Fix error with work_cancel RPC request

nano/core_test/fakes/work_peer.hpp

@@ -33,7 +33,6 @@ enum class work_peer_type
 class work_peer_connection : public std::enable_shared_from_this<work_peer_connection>
 {
 	const std::string generic_error = "Unable to parse JSON";
-	const std::string empty_response = "Empty response";
 
 public:
 	work_peer_connection (asio::io_context & ioc_a, work_peer_type const type_a, nano::work_version const version_a, nano::work_pool & pool_a, std::function<void(bool const)> on_generation_a, std::function<void()> on_cancel_a) :
@@ -126,6 +125,16 @@ class work_peer_connection : public std::enable_shared_from_this<work_peer_conne
 		beast::ostream (response.body ()) << ostream.str ();
 	}
 
+	void handle_cancel ()
+	{
+		on_cancel ();
+		ptree::ptree message_l;
+		message_l.put ("success", "");
+		std::stringstream ostream;
+		ptree::write_json (ostream, message_l);
+		beast::ostream (response.body ()) << ostream.str ();
+	}
+
 	void handle_generate (nano::block_hash const & hash_a)
 	{
 		if (type == work_peer_type::good)
@@ -176,9 +185,7 @@ class work_peer_connection : public std::enable_shared_from_this<work_peer_conne
 		}
 		else if (action_text == "work_cancel")
 		{
-			error (empty_response);
-			on_cancel ();
-			write_response ();
+			handle_cancel ();
 		}
 		else
 		{

nano/lib/errors.cpp

@@ -127,6 +127,8 @@ std::string nano::error_rpc_messages::message (int ev) const
 	{
 		case nano::error_rpc::generic:
 			return "Unknown error";
+		case nano::error_rpc::empty_response:
+			return "Empty response";
 		case nano::error_rpc::bad_destination:
 			return "Bad destination account";
 		case nano::error_rpc::bad_difficulty_format:

nano/lib/errors.hpp

@@ -76,6 +76,7 @@ enum class error_blocks
 enum class error_rpc
 {
 	generic = 1,
+	empty_response,
 	bad_destination,
 	bad_difficulty_format,
 	bad_key,

nano/node/json_handler.cpp

@@ -148,10 +148,15 @@ void nano::json_handler::process_request (bool unsafe_a)
 
 void nano::json_handler::response_errors ()
 {
-	if (ec || response_l.empty ())
+	if (!ec && response_l.empty ())
+	{
+		// Return an error code if no response data was given
+		ec = nano::error_rpc::empty_response;
+	}
+	if (ec)
 	{
 		boost::property_tree::ptree response_error;
-		response_error.put ("error", ec ? ec.message () : "Empty response");
+		response_error.put ("error", ec.message ());
 		std::stringstream ostream;
 		boost::property_tree::write_json (ostream, response_error);
 		response (ostream.str ());
@@ -4861,6 +4866,7 @@ void nano::json_handler::work_cancel ()
 	if (!ec)
 	{
 		node.observers.work_cancel.notify (hash);
+		response_l.put ("success", "");
 	}
 	response_errors ();
 }

nano/rpc_test/rpc.cpp

@@ -2999,6 +2999,8 @@ TEST (rpc, work_cancel)
 		ASSERT_TIMELY (10s, response1.status != 0);
 		ASSERT_EQ (200, response1.status);
 		ASSERT_NO_ERROR (ec);
+		std::string success (response1.json.get<std::string> ("success"));
+		ASSERT_TRUE (success.empty ());
 	}
 }