There does not need to be a transaction on any ledger for the receipt of the forked coins to be income.
What makes them income is that you received the forked coins, whether that fork is a true fork or just a new ledger that is otherwise identical to the old one. The IRS doesn't care about those technical details.
Situation 1 would apply if for example you choose not to receive the forked coins or if for some reason your exchange didn't recognize the fork and thus never credited any new fork coins to you.
> I don't know what it would even mean to have a "hard fork" which does not maintain the previous state of the blockchain.
Some of these things have edited the prior state... heck even the purpose of the eth/etc hardfork was taking coins from the 'dao hacker' and assigning them to the ethereum foundation. There was some "united bitcoin" where you had to transact during some particular window to get granted coins, etc.
I agree that the case where there is a fork and where you don't get coins is degenerate-- plus the tax treatment in that case is obvious.
There does not need to be a transaction on any ledger for the receipt of the forked coins to be income.
What makes them income is that you received the forked coins, whether that fork is a true fork or just a new ledger that is otherwise identical to the old one. The IRS doesn't care about those technical details.
Situation 1 would apply if for example you choose not to receive the forked coins or if for some reason your exchange didn't recognize the fork and thus never credited any new fork coins to you.