Merge bitcoin/bitcoin#24505: wallet: Add a deprecation warning for newly created legacy wallets

6115218 wallet: Add a deprecation warning for newly created legacy wallets (Andrew Chow)

Pull request description:

  As we slowly deprecate legacy wallets, we need to warn users that are making new legacy wallets that their wallet type is going to be unsupported in the future.

ACKs for top commit:
  jonatack:
    ACK 6115218
  S3RK:
    reACK 6115218
  theStack:
    ACK 6115218

Tree-SHA512: e89bfb8168869542498958f0c9a2ab302dfd43287f8a49e7d9e09f60438a567bb8b7219a4e569797ee819b30b624f532fcc0b70c6aa0edcb392a301b8ce8b541

Author: MarcoFalke

src/wallet/rpc/wallet.cpp

@@ -315,7 +315,9 @@ static RPCHelpMan createwallet()
             {"blank", RPCArg::Type::BOOL, RPCArg::Default{false}, "Create a blank wallet. A blank wallet has no keys or HD seed. One can be set using sethdseed."},
             {"passphrase", RPCArg::Type::STR, RPCArg::Optional::OMITTED_NAMED_ARG, "Encrypt the wallet with this passphrase."},
             {"avoid_reuse", RPCArg::Type::BOOL, RPCArg::Default{false}, "Keep track of coin reuse, and treat dirty and clean coins differently with privacy considerations in mind."},
-            {"descriptors", RPCArg::Type::BOOL, RPCArg::Default{true}, "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation"},
+            {"descriptors", RPCArg::Type::BOOL, RPCArg::Default{true}, "Create a native descriptor wallet. The wallet will use descriptors internally to handle address creation."
+                                                                       " Setting to \"false\" will create a legacy wallet; however, the legacy wallet type is being deprecated and"
+                                                                       " support for creating and opening legacy wallets will be removed in the future."},
             {"load_on_startup", RPCArg::Type::BOOL, RPCArg::Optional::OMITTED_NAMED_ARG, "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
             {"external_signer", RPCArg::Type::BOOL, RPCArg::Default{false}, "Use an external signer such as a hardware wallet. Requires -signer to be configured. Wallet creation will fail if keys cannot be fetched. Requires disable_private_keys and descriptors set to true."},
         },

src/wallet/wallet.cpp

@@ -354,6 +354,11 @@ std::shared_ptr<CWallet> CreateWallet(WalletContext& context, const std::string&
     // Write the wallet settings
     UpdateWalletSetting(*context.chain, name, load_on_start, warnings);
 
+    // Legacy wallets are being deprecated, warn if a newly created wallet is legacy
+    if (!(wallet_creation_flags & WALLET_FLAG_DESCRIPTORS)) {
+        warnings.push_back(_("Wallet created successfully. The legacy wallet type is being deprecated and support for creating and opening legacy wallets will be removed in the future."));
+    }
+
     status = DatabaseStatus::SUCCESS;
     return wallet;
 }

test/functional/wallet_createwallet.py

@@ -164,5 +164,10 @@ def run_test(self):
         self.log.info('Using a passphrase with private keys disabled returns error')
         assert_raises_rpc_error(-4, 'Passphrase provided but private keys are disabled. A passphrase is only used to encrypt private keys, so cannot be used for wallets with private keys disabled.', self.nodes[0].createwallet, wallet_name='w9', disable_private_keys=True, passphrase='thisisapassphrase')
 
+        if self.is_bdb_compiled():
+            self.log.info("Test legacy wallet deprecation")
+            res = self.nodes[0].createwallet(wallet_name="legacy_w0", descriptors=False, passphrase=None)
+            assert_equal(res["warning"], "Wallet created successfully. The legacy wallet type is being deprecated and support for creating and opening legacy wallets will be removed in the future.")
+
 if __name__ == '__main__':
     CreateWalletTest().main()