RPC/Wallet: unloadwallet: Clarify docs/error when both the RPC endpoint and wallet_name parameter specify a wallet

Author: luke-jr

src/wallet/rpcwallet.cpp

@@ -2792,7 +2792,7 @@ static RPCHelpMan unloadwallet()
                 "Unloads the wallet referenced by the request endpoint otherwise unloads the wallet specified in the argument.\n"
                 "Specifying the wallet name on a wallet endpoint is invalid.",
                 {
-                    {"wallet_name", RPCArg::Type::STR, /* default */ "the wallet name from the RPC request", "The name of the wallet to unload."},
+                    {"wallet_name", RPCArg::Type::STR, /* default */ "the wallet name from the RPC endpoint", "The name of the wallet to unload. Must be provided in the RPC endpoint or this parameter (but not both)."},
                     {"load_on_startup", RPCArg::Type::BOOL, /* default */ "null", "Save wallet name to persistent settings and load on startup. True to add wallet to startup list, false to remove, null to leave unchanged."},
                 },
                 RPCResult{RPCResult::Type::OBJ, "", "", {
@@ -2807,7 +2807,7 @@ static RPCHelpMan unloadwallet()
     std::string wallet_name;
     if (GetWalletNameFromJSONRPCRequest(request, wallet_name)) {
         if (!request.params[0].isNull()) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot unload the requested wallet");
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Both the RPC endpoint wallet and wallet_name parameter were provided (only one allowed)");
         }
     } else {
         wallet_name = request.params[0].get_str();

test/functional/wallet_multiwallet.py

@@ -355,7 +355,8 @@ def wallet_file(name):
         assert_raises_rpc_error(-1, "JSON value is not a string as expected", self.nodes[0].unloadwallet)
         assert_raises_rpc_error(-18, "Requested wallet does not exist or is not loaded", self.nodes[0].unloadwallet, "dummy")
         assert_raises_rpc_error(-18, "Requested wallet does not exist or is not loaded", node.get_wallet_rpc("dummy").unloadwallet)
-        assert_raises_rpc_error(-8, "Cannot unload the requested wallet", w1.unloadwallet, "w2"),
+        assert_raises_rpc_error(-8, "Both the RPC endpoint wallet and wallet_name parameter were provided (only one allowed)", w1.unloadwallet, "w2"),
+        assert_raises_rpc_error(-8, "Both the RPC endpoint wallet and wallet_name parameter were provided (only one allowed)", w1.unloadwallet, "w1"),
 
         # Successfully unload the specified wallet name
         self.nodes[0].unloadwallet("w1")