wallet: init, don't error out when loading legacy wallets

Instead of failing during initialization when encountering a legacy wallet, skip
loading the wallet and notify the user accordingly.

This allows users to access migration functionalities without needing to manually
remove the wallet from settings.json or resort to using the bitcoin-wallet utility.

This means that GUI users will be able to use the migration button, and bitcoin-cli
users will be able to call the migratewallet RPC directly after init.

src/wallet/db.h

@@ -184,6 +184,7 @@ enum class DatabaseStatus {
     SUCCESS,
     FAILED_BAD_PATH,
     FAILED_BAD_FORMAT,
+    FAILED_LEGACY_DISABLED,
     FAILED_ALREADY_LOADED,
     FAILED_ALREADY_EXISTS,
     FAILED_NOT_FOUND,

src/wallet/load.cpp

@@ -99,6 +99,10 @@ bool VerifyWallets(WalletContext& context)
         if (!MakeWalletDatabase(wallet_file, options, status, error_string)) {
             if (status == DatabaseStatus::FAILED_NOT_FOUND) {
                 chain.initWarning(Untranslated(strprintf("Skipping -wallet path that doesn't exist. %s", error_string.original)));
+            } else if (status == DatabaseStatus::FAILED_LEGACY_DISABLED) {
+                // Skipping legacy wallets as they will not be loaded.
+                // This will be properly communicated to the user during the loading process.
+                continue;
             } else {
                 chain.initError(error_string);
                 return false;
@@ -132,8 +136,13 @@ bool LoadWallets(WalletContext& context)
             bilingual_str error;
             std::vector<bilingual_str> warnings;
             std::unique_ptr<WalletDatabase> database = MakeWalletDatabase(name, options, status, error);
-            if (!database && status == DatabaseStatus::FAILED_NOT_FOUND) {
+            if (!database) {
-                continue;
+                if (status == DatabaseStatus::FAILED_NOT_FOUND) continue;
+                if (status == DatabaseStatus::FAILED_LEGACY_DISABLED) {
+                    // Inform user that legacy wallet is not loaded and suggest upgrade options
+                    chain.initWarning(error);
+                    continue;
+                }
             }
             chain.initMessage(_("Loading wallet…"));
             std::shared_ptr<CWallet> pwallet = database ? CWallet::Create(context, name, std::move(database), options.create_flags, error, warnings) : nullptr;

src/wallet/rpc/util.cpp

@@ -123,6 +123,7 @@ void HandleWalletError(const std::shared_ptr<CWallet> wallet, DatabaseStatus& st
         switch (status) {
             case DatabaseStatus::FAILED_NOT_FOUND:
             case DatabaseStatus::FAILED_BAD_FORMAT:
+            case DatabaseStatus::FAILED_LEGACY_DISABLED:
                 code = RPC_WALLET_NOT_FOUND;
                 break;
             case DatabaseStatus::FAILED_ALREADY_LOADED:

src/wallet/walletdb.cpp

@@ -1383,8 +1383,8 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
 
     // BERKELEY_RO can only be opened if require_format was set, which only occurs in migration.
     if (format && format == DatabaseFormat::BERKELEY_RO && (!options.require_format || options.require_format != DatabaseFormat::BERKELEY_RO)) {
-        error = Untranslated(strprintf("Failed to open database path '%s'. The wallet appears to be a Legacy wallet, please use the wallet migration tool (migratewallet RPC).", fs::PathToString(path)));
+        error = Untranslated(strprintf("Failed to open database path '%s'. The wallet appears to be a Legacy wallet, please use the wallet migration tool (migratewallet RPC or the GUI option).", fs::PathToString(path)));
-        status = DatabaseStatus::FAILED_BAD_FORMAT;
+        status = DatabaseStatus::FAILED_LEGACY_DISABLED;
         return nullptr;
     }
 

test/functional/wallet_backwards_compatibility.py

@@ -378,7 +378,7 @@ class BackwardsCompatibilityTest(BitcoinTestFramework):
 
             # Restore the wallet to master
             # Legacy wallets are no longer supported. Trying to load these should result in an error
-            assert_raises_rpc_error(-18, "The wallet appears to be a Legacy wallet, please use the wallet migration tool (migratewallet RPC)", node_master.restorewallet, wallet_name, backup_path)
+            assert_raises_rpc_error(-18, "The wallet appears to be a Legacy wallet, please use the wallet migration tool (migratewallet RPC or the GUI option)", node_master.restorewallet, wallet_name, backup_path)
 
         self.test_v22_inactivehdchain_path()