Folia/patches/server/0004-Max-pending-logins.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Thu, 9 Mar 2023 20:50:15 -0800
Subject: [PATCH] Max pending logins

Should help the floodgates on launch

diff --git a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
index 2e96377d628b3a07fb565020074d665f594f32e8..75b1877f8c3e4da3183437f327ef3376fd0a3c21 100644
--- a/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerLoginPacketListenerImpl.java
@@ -85,7 +85,7 @@ public class ServerLoginPacketListenerImpl implements ServerLoginPacketListener,
             UUID uniqueId = UUIDUtil.getOrCreatePlayerUUID(this.gameProfile);
             if (this.server.getPlayerList().pushPendingJoin(name, uniqueId, this.connection)) {
                 this.handleAcceptedLogin();
-            }
+            } else { --this.tick; } // Folia - max concurrent logins
             // Folia end - region threading - rewrite login process
         } // Folia - region threading - remove delayed accept
 
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 9aa12c2ae7d86604583e98ba9872ad613882c867..39d404c278bdc1227cb806bb257492493d05a439 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -180,6 +180,17 @@ public abstract class PlayerList {
             conflictingId = this.connectionById.get(byId);
 
             if (conflictingName == null && conflictingId == null) {
+                // Folia start - max concurrent login
+                int loggedInCount = 0;
+                for (Connection value : this.connectionById.values()) {
+                    if (value.isPlayerConnected()) {
+                        ++loggedInCount;
+                    }
+                }
+                if ((this.connectionById.size() - loggedInCount) >= io.papermc.paper.configuration.GlobalConfiguration.get().misc.maxJoinsPerTick) {
+                    return false;
+                }
+                // Folia end - max concurrent login
                 this.connectionByName.put(userName, conn);
                 this.connectionById.put(byId, conn);
             }