[diminoten]

> Of course, any still-pending transactions in A will still be pending in the queues of the miners working on fork B, and so all transactions will eventually be validated.

I don't understand this. So you have fork A and fork B, and once fork B wins, what happens to the transactions being done on fork A? Discarded? Do transactions sometimes not ever get verified?

From what I've quoted, I'm guessing no, transactions in fork A somehow get verified by work being done in fork B. How? Do these transactions exist in both forks?

Also, in general, how do p2p networks facilitate the finding of nodes? The links provided [0] describes how a node figures out what to tell other nodes about itself [0], and how to talk to other nodes once they've been discovered [1], but how does a node actually find other nodes, to begin with? Best I can tell it's just a text file with a bunch of "starter" nodes.

    [0] - https://en.bitcoin.it/wiki/Satoshi_Client_Node_Discovery
    [1] - https://en.bitcoin.it/wiki/Network

[ufmace]

I'm pretty sure that for normal operation, a transaction gets broadcast to the network, and all miners see it and try to include it in their blocks. Each miner has a queue of unverified transactions to include in the blocks it's trying to build. When the miner gets a valid block from another miner, then it removes all of the transactions in that block from it's queue.

In a legit fork with no attempt at malicious action, there's no reason for the transactions in the forks to be any different, since all of the miners are seeing the same transactions broadcast to the network and have essentially the same transaction queue.

For an attempted double-spend attack, miners already check that there isn't a double-spend in the nodes in their block, so they would drop the second transaction they got trying to spend the same coins.

Since a double-spend can't happen in a single block, the double-spend attack relies on 2 miners working on different blocks, where the attacker-controlled miner is semi-isolated from the network and does not include the original spend transaction, but instead the attacker's second spend transaction. If the attack miner solves the block before any other miner on the network and broadcasts it, then the rest of the miners will accept it and reject the original spend transaction as a double-spend, leaving whoever was going to receive it with no coins.

[gus_massa]

The non incompatible transactions will be present in both forks, and they will get validated and fixed whatever fork wins. This includes most of the transactions that are not related to the double spending.

In the case of a double spending, each transaction can live in only one of the forks, and the decedents [1] transactions can be validated only in the same fork. When a fork wins, all the transactions that are incompatible can’t be added and they disappear.

[1] Sopuse that X sends the same bitcoins to A and B. Then A send these bitcoins to A1, that sends these bitcoins to A2. During the same time B send these bitcoins to B1, that sends these bitcoins to B2. Then you have two forks, one with the A, A1 and A2 transactions and another with the B, B1 and B2 transactions. Only these transactions have problems and one half of them will disappear, all the other transactions will apear in both forks.