diff options
| -rw-r--r-- | src/policy/feerate.cpp | 6 | ||||
| -rw-r--r-- | src/policy/feerate.h | 1 | ||||
| -rw-r--r-- | src/test/amount_tests.cpp | 10 | ||||
| -rw-r--r-- | src/test/transaction_tests.cpp | 4 | ||||
| -rwxr-xr-x | test/functional/rpc_fundrawtransaction.py | 28 | ||||
| -rw-r--r-- | test/functional/test_framework/util.py | 18 | ||||
| -rwxr-xr-x | test/functional/wallet_keypool.py | 2 |
7 files changed, 57 insertions, 12 deletions
diff --git a/src/policy/feerate.cpp b/src/policy/feerate.cpp index 25b9282b4e..ce149067b7 100644 --- a/src/policy/feerate.cpp +++ b/src/policy/feerate.cpp @@ -7,6 +7,8 @@ #include <tinyformat.h> +#include <cmath> + CFeeRate::CFeeRate(const CAmount& nFeePaid, uint32_t num_bytes) { const int64_t nSize{num_bytes}; @@ -22,7 +24,9 @@ CAmount CFeeRate::GetFee(uint32_t num_bytes) const { const int64_t nSize{num_bytes}; - CAmount nFee = nSatoshisPerK * nSize / 1000; + // Be explicit that we're converting from a double to int64_t (CAmount) here. + // We've previously had issues with the silent double->int64_t conversion. + CAmount nFee{static_cast<CAmount>(std::ceil(nSatoshisPerK * nSize / 1000.0))}; if (nFee == 0 && nSize != 0) { if (nSatoshisPerK > 0) nFee = CAmount(1); diff --git a/src/policy/feerate.h b/src/policy/feerate.h index b16f3f8251..8ba896bb01 100644 --- a/src/policy/feerate.h +++ b/src/policy/feerate.h @@ -48,6 +48,7 @@ public: CFeeRate(const CAmount& nFeePaid, uint32_t num_bytes); /** * Return the fee in satoshis for the given size in bytes. + * If the calculated fee would have fractional satoshis, then the returned fee will always be rounded up to the nearest satoshi. */ CAmount GetFee(uint32_t num_bytes) const; /** diff --git a/src/test/amount_tests.cpp b/src/test/amount_tests.cpp index 114fe3907c..aa23d71671 100644 --- a/src/test/amount_tests.cpp +++ b/src/test/amount_tests.cpp @@ -48,13 +48,13 @@ BOOST_AUTO_TEST_CASE(GetFeeTest) BOOST_CHECK_EQUAL(feeRate.GetFee(9e3), CAmount(-9e3)); feeRate = CFeeRate(123); - // Truncates the result, if not integer + // Rounds up the result, if not integer BOOST_CHECK_EQUAL(feeRate.GetFee(0), CAmount(0)); BOOST_CHECK_EQUAL(feeRate.GetFee(8), CAmount(1)); // Special case: returns 1 instead of 0 - BOOST_CHECK_EQUAL(feeRate.GetFee(9), CAmount(1)); - BOOST_CHECK_EQUAL(feeRate.GetFee(121), CAmount(14)); - BOOST_CHECK_EQUAL(feeRate.GetFee(122), CAmount(15)); - BOOST_CHECK_EQUAL(feeRate.GetFee(999), CAmount(122)); + BOOST_CHECK_EQUAL(feeRate.GetFee(9), CAmount(2)); + BOOST_CHECK_EQUAL(feeRate.GetFee(121), CAmount(15)); + BOOST_CHECK_EQUAL(feeRate.GetFee(122), CAmount(16)); + BOOST_CHECK_EQUAL(feeRate.GetFee(999), CAmount(123)); BOOST_CHECK_EQUAL(feeRate.GetFee(1e3), CAmount(123)); BOOST_CHECK_EQUAL(feeRate.GetFee(9e3), CAmount(1107)); diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp index c813fbea32..252a85c282 100644 --- a/src/test/transaction_tests.cpp +++ b/src/test/transaction_tests.cpp @@ -810,10 +810,10 @@ BOOST_AUTO_TEST_CASE(test_IsStandard) // nDustThreshold = 182 * 3702 / 1000 dustRelayFee = CFeeRate(3702); // dust: - t.vout[0].nValue = 673 - 1; + t.vout[0].nValue = 674 - 1; CheckIsNotStandard(t, "dust"); // not dust: - t.vout[0].nValue = 673; + t.vout[0].nValue = 674; CheckIsStandard(t); dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE); diff --git a/test/functional/rpc_fundrawtransaction.py b/test/functional/rpc_fundrawtransaction.py index b0e46c6ca7..90d57c9c76 100755 --- a/test/functional/rpc_fundrawtransaction.py +++ b/test/functional/rpc_fundrawtransaction.py @@ -136,6 +136,7 @@ class RawTransactionsTest(BitcoinTestFramework): self.test_include_unsafe() self.test_external_inputs() self.test_22670() + self.test_feerate_rounding() def test_change_position(self): """Ensure setting changePosition in fundraw with an exact match is handled properly.""" @@ -1129,6 +1130,33 @@ class RawTransactionsTest(BitcoinTestFramework): do_fund_send(upper_bound) self.restart_node(0) + self.connect_nodes(0, 1) + self.connect_nodes(0, 2) + self.connect_nodes(0, 3) + + def test_feerate_rounding(self): + self.log.info("Test that rounding of GetFee does not result in an assertion") + + self.nodes[1].createwallet("roundtest") + w = self.nodes[1].get_wallet_rpc("roundtest") + + addr = w.getnewaddress(address_type="bech32") + self.nodes[0].sendtoaddress(addr, 1) + self.generate(self.nodes[0], 1) + self.sync_all() + + # A P2WPKH input costs 68 vbytes; With a single P2WPKH output, the rest of the tx is 42 vbytes for a total of 110 vbytes. + # At a feerate of 1.85 sat/vb, the input will need a fee of 125.8 sats and the rest 77.7 sats + # The entire tx fee should be 203.5 sats. + # Coin selection rounds the fee individually instead of at the end (due to how CFeeRate::GetFee works). + # If rounding down (which is the incorrect behavior), then the calculated fee will be 125 + 77 = 202. + # If rounding up, then the calculated fee will be 126 + 78 = 204. + # In the former case, the calculated needed fee is higher than the actual fee being paid, so an assertion is reached + # To test this does not happen, we subtract 202 sats from the input value. If working correctly, this should + # fail with insufficient funds rather than bitcoind asserting. + rawtx = w.createrawtransaction(inputs=[], outputs=[{self.nodes[0].getnewaddress(address_type="bech32"): 1 - 0.00000202}]) + assert_raises_rpc_error(-4, "Insufficient funds", w.fundrawtransaction, rawtx, {"fee_rate": 1.85}) + if __name__ == '__main__': RawTransactionsTest().main() diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py index 9f5bca6884..0678e2e6fe 100644 --- a/test/functional/test_framework/util.py +++ b/test/functional/test_framework/util.py @@ -36,12 +36,12 @@ def assert_approx(v, vexp, vspan=0.00001): def assert_fee_amount(fee, tx_size, feerate_BTC_kvB): """Assert the fee is in range.""" - feerate_BTC_vB = feerate_BTC_kvB / 1000 - target_fee = satoshi_round(tx_size * feerate_BTC_vB) + target_fee = get_fee(tx_size, feerate_BTC_kvB) if fee < target_fee: raise AssertionError("Fee of %s BTC too low! (Should be %s BTC)" % (str(fee), str(target_fee))) # allow the wallet's estimation to be at most 2 bytes off - if fee > (tx_size + 2) * feerate_BTC_vB: + high_fee = get_fee(tx_size + 2, feerate_BTC_kvB) + if fee > high_fee: raise AssertionError("Fee of %s BTC too high! (Should be %s BTC)" % (str(fee), str(target_fee))) @@ -218,6 +218,18 @@ def str_to_b64str(string): return b64encode(string.encode('utf-8')).decode('ascii') +def ceildiv(a, b): + """Divide 2 ints and round up to next int rather than round down""" + return -(-a // b) + + +def get_fee(tx_size, feerate_btc_kvb): + """Calculate the fee in BTC given a feerate is BTC/kvB. Reflects CFeeRate::GetFee""" + feerate_sat_kvb = int(feerate_btc_kvb * Decimal(1e8)) # Fee in sat/kvb as an int to avoid float precision errors + target_fee_sat = ceildiv(feerate_sat_kvb * tx_size, 1000) # Round calculated fee up to nearest sat + return satoshi_round(target_fee_sat / Decimal(1e8)) # Truncate BTC result to nearest sat + + def satoshi_round(amount): return Decimal(amount).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN) diff --git a/test/functional/wallet_keypool.py b/test/functional/wallet_keypool.py index 79235646b0..5807a92b9d 100755 --- a/test/functional/wallet_keypool.py +++ b/test/functional/wallet_keypool.py @@ -193,7 +193,7 @@ class KeyPoolTest(BitcoinTestFramework): assert_equal("psbt" in res, True) # create a transaction without change at the maximum fee rate, such that the output is still spendable: - res = w2.walletcreatefundedpsbt(inputs=[], outputs=[{destination: 0.00010000}], options={"subtractFeeFromOutputs": [0], "feeRate": 0.0008824}) + res = w2.walletcreatefundedpsbt(inputs=[], outputs=[{destination: 0.00010000}], options={"subtractFeeFromOutputs": [0], "feeRate": 0.0008823}) assert_equal("psbt" in res, True) assert_equal(res["fee"], Decimal("0.00009706")) |