Extension of Rail bug 2 and 3, simply place a minecart on top of the rail, then retract it by using a sticky piston, then re-extend again, and the minecart still exist.
*Rail bug 1 and 3 can allow players to create a rail generator. Please remove this weird, but awesome bug.
To reproduce it, place a rail, then up 2 blocks from the rail, place a stick piston facing downwards, extend it, and retract it, and you have sucessfully reproduce the bug.