Mempool trimming regression: removes local wallet transactions #6959

1. 
   luke-jr commented at 9:37 am on November 6, 2015: member

   #6722 introduces the possibility of removing transactions generated by the local wallet from its mempool, but fails to update CMerkleTx::GetDepthInMainChain which assumes a transaction neither in the blockchain nor the mempool must be conflicted. Since the wallet transaction is now assumed to be conflicted, the wallet will happily produce a double-spend using the same inputs again.
2. 
   jonasschnelli commented at 9:45 am on November 6, 2015: contributor

   During another case i was also stumbling over a GetDepthInMainChain() inconsistency. IMO the wallet should keep it’s own height cache or even it’s own headers-only-chain (anyways required in case of process separation).

   But anyways; the bitcoin-core local wallet (and other wallets) need to find a way to handle removed transactions from the mempool without marking them as conflicted.

   But you are saying using inputs from a conflicted transaction results in a double-spend? The transaction was removed from the mempool and is not in the chain,… that means it’s available again for coin selection, isn’t it?

3. 
   luke-jr commented at 9:50 am on November 6, 2015: member

   In most cases, it means the wallet wishes to keep it in the mempool and rebroadcast until it is mined.
4. 
   jonasschnelli commented at 10:09 am on November 6, 2015: contributor

   Yes. Such use cases, together with the FSS-RBF (or CPFP) need to be handled by the wallet.
5. laanwj added the label Wallet on Nov 6, 2015
6. 
   jgarzik commented at 12:43 pm on November 6, 2015: contributor

   Yes - this problem was the same one that merge-blocked mempool janitor… Need to solve for local wallet
7. laanwj added the label Mempool on Nov 6, 2015
8. sturles referenced this in commit b79c9f2be6 on Nov 12, 2015
9. 
   MarcoFalke commented at 0:04 am on April 27, 2020: member

   Is this still an issue with a recent version of Bitcoin Core? If yes, what are the steps to reproduce?
10. MarcoFalke closed this on Apr 27, 2020

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11. DrahtBot locked this on Feb 15, 2022

Contributors
luke-jr jonasschnelli jgarzik MarcoFalke

Labels
Wallet Mempool