wallet: don’t back-date locktime when replacing/fee bumping #26526

1. 
   0xB10C commented at 5:35 pm on November 17, 2022: member

   As mentioned in #26451 (comment) example 3:

   If we do anti-fee sniping, the Bitcoin Core wallet has a 10% chance to back-date the locktime of a transaction to up to 100 blocks. Electrum has similar behavior.

   https://github.com/bitcoin/bitcoin/blob/48174c0f287b19931ca110670610bd03a03eb914/src/wallet/spend.cpp#L725-L731

   When we fee-bump a transaction, it can happen that we have a higher locktime in replaced transaction that in the replacement transaction. This is a clear indication that we are in fact a Bitcoin Core or Electrum wallet doing the replacement. I think this is something we should try to avoid.

   related: #26527 electrum issue: https://github.com/spesmilo/electrum/issues/8073

2. 0xB10C added the label Feature on Nov 17, 2022
3. MarcoFalke added the label Wallet on Nov 17, 2022
4. MarcoFalke added the label RPC/REST/ZMQ on Nov 17, 2022
5. 
   Xekyo commented at 8:29 pm on January 10, 2023: member

   Good catch, yes that should be checked when we create a replacement.

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0xB10C Xekyo

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Feature Wallet RPC/REST/ZMQ