rpc: for sat/vB fee rates, limit ParseFixedPoint decimals to 3

Author: jonatack

src/wallet/rpcwallet.cpp

@@ -216,7 +216,8 @@ static void SetFeeEstimateMode(const CWallet& wallet, CCoinControl& cc, const Un
         if (!estimate_mode.isNull() && estimate_mode.get_str() != "unset") {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot specify both estimate_mode and fee_rate");
         }
-        cc.m_feerate = CFeeRate(AmountFromValue(fee_rate), COIN);
+        // Fee rates in sat/vB cannot represent more than 3 significant digits.
+        cc.m_feerate = CFeeRate{AmountFromValue(fee_rate, /* decimals */ 3)};
         if (override_min_fee) cc.fOverrideFeeRate = true;
         // Default RBF to true for explicit fee_rate, if unset.
         if (!cc.m_signal_bip125_rbf) cc.m_signal_bip125_rbf = true;

test/functional/rpc_fundrawtransaction.py

@@ -773,7 +773,7 @@ def test_option_feerate(self):
                 assert_raises_rpc_error(-3, "Invalid amount", node.fundrawtransaction, rawtx, {param: invalid_value, "add_inputs": True})
 
         self.log.info("Test min fee rate checks are bypassed with fundrawtxn, e.g. a fee_rate under 1 sat/vB is allowed")
-        node.fundrawtransaction(rawtx, {"fee_rate": 0.99999999, "add_inputs": True})
+        node.fundrawtransaction(rawtx, {"fee_rate": 0.999, "add_inputs": True})
         node.fundrawtransaction(rawtx, {"feeRate": 0.00000999, "add_inputs": True})
 
         self.log.info("- raises RPC error if both feeRate and fee_rate are passed")

test/functional/rpc_psbt.py

@@ -195,7 +195,7 @@ def run_test(self):
         assert_approx(res2["fee"], 0.055, 0.005)
 
         self.log.info("Test min fee rate checks with walletcreatefundedpsbt are bypassed, e.g. a fee_rate under 1 sat/vB is allowed")
-        res3 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"fee_rate": "0.99999999", "add_inputs": True})
+        res3 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"fee_rate": "0.999", "add_inputs": True})
         assert_approx(res3["fee"], 0.00000381, 0.0000001)
         res4 = self.nodes[1].walletcreatefundedpsbt(inputs, outputs, 0, {"feeRate": 0.00000999, "add_inputs": True})
         assert_approx(res4["fee"], 0.00000381, 0.0000001)

test/functional/wallet_basic.py

@@ -265,7 +265,7 @@ def run_test(self):
         # Test setting explicit fee rate just below the minimum.
         self.log.info("Test sendmany raises 'fee rate too low' if fee_rate of 0.99999999 is passed")
         assert_raises_rpc_error(-6, "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)",
-            self.nodes[2].sendmany, amounts={address: 10}, fee_rate=0.99999999)
+            self.nodes[2].sendmany, amounts={address: 10}, fee_rate=0.999)
 
         self.log.info("Test sendmany raises if an invalid fee_rate is passed")
         # Test fee_rate with zero values.
@@ -458,7 +458,7 @@ def run_test(self):
             # Test setting explicit fee rate just below the minimum.
             self.log.info("Test sendtoaddress raises 'fee rate too low' if fee_rate of 0.99999999 is passed")
             assert_raises_rpc_error(-6, "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)",
-                self.nodes[2].sendtoaddress, address=address, amount=1, fee_rate=0.99999999)
+                self.nodes[2].sendtoaddress, address=address, amount=1, fee_rate=0.999)
 
             self.log.info("Test sendtoaddress raises if an invalid fee_rate is passed")
             # Test fee_rate with zero values.

test/functional/wallet_send.py

@@ -350,10 +350,11 @@ def run_test(self):
 
         # Test setting explicit fee rate just below the minimum of 1 sat/vB.
         self.log.info("Explicit fee rate raises RPC error 'fee rate too low' if fee_rate of 0.99999999 is passed")
-        self.test_send(from_wallet=w0, to_wallet=w1, amount=1, fee_rate=0.99999999,
-            expect_error=(-4, "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)"))
-        self.test_send(from_wallet=w0, to_wallet=w1, amount=1, arg_fee_rate=0.99999999,
-            expect_error=(-4, "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)"))
+        msg = "Fee rate (0.999 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)"
+        self.test_send(from_wallet=w0, to_wallet=w1, amount=1, fee_rate=0.999, expect_error=(-4, msg))
+        self.test_send(from_wallet=w0, to_wallet=w1, amount=1, arg_fee_rate=0.999, expect_error=(-4, msg))
+
+        self.log.info("Explicit fee rate raises if invalid fee_rate is passed")
         # Test fee_rate with zero values.
         msg = "Fee rate (0.000 sat/vB) is lower than the minimum fee rate setting (1.000 sat/vB)"
         for zero_value in [0, 0.000, 0.00000000, "0", "0.000", "0.00000000"]: