Merge bitcoin#20101: rpc: change no wallet loaded message to be clearer

907f142 rpc: change no wallet loaded message to be clearer (Andrew Chow)

Pull request description:

  Changes the no wallet is loaded rpc error message to be clearer that no wallet is loaded and how the user can load or create a wallet. Also changes the error code from METHOD_NOT_FOUND to RPC_WALLET_NOT_FOUND as that makes more sense.

ACKs for top commit:
  MarcoFalke:
    review ACK 907f142
  kristapsk:
    ACK 907f142. In addition to standard tests, just in case tested that this doesn't break anything with JoinMarket.
  meshcollider:
    utACK 907f142

Tree-SHA512: 4b413e6ab5430ec75a79de9db6583f2f3f38ccdf71aa373d8386a56e64f07f92200c8107c8c82c92c7c431d739615977c208b771a24c5960fa8676789b5497a2

src/wallet/rpcwallet.cpp

@@ -81,7 +81,7 @@ bool EnsureWalletIsAvailable(CWallet * const pwallet, bool avoidException)
     if (avoidException) return false;
     if (!HasWallets()) {
         throw JSONRPCError(
-            RPC_METHOD_NOT_FOUND, "Method not found (wallet method is disabled because no wallet is loaded)");
+            RPC_WALLET_NOT_FOUND, "No wallet is loaded. Load a wallet using loadwallet or create a new one with createwallet. (Note: A default wallet is no longer automatically created)");
     }
     throw JSONRPCError(RPC_WALLET_NOT_SPECIFIED,
         "Wallet file not specified (must request wallet RPC through /wallet/<filename> uri-path).");

test/functional/wallet_multiwallet.py

@@ -183,7 +183,7 @@ def wallet_file(name):
 
         self.restart_node(0, ['-nowallet'])
         assert_equal(node.listwallets(), [])
-        assert_raises_rpc_error(-32601, "Method not found", node.getwalletinfo)
+        assert_raises_rpc_error(-18, "No wallet is loaded. Load a wallet using loadwallet or create a new one with createwallet. (Note: A default wallet is no longer automatically created)", node.getwalletinfo)
 
         self.log.info("Load first wallet")
         loadwallet_name = node.loadwallet(wallet_names[0])
@@ -278,7 +278,7 @@ def wallet_file(name):
         for wallet_name in self.nodes[0].listwallets():
             self.nodes[0].unloadwallet(wallet_name)
         assert_equal(self.nodes[0].listwallets(), [])
-        assert_raises_rpc_error(-32601, "Method not found (wallet method is disabled because no wallet is loaded)", self.nodes[0].getwalletinfo)
+        assert_raises_rpc_error(-18, "No wallet is loaded. Load a wallet using loadwallet or create a new one with createwallet. (Note: A default wallet is no longer automatically created)", self.nodes[0].getwalletinfo)
 
         # Successfully load a previously unloaded wallet
         self.nodes[0].loadwallet('w1')