Merge bitcoin/bitcoin#26990: cli: Improve error message on multiwallet cli-side commands

54227e681a rpc, cli: improve error message on multiwallet mode (pablomartin4btc)

Pull request description:

  Running a CLI command when multiple wallets are loaded and `-rpcwallet` is not specified, should return a clearer error.

  Currently in `master`:

  ```
  $ bitcoin-cli -regtest -generate 1
  error code: -19
  error message:
  Wallet file not specified (must request wallet RPC through /wallet/<filename> uri-path).
  Try adding "-rpcwallet=<filename>" option to bitcoin-cli command line.
  ```

  With this change:

  ```
  $ bitcoin-cli -regtest -generate 1
  error code: -19
  error message:
  Multiple wallets are loaded. Please select which wallet to use by requesting the RPC through the /wallet/<walletname> URI path. Or for the CLI, specify the "-rpcwallet=<walletname>" option before the command (run "bitcoin-cli -h" for help or "bitcoin-cli listwallets" to see which wallets are currently loaded).
  ```

ACKs for top commit:
  maflcko:
    review ACK 54227e681a
  achow101:
    ACK 54227e681a
  furszy:
    utACK 54227e681a
  mzumsande:
    Code Review ACK 54227e681a
  jonatack:
    ACK 54227e681a

Tree-SHA512: 51ff24f64858aa6be6adf6f20105c9f076ebea743780bf2a4399f7fe8b5239cbb1ea06d32b2ef5e850da2369abb0ef7a52c50c2b8f31f4ca90d3a486abc9b77e

src/bitcoin-cli.cpp

@@ -950,7 +950,8 @@ static void ParseError(const UniValue& error, std::string& strPrint, int& nRet)
             strPrint += ("error message:\n" + err_msg.get_str());
         }
         if (err_code.isNum() && err_code.getInt<int>() == RPC_WALLET_NOT_SPECIFIED) {
-            strPrint += "\nTry adding \"-rpcwallet=<filename>\" option to bitcoin-cli command line.";
+            strPrint += " Or for the CLI, specify the \"-rpcwallet=<walletname>\" option before the command";
+            strPrint += " (run \"bitcoin-cli -h\" for help or \"bitcoin-cli listwallets\" to see which wallets are currently loaded).";
         }
     } else {
         strPrint = "error: " + error.write();

src/wallet/rpc/util.cpp

@@ -91,7 +91,7 @@ std::shared_ptr<CWallet> GetWalletForJSONRPCRequest(const JSONRPCRequest& reques
             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).");
+        "Multiple wallets are loaded. Please select which wallet to use by requesting the RPC through the /wallet/<walletname> URI path.");
 }
 
 void EnsureWalletIsUnlocked(const CWallet& wallet)

test/functional/interface_bitcoin_cli.py

@@ -30,7 +30,12 @@ JSON_PARSING_ERROR = 'error: Error parsing JSON: foo'
 BLOCKS_VALUE_OF_ZERO = 'error: the first argument (number of blocks to generate, default: 1) must be an integer value greater than zero'
 TOO_MANY_ARGS = 'error: too many arguments (maximum 2 for nblocks and maxtries)'
 WALLET_NOT_LOADED = 'Requested wallet does not exist or is not loaded'
-WALLET_NOT_SPECIFIED = 'Wallet file not specified'
+WALLET_NOT_SPECIFIED = (
+    "Multiple wallets are loaded. Please select which wallet to use by requesting the RPC "
+    "through the /wallet/<walletname> URI path. Or for the CLI, specify the \"-rpcwallet=<walletname>\" "
+    "option before the command (run \"bitcoin-cli -h\" for help or \"bitcoin-cli listwallets\" to see "
+    "which wallets are currently loaded)."
+)
 
 
 def cli_get_info_string_to_dict(cli_get_info_string):
@@ -331,6 +336,10 @@ class TestBitcoinCli(BitcoinTestFramework):
             n4 = 10
             blocks = self.nodes[0].getblockcount()
 
+            self.log.info('Test -generate -rpcwallet=<filename> raise RPC error')
+            wallet2_path = f'-rpcwallet={self.nodes[0].wallets_path / wallets[2] / self.wallet_data_filename}'
+            assert_raises_rpc_error(-18, WALLET_NOT_LOADED, self.nodes[0].cli(wallet2_path, '-generate').echo)
+
             self.log.info('Test -generate -rpcwallet with no args')
             generate = self.nodes[0].cli(rpcwallet2, '-generate').send_cli()
             assert_equal(set(generate.keys()), {'address', 'blocks'})

test/functional/wallet_multiwallet.py

@@ -229,7 +229,7 @@ class MultiWalletTest(BitcoinTestFramework):
         assert_raises_rpc_error(-18, "Requested wallet does not exist or is not loaded", wallet_bad.getwalletinfo)
 
         # accessing wallet RPC without using wallet endpoint fails
-        assert_raises_rpc_error(-19, "Wallet file not specified", node.getwalletinfo)
+        assert_raises_rpc_error(-19, "Multiple wallets are loaded. Please select which wallet", node.getwalletinfo)
 
         w1, w2, w3, w4, *_ = wallets
         self.generatetoaddress(node, nblocks=COINBASE_MATURITY + 1, address=w1.getnewaddress(), sync_fun=self.no_op)
@@ -275,7 +275,7 @@ class MultiWalletTest(BitcoinTestFramework):
         loadwallet_name = node.loadwallet(wallet_names[1])
         assert_equal(loadwallet_name['name'], wallet_names[1])
         assert_equal(node.listwallets(), wallet_names[0:2])
-        assert_raises_rpc_error(-19, "Wallet file not specified", node.getwalletinfo)
+        assert_raises_rpc_error(-19, "Multiple wallets are loaded. Please select which wallet", node.getwalletinfo)
         w2 = node.get_wallet_rpc(wallet_names[1])
         w2.getwalletinfo()