Remove usehd option and warn when it is used

Removed the -usehd option so wallets cannot be made to be non-hd
anymore. A warning will be displayed when the option is set.

src/wallet/init.cpp

@@ -29,7 +29,6 @@ std::string GetWalletHelpString(bool showDebug)
     strUsage += HelpMessageOpt("-salvagewallet", _("Attempt to recover private keys from a corrupt wallet on startup"));
     strUsage += HelpMessageOpt("-spendzeroconfchange", strprintf(_("Spend unconfirmed change when sending transactions (default: %u)"), DEFAULT_SPEND_ZEROCONF_CHANGE));
     strUsage += HelpMessageOpt("-txconfirmtarget=<n>", strprintf(_("If paytxfee is not set, include enough fee so transactions begin confirmation on average within n blocks (default: %u)"), DEFAULT_TX_CONFIRM_TARGET));
-    strUsage += HelpMessageOpt("-usehd", _("Use hierarchical deterministic key generation (HD) after BIP32. Only has effect during wallet creation/first start") + " " + strprintf(_("(default: %u)"), DEFAULT_USE_HD_WALLET));
     strUsage += HelpMessageOpt("-walletrbf", strprintf(_("Send transactions with full-RBF opt-in enabled (default: %u)"), DEFAULT_WALLET_RBF));
     strUsage += HelpMessageOpt("-upgradewallet", _("Upgrade wallet to latest format on startup"));
     strUsage += HelpMessageOpt("-wallet=<file>", _("Specify wallet file (within data directory)") + " " + strprintf(_("(default: %s)"), DEFAULT_WALLET_DAT));

src/wallet/wallet.cpp

@@ -3829,17 +3829,13 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
 
     if (fFirstRun)
     {
-        // Create new keyUser and set as default key
-        if (gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET) && !walletInstance->IsHDEnabled()) {
+        // ensure this wallet.dat can only be opened by clients supporting HD with chain split and expects no default key
+        walletInstance->SetMinVersion(FEATURE_NO_DEFAULT_KEY);
 
-            // ensure this wallet.dat can only be opened by clients supporting HD with chain split and expects no default key
-            walletInstance->SetMinVersion(FEATURE_NO_DEFAULT_KEY);
-
-            // generate a new master key
-            CPubKey masterPubKey = walletInstance->GenerateNewHDMasterKey();
-            if (!walletInstance->SetHDMasterKey(masterPubKey))
-                throw std::runtime_error(std::string(__func__) + ": Storing master key failed");
-        }
+        // generate a new master key
+        CPubKey masterPubKey = walletInstance->GenerateNewHDMasterKey();
+        if (!walletInstance->SetHDMasterKey(masterPubKey))
+            throw std::runtime_error(std::string(__func__) + ": Storing master key failed");
 
         // Top up the keypool
         if (!walletInstance->TopUpKeyPool()) {
@@ -3852,7 +3848,7 @@ CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
     else if (gArgs.IsArgSet("-usehd")) {
         bool useHD = gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET);
         if (walletInstance->IsHDEnabled() && !useHD) {
-            InitError(strprintf(_("Error loading %s: You can't disable HD on an already existing HD wallet"), walletFile));
+            InitError(strprintf(_("Error loading %s: You can't disable HD on an already existing HD wallet or create new non-HD wallets."), walletFile));
             return nullptr;
         }
         if (!walletInstance->IsHDEnabled() && useHD) {

test/functional/keypool-topup.py

@@ -23,7 +23,7 @@ class KeypoolRestoreTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 2
-        self.extra_args = [['-usehd=0'], ['-usehd=1', '-keypool=100', '-keypoolmin=20']]
+        self.extra_args = [[], ['-keypool=100', '-keypoolmin=20']]
 
     def run_test(self):
         self.tmpdir = self.options.tmpdir

test/functional/wallet-hd.py

@@ -15,17 +15,11 @@ class WalletHDTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 2
-        self.extra_args = [['-usehd=0'], ['-usehd=1', '-keypool=0']]
+        self.extra_args = [[], ['-keypool=0']]
 
     def run_test (self):
         tmpdir = self.options.tmpdir
 
-        # Make sure can't switch off usehd after wallet creation
-        self.stop_node(1)
-        self.assert_start_raises_init_error(1, ['-usehd=0'], 'already existing HD wallet')
-        self.start_node(1)
-        connect_nodes_bi(self.nodes, 0, 1)
-
         # Make sure we use hd, keep masterkeyid
         masterkeyid = self.nodes[1].getwalletinfo()['hdmasterkeyid']
         assert_equal(len(masterkeyid), 40)

test/functional/wallet.py

@@ -10,10 +10,9 @@ class WalletTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 4
         self.setup_clean_chain = True
-        self.extra_args = [['-usehd={:d}'.format(i%2==0)] for i in range(4)]
 
     def setup_network(self):
-        self.add_nodes(4, self.extra_args)
+        self.add_nodes(4)
         self.start_node(0)
         self.start_node(1)
         self.start_node(2)