0028-Make-EntityCollisionContext-a-live-representation.patch

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 ebe65474a4a05ff1637d7f37ebcfe690af59def5..42142c512b12e5b269c19f1e821c50e7496a5f25 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/EntityCollisionContext.java
@@ -19,47 +19,66 @@ public class EntityCollisionContext implements CollisionContext {
             return defaultValue;
         }
     };
-    private final boolean descending;
-    private final double entityBottom;
-    private final ItemStack heldItem;
-    private final Predicate<FluidState> canStandOnFluid;
+    // Pufferfish start - remove these and pray no plugin uses them
+    // private final boolean descending;
+    // private final double entityBottom;
+    // private final ItemStack heldItem;
+    // private final Predicate<FluidState> canStandOnFluid;
+    // Pufferfish end
     @Nullable
     private final Entity entity;
 
     protected EntityCollisionContext(boolean descending, double minY, ItemStack heldItem, Predicate<FluidState> walkOnFluidPredicate, @Nullable Entity entity) {
-        this.descending = descending;
-        this.entityBottom = minY;
-        this.heldItem = heldItem;
-        this.canStandOnFluid = walkOnFluidPredicate;
+        // Pufferfish start - remove these
+        // this.descending = descending;
+        // this.entityBottom = minY;
+        // this.heldItem = heldItem;
+        // this.canStandOnFluid = walkOnFluidPredicate;
+        // Pufferfish end
         this.entity = entity;
     }
 
     /** @deprecated */
     @Deprecated
     protected EntityCollisionContext(Entity entity) {
-        this(entity.isDescending(), entity.getY(), entity instanceof LivingEntity ? ((LivingEntity)entity).getMainHandItem() : ItemStack.EMPTY, entity instanceof LivingEntity ? ((LivingEntity)entity)::canStandOnFluid : (fluidState) -> {
-            return false;
-        }, entity);
+        // Pufferfish start - remove this
+        // this(entity.isDescending(), entity.getY(), entity instanceof LivingEntity ? ((LivingEntity)entity).getMainHandItem() : ItemStack.EMPTY, entity instanceof LivingEntity ? ((LivingEntity)entity)::canStandOnFluid : (fluidState) -> {
+        //     return false;
+        // }, entity);
+        // Pufferfish end
+        this.entity = entity;
     }
 
     @Override
     public boolean isHoldingItem(Item item) {
-        return this.heldItem.is(item);
+        // Pufferfish start
+        Entity entity = this.entity;
+        if (entity instanceof LivingEntity livingEntity) {
+            return livingEntity.getMainHandItem().is(item);
+        }
+        return ItemStack.EMPTY.is(item);
+        // Pufferfish end
     }
 
     @Override
     public boolean canStandOnFluid(FluidState stateAbove, FluidState state) {
-        return this.canStandOnFluid.test(state) && !stateAbove.getType().isSame(state.getType());
+        // Pufferfish start
+        Entity entity = this.entity;
+        if (entity instanceof LivingEntity livingEntity) {
+            return livingEntity.canStandOnFluid(state) && !stateAbove.getType().isSame(state.getType());
+        }
+        return false;
+        // Pufferfish end
     }
 
     @Override
     public boolean isDescending() {
-        return this.descending;
+        return this.entity != null && this.entity.isDescending(); // Pufferfish
     }
 
     @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; // Pufferfish
     }
 
     @Nullable