What happens (or is it possible) when there's sidepots that have no players competing for them?

Question

I'm wondering let's say this situation:

at the flop: (mainpot: 400)
P1. All in 100
P2. All in 50
P3. Rise 200
P4. Call 200

If I'm right, that would give us:

Mainpot: (400 + (50*4))-> p1,p2,p3,p4
Sidepot 1: (50 * 3)  -> p1,p3,p4
Sidepot 2: (100 * 2) -> p3,p4

but then both P3 and P4, have to quit the game (disconnected or something), what happens with sidepot 2?

Answer 1

Most online pokersoftwares work with the same rules at this point:

As soon as you disconnect or quit your timebank will be activated. If it runs off, you check or autofold on raise.

So P3 or P4 would get this pot - depends on their cards.

And on next hand they just autofold and blind down until they've no chips anymore.