Merge bitcoin/bitcoin#26646: validation, bugfix: provide more info in *MempoolAcceptResult

264f9ef [validation] return MempoolAcceptResult for every tx on PCKG_TX failure (glozow)
dae81e0 [refactor] rename variables in AcceptPackage for clarity (glozow)
da484bc [doc] release note effective-feerate and effective-includes RPC results (glozow)
5eab397 [validation] remove PackageMempoolAcceptResult::m_package_feerate (glozow)
601bac8 [rpc] return effective-includes in testmempoolaccept and submitpackage (glozow)
1691eaa [rpc] return effective-feerate in testmempoolaccept and submitpackage (glozow)
d6c7b78 [validation] return wtxids of other transactions whose fees were used (glozow)
1605886 [validation] return effective feerate from mempool validation (glozow)
5d35b4a [test] package validation quits early due to non-policy, non-missing-inputs failure (glozow)
be2e4d9 [validation] when quitting early in AcceptPackage, set package_state and tx result (glozow)

Pull request description:

  This PR fixes a bug and improves the mempool accept interface to return information more predictably.

  Bug: In package validation, we first try the transactions individually (see doc/policy/packages.md for more explanation) and, if they all failed for missing inputs and policy-related (i.e. fee) reasons, we'll try package validation. Otherwise, we'll just "quit early" since, for example, if a transaction had an invalid signature, adding a child will not help make it valid. Currently, when we quit early, we're not setting the `package_state` to be invalid, so the caller might think it succeeded. Also, we're returning no results - it makes more sense to return the individual transaction failure. Thanks instagibbs for catching bitcoin/bitcoin#25038 (comment)!

  Also, make the package results interface generally more useful/predictable:
  - Always return the feerate at which a transaction was considered for `CheckFeeRate` in `MempoolAcceptResult::m_effective_feerate` when it was successful. This can replace the current `PackageMempoolAcceptResult::m_package_feerate`, which only sometimes exists.
  - Always provide an entry for every transaction in `PackageMempoolAcceptResult::m_tx_results` when the error is `PCKG_TX`.

ACKs for top commit:
  instagibbs:
    reACK bitcoin/bitcoin@264f9ef
  achow101:
    ACK 264f9ef
  naumenkogs:
    reACK 264f9ef

Tree-SHA512: ce7fd9927a80030317cc6157822596e85a540feff5dbf5eea7c62da2eb50c917cdddc9da1e2ff62cc18b98b27d360151811546bd9d498859679a04bbee090837

Author: glozow

release-notes-26646.md

@@ -0,0 +1,8 @@
+JSON-RPC
+--------
+
+The `testmempoolaccept` RPC now returns 2 additional results within the "fees" result:
+"effective-feerate" is the feerate including fees and sizes of transactions validated together if
+package validation was used, and also includes any modified fees from prioritisetransaction. The
+"effective-includes" result lists the wtxids of transactions whose modified fees and sizes were used
+in the effective-feerate (#26646).

src/rpc/mempool.cpp

@@ -126,6 +126,10 @@ static RPCHelpMan testmempoolaccept()
                     {RPCResult::Type::OBJ, "fees", /*optional=*/true, "Transaction fees (only present if 'allowed' is true)",
                     {
                         {RPCResult::Type::STR_AMOUNT, "base", "transaction fee in " + CURRENCY_UNIT},
+                        {RPCResult::Type::STR_AMOUNT, "effective-feerate", /*optional=*/false, "the effective feerate in " + CURRENCY_UNIT + " per KvB. May differ from the base feerate if, for example, there are modified fees from prioritisetransaction or a package feerate was used."},
+                        {RPCResult::Type::ARR, "effective-includes", /*optional=*/false, "transactions whose fees and vsizes are included in effective-feerate.",
+                            {RPCResult{RPCResult::Type::STR_HEX, "", "transaction wtxid in hex"},
+                        }},
                     }},
                     {RPCResult::Type::STR, "reject-reason", /*optional=*/true, "Rejection string (only present when 'allowed' is false)"},
                 }},
@@ -217,6 +221,12 @@ static RPCHelpMan testmempoolaccept()
                         result_inner.pushKV("vsize", virtual_size);
                         UniValue fees(UniValue::VOBJ);
                         fees.pushKV("base", ValueFromAmount(fee));
+                        fees.pushKV("effective-feerate", ValueFromAmount(tx_result.m_effective_feerate.value().GetFeePerK()));
+                        UniValue effective_includes_res(UniValue::VARR);
+                        for (const auto& wtxid : tx_result.m_wtxids_fee_calculations.value()) {
+                            effective_includes_res.push_back(wtxid.ToString());
+                        }
+                        fees.pushKV("effective-includes", effective_includes_res);
                         result_inner.pushKV("fees", fees);
                     }
                 } else {
@@ -768,10 +778,13 @@ static RPCHelpMan submitpackage()
                         {RPCResult::Type::NUM, "vsize", "Virtual transaction size as defined in BIP 141."},
                         {RPCResult::Type::OBJ, "fees", "Transaction fees", {
                             {RPCResult::Type::STR_AMOUNT, "base", "transaction fee in " + CURRENCY_UNIT},
+                            {RPCResult::Type::STR_AMOUNT, "effective-feerate", /*optional=*/true, "if the transaction was not already in the mempool, the effective feerate in " + CURRENCY_UNIT + " per KvB. For example, the package feerate and/or feerate with modified fees from prioritisetransaction."},
+                            {RPCResult::Type::ARR, "effective-includes", /*optional=*/true, "if effective-feerate is provided, the wtxids of the transactions whose fees and vsizes are included in effective-feerate.",
+                                {{RPCResult::Type::STR_HEX, "", "transaction wtxid in hex"},
+                            }},
                         }},
                     }}
                 }},
-                {RPCResult::Type::STR_AMOUNT, "package-feerate", /*optional=*/true, "package feerate used for feerate checks in " + CURRENCY_UNIT + " per KvB. Excludes transactions which were deduplicated or accepted individually."},
                 {RPCResult::Type::ARR, "replaced-transactions", /*optional=*/true, "List of txids of replaced transactions",
                 {
                     {RPCResult::Type::STR_HEX, "", "The transaction id"},
@@ -856,6 +869,7 @@ static RPCHelpMan submitpackage()
                 CHECK_NONFATAL(it != package_result.m_tx_results.end());
                 UniValue result_inner{UniValue::VOBJ};
                 result_inner.pushKV("txid", tx->GetHash().GetHex());
+                const auto& tx_result = it->second;
                 if (it->second.m_result_type == MempoolAcceptResult::ResultType::DIFFERENT_WITNESS) {
                     result_inner.pushKV("other-wtxid", it->second.m_other_wtxid.value().GetHex());
                 }
@@ -864,6 +878,17 @@ static RPCHelpMan submitpackage()
                     result_inner.pushKV("vsize", int64_t{it->second.m_vsize.value()});
                     UniValue fees(UniValue::VOBJ);
                     fees.pushKV("base", ValueFromAmount(it->second.m_base_fees.value()));
+                    if (tx_result.m_result_type == MempoolAcceptResult::ResultType::VALID) {
+                        // Effective feerate is not provided for MEMPOOL_ENTRY transactions even
+                        // though modified fees is known, because it is unknown whether package
+                        // feerate was used when it was originally submitted.
+                        fees.pushKV("effective-feerate", ValueFromAmount(tx_result.m_effective_feerate.value().GetFeePerK()));
+                        UniValue effective_includes_res(UniValue::VARR);
+                        for (const auto& wtxid : tx_result.m_wtxids_fee_calculations.value()) {
+                            effective_includes_res.push_back(wtxid.ToString());
+                        }
+                        fees.pushKV("effective-includes", effective_includes_res);
+                    }
                     result_inner.pushKV("fees", fees);
                     if (it->second.m_replaced_transactions.has_value()) {
                         for (const auto& ptx : it->second.m_replaced_transactions.value()) {
@@ -874,9 +899,6 @@ static RPCHelpMan submitpackage()
                 tx_result_map.pushKV(tx->GetWitnessHash().GetHex(), result_inner);
             }
             rpc_result.pushKV("tx-results", tx_result_map);
-            if (package_result.m_package_feerate.has_value()) {
-                rpc_result.pushKV("package-feerate", ValueFromAmount(package_result.m_package_feerate.value().GetFeePerK()));
-            }
             UniValue replaced_list(UniValue::VARR);
             for (const uint256& hash : replaced_txids) replaced_list.push_back(hash.ToString());
             rpc_result.pushKV("replaced-transactions", replaced_list);