Kick players when shutting down server and there is a crash due to a …

…Lua stack exception

src/environment.cpp

@@ -39,6 +39,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapblock_mesh.h"
 #include "event.h"
 #endif
+#include "server.h"
 #include "daynightratio.h"
 #include "map.h"
 #include "emerge.h"
@@ -425,6 +426,15 @@ bool ServerEnvironment::line_of_sight(v3f pos1, v3f pos2, float stepsize, v3s16
 	return true;
 }
 
+void ServerEnvironment::kickAllPlayers(const std::string &reason)
+{
+	for (std::vector<Player*>::iterator it = m_players.begin();
+			it != m_players.end();
+			++it) {
+		((Server*)m_gamedef)->DenyAccess_Legacy((*it)->peer_id, utf8_to_wide(reason));
+	}
+}
+
 void ServerEnvironment::saveLoadedPlayers()
 {
 	std::string players_path = m_path_world + DIR_DELIM "players";

src/environment.h

@@ -221,6 +221,7 @@ class ServerEnvironment : public Environment
 	float getSendRecommendedInterval()
 		{ return m_recommended_send_interval; }
 
+	void kickAllPlayers(const std::string &reason);
 	// Save players
 	void saveLoadedPlayers();
 	void savePlayer(const std::string &playername);

src/server.cpp

@@ -394,10 +394,13 @@ Server::~Server()
 		// Execute script shutdown hooks
 		m_script->on_shutdown();
 
-		infostream<<"Server: Saving players"<<std::endl;
+		infostream << "Server: Saving players" << std::endl;
 		m_env->saveLoadedPlayers();
 
-		infostream<<"Server: Saving environment metadata"<<std::endl;
+		infostream << "Server: kick players" << std::endl;
+		m_env->kickAllPlayers("Server shutting down...");
+
+		infostream << "Server: Saving environment metadata" << std::endl;
 		m_env->saveMeta();
 	}
 
@@ -499,6 +502,7 @@ void Server::step(float dtime)
 			throw ServerError(async_err);
 		}
 		else {
+			m_env->kickAllPlayers("The server has crashed. Disconnecting all players. Please reconnect soon...");
 			errorstream << "UNRECOVERABLE error occurred. Stopping server. "
 					<< "Please fix the following error:" << std::endl
 					<< async_err << std::endl;