#760 Fix single session feature

- Move the check from PlayerLoginEvent to AsyncPlayerPreLoginEvent. Single session can only be implemented with PreLoginEvent; it is already to late to check this in the PlayerLoginEvent. Ergo, we cannot offer this for CraftBukkit.
- Remove interactions with LimboCache - no interactions with LimboCache expected until after OnJoinVerification checks. (Thanks sgdc3!)

src/main/java/fr/xephi/authme/listener/AuthMePlayerListener.java

@@ -217,6 +217,9 @@ public class AuthMePlayerListener implements Listener {
             onJoinVerifier.checkAntibot(name, isAuthAvailable);
             onJoinVerifier.checkKickNonRegistered(isAuthAvailable);
             onJoinVerifier.checkIsValidName(name);
+            // Note #760: Single session must be checked here - checking with PlayerLoginEvent is too late and
+            // the first connection will have been kicked. This means this feature doesn't work on CraftBukkit.
+            onJoinVerifier.checkSingleSession(name);
         } catch (FailedVerificationException e) {
             event.setKickMessage(m.retrieveSingle(e.getReason(), e.getArgs()));
             event.setLoginResult(AsyncPlayerPreLoginEvent.Result.KICK_OTHER);
@@ -243,7 +246,6 @@ public class AuthMePlayerListener implements Listener {
             onJoinVerifier.checkKickNonRegistered(isAuthAvailable);
             onJoinVerifier.checkIsValidName(name);
             onJoinVerifier.checkNameCasing(player, auth);
-            onJoinVerifier.checkSingleSession(player);
             onJoinVerifier.checkPlayerCountry(isAuthAvailable, event);
         } catch (FailedVerificationException e) {
             event.setKickMessage(m.retrieveSingle(e.getReason(), e.getArgs()));

src/main/java/fr/xephi/authme/listener/OnJoinVerifier.java

@@ -3,9 +3,6 @@ package fr.xephi.authme.listener;
 import fr.xephi.authme.AntiBot;
 import fr.xephi.authme.ConsoleLogger;
 import fr.xephi.authme.cache.auth.PlayerAuth;
-import fr.xephi.authme.cache.auth.PlayerCache;
-import fr.xephi.authme.cache.limbo.LimboCache;
-import fr.xephi.authme.cache.limbo.LimboPlayer;
 import fr.xephi.authme.datasource.DataSource;
 import fr.xephi.authme.initialization.Reloadable;
 import fr.xephi.authme.output.MessageKey;
@@ -18,7 +15,6 @@ import fr.xephi.authme.settings.properties.RegistrationSettings;
 import fr.xephi.authme.settings.properties.RestrictionSettings;
 import fr.xephi.authme.util.BukkitService;
 import fr.xephi.authme.util.StringUtils;
-import fr.xephi.authme.util.Utils;
 import fr.xephi.authme.util.ValidationService;
 import org.bukkit.Server;
 import org.bukkit.entity.Player;
@@ -49,8 +45,6 @@ class OnJoinVerifier implements Reloadable {
     @Inject
     private BukkitService bukkitService;
     @Inject
-    private LimboCache limboCache;
-    @Inject
     private Server server;
 
     private Pattern nicknamePattern;
@@ -187,21 +181,15 @@ class OnJoinVerifier implements Reloadable {
      * Checks if a player with the same name (case-insensitive) is already playing and refuses the
      * connection if so configured.
      *
-     * @param player the player to verify
+     * @param name the player name to check
      */
-    public void checkSingleSession(Player player) throws FailedVerificationException {
+    public void checkSingleSession(String name) throws FailedVerificationException {
         if (!settings.getProperty(RestrictionSettings.FORCE_SINGLE_SESSION)) {
             return;
         }
 
-        Player onlinePlayer = bukkitService.getPlayerExact(player.getName());
+        Player onlinePlayer = bukkitService.getPlayerExact(name);
         if (onlinePlayer != null) {
-            String name = player.getName().toLowerCase();
-            LimboPlayer limbo = limboCache.getLimboPlayer(name);
-            if (limbo != null && PlayerCache.getInstance().isAuthenticated(name)) {
-                Utils.addNormal(player, limbo.getGroup());
-                limboCache.deleteLimboPlayer(name);
-            }
             throw new FailedVerificationException(MessageKey.USERNAME_ALREADY_ONLINE_ERROR);
         }
     }

src/test/java/fr/xephi/authme/listener/OnJoinVerifierTest.java

@@ -3,7 +3,6 @@ package fr.xephi.authme.listener;
 import fr.xephi.authme.AntiBot;
 import fr.xephi.authme.TestHelper;
 import fr.xephi.authme.cache.auth.PlayerAuth;
-import fr.xephi.authme.cache.limbo.LimboCache;
 import fr.xephi.authme.datasource.DataSource;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
@@ -67,8 +66,6 @@ public class OnJoinVerifierTest {
     @Mock
     private BukkitService bukkitService;
     @Mock
-    private LimboCache limboCache;
-    @Mock
     private Server server;
 
     @Rule
@@ -341,21 +338,21 @@ public class OnJoinVerifierTest {
     @Test
     public void shouldAcceptNameThatIsNotOnline() throws FailedVerificationException {
         // given
-        Player player = newPlayerWithName("bobby");
+        String name = "bobby";
         given(settings.getProperty(RestrictionSettings.FORCE_SINGLE_SESSION)).willReturn(true);
         given(bukkitService.getPlayerExact("bobby")).willReturn(null);
 
         // when
-        onJoinVerifier.checkSingleSession(player);
+        onJoinVerifier.checkSingleSession(name);
 
         // then
-        verifyZeroInteractions(limboCache);
+        verify(bukkitService).getPlayerExact(name);
     }
 
     @Test
     public void shouldRejectNameAlreadyOnline() throws FailedVerificationException {
         // given
-        Player player = newPlayerWithName("Charlie");
+        String name = "Charlie";
         Player onlinePlayer = newPlayerWithName("charlie");
         given(bukkitService.getPlayerExact("Charlie")).willReturn(onlinePlayer);
         given(settings.getProperty(RestrictionSettings.FORCE_SINGLE_SESSION)).willReturn(true);
@@ -364,22 +361,20 @@ public class OnJoinVerifierTest {
         expectValidationExceptionWith(MessageKey.USERNAME_ALREADY_ONLINE_ERROR);
 
         // when / then
-        onJoinVerifier.checkSingleSession(player);
-        verify(limboCache).getLimboPlayer("charlie");
+        onJoinVerifier.checkSingleSession(name);
     }
 
     @Test
     public void shouldAcceptAlreadyOnlineNameForDisabledSetting() throws FailedVerificationException {
         // given
-        Player player = newPlayerWithName("Felipe");
+        String name = "Felipe";
         given(settings.getProperty(RestrictionSettings.FORCE_SINGLE_SESSION)).willReturn(false);
 
         // when
-        onJoinVerifier.checkSingleSession(player);
+        onJoinVerifier.checkSingleSession(name);
 
         // then
         verifyZeroInteractions(bukkitService);
-        verifyZeroInteractions(limboCache);
     }
 
     private static Player newPlayerWithName(String name) {