wallet2: remember daemon address overrides when loading a new wallet

src/wallet/wallet2.cpp

@@ -149,6 +149,9 @@ static const std::string MULTISIG_EXTRA_INFO_MAGIC = "MultisigxV1";
 
 static const std::string ASCII_OUTPUT_MAGIC = "MoneroAsciiDataV1";
 
+boost::mutex tools::wallet2::default_daemon_address_lock;
+std::string tools::wallet2::default_daemon_address = "";
+
 namespace
 {
   std::string get_default_ringdb_path()
@@ -412,6 +415,15 @@ std::unique_ptr<tools::wallet2> make_basic(const boost::program_options::variabl
     daemon_port = get_config(nettype).RPC_DEFAULT_PORT;
   }
 
+  // if no daemon settings are given and we have a previous one, reuse that one
+  if (command_line::is_arg_defaulted(vm, opts.daemon_host) && command_line::is_arg_defaulted(vm, opts.daemon_port) && command_line::is_arg_defaulted(vm, opts.daemon_address))
+  {
+    // not a bug: taking a const ref to a temporary in this way is actually ok in a recent C++ standard
+    const std::string &def = tools::wallet2::get_default_daemon_address();
+    if (!def.empty())
+      daemon_address = def;
+  }
+
   if (daemon_address.empty())
     daemon_address = std::string("http://") + daemon_host + ":" + std::to_string(daemon_port);
 
@@ -1312,8 +1324,15 @@ bool wallet2::set_daemon(std::string daemon_address, boost::optional<epee::net_u
     m_node_rpc_proxy.invalidate();
   }
 
-  MINFO("setting daemon to " << get_daemon_address());
-  return m_http_client.set_server(get_daemon_address(), get_daemon_login(), std::move(ssl_options));
+  const std::string address = get_daemon_address();
+  MINFO("setting daemon to " << address);
+  bool ret =  m_http_client.set_server(address, get_daemon_login(), std::move(ssl_options));
+  if (ret)
+  {
+    CRITICAL_REGION_LOCAL(default_daemon_address_lock);
+    default_daemon_address = address;
+  }
+  return ret;
 }
 //----------------------------------------------------------------------------------------------------
 bool wallet2::init(std::string daemon_address, boost::optional<epee::net_utils::http::login> daemon_login, boost::asio::ip::tcp::endpoint proxy, uint64_t upper_transaction_weight_limit, bool trusted_daemon, epee::net_utils::ssl_options_t ssl_options)

src/wallet/wallet2.h

@@ -1386,6 +1386,8 @@ private:
     uint64_t credits() const { return m_rpc_payment_state.credits; }
     void credit_report(uint64_t &expected_spent, uint64_t &discrepancy) const { expected_spent = m_rpc_payment_state.expected_spent; discrepancy = m_rpc_payment_state.discrepancy; }
 
+    static std::string get_default_daemon_address() { CRITICAL_REGION_LOCAL(default_daemon_address_lock); return default_daemon_address; }
+
   private:
     /*!
      * \brief  Stores wallet information to wallet file.
@@ -1623,6 +1625,9 @@ private:
     std::unique_ptr<wallet_device_callback> m_device_callback;
 
     ExportFormat m_export_format;
+
+    static boost::mutex default_daemon_address_lock;
+    static std::string default_daemon_address;
   };
 }
 BOOST_CLASS_VERSION(tools::wallet2, 29)