Fixes PSPE by add option to configure excessive signs

src/api/main/java/io/akarin/server/core/AkarinGlobalConfig.java

@@ -195,4 +195,9 @@ public class AkarinGlobalConfig {
     private static void disallowBeforeLogin() {
         disallowBeforeLogin = getBoolean("alternative.disallow-before-login-event", disallowBeforeLogin);
     }
+    
+    public static boolean allowExcessiveSigns = false;
+    private static void allowExcessiveSigns() {
+        allowExcessiveSigns = getBoolean("alternative.allow-excessive-signs", allowExcessiveSigns);
+    }
 }

src/main/java/net/minecraft/server/NetworkManager.java

@@ -5,6 +5,7 @@ import com.google.common.collect.Queues;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 
+import io.akarin.server.core.AkarinGlobalConfig;
 import io.akarin.server.core.PacketType;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
@@ -291,12 +292,14 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet<?>> {
         }
 
         // Paper start
+        if (AkarinGlobalConfig.allowExcessiveSigns) { // Akarin
         java.util.List<Packet> extraPackets = packet.getExtraPackets();
         if (extraPackets != null && !extraPackets.isEmpty()) {
             for (Packet extraPacket : extraPackets) {
                 this.dispatchPacket(extraPacket, genericfuturelistener);
             }
         }
+        } // Akarin
         // Paper end
 
     }

src/main/java/net/minecraft/server/PacketPlayOutMapChunk.java

@@ -2,9 +2,12 @@ package net.minecraft.server;
 
 import com.destroystokyo.paper.antixray.ChunkPacketInfo; // Paper - Anti-Xray
 import com.google.common.collect.Lists;
+
+import io.akarin.server.core.AkarinGlobalConfig;
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import java.io.IOException;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map.Entry;
@@ -24,7 +27,7 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
     }
 
     // Paper start
-    private final java.util.List<Packet> extraPackets = new java.util.ArrayList<>();
+    private final java.util.List<Packet> extraPackets = AkarinGlobalConfig.allowExcessiveSigns ? new java.util.ArrayList<>() : Collections.emptyList(); // Akarin
     private static final int SKIP_EXCESSIVE_SIGNS_LIMIT = Integer.getInteger("Paper.excessiveSignsLimit", 500);
     public java.util.List<Packet> getExtraPackets() {
         return extraPackets;
@@ -58,12 +61,14 @@ public class PacketPlayOutMapChunk implements Packet<PacketListenerPlayOut> {
 
             if (this.f() || (i & 1 << j) != 0) {
                 // Paper start - send signs separately
+                if (AkarinGlobalConfig.allowExcessiveSigns) { // Akarin
                 if (tileentity instanceof TileEntitySign) {
                     if (SKIP_EXCESSIVE_SIGNS_LIMIT < 0 || ++totalSigns < SKIP_EXCESSIVE_SIGNS_LIMIT) {
                         extraPackets.add(tileentity.getUpdatePacket());
                     }
                     continue;
                 }
+                } // Akarin
                 // Paper end
 
                 NBTTagCompound nbttagcompound = tileentity.aa_();