From c7ae032d5afd748bb491af5b081d3be47aa4e00f Mon Sep 17 00:00:00 2001
From: magenoxx <magenoxx@gmail>
Date: Wed, 22 Jun 2011 20:35:16 +0400
Subject: [PATCH] Fixed possible NPE between callbacks (as client and server
 are not synchronized between calls)

---
 .../src/mage/interfaces/callback/CallbackClientDaemon.java  | 4 +++-
 Mage.Server/src/main/java/mage/server/ServerImpl.java       | 6 +++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Mage.Common/src/mage/interfaces/callback/CallbackClientDaemon.java b/Mage.Common/src/mage/interfaces/callback/CallbackClientDaemon.java
index 95a6ecdc40b..b643f570f9c 100644
--- a/Mage.Common/src/mage/interfaces/callback/CallbackClientDaemon.java
+++ b/Mage.Common/src/mage/interfaces/callback/CallbackClientDaemon.java
@@ -64,7 +64,9 @@ public class CallbackClientDaemon extends Thread {
 					@Override
 					public void run() {
 						try {
-							client.processCallback(callback);
+							if (callback != null) {
+								client.processCallback(callback);
+							}
 						}
 						catch (Exception ex) {
 							logger.fatal("CallbackClientDaemon error ", ex);
diff --git a/Mage.Server/src/main/java/mage/server/ServerImpl.java b/Mage.Server/src/main/java/mage/server/ServerImpl.java
index 7b8852c4157..be7798e7993 100644
--- a/Mage.Server/src/main/java/mage/server/ServerImpl.java
+++ b/Mage.Server/src/main/java/mage/server/ServerImpl.java
@@ -101,7 +101,11 @@ public class ServerImpl extends RemoteServer implements Server {
 
 	@Override
 	public ClientCallback callback(UUID sessionId) {
-		return SessionManager.getInstance().getSession(sessionId).callback();
+		Session session = SessionManager.getInstance().getSession(sessionId);
+		if (session == null) {
+			return null;
+		}
+		return session.callback();
 	}
 
 	@Override