PaperMC/paper-server/nms-patches/net/minecraft/network/PacketDataSerializer.patch

--- a/net/minecraft/network/PacketDataSerializer.java
+++ b/net/minecraft/network/PacketDataSerializer.java
@@ -81,6 +81,8 @@
 import org.joml.Quaternionf;
 import org.joml.Vector3f;
 
+import org.bukkit.craftbukkit.inventory.CraftItemStack; // CraftBukkit
+
 public class PacketDataSerializer extends ByteBuf {
 
     private static final int MAX_VARINT_SIZE = 5;
@@ -220,7 +222,7 @@
 
     public <T, C extends Collection<T>> C readCollection(IntFunction<C> intfunction, PacketDataSerializer.a<T> packetdataserializer_a) {
         int i = this.readVarInt();
-        C c0 = (Collection) intfunction.apply(i);
+        C c0 = intfunction.apply(i); // CraftBukkit - decompile error
 
         for (int j = 0; j < i; ++j) {
             c0.add(packetdataserializer_a.apply(this));
@@ -231,7 +233,7 @@
 
     public <T> void writeCollection(Collection<T> collection, PacketDataSerializer.b<T> packetdataserializer_b) {
         this.writeVarInt(collection.size());
-        Iterator iterator = collection.iterator();
+        Iterator<T> iterator = collection.iterator(); // CraftBukkit - decompile error
 
         while (iterator.hasNext()) {
             T t0 = iterator.next();
@@ -258,12 +260,12 @@
 
     public void writeIntIdList(IntList intlist) {
         this.writeVarInt(intlist.size());
-        intlist.forEach(this::writeVarInt);
+        intlist.forEach((java.util.function.IntConsumer) this::writeVarInt); // CraftBukkit - decompile error
     }
 
     public <K, V, M extends Map<K, V>> M readMap(IntFunction<M> intfunction, PacketDataSerializer.a<K> packetdataserializer_a, PacketDataSerializer.a<V> packetdataserializer_a1) {
         int i = this.readVarInt();
-        M m0 = (Map) intfunction.apply(i);
+        M m0 = intfunction.apply(i); // CraftBukkit - decompile error
 
         for (int j = 0; j < i; ++j) {
             K k0 = packetdataserializer_a.apply(this);
@@ -297,7 +299,7 @@
     }
 
     public <E extends Enum<E>> void writeEnumSet(EnumSet<E> enumset, Class<E> oclass) {
-        E[] ae = (Enum[]) oclass.getEnumConstants();
+        E[] ae = oclass.getEnumConstants(); // CraftBukkit - decompile error
         BitSet bitset = new BitSet(ae.length);
 
         for (int i = 0; i < ae.length; ++i) {
@@ -308,7 +310,7 @@
     }
 
     public <E extends Enum<E>> EnumSet<E> readEnumSet(Class<E> oclass) {
-        E[] ae = (Enum[]) oclass.getEnumConstants();
+        E[] ae = oclass.getEnumConstants(); // CraftBukkit - decompile error
         BitSet bitset = this.readFixedBitSet(ae.length);
         EnumSet<E> enumset = EnumSet.noneOf(oclass);
 
@@ -545,7 +547,7 @@
     }
 
     public <T extends Enum<T>> T readEnum(Class<T> oclass) {
-        return ((Enum[]) oclass.getEnumConstants())[this.readVarInt()];
+        return ((T[]) oclass.getEnumConstants())[this.readVarInt()]; // CraftBukkit - fix decompile error
     }
 
     public PacketDataSerializer writeEnum(Enum<?> oenum) {
@@ -622,7 +624,7 @@
         } else {
             try {
                 NBTCompressedStreamTools.write(nbttagcompound, (DataOutput) (new ByteBufOutputStream(this)));
-            } catch (IOException ioexception) {
+            } catch (Exception ioexception) { // CraftBukkit - IOException -> Exception
                 throw new EncoderException(ioexception);
             }
         }
@@ -659,7 +661,7 @@
     }
 
     public PacketDataSerializer writeItem(ItemStack itemstack) {
-        if (itemstack.isEmpty()) {
+        if (itemstack.isEmpty() || itemstack.getItem() == null) { // CraftBukkit - NPE fix itemstack.getItem()
             this.writeBoolean(false);
         } else {
             this.writeBoolean(true);
@@ -688,6 +690,11 @@
             ItemStack itemstack = new ItemStack(item, b0);
 
             itemstack.setTag(this.readNbt());
+            // CraftBukkit start
+            if (itemstack.getTag() != null) {
+                CraftItemStack.setItemMeta(itemstack, CraftItemStack.getItemMeta(itemstack));
+            }
+            // CraftBukkit end
             return itemstack;
         }
     }