Added new client-server incompatible checks:

* added strict mode (client and server versions must be same, see MAGE_VERSION_MINOR_PATCH_MUST_BE_SAME);
 * you must enable string mode after github code changes in serializeable classes (see #4459);
 * added client-side version checks;
 * added error message on wrong version disconnects.

Mage.Client/src/main/java/mage/client/MageFrame.java

@@ -767,7 +767,7 @@ public class MageFrame extends javax.swing.JFrame implements MageClient {
                 prepareAndShowTablesPane();
                 return true;
             } else {
-                showMessage("Unable connect to server");
+                showMessage("Unable connect to server: " + SessionHandler.getLastConnectError());
             }
         } finally {
             setCursor(new Cursor(Cursor.DEFAULT_CURSOR));

Mage.Client/src/main/java/mage/client/SessionHandler.java

@@ -1,6 +1,5 @@
 package mage.client;
 
-import java.util.*;
 import mage.cards.decks.DeckCardLists;
 import mage.client.chat.LocalCommands;
 import mage.client.dialog.PreferencesDialog;
@@ -16,12 +15,15 @@ import mage.remote.Session;
 import mage.remote.SessionImpl;
 import mage.view.*;
 
+import java.util.*;
+
 /**
  * Created by IGOUDT on 15-9-2016.
  */
 public final class SessionHandler {
 
     private static Session session;
+    private static String lastConnectError = "";
 
     public static void startSession(MageFrame mageFrame) {
 
@@ -46,7 +48,17 @@ public final class SessionHandler {
     }
 
     public static boolean connect(Connection connection) {
-        return session.connect(connection);
+        lastConnectError = "";
+        if (session.connect(connection)) {
+            return true;
+        } else {
+            lastConnectError = session.getLastError();
+            return false;
+        }
+    }
+
+    public static String getLastConnectError() {
+        return lastConnectError;
     }
 
     public static boolean stopConnecting() {

Mage.Client/src/main/java/mage/client/dialog/ConnectDialog.java

@@ -10,6 +10,7 @@ import mage.cards.repository.ExpansionRepository;
 import mage.choices.Choice;
 import mage.choices.ChoiceImpl;
 import mage.client.MageFrame;
+import mage.client.SessionHandler;
 import mage.client.preference.MagePreferences;
 import mage.client.util.Config;
 import mage.client.util.gui.countryBox.CountryItemEditor;
@@ -513,7 +514,7 @@ public class ConnectDialog extends MageDialog {
             connection.setForceDBComparison(this.chkForceUpdateDB.isSelected() || redownloadDatabase);
             String allMAC = "";
             try {
-                allMAC = connection.getMAC();
+                allMAC = Connection.getMAC();
             } catch (SocketException ex) {
             }
             connection.setUserIdStr(System.getProperty("user.name") + ":" + System.getProperty("os.name") + ":" + MagePreferences.getUserNames() + ":" + allMAC);
@@ -535,6 +536,7 @@ public class ConnectDialog extends MageDialog {
     private class ConnectTask extends SwingWorker<Boolean, Void> {
 
         private boolean result = false;
+        private String lastConnectError = "";
 
         private static final int CONNECTION_TIMEOUT_MS = 2100;
 
@@ -543,6 +545,7 @@ public class ConnectDialog extends MageDialog {
             lblStatus.setText("Connecting...");
             btnConnect.setEnabled(false);
             result = MageFrame.connect(connection);
+            lastConnectError = SessionHandler.getLastConnectError();
             return result;
         }
 
@@ -556,7 +559,7 @@ public class ConnectDialog extends MageDialog {
                     connected();
                     MageFrame.getInstance().prepareAndShowTablesPane();
                 } else {
-                    lblStatus.setText("Could not connect");
+                    lblStatus.setText("Could not connect: " + lastConnectError);
                 }
             } catch (InterruptedException ex) {
                 logger.fatal("Update Players Task error", ex);

Mage.Common/src/main/java/mage/remote/SessionImpl.java

@@ -61,6 +61,7 @@ public class SessionImpl implements Session {
 
     private boolean canceled = false;
     private boolean jsonLogActive = false;
+    private String lastError = "";
 
     static {
         debugMode = System.getProperty("debug.mage") != null;
@@ -195,20 +196,29 @@ public class SessionImpl implements Session {
                 && handleRemotingTaskExceptions(new RemotingTask() {
             @Override
             public boolean run() throws Throwable {
+                setLastError("");
                 logger.info("Trying to log-in as " + getUserName() + " to XMAGE server at " + connection.getHost() + ':' + connection.getPort());
                 boolean registerResult;
                 if (connection.getAdminPassword() == null) {
                     // for backward compatibility. don't remove twice call - first one does nothing but for version checking
                     registerResult = server.connectUser(connection.getUsername(), connection.getPassword(), sessionId, client.getVersion(), connection.getUserIdStr());
-                    if (registerResult) {
-                        server.setUserData(connection.getUsername(), sessionId, connection.getUserData(), client.getVersion().toString(), connection.getUserIdStr());
-                    }
                 } else {
                     registerResult = server.connectAdmin(connection.getAdminPassword(), sessionId, client.getVersion());
                 }
                 if (registerResult) {
                     serverState = server.getServerState();
+
+                    // client side check for incompatible versions
+                    if (client.getVersion().compareTo(serverState.getVersion()) != 0) {
+                        String err = "Client and server versions are incompatible.";
+                        setLastError(err);
+                        logger.info(err);
+                        disconnect(false);
+                        return false;
+                    }
+
                     if (!connection.getUsername().equals("Admin")) {
+                        server.setUserData(connection.getUsername(), sessionId, connection.getUserData(), client.getVersion().toString(), connection.getUserIdStr());
                         updateDatabase(connection.isForceDBComparison(), serverState);
                     }
                     logger.info("Logged-in as " + getUserName() + " to MAGE server at " + connection.getHost() + ':' + connection.getPort());
@@ -1621,6 +1631,15 @@ public class SessionImpl implements Session {
         this.jsonLogActive = jsonLogActive;
     }
 
+    private void setLastError(String error) {
+        lastError = error;
+    }
+
+    @Override
+    public String getLastError() {
+        return lastError;
+    }
+
 }
 
 class MageAuthenticator extends Authenticator {

Mage.Common/src/main/java/mage/remote/interfaces/Connect.java

@@ -1,4 +1,3 @@
-
 package mage.remote.interfaces;
 
 import mage.remote.Connection;
@@ -43,4 +42,6 @@ public interface Connect {
     boolean lockUser(String userName, long durationMinute);
 
     String getSessionId();
+
+    String getLastError();
 }

Mage.Common/src/main/java/mage/utils/MageVersion.java

@@ -16,7 +16,9 @@ public class MageVersion implements Serializable, Comparable<MageVersion> {
     public final static int MAGE_VERSION_MINOR = 4;
     public final static int MAGE_VERSION_PATCH = 33;
     public final static String MAGE_EDITION_INFO = ""; // set "-beta" for 1.4.32-betaV0
-    public final static String MAGE_VERSION_MINOR_PATCH = "V0";
+    public final static String MAGE_VERSION_MINOR_PATCH = "V1"; // default V0
+    // strict mode
+    private final static boolean MAGE_VERSION_MINOR_PATCH_MUST_BE_SAME = true; // set true on uncompatible github changes, set false after new major release (after MAGE_VERSION_PATCH changes)
 
     private final int major;
     private final int minor;
@@ -74,7 +76,9 @@ public class MageVersion implements Serializable, Comparable<MageVersion> {
         if (patch != o.patch) {
             return patch - o.patch;
         }
+        if (MAGE_VERSION_MINOR_PATCH_MUST_BE_SAME && !minorPatch.equals(o.minorPatch)) {
+            return minorPatch.compareTo(o.minorPatch);
+        }
         return editionInfo.compareTo(o.editionInfo);
     }
-
 }