null safety on auth/handshake errors

connector/src/main/java/org/geysermc/connector/network/session/GeyserSession.java

@@ -158,10 +158,14 @@ public class GeyserSession implements PlayerSession, Player {
     public void disconnect(String reason) {
         if (!closed) {
             loggedIn = false;
+            if (downstream != null && downstream.getSession() != null) {
                 downstream.getSession().disconnect(reason);
+            }
+            if (upstream != null) {
                 upstream.disconnect(reason);
             }
         }
+    }
 
     @Override
     public boolean isClosed() {

connector/src/main/java/org/geysermc/connector/utils/LoginEncryptionUtils.java

@@ -150,10 +150,13 @@ public class LoginEncryptionUtils {
                     return false;
 
                 CustomFormResponse response = (CustomFormResponse) customFormWindow.getResponse();
+
+                if (response != null) {
                     String email = response.getInputResponses().get(2);
                     String password = response.getInputResponses().get(3);
 
                     session.authenticate(email, password);
+                }
 
                 // TODO should we clear the window cache in all cases or just if not already logged in?
                 // Clear windows so authentication data isn't accidentally cached