PaperSpigot fix (https://github.com/PaperSpigot/Paper-1.7/blob/master/Spigot-Server-Patches/0039-Improve-Network-Manager-packet-handling.patch)

patches/net/minecraft/network/NetworkManager.java.patch

@@ -68,6 +68,18 @@
          if (this.channel != null && this.channel.isOpen())
          {
              this.flushOutboundQueue();
+@@ -181,9 +206,9 @@
+     {
+         if (this.channel != null && this.channel.isOpen())
+         {
+-            while (!this.outboundPacketsQueue.isEmpty())
++            NetworkManager.InboundHandlerTuplePacketListener inboundhandlertuplepacketlistener = null;
++            while ((inboundhandlertuplepacketlistener = (NetworkManager.InboundHandlerTuplePacketListener)this.outboundPacketsQueue.poll()) != null)
+             {
+-                NetworkManager.InboundHandlerTuplePacketListener inboundhandlertuplepacketlistener = (NetworkManager.InboundHandlerTuplePacketListener)this.outboundPacketsQueue.poll();
+                 this.dispatchPacket(inboundhandlertuplepacketlistener.field_150774_a, inboundhandlertuplepacketlistener.field_150773_b);
+             }
+         }
 @@ -208,7 +233,15 @@
          {
              for (int i = 1000; !this.receivedPacketsQueue.isEmpty() && i >= 0; --i)
@@ -123,3 +135,9 @@
      static class InboundHandlerTuplePacketListener
          {
              private final Packet field_150774_a;
+@@ -334,4 +377,4 @@
+                 this.field_150773_b = p_i45146_2_;
+             }
+         }
+-}
++}