What happens if a transaction is submitted that spends a coinbase output early?
Is the transaction just placed in the orphan pool and potentially lost by the time the timeout ends? In theory, they should be higher priority than normal orphans, since they are guaranteed to be valid eventually.
Is the transaction just placed in the orphan pool and potentially lost by the time the timeout ends? In theory, they should be higher priority than normal orphans, since they are guaranteed to be valid eventually.
I don't think they are guaranteed to be valid eventually. For example, it could be the case that the first block in which the coinbase becomes spendable (so 100 blocks after the block it is mined in) sends the funds it to a different address than the one you saved in your mempool.
AFAIK, the current invariant of the mempool is that all the transactions could be gathered up into one big block (assuming the 1 MB restriction doesn't apply). This would have to change to allow relaying of prematures coinbase spends. The block building code would have to take this into account as well, making sure it doesn't build a block that will be invalid.
I like the idea of being able to use this for things like award pool payouts immediately after a block is solved, though.
