Auto merge of #4402 - oxarbitrage:issue4326, r=str4d

Add -lightwalletd experimental option

Similar to `-insightexplorer` but loading less indexes.

After testing and code review this should be able to close https://github.com/zcash/zcash/issues/4326

qa/rpc-tests/addressindex.py

@@ -3,14 +3,14 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or https://www.opensource.org/licenses/mit-license.php .
 #
-# Test addressindex generation and fetching for insightexplorer
+# Test addressindex generation and fetching for insightexplorer or lightwalletd
 # 
 # RPCs tested here:
 #
 #   getaddresstxids
 #   getaddressbalance
 #   getaddressdeltas
-#   getaddressutxos
+#   getaddressutxos - available only for insightexplorer
 #   getaddressmempool
 
 
@@ -22,7 +22,7 @@ from test_framework.util import (
     start_nodes,
     stop_nodes,
     connect_nodes,
-    wait_bitcoinds,
+    wait_bitcoinds
 )
 
 from test_framework.script import (
@@ -46,14 +46,18 @@ class AddressIndexTest(BitcoinTestFramework):
 
     def setup_chain(self):
         print("Initializing test directory "+self.options.tmpdir)
-        initialize_chain_clean(self.options.tmpdir, 3)
+        initialize_chain_clean(self.options.tmpdir, 4)
 
     def setup_network(self):
         # -insightexplorer causes addressindex to be enabled (fAddressIndex = true)
-        args = ('-debug', '-txindex', '-experimentalfeatures', '-insightexplorer')
+        args_insight = ('-debug', '-txindex', '-experimentalfeatures', '-insightexplorer')
-        self.nodes = start_nodes(3, self.options.tmpdir, [args] * 3)
+        # -lightwallet also causes addressindex to be enabled
+        args_lightwallet = ('-debug', '-txindex', '-experimentalfeatures', '-lightwalletd')
+        self.nodes = start_nodes(4, self.options.tmpdir, [args_insight] * 3 + [args_lightwallet])
+
         connect_nodes(self.nodes[0], 1)
         connect_nodes(self.nodes[0], 2)
+        connect_nodes(self.nodes[0], 3) # node3 is only for testing lightwalletd
 
         self.is_network_split = False
         self.sync_all()
@@ -120,6 +124,9 @@ class AddressIndexTest(BitcoinTestFramework):
 
         assert_equal(len(self.nodes[1].getaddresstxids(addr_p2pkh)), 105)
         assert_equal(len(self.nodes[1].getaddresstxids(addr_p2sh)), 105)
+        # test getaddresstxids for lightwalletd
+        assert_equal(len(self.nodes[3].getaddresstxids(addr_p2pkh)), 105)
+        assert_equal(len(self.nodes[3].getaddresstxids(addr_p2sh)), 105)
 
         # only the oldest 5 transactions are in the unspent list,
         # dup addresses are ignored
@@ -181,6 +188,9 @@ class AddressIndexTest(BitcoinTestFramework):
         # check that duplicate addresses are processed correctly
         mempool = self.nodes[0].getaddressmempool({'addresses': [addr2, addr1, addr2]})
         assert_equal(len(mempool), 3)
+        # test getaddressmempool for lightwalletd node
+        mempool = self.nodes[3].getaddressmempool({'addresses': [addr2, addr1, addr2]})
+        assert_equal(len(mempool), 3)
 
         # addr2 (first arg)
         assert_equal(mempool[0]['address'], addr2)
@@ -253,8 +263,12 @@ class AddressIndexTest(BitcoinTestFramework):
         tx = self.nodes[0].getrawtransaction(txid, 1)
         change_vout = list(filter(lambda v: v['valueZat'] != 3 * COIN, tx['vout']))
         change = change_vout[0]['scriptPubKey']['addresses'][0]
-        bal = self.nodes[2].getaddressbalance(change)
+
+        # test getaddressbalance
+        for node in (2, 3):
+            bal = self.nodes[node].getaddressbalance(change)
             assert(bal['received'] > 0)
+
         # the inequality is due to randomness in the tx fee
         assert(bal['received'] < (4 - 3) * COIN)
         assert_equal(bal['received'], bal['balance'])
@@ -283,7 +297,9 @@ class AddressIndexTest(BitcoinTestFramework):
         # set(txids_all) removes its (expected) duplicates
         assert_equal(set(multitxids), set(txids_all))
 
-        deltas = self.nodes[1].getaddressdeltas({'addresses': [addr1]})
+        # test getaddressdeltas
+        for node in (1, 3):
+            deltas = self.nodes[node].getaddressdeltas({'addresses': [addr1]})
             assert_equal(len(deltas), len(expected_deltas))
             for i in range(len(deltas)):
                 assert_equal(deltas[i]['address'],  addr1)

src/experimental_features.cpp

@@ -10,6 +10,7 @@ bool fExperimentalDeveloperEncryptWallet = false;
 bool fExperimentalDeveloperSetPoolSizeZero = false;
 bool fExperimentalPaymentDisclosure = false;
 bool fExperimentalInsightExplorer = false;
+bool fExperimentalLightWalletd = false;
 
 boost::optional<std::string> InitExperimentalMode()
 {
@@ -18,6 +19,7 @@ boost::optional<std::string> InitExperimentalMode()
     fExperimentalDeveloperSetPoolSizeZero = GetBoolArg("-developersetpoolsizezero", false);
     fExperimentalPaymentDisclosure = GetBoolArg("-paymentdisclosure", false);
     fExperimentalInsightExplorer = GetBoolArg("-insightexplorer", false);
+    fExperimentalLightWalletd  = GetBoolArg("-lightwalletd", false);
 
     // Fail if user has set experimental options without the global flag
     if (!fExperimentalMode) {
@@ -29,6 +31,8 @@ boost::optional<std::string> InitExperimentalMode()
             return _("Payment disclosure requires -experimentalfeatures.");
         } else if (fExperimentalInsightExplorer) {
             return _("Insight explorer requires -experimentalfeatures.");
+        } else if (fExperimentalLightWalletd) {
+            return _("Light Walletd requires -experimentalfeatures.");
         }
     }
     return boost::none;
@@ -45,6 +49,8 @@ std::vector<std::string> GetExperimentalFeatures()
         experimentalfeatures.push_back("paymentdisclosure");
     if (fExperimentalInsightExplorer)
         experimentalfeatures.push_back("insightexplorer");
+    if (fExperimentalLightWalletd)
+        experimentalfeatures.push_back("lightwalletd");
 
     return experimentalfeatures;
 }

src/experimental_features.h

@@ -10,6 +10,7 @@ extern bool fExperimentalDeveloperEncryptWallet;
 extern bool fExperimentalDeveloperSetPoolSizeZero;
 extern bool fExperimentalPaymentDisclosure;
 extern bool fExperimentalInsightExplorer;
+extern bool fExperimentalLightWalletd;
 
 boost::optional<std::string> InitExperimentalMode();
 std::vector<std::string> GetExperimentalFeatures();

src/gtest/test_rpc.cpp

@@ -26,3 +26,44 @@ TEST(rpc, CheckBlockToJSONReturnsMinifiedSolution) {
     UniValue obj = blockToJSON(block, &index);
     EXPECT_EQ("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", find_value(obj, "solution").get_str());
 }
+
+TEST(rpc, CheckExperimentalDisabledHelpMsg) {
+
+    EXPECT_EQ(experimentalDisabledHelpMsg("somerpc", {"somevalue"}),
+        "\nWARNING: somerpc is disabled.\n"
+        "To enable it, restart zcashd with the following command line options:\n"
+        "-experimentalfeatures and -somevalue\n\n"
+        "Alternatively add these two lines to the zcash.conf file:\n\n"
+        "experimentalfeatures=1\n"
+        "somevalue=1\n");
+
+    EXPECT_EQ(experimentalDisabledHelpMsg("somerpc", {"somevalue", "someothervalue"}),
+        "\nWARNING: somerpc is disabled.\n"
+        "To enable it, restart zcashd with the following command line options:\n"
+        "-experimentalfeatures and -somevalue"
+        " or:\n-experimentalfeatures and -someothervalue"
+        "\n\n"
+        "Alternatively add these two lines to the zcash.conf file:\n\n"
+        "experimentalfeatures=1\n"
+        "somevalue=1\n"
+        "\nor:\n\n"
+        "experimentalfeatures=1\n"
+        "someothervalue=1\n");
+
+    EXPECT_EQ(experimentalDisabledHelpMsg("somerpc", {"somevalue", "someothervalue", "athirdvalue"}),
+        "\nWARNING: somerpc is disabled.\n"
+        "To enable it, restart zcashd with the following command line options:\n"
+        "-experimentalfeatures and -somevalue"
+        " or:\n-experimentalfeatures and -someothervalue"
+        " or:\n-experimentalfeatures and -athirdvalue"
+         "\n\n"
+        "Alternatively add these two lines to the zcash.conf file:\n\n"
+        "experimentalfeatures=1\n"
+        "somevalue=1\n"
+        "\nor:\n\n"
+        "experimentalfeatures=1\n"
+        "someothervalue=1\n"
+        "\nor:\n\n"
+        "experimentalfeatures=1\n"
+        "athirdvalue=1\n");
+}

src/init.cpp

@@ -1421,6 +1421,14 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
                     break;
                 }
 
+                // Check for changed -lightwalletd state
+                bool fLightWalletdPreviouslySet = false;
+                pblocktree->ReadFlag("lightwalletd", fLightWalletdPreviouslySet);
+                if (fExperimentalLightWalletd != fLightWalletdPreviouslySet) {
+                    strLoadError = _("You need to rebuild the database using -reindex to change -lightwalletd");
+                    break;
+                }
+
                 // Check for changed -prune state.  What we are concerned about is a user who has pruned blocks
                 // in the past, but is now trying to run unpruned.
                 if (fHavePruned && !fPruneMode) {

src/main.cpp

@@ -70,7 +70,7 @@ int nScriptCheckThreads = 0;
 bool fImporting = false;
 std::atomic_bool fReindex(false);
 bool fTxIndex = false;
-bool fAddressIndex = false;     // insightexplorer
+bool fAddressIndex = false;     // insightexplorer || lightwalletd
 bool fSpentIndex = false;       // insightexplorer
 bool fTimestampIndex = false;   // insightexplorer
 bool fHavePruned = false;
@@ -4498,14 +4498,22 @@ bool static LoadBlockIndexDB()
     pblocktree->ReadFlag("txindex", fTxIndex);
     LogPrintf("%s: transaction index %s\n", __func__, fTxIndex ? "enabled" : "disabled");
 
-    // insightexplorer
+    // insightexplorer and lightwalletd
     // Check whether block explorer features are enabled
     bool fInsightExplorer = false;
+    bool fLightWalletd = false;
     pblocktree->ReadFlag("insightexplorer", fInsightExplorer);
+    pblocktree->ReadFlag("lightwalletd", fLightWalletd);
     LogPrintf("%s: insight explorer %s\n", __func__, fInsightExplorer ? "enabled" : "disabled");
-    fAddressIndex = fInsightExplorer;
+    LogPrintf("%s: light wallet daemon %s\n", __func__, fLightWalletd ? "enabled" : "disabled");
-    fSpentIndex = fInsightExplorer;
+    if (fInsightExplorer) {
-    fTimestampIndex = fInsightExplorer;
+        fAddressIndex = true;
+        fSpentIndex = true;
+        fTimestampIndex = true;
+    }
+    else if (fLightWalletd) {
+        fAddressIndex = true;
+    }
 
     // Fill in-memory data
     BOOST_FOREACH(const PAIRTYPE(uint256, CBlockIndex*)& item, mapBlockIndex)
@@ -4845,11 +4853,17 @@ bool InitBlockIndex(const CChainParams& chainparams)
     fTxIndex = GetBoolArg("-txindex", DEFAULT_TXINDEX);
     pblocktree->WriteFlag("txindex", fTxIndex);
 
-    // Use the provided setting for -insightexplorer in the new database
+    // Use the provided setting for -insightexplorer or -lightwalletd in the new database
     pblocktree->WriteFlag("insightexplorer", fExperimentalInsightExplorer);
-    fAddressIndex = fExperimentalInsightExplorer;
+    pblocktree->WriteFlag("lightwalletd", fExperimentalLightWalletd);
-    fSpentIndex = fExperimentalInsightExplorer;
+    if (fExperimentalInsightExplorer) {
-    fTimestampIndex = fExperimentalInsightExplorer;
+        fAddressIndex = true;
+        fSpentIndex = true;
+        fTimestampIndex = true;
+    }
+    else if (fExperimentalLightWalletd) {
+        fAddressIndex = true;
+    }
 
     LogPrintf("Initializing databases...\n");
 

src/rpc/blockchain.cpp

@@ -408,8 +408,8 @@ UniValue getrawmempool(const UniValue& params, bool fHelp)
 UniValue getblockdeltas(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getblockdeltas", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getblockdeltas", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -462,7 +462,7 @@ UniValue getblockdeltas(const UniValue& params, bool fHelp)
             + HelpExampleRpc("getblockdeltas", "\"00227e566682aebd6a7a5b772c96d7a999cadaebeaf1ce96f4191a3aad58b00b\"")
         );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getblockdeltas is disabled. "
             "Run './zcash-cli help getblockdeltas' for instructions on how to enable this feature.");
     }
@@ -491,8 +491,8 @@ UniValue getblockdeltas(const UniValue& params, bool fHelp)
 UniValue getblockhashes(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getblockhashes", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getblockhashes", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() < 2)
         throw runtime_error(
@@ -525,7 +525,7 @@ UniValue getblockhashes(const UniValue& params, bool fHelp)
             + HelpExampleCli("getblockhashes", "1558141697 1558141576 '{\"noOrphans\":false, \"logicalTimes\":true}'")
             );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getblockhashes is disabled. "
             "Run './zcash-cli help getblockhashes' for instructions on how to enable this feature.");
     }

src/rpc/misc.cpp

@@ -576,8 +576,8 @@ static bool getAddressesFromParams(
 UniValue getaddressmempool(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getaddressmempool", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getaddressmempool", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -611,7 +611,7 @@ UniValue getaddressmempool(const UniValue& params, bool fHelp)
             + HelpExampleRpc("getaddressmempool", "{\"addresses\": [\"tmYXBYJj1K7vhejSec5osXK2QsGa5MTisUQ\"]}")
         );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getaddressmempool is disabled. "
             "Run './zcash-cli help getaddressmempool' for instructions on how to enable this feature.");
     }
@@ -656,7 +656,7 @@ UniValue getaddressutxos(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
     if (!fExperimentalInsightExplorer) {
-        disabledMsg = experimentalDisabledHelpMsg("getaddressutxos", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getaddressutxos", {"insightexplorer"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -812,8 +812,8 @@ static void getAddressesInHeightRange(
 UniValue getaddressdeltas(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getaddressdeltas", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getaddressdeltas", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -873,7 +873,7 @@ UniValue getaddressdeltas(const UniValue& params, bool fHelp)
             + HelpExampleRpc("getaddressdeltas", "{\"addresses\": [\"tmYXBYJj1K7vhejSec5osXK2QsGa5MTisUQ\"], \"start\": 1000, \"end\": 2000, \"chainInfo\": true}")
         );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getaddressdeltas is disabled. "
             "Run './zcash-cli help getaddressdeltas' for instructions on how to enable this feature.");
     }
@@ -941,8 +941,8 @@ UniValue getaddressdeltas(const UniValue& params, bool fHelp)
 UniValue getaddressbalance(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getaddressbalance", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getaddressbalance", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -969,7 +969,7 @@ UniValue getaddressbalance(const UniValue& params, bool fHelp)
             + HelpExampleRpc("getaddressbalance", "{\"addresses\": [\"tmYXBYJj1K7vhejSec5osXK2QsGa5MTisUQ\"]}")
         );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getaddressbalance is disabled. "
             "Run './zcash-cli help getaddressbalance' for instructions on how to enable this feature.");
     }
@@ -998,8 +998,8 @@ UniValue getaddressbalance(const UniValue& params, bool fHelp)
 UniValue getaddresstxids(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
-        disabledMsg = experimentalDisabledHelpMsg("getaddresstxids", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getaddresstxids", {"insightexplorer", "lightwalletd"});
     }
     if (fHelp || params.size() != 1)
         throw runtime_error(
@@ -1029,7 +1029,7 @@ UniValue getaddresstxids(const UniValue& params, bool fHelp)
             + HelpExampleRpc("getaddresstxids", "{\"addresses\": [\"tmYXBYJj1K7vhejSec5osXK2QsGa5MTisUQ\"], \"start\": 1000, \"end\": 2000}")
         );
 
-    if (!fExperimentalInsightExplorer) {
+    if (!(fExperimentalInsightExplorer || fExperimentalLightWalletd)) {
         throw JSONRPCError(RPC_MISC_ERROR, "Error: getaddresstxids is disabled. "
             "Run './zcash-cli help getaddresstxids' for instructions on how to enable this feature.");
     }
@@ -1064,7 +1064,7 @@ UniValue getspentinfo(const UniValue& params, bool fHelp)
 {
     std::string disabledMsg = "";
     if (!fExperimentalInsightExplorer) {
-        disabledMsg = experimentalDisabledHelpMsg("getspentinfo", "insightexplorer");
+        disabledMsg = experimentalDisabledHelpMsg("getspentinfo", {"insightexplorer"});
     }
     if (fHelp || params.size() != 1 || !params[0].isObject())
         throw runtime_error(

src/rpc/server.cpp

@@ -467,14 +467,32 @@ std::string HelpExampleRpc(const std::string& methodname, const std::string& arg
         "\"method\": \"" + methodname + "\", \"params\": [" + args + "] }' -H 'content-type: text/plain;' http://127.0.0.1:8232/\n";
 }
 
-string experimentalDisabledHelpMsg(const string& rpc, const string& enableArg)
+std::string experimentalDisabledHelpMsg(const std::string& rpc, const std::vector<string>& enableArgs)
 {
-    return "\nWARNING: " + rpc + " is disabled.\n"
+    std::string cmd, config = "";
-        "To enable it, restart zcashd with the -experimentalfeatures and\n"
+    const auto size = enableArgs.size();
-        "-" + enableArg + " commandline options, or add these two lines\n"
+    assert(size > 0);
-        "to the zcash.conf file:\n\n"
+
-        "experimentalfeatures=1\n"
+    for (size_t i = 0; i < size; ++i)
-        + enableArg + "=1\n";
+    {
+        if (size == 1 || i == 0)
+        {
+            cmd += "-experimentalfeatures and -" + enableArgs.at(i);
+            config += "experimentalfeatures=1\n";
+            config += enableArgs.at(i) + "=1\n";
+        }
+        else {
+            cmd += " or:\n-experimentalfeatures and -" + enableArgs.at(i);
+            config += "\nor:\n\n";
+            config += "experimentalfeatures=1\n";
+            config += enableArgs.at(i) + "=1\n";
+        }
+    }
+    return "\nWARNING: " + rpc + " is disabled.\n" +
+        "To enable it, restart zcashd with the following command line options:\n"
+        + cmd + "\n\n" +
+        "Alternatively add these two lines to the zcash.conf file:\n\n"
+        + config;
 }
 
 void RPCRegisterTimerInterface(RPCTimerInterface *iface)

src/rpc/server.h

@@ -183,6 +183,6 @@ void InterruptRPC();
 void StopRPC();
 std::string JSONRPCExecBatch(const UniValue& vReq);
 
-extern std::string experimentalDisabledHelpMsg(const std::string& rpc, const std::string& enableArg);
+extern std::string experimentalDisabledHelpMsg(const std::string& rpc, const std::vector<std::string>& enableArgs);
 
 #endif // BITCOIN_RPCSERVER_H

src/wallet/rpcdisclosure.cpp

@@ -43,7 +43,7 @@ UniValue z_getpaymentdisclosure(const UniValue& params, bool fHelp)
 
     string disabledMsg = "";
     if (!fExperimentalPaymentDisclosure) {
-        disabledMsg = experimentalDisabledHelpMsg("z_getpaymentdisclosure", "paymentdisclosure");
+        disabledMsg = experimentalDisabledHelpMsg("z_getpaymentdisclosure", {"paymentdisclosure"});
     }
 
     if (fHelp || params.size() < 3 || params.size() > 4 )
@@ -148,7 +148,7 @@ UniValue z_validatepaymentdisclosure(const UniValue& params, bool fHelp)
 
     string disabledMsg = "";
     if (!fExperimentalPaymentDisclosure) {
-        disabledMsg = experimentalDisabledHelpMsg("z_validatepaymentdisclosure", "paymentdisclosure");
+        disabledMsg = experimentalDisabledHelpMsg("z_validatepaymentdisclosure", {"paymentdisclosure"});
     }
 
     if (fHelp || params.size() != 1)

src/wallet/rpcwallet.cpp

@@ -2041,7 +2041,7 @@ UniValue encryptwallet(const UniValue& params, bool fHelp)
 
     std::string disabledMsg = "";
     if (!fExperimentalDeveloperEncryptWallet) {
-        disabledMsg = experimentalDisabledHelpMsg("encryptwallet", "developerencryptwallet");
+        disabledMsg = experimentalDisabledHelpMsg("encryptwallet", {"developerencryptwallet"});
     }
 
     if (!pwalletMain->IsCrypted() && (fHelp || params.size() != 1))