test: cover node-local mempool policy and minimum relay fee #36265

This test demonstrates that if minimum relay fee of one node is not met for a transaction then another node with lower minimum relay fee will accept the same transaction. The test covers the node-local mempool policy. The transaction itself is valid, each node independently decides whether its local mempool policy will admit and relay it. Node 0 uses -minrelaytxfee=0.00001000 BTC/kvB (10 sat/vB); Node 1 uses -minrelaytxfee=0.00000500 BTC/kvB (5 sat/vB). The test submits one 6 sat/vB transaction. I ran build/test/functional/rpc_net.py, and it completed successfully.

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Code Coverage & Benchmarks

For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/36265.

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Was this LLM generated? What are the steps to test this? What is the output before and after the changes here?

Which mutation is this killing? What coverage is this adding?

Please note that contributors are required to fully understand their authored code themselves. Also, LLM generated content is not allowed in comments/communications.

See https://github.com/bitcoin/bitcoin/blob/master/doc/AI_POLICY.md

Was this LLM generated? What are the steps to test this? What is the output before and after the changes here?

Which mutation is this killing? What coverage is this adding?

Please note that contributors are required to fully understand their authored code themselves. Also, LLM generated content is not allowed in comments/communications.

See https://github.com/bitcoin/bitcoin/blob/master/doc/AI_POLICY.md

The comments are not LLM generated. You can test it using the command: build/test/functional/rpc_net.py before there was no direct assertion that the same transaction gets different admission results under those two node policies, now there is. if fee-threshold comparison or per-node policy selection changed so both nodes accepted/rejected incorrectly, the test should fail. The test covers the cross-node behaviour for different minrelaytxfee configurations.

So basically the scenario is if one node rejects a transaction because of minimum relay fee then another node can accept the same transaction which has low minimum relay fee.

This change doesn't make sense to me. We do test min relay fee pretty exhaustively, so I don't think this a/b test adds anything. It is also in an otherwise completely unrelated test file. Closing this again.