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.

7 files changed, 32 insertions, 25 deletions

diff --git a/src/interfaces/wallet.cpp b/src/interfaces/wallet.cpp
index d19d0406b6..94c63da84e 100644
--- a/src/interfaces/wallet.cpp
+++ b/src/interfaces/wallet.cpp
@@ -488,8 +488,7 @@ public:
 class WalletClientImpl : public WalletClient
 {
 public:
-    WalletClientImpl(Chain& chain, ArgsManager& args, std::vector<std::string> wallet_filenames)
-        : m_wallet_filenames(std::move(wallet_filenames))
+    WalletClientImpl(Chain& chain, ArgsManager& args)
     {
         m_context.chain = &chain;
         m_context.args = &args;
@@ -506,8 +505,8 @@ public:
             m_rpc_handlers.emplace_back(m_context.chain->handleRpc(m_rpc_commands.back()));
         }
     }
-    bool verify() override { return VerifyWallets(*m_context.chain, m_wallet_filenames); }
-    bool load() override { return LoadWallets(*m_context.chain, m_wallet_filenames); }
+    bool verify() override { return VerifyWallets(*m_context.chain); }
+    bool load() override { return LoadWallets(*m_context.chain); }
     void start(CScheduler& scheduler) override { return StartWallets(scheduler, *Assert(m_context.args)); }
     void flush() override { return FlushWallets(); }
     void stop() override { return StopWallets(); }
@@ -566,9 +565,9 @@ public:
 
 std::unique_ptr<Wallet> MakeWallet(const std::shared_ptr<CWallet>& wallet) { return wallet ? MakeUnique<WalletImpl>(wallet) : nullptr; }
 
-std::unique_ptr<WalletClient> MakeWalletClient(Chain& chain, ArgsManager& args, std::vector<std::string> wallet_filenames)
+std::unique_ptr<WalletClient> MakeWalletClient(Chain& chain, ArgsManager& args)
 {
-    return MakeUnique<WalletClientImpl>(chain, args, std::move(wallet_filenames));
+    return MakeUnique<WalletClientImpl>(chain, args);
 }
 
 } // namespace interfaces
diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index b1afbbfd7c..6ccfd7fc20 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -411,7 +411,7 @@ std::unique_ptr<Wallet> MakeWallet(const std::shared_ptr<CWallet>& wallet);
 
 //! Return implementation of ChainClient interface for a wallet client. This
 //! function will be undefined in builds where ENABLE_WALLET is false.
-std::unique_ptr<WalletClient> MakeWalletClient(Chain& chain, ArgsManager& args, std::vector<std::string> wallet_filenames);
+std::unique_ptr<WalletClient> MakeWalletClient(Chain& chain, ArgsManager& args);
 
 } // namespace interfaces
 
diff --git a/src/wallet/init.cpp b/src/wallet/init.cpp
index 3910599ca7..5d8c4fba29 100644
--- a/src/wallet/init.cpp
+++ b/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));
 }
diff --git a/src/wallet/load.cpp b/src/wallet/load.cpp
index c5d045e9ef..1b057000d2 100644
--- a/src/wallet/load.cpp
+++ b/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()
diff --git a/src/wallet/load.h b/src/wallet/load.h
index ff4f5b4b23..e12343de27 100644
--- a/src/wallet/load.h
+++ b/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);
diff --git a/src/wallet/test/init_test_fixture.cpp b/src/wallet/test/init_test_fixture.cpp
index c23dea1338..c80310045a 100644
--- a/src/wallet/test/init_test_fixture.cpp
+++ b/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;
diff --git a/src/wallet/test/wallet_test_fixture.h b/src/wallet/test/wallet_test_fixture.h
index 12ad13b49b..ba8a5ff1f3 100644
--- a/src/wallet/test/wallet_test_fixture.h
+++ b/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;
 };