Merge #15996: rpc: Deprecate totalfee argument in `bumpfee`

2f7eb772f6250442d4a0071318047cb2deeb31fa Add RPC bumpfee totalFee deprecation test (Jon Atack)
a92d9ce8cf355e18e43e1f207e4be9e42e7ec81a deprecate totalFee argument in bumpfee RPC call (Gregory Sanders)

Pull request description:

  totalFee argument is of questionable use, and should be removed in favor of feerate-based features.

  I first moved IsDeprecatedRPCEnabled because `bitcoin-wallet` doesn't link `libbitcoin_server`.

ACKs for top commit:
  ryanofsky:
    utACK 2f7eb772f6250442d4a0071318047cb2deeb31fa. Only change since last review is leaving IsDeprecatedRPCEnabled in its happy home, and switching to rpcEnableDeprecated instead. (Thanks!)
  jonatack:
    ACK 2f7eb772f6250442d4a0071318047cb2deeb31fa. Built locally, manually tested rpc bumpfee, help output ([gist](https://gist.github.com/jonatack/863673eacc02f9da39ff6d6712f9d837)), all tests pass. Travis failures appears to be unrelated, the [bitcoin builds are green](https://bitcoinbuilds.org/index.php?build=121).
  meshcollider:
    Code Review ACK 2f7eb772f6250442d4a0071318047cb2deeb31fa

Tree-SHA512: c97465205ee59575df37894bcbb6c4ecf8858dd8fe9d89503f9342b226768c1dcb553153bc9eb3055f7bf5eb41573e48b8efa57e083cd255793cbe5280f0026a

4 files changed, 62 insertions, 3 deletions

diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index ab732dc0d8..7af009f430 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3263,12 +3263,12 @@ static UniValue bumpfee(const JSONRPCRequest& request)
                 "\nBumps the fee of an opt-in-RBF transaction T, replacing it with a new transaction B.\n"
                 "An opt-in RBF transaction with the given txid must be in the wallet.\n"
                 "The command will pay the additional fee by reducing change outputs or adding inputs when necessary. It may add a new change output if one does not already exist.\n"
-                "If `totalFee` is given, adding inputs is not supported, so there must be a single change output that is big enough or it will fail.\n"
+                "If `totalFee` (DEPRECATED) is given, adding inputs is not supported, so there must be a single change output that is big enough or it will fail.\n"
                 "All inputs in the original transaction will be included in the replacement transaction.\n"
                 "The command will fail if the wallet or mempool contains a transaction that spends one of T's outputs.\n"
                 "By default, the new fee will be calculated automatically using estimatesmartfee.\n"
                 "The user can specify a confirmation target for estimatesmartfee.\n"
-                "Alternatively, the user can specify totalFee, or use RPC settxfee to set a higher fee rate.\n"
+                "Alternatively, the user can specify totalFee (DEPRECATED), or use RPC settxfee to set a higher fee rate.\n"
                 "At a minimum, the new fee rate must be high enough to pay an additional new relay fee (incrementalfee\n"
                 "returned by getnetworkinfo) to enter the node's mempool.\n",
                 {
@@ -3276,7 +3276,7 @@ static UniValue bumpfee(const JSONRPCRequest& request)
                     {"options", RPCArg::Type::OBJ, RPCArg::Optional::OMITTED_NAMED_ARG, "",
                         {
                             {"confTarget", RPCArg::Type::NUM, /* default */ "fallback to wallet's default", "Confirmation target (in blocks)"},
-                            {"totalFee", RPCArg::Type::NUM, /* default */ "fallback to 'confTarget'", "Total fee (NOT feerate) to pay, in satoshis.\n"
+                            {"totalFee", RPCArg::Type::NUM, /* default */ "fallback to 'confTarget'", "Total fee (NOT feerate) to pay, in satoshis. (DEPRECATED)\n"
             "                         In rare cases, the actual fee paid might be slightly higher than the specified\n"
             "                         totalFee if the tx change output has to be removed because it is too close to\n"
             "                         the dust threshold."},
@@ -3331,6 +3331,9 @@ static UniValue bumpfee(const JSONRPCRequest& request)
         } else if (options.exists("confTarget")) { // TODO: alias this to conf_target
             coin_control.m_confirm_target = ParseConfirmTarget(options["confTarget"], pwallet->chain().estimateMaxBlocks());
         } else if (options.exists("totalFee")) {
+            if (!pwallet->chain().rpcEnableDeprecated("totalFee")) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "totalFee argument has been deprecated and will be removed in 0.20. Please use -deprecatedrpc=totalFee to continue using this argument until removal.");
+            }
             totalFee = options["totalFee"].get_int64();
             if (totalFee <= 0) {
                 throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid totalFee %s (must be greater than 0)", FormatMoney(totalFee)));
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index 0db8382733..7ad2b78d4e 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -175,6 +175,7 @@ BASE_SCRIPTS = [
     'rpc_bind.py --nonloopback',
     'mining_basic.py',
     'wallet_bumpfee.py',
+    'wallet_bumpfee_totalfee_deprecation.py',
     'rpc_named_arguments.py',
     'wallet_listsinceblock.py',
     'p2p_leak.py',
diff --git a/test/functional/wallet_bumpfee.py b/test/functional/wallet_bumpfee.py
index 030eb50791..bfc01e3f5e 100755
--- a/test/functional/wallet_bumpfee.py
+++ b/test/functional/wallet_bumpfee.py
@@ -37,6 +37,7 @@ class BumpFeeTest(BitcoinTestFramework):
         self.extra_args = [[
             "-walletrbf={}".format(i),
             "-mintxfee=0.00002",
+            "-deprecatedrpc=totalFee",
         ] for i in range(self.num_nodes)]
 
     def skip_test_if_missing_module(self):
diff --git a/test/functional/wallet_bumpfee_totalfee_deprecation.py b/test/functional/wallet_bumpfee_totalfee_deprecation.py
new file mode 100755
index 0000000000..b8e097c32e
--- /dev/null
+++ b/test/functional/wallet_bumpfee_totalfee_deprecation.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+# Copyright (c) 2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test deprecation of passing `totalFee` to the bumpfee RPC."""
+from decimal import Decimal
+
+from test_framework.messages import BIP125_SEQUENCE_NUMBER
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_raises_rpc_error
+
+class BumpFeeWithTotalFeeArgumentDeprecationTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 2
+        self.extra_args = [[
+            "-walletrbf={}".format(i),
+            "-mintxfee=0.00002",
+        ] for i in range(self.num_nodes)]
+
+    def skip_test_if_missing_module(self):
+        self.skip_if_no_wallet()
+
+    def run_test(self):
+        peer_node, rbf_node = self.nodes
+        peer_node.generate(110)
+        self.sync_all()
+        peer_node.sendtoaddress(rbf_node.getnewaddress(), 0.001)
+        self.sync_all()
+        peer_node.generate(1)
+        self.sync_all()
+        rbfid = spend_one_input(rbf_node, peer_node.getnewaddress())
+
+        self.log.info("Testing bumpfee with totalFee argument raises RPC error with deprecation message")
+        assert_raises_rpc_error(
+            -8,
+            "totalFee argument has been deprecated and will be removed in 0.20. " +
+            "Please use -deprecatedrpc=totalFee to continue using this argument until removal.",
+            rbf_node.bumpfee, rbfid, {"totalFee": 2000})
+
+        self.log.info("Testing bumpfee without totalFee argument does not raise")
+        rbf_node.bumpfee(rbfid)
+
+def spend_one_input(node, dest_address, change_size=Decimal("0.00049000")):
+    tx_input = dict(sequence=BIP125_SEQUENCE_NUMBER,
+                    **next(u for u in node.listunspent() if u["amount"] == Decimal("0.00100000")))
+    destinations = {dest_address: Decimal("0.00050000")}
+    destinations[node.getrawchangeaddress()] = change_size
+    rawtx = node.createrawtransaction([tx_input], destinations)
+    signedtx = node.signrawtransactionwithwallet(rawtx)
+    txid = node.sendrawtransaction(signedtx["hex"])
+    return txid
+
+if __name__ == "__main__":
+    BumpFeeWithTotalFeeArgumentDeprecationTest().main()