Do not create default wallet

No longer create a default wallet. The default wallet will still be
loaded if it exists and not other wallets were specified (anywhere,
including settings.json, bitcoin.conf, and command line).

Tests are updated to be started with -wallet= if they need the default
wallet.

Added test to wallet_startup.py testing that no default wallet is
created and that it is loaded if it exists and no other wallets were
specified.

src/wallet/init.cpp

@@ -107,16 +107,7 @@ void WalletInit::Construct(NodeContext& node) const
         LogPrintf("Wallet disabled!\n");
         return;
     }
-    // If there's no -wallet setting with a list of wallets to load, set it to
-    // load the default "" wallet.
-    if (!args.IsArgSet("wallet")) {
-        args.LockSettings([&](util::Settings& settings) {
-            util::SettingsValue wallets(util::SettingsValue::VARR);
-            wallets.push_back(""); // Default wallet name is ""
-            settings.rw_settings["wallet"] = wallets;
-        });
-    }
-    auto wallet_client = interfaces::MakeWalletClient(*node.chain, args, args.GetArgs("-wallet"));
+    auto wallet_client = interfaces::MakeWalletClient(*node.chain, args);
     node.wallet_client = wallet_client.get();
     node.chain_clients.emplace_back(std::move(wallet_client));
 }

src/wallet/load.cpp

@@ -16,7 +16,7 @@
 
 #include <univalue.h>
 
-bool VerifyWallets(interfaces::Chain& chain, const std::vector<std::string>& wallet_files)
+bool VerifyWallets(interfaces::Chain& chain)
 {
     if (gArgs.IsArgSet("-walletdir")) {
         fs::path wallet_dir = gArgs.GetArg("-walletdir", "");
@@ -41,10 +41,27 @@ bool VerifyWallets(interfaces::Chain& chain, const std::vector<std::string>& wal
 
     chain.initMessage(_("Verifying wallet(s)...").translated);
 
+    // For backwards compatibility if an unnamed top level wallet exists in the
+    // wallets directory, include it in the default list of wallets to load.
+    if (!gArgs.IsArgSet("wallet")) {
+        DatabaseOptions options;
+        DatabaseStatus status;
+        bilingual_str error_string;
+        options.require_existing = true;
+        options.verify = false;
+        if (MakeWalletDatabase("", options, status, error_string)) {
+            gArgs.LockSettings([&](util::Settings& settings) {
+                util::SettingsValue wallets(util::SettingsValue::VARR);
+                wallets.push_back(""); // Default wallet name is ""
+                settings.rw_settings["wallet"] = wallets;
+            });
+        }
+    }
+
     // Keep track of each wallet absolute path to detect duplicates.
     std::set<fs::path> wallet_paths;
 
-    for (const auto& wallet_file : wallet_files) {
+    for (const auto& wallet_file : gArgs.GetArgs("-wallet")) {
         const fs::path path = fs::absolute(wallet_file, GetWalletDir());
 
         if (!wallet_paths.insert(path).second) {
@@ -65,10 +82,10 @@ bool VerifyWallets(interfaces::Chain& chain, const std::vector<std::string>& wal
     return true;
 }
 
-bool LoadWallets(interfaces::Chain& chain, const std::vector<std::string>& wallet_files)
+bool LoadWallets(interfaces::Chain& chain)
 {
     try {
-        for (const std::string& name : wallet_files) {
+        for (const std::string& name : gArgs.GetArgs("-wallet")) {
             DatabaseOptions options;
             DatabaseStatus status;
             options.verify = false; // No need to verify, assuming verified earlier in VerifyWallets()

src/wallet/load.h

@@ -17,10 +17,10 @@ class Chain;
 } // namespace interfaces
 
 //! Responsible for reading and validating the -wallet arguments and verifying the wallet database.
-bool VerifyWallets(interfaces::Chain& chain, const std::vector<std::string>& wallet_files);
+bool VerifyWallets(interfaces::Chain& chain);
 
 //! Load wallet databases.
-bool LoadWallets(interfaces::Chain& chain, const std::vector<std::string>& wallet_files);
+bool LoadWallets(interfaces::Chain& chain);
 
 //! Complete startup of wallets.
 void StartWallets(CScheduler& scheduler, const ArgsManager& args);

src/wallet/test/init_test_fixture.cpp

@@ -10,7 +10,7 @@
 
 InitWalletDirTestingSetup::InitWalletDirTestingSetup(const std::string& chainName) : BasicTestingSetup(chainName)
 {
-    m_wallet_client = MakeWalletClient(*m_chain, *Assert(m_node.args), {});
+    m_wallet_client = MakeWalletClient(*m_chain, *Assert(m_node.args));
 
     std::string sep;
     sep += fs::path::preferred_separator;

src/wallet/test/wallet_test_fixture.h

@@ -21,7 +21,7 @@ struct WalletTestingSetup : public TestingSetup {
     explicit WalletTestingSetup(const std::string& chainName = CBaseChainParams::MAIN);
 
     std::unique_ptr<interfaces::Chain> m_chain = interfaces::MakeChain(m_node);
-    std::unique_ptr<interfaces::WalletClient> m_wallet_client = interfaces::MakeWalletClient(*m_chain, *Assert(m_node.args), {});
+    std::unique_ptr<interfaces::WalletClient> m_wallet_client = interfaces::MakeWalletClient(*m_chain, *Assert(m_node.args));
     CWallet m_wallet;
     std::unique_ptr<interfaces::Handler> m_chain_notifications_handler;
 };