Replaced open port check with server crash check

client/CServerHandler.cpp

@@ -181,17 +181,7 @@ void CServerHandler::startLocalServerAndConnect()
 		threadRunLocalServer->join();
 
 	th->update();
-	
-	auto errorMsg = CGI->generaltexth->translate("vcmi.server.errors.existingProcess");
-
-// TODO: restore
-//	if (!checkNetworkPortIsFree(localhostAddress, getDefaultPort()))
-//	{
-//		logNetwork->error("Port is busy, check if another instance of vcmiserver is working");
-//		CInfoWindow::showInfoDialog(errorMsg, {});
-//		return;
-//	}
-	
+
 #if defined(SINGLE_PROCESS_APP)
 	boost::condition_variable cond;
 	std::vector<std::string> args{"--uuid=" + uuid, "--port=" + std::to_string(getLocalPort())};
@@ -962,6 +952,14 @@ void CServerHandler::threadRunServer()
 	}
 	else
 	{
+		if (state != EClientState::DISCONNECTING)
+		{
+			if (state == EClientState::CONNECTING)
+				CInfoWindow::showInfoDialog(CGI->generaltexth->translate("vcmi.server.errors.existingProcess"), {});
+			else
+				CInfoWindow::showInfoDialog(CGI->generaltexth->translate("vcmi.server.errors.serverCrashed"), {});
+		}
+
 		state = EClientState::CONNECTION_CANCELLED; // stop attempts to reconnect
 		logNetwork->error("Error: server failed to close correctly or crashed!");
 		logNetwork->error("Check %s for more info", logName);

lib/network/NetworkClient.cpp

@@ -13,23 +13,6 @@
 
 VCMI_LIB_NAMESPACE_BEGIN
 
-DLL_LINKAGE bool checkNetworkPortIsFree(const std::string & host, uint16_t port)
-{
-	boost::asio::io_service io;
-	NetworkAcceptor acceptor(io);
-
-	boost::system::error_code ec;
-	acceptor.open(boost::asio::ip::tcp::v4(), ec);
-	if (ec)
-		return false;
-
-	acceptor.bind(boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), port), ec);
-	if (ec)
-		return false;
-
-	return true;
-}
-
 NetworkClient::NetworkClient(INetworkClientListener & listener)
 	: io(new NetworkService)
 	, socket(new NetworkSocket(*io))

lib/network/NetworkClient.h

@@ -14,10 +14,6 @@
 
 VCMI_LIB_NAMESPACE_BEGIN
 
-/// Function that attempts to open specified port on local system to determine whether port is in use
-/// Returns: true if port is free and can be used to receive connections
-DLL_LINKAGE bool checkNetworkPortIsFree(const std::string & host, uint16_t port);
-
 class NetworkConnection;
 
 class DLL_LINKAGE NetworkClient : boost::noncopyable, public INetworkConnectionListener