Fix disconnect issues in 1.7-specific logic.

proxy/src/main/java/com/velocitypowered/proxy/connection/MinecraftConnection.java

@@ -223,13 +223,10 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
    */
   public void closeWith(Object msg) {
     if (channel.isActive()) {
-      boolean is1Point8 = this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) >= 0;
-      boolean isLegacyOrPing = this.getState() == StateRegistry.HANDSHAKE
-          || this.getState() == StateRegistry.STATUS;
-      if (channel.eventLoop().inEventLoop() && (is1Point8 || isLegacyOrPing)) {
-        knownDisconnect = true;
-        channel.writeAndFlush(msg).addListener(ChannelFutureListener.CLOSE);
-      } else {
+      boolean is1_7 = this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_8) < 0
+          && this.getProtocolVersion().compareTo(ProtocolVersion.MINECRAFT_1_7_2) >= 0;
+      if (is1_7) {
+        channel.eventLoop().execute(() -> {
           // 1.7.x versions have a race condition with switching protocol states, so just explicitly
           // close the connection after a short while.
           this.setAutoReading(false);
@@ -237,6 +234,10 @@ public class MinecraftConnection extends ChannelInboundHandlerAdapter {
             knownDisconnect = true;
             channel.writeAndFlush(msg).addListener(ChannelFutureListener.CLOSE);
           }, 250, TimeUnit.MILLISECONDS);
+        });
+      } else {
+        knownDisconnect = true;
+        channel.writeAndFlush(msg).addListener(ChannelFutureListener.CLOSE);
       }
     }
   }

proxy/src/main/java/com/velocitypowered/proxy/connection/client/LoginSessionHandler.java

@@ -208,7 +208,7 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
         onlineMode);
     final GameProfile finalProfile = profile;
 
-    server.getEventManager().fire(profileRequestEvent).thenCompose(profileEvent -> {
+    server.getEventManager().fire(profileRequestEvent).thenComposeAsync(profileEvent -> {
       if (mcConnection.isClosed()) {
         // The player disconnected after we authenticated them.
         return CompletableFuture.completedFuture(null);
@@ -234,7 +234,7 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
               completeLoginProtocolPhaseAndInitialize(player);
             }
           }, mcConnection.eventLoop());
-    }).exceptionally((ex) -> {
+    }, mcConnection.eventLoop()).exceptionally((ex) -> {
       logger.error("Exception during connection of {}", finalProfile, ex);
       return null;
     });