From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Paul Sauve <paul@technove.co>
Date: Sun, 9 May 2021 18:35:05 -0500
Subject: [PATCH] Make EntityCollisionContext a live representation

While Context is in the name, it is not used as a context. Instead it is
always created, use temporarily, then thrown away. This means having a
lot of fields to initialize and make space for is useless. I cannot find
anywhere in the codebase where this is used as a context which may be
saved for later, so this should be safe assuming plugins don't use it
for some strange reason.

diff --git a/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java b/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java
index fcb7bd9f3b6b6ada0f2e5692bce32ab76b8798a7..61c2096f2c034dbc3ad33b193b058c7d0d05e909 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java
@@ -22,55 +22,82 @@ public class EntityCollisionContext implements CollisionContext {
             return defaultValue;
         }
     };
-    private final boolean descending;
-    private final double entityBottom;
-    private final ItemStack heldItem;
-    private final ItemStack footItem;
-    private final Predicate<Fluid> canStandOnFluid;
-    private final Optional<Entity> entity;
+    // Airplane start - remove these and pray no plugin uses them
+    //private final boolean descending;
+    //private final double entityBottom;
+    //private final ItemStack heldItem;
+    //private final ItemStack footItem;
+    //private final Predicate<Fluid> canStandOnFluid;
+    // Airplane end
+    private final @org.jetbrains.annotations.Nullable Entity entity; // Airplane
 
     protected EntityCollisionContext(boolean descending, double minY, ItemStack boots, ItemStack heldItem, Predicate<Fluid> walkOnFluidPredicate, Optional<Entity> entity) {
-        this.descending = descending;
-        this.entityBottom = minY;
-        this.footItem = boots;
-        this.heldItem = heldItem;
-        this.canStandOnFluid = walkOnFluidPredicate;
-        this.entity = entity;
+        // Airplane start
+        //this.descending = descending;
+        //this.entityBottom = minY;
+        //this.footItem = boots;
+        //this.heldItem = heldItem;
+        ///this.canStandOnFluid = walkOnFluidPredicate;
+        this.entity = entity.orElse(null);
+        // Airplane end
     }
 
     @Deprecated
     protected EntityCollisionContext(Entity entity) {
+        // Airplane start - remove unneeded things
+        /*
         this(entity.isDescending(), entity.getY(), entity instanceof LivingEntity ? ((LivingEntity)entity).getItemBySlot(EquipmentSlot.FEET) : ItemStack.EMPTY, entity instanceof LivingEntity ? ((LivingEntity)entity).getMainHandItem() : ItemStack.EMPTY, entity instanceof LivingEntity ? ((LivingEntity)entity)::canStandOnFluid : (fluid) -> {
             return false;
         }, Optional.of(entity));
+         */
+        this.entity = entity;
+        // Airplane end
     }
 
     @Override
     public boolean hasItemOnFeet(Item item) {
-        return this.footItem.is(item);
+        // Airplane start
+        Entity entity = this.entity;
+        if (entity instanceof LivingEntity livingEntity) {
+            return livingEntity.getItemBySlot(EquipmentSlot.FEET).is(item);
+        }
+        return ItemStack.EMPTY.is(item);
+        // Airplane end
     }
 
     @Override
     public boolean isHoldingItem(Item item) {
-        return this.heldItem.is(item);
+        // Airplane start
+        Entity entity = this.entity;
+        if (entity instanceof LivingEntity livingEntity) {
+            return livingEntity.getMainHandItem().is(item);
+        }
+        return ItemStack.EMPTY.is(item);
+        // Airplane end
     }
 
     @Override
     public boolean canStandOnFluid(FluidState state, FlowingFluid fluid) {
-        return this.canStandOnFluid.test(fluid) && !state.getType().isSame(fluid);
+        // Airplane start
+        Entity entity = this.entity;
+        if (entity instanceof LivingEntity livingEntity) {
+            return livingEntity.canStandOnFluid(fluid) && !state.getType().isSame(fluid);
+        }
+        return false;
+        // Airplane end
     }
 
     @Override
     public boolean isDescending() {
-        return this.descending;
+        return this.entity != null && this.entity.isDescending(); // Airplane
     }
 
     @Override
     public boolean isAbove(VoxelShape shape, BlockPos pos, boolean defaultValue) {
-        return this.entityBottom > (double)pos.getY() + shape.max(Direction.Axis.Y) - (double)1.0E-5F;
+        return (this.entity == null ? -Double.MAX_VALUE : entity.getY()) > (double)pos.getY() + shape.max(Direction.Axis.Y) - (double)1.0E-5F; // Airplane
     }
 
     public Optional<Entity> getEntity() {
-        return this.entity;
+        return Optional.ofNullable(this.entity); // Airplane
     }
 }