wallet: Explicitly say migratewallet on encrypted wallets is unsupported

src/wallet/rpc/wallet.cpp

@@ -730,7 +730,9 @@ static RPCHelpMan migratewallet()
             std::shared_ptr<CWallet> wallet = GetWalletForJSONRPCRequest(request);
             if (!wallet) return NullUniValue;
 
-            EnsureWalletIsUnlocked(*wallet);
+            if (wallet->IsCrypted()) {
+                throw JSONRPCError(RPC_WALLET_WRONG_ENC_STATE, "Error: migratewallet on encrypted wallets is currently unsupported.");
+            }
 
             WalletContext& context = EnsureWalletContext(request.context);
 

test/functional/wallet_migration.py

@@ -399,8 +399,7 @@ class WalletMigrationTest(BitcoinTestFramework):
 
         wallet.encryptwallet("pass")
 
-        wallet.walletpassphrase("pass", 10)
-        assert_raises_rpc_error(-4, "Error: Unable to produce descriptors for this legacy wallet. Make sure the wallet is unlocked first", wallet.migratewallet)
+        assert_raises_rpc_error(-15, "Error: migratewallet on encrypted wallets is currently unsupported.", wallet.migratewallet)
         # TODO: Fix migratewallet so that we can actually migrate encrypted wallets
 
     def run_test(self):