Use DefaultedList for equipment tracking

Because on 1.11+ a `null` item stack is not something that should exist.
This then also allows us to compare item stacks by value rather than only by
reference, potentially saving a few redundant entity equipment update
packets (but more importantly, also allows us to store a copy instead of the
original, which will be important for the next commit).

src/main/java/com/replaymod/core/versions/Patterns.java

@@ -15,6 +15,7 @@ import net.minecraft.client.render.Tessellator;
 import net.minecraft.client.render.entity.EntityRenderDispatcher;
 import net.minecraft.client.sound.PositionedSoundInstance;
 import net.minecraft.entity.player.PlayerInventory;
+import net.minecraft.item.ItemStack;
 import net.minecraft.resource.Resource;
 import net.minecraft.resource.ResourceManager;
 import net.minecraft.text.LiteralText;
@@ -49,6 +50,10 @@ import net.minecraft.client.util.Window;
 //$$ import net.minecraft.client.gui.GuiButton;
 //#endif
 
+//#if MC>=11100
+import net.minecraft.util.collection.DefaultedList;
+//#endif
+
 //#if MC>=10904
 import net.minecraft.sound.SoundEvent;
 import net.minecraft.util.crash.CrashCallable;
@@ -669,4 +674,13 @@ class Patterns {
         return manager.getResource(id);
         //#endif
     }
+
+    @Pattern
+    private static List<ItemStack> DefaultedList_ofSize_ItemStack_Empty(int size) {
+        //#if MC>=11100
+        return DefaultedList.ofSize(size, ItemStack.EMPTY);
+        //#else
+        //$$ return java.util.Arrays.asList(new ItemStack[size]);
+        //#endif
+    }
 }

src/main/java/com/replaymod/recording/handler/RecordingEventHandler.java

@@ -40,6 +40,10 @@ import java.util.Collections;
 //$$ import net.minecraft.network.play.server.SPacketUseBed;
 //#endif
 
+//#if MC>=11100
+import net.minecraft.util.collection.DefaultedList;
+//#endif
+
 //#if MC>=10904
 import net.minecraft.network.packet.s2c.play.EntityTrackerUpdateS2CPacket;
 import net.minecraft.network.packet.s2c.play.WorldEventS2CPacket;
@@ -53,6 +57,7 @@ import net.minecraft.util.math.BlockPos;
 //$$ import net.minecraft.util.MathHelper;
 //#endif
 
+import java.util.List;
 import java.util.Objects;
 
 import static com.replaymod.core.versions.MCVer.*;
@@ -63,7 +68,7 @@ public class RecordingEventHandler extends EventRegistrations {
     private final PacketListener packetListener;
 
     private Double lastX, lastY, lastZ;
-    private ItemStack[] playerItems = new ItemStack[6];
+    private final List<ItemStack> playerItems = DefaultedList.ofSize(6, ItemStack.EMPTY);
     private int ticksSinceLastCorrection;
     private boolean wasSleeping;
     private int lastRiding = -1;
@@ -260,8 +265,8 @@ public class RecordingEventHandler extends EventRegistrations {
             //$$     ItemStack stack = player.getEquipmentInSlot(slot);
             //$$     int index = slot;
             //#endif
-                if (playerItems[index] != stack) {
+                if (!ItemStack.areEqual(playerItems.get(index), stack)) {
-                    playerItems[index] = stack;
+                    playerItems.set(index, stack);
                     //#if MC>=11600
                     packetListener.save(new EntityEquipmentUpdateS2CPacket(player.getEntityId(), Collections.singletonList(Pair.of(slot, stack))));
                     //#else

versions/1.11.2/mapping.txt

@@ -1 +1,2 @@
 net.minecraft.item.ItemStack EMPTY field_190927_a
+net.minecraft.util.NonNullList withSize() func_191197_a()