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

--- a/net/minecraft/network/PacketDataSerializer.java
+++ b/net/minecraft/network/PacketDataSerializer.java
@@ -54,6 +54,8 @@
 import net.minecraft.world.phys.MovingObjectPositionBlock;
 import net.minecraft.world.phys.Vec3D;
 
+import org.bukkit.craftbukkit.inventory.CraftItemStack; // CraftBukkit
+
 public class PacketDataSerializer extends ByteBuf {
 
     private static final int MAX_VARINT_SIZE = 5;
@@ -122,7 +124,7 @@
 
     public <T, C extends Collection<T>> C readCollection(IntFunction<C> intfunction, Function<PacketDataSerializer, T> function) {
         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(function.apply(this));
@@ -133,7 +135,7 @@
 
     public <T> void writeCollection(Collection<T> collection, BiConsumer<PacketDataSerializer, T> biconsumer) {
         this.writeVarInt(collection.size());
-        Iterator iterator = collection.iterator();
+        Iterator<T> iterator = collection.iterator(); // CraftBukkit - decompile error
 
         while (iterator.hasNext()) {
             T t0 = iterator.next();
@@ -144,7 +146,7 @@
     }
 
     public <T> List<T> readList(Function<PacketDataSerializer, T> function) {
-        return (List) this.readCollection(Lists::newArrayListWithCapacity, function);
+        return (List) this.readCollection((java.util.function.IntFunction) Lists::newArrayListWithCapacity, function); // CraftBukkit - decompile error
     }
 
     public IntList readIntIdList() {
@@ -160,12 +162,12 @@
 
     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, Function<PacketDataSerializer, K> function, Function<PacketDataSerializer, V> function1) {
         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 = function.apply(this);
@@ -354,7 +356,7 @@
     }
 
     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) {
@@ -431,7 +433,7 @@
         } else {
             try {
                 NBTCompressedStreamTools.write(nbttagcompound, (DataOutput) (new ByteBufOutputStream(this)));
-            } catch (IOException ioexception) {
+            } catch (Exception ioexception) { // CraftBukkit - IOException -> Exception
                 throw new EncoderException(ioexception);
             }
         }
@@ -468,7 +470,7 @@
     }
 
     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);
@@ -497,6 +499,11 @@
             ItemStack itemstack = new ItemStack(Item.byId(i), b0);
 
             itemstack.setTag(this.readNbt());
+            // CraftBukkit start
+            if (itemstack.getTag() != null) {
+                CraftItemStack.setItemMeta(itemstack, CraftItemStack.getItemMeta(itemstack));
+            }
+            // CraftBukkit end
             return itemstack;
         }
     }