try to be more judicious when cleaning up idlers and entering and leaving sessions

metaserver/games.cpp

@@ -89,6 +89,9 @@ void CreateGame(Session *session, char *description, char *map,
 	game->Prev = NULL;
 	Games = game;
 
+	if (session->Game) {
+		PartGame(session);
+	}
 	session->Game = game;
 }
 
@@ -120,6 +123,7 @@ int CancelGame(Session *session)
 		game->Sessions[i]->Game = NULL;
 	}
 
+	session->Game = NULL;
 	delete game;
 	return 0;
 }
@@ -145,7 +149,7 @@ int JoinGame(Session *session, int id, char *password, unsigned long *host, int
 	GameData *game;
 
 	if (session->Game) {
-		return -1; // Already in a game
+		PartGame(session);
 	}
 
 	game = Games;

metaserver/netdriver.cpp

@@ -42,6 +42,7 @@
 #endif
 
 #include "stratagus.h"
+#include "games.h"
 #include "netdriver.h"
 #include "net_lowlevel.h"
 
@@ -228,6 +229,7 @@ static int KillSession(Session *session)
 	NetCloseTCP(session->Sock);
 	Pool->Sockets->DelSocket(session->Sock);
 	UNLINK(Pool->First, session, Pool->Last, Pool->Count);
+	PartGame(session);
 	delete session;
 	return 0;
 }

src/network/master.cpp

@@ -157,9 +157,11 @@ void CMetaClient::Close()
 int CMetaClient::Send(const std::string cmd)
 {
 	int ret = -1;
-	std::string mes(cmd);
-	mes.append("\n");
-	ret = metaSocket.Send(mes.c_str(), mes.size());
+	if (metaSocket.IsValid()) {
+		std::string mes(cmd);
+		mes.append("\n");
+		ret = metaSocket.Send(mes.c_str(), mes.size());
+	}
 	return ret;
 }