b0g0_ctf - locked ETH

[sammy-tm]

##Description

If a depositor transfers an NFT to another depositor, and the other depositor withdraws, the ETH from the first depositor gets locked in the contract forever.

Imagine this scenario :

D1 : Deposits and gets NFT 1 and transfers to D2
D2 : Deposits and gets NFT 2
D2 : Burns NFT 1

Now, deposits[D2] will be zero, so even if D2 burns NFT 2, he won't get his deposit back and there is no way to recover this ETH

##Impact

Permanent loss of funds

[X1pherW0lf]

D2's NFT2 will be stuck as well since his deposit becomes 0 so only way to recover is to D2 sends NFT 2 to D1 and withdraw lol

[BogoCvetkov]

Good one! Valid - first submission for that issue

[BogoCvetkov]

I'm splitting this between this report and #23